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1.  Expatriates ill after travel: Results from the Geosentinel Surveillance Network 
BMC Infectious Diseases  2012;12:386.
Background
Expatriates are a distinct population at unique risk for health problems related to their travel exposure.
Methods
We analyzed GeoSentinel data comparing ill returned expatriates with other travelers for demographics, travel characteristics, and proportionate morbidity (PM) for travel-related illness.
Results
Our study included 2,883 expatriates and 11,910 non-expatriates who visited GeoSentinel clinics ill after travel. Expatriates were more likely to be male, do volunteer work, be long-stay travelers (>6 months), and have sought pre-travel advice. Compared to non-expatriates, expatriates returning from Africa had higher proportionate morbidity (PM) for malaria, filariasis, schistosomiasis, and hepatitis E; expatriates from the Asia-Pacific region had higher PM for strongyloidiasis, depression, and anxiety; expatriates returning from Latin America had higher PM for mononucleosis and ingestion-related infections (giardiasis, brucellosis). Expatriates returning from all three regions had higher PM for latent TB, amebiasis, and gastrointestinal infections (other than acute diarrhea) compared to non-expatriates. When the data were stratified by travel reason, business expatriates had higher PM for febrile systemic illness (malaria and dengue) and vaccine-preventable infections (hepatitis A), and volunteer expatriates had higher PM for parasitic infections. Expatriates overall had higher adjusted odds ratios for latent TB and lower odds ratios for acute diarrhea and dermatologic illness.
Conclusions
Ill returned expatriates differ from other travelers in travel characteristics and proportionate morbidity for specific diseases, based on the region of exposure and travel reason. They are more likely to present with more serious illness.
doi:10.1186/1471-2334-12-386
PMCID: PMC3546948  PMID: 23273048
Expatriate; Travelers; GeoSentinel; Malaria
2.  Characteristics of multidrug-resistant tuberculosis in Namibia 
BMC Infectious Diseases  2012;12:385.
Background
To describe the epidemiology and possible risk factors for the development of multidrug-resistant tuberculosis (MDR-TB) in Namibia.
Methods
Using medical records and patient questionnaires, we conducted a case-control study among patients diagnosed with TB between January 2007 and March 2009. Cases were defined as patients with laboratory-confirmed MDR-TB; controls had laboratory-confirmed drug-susceptible TB or were being treated with WHO Category I or Category II treatment regimens.
Results
We enrolled 117 MDR-TB cases and 251 TB controls, of which 100% and 2% were laboratory-confirmed, respectively. Among cases, 97% (113/117) had been treated for TB before the current episode compared with 46% (115/251) of controls (odds ratio [OR] 28.7, 95% confidence interval [CI] 10.3–80.5). Cases were significantly more likely to have been previously hospitalized (OR 1.9, 95% CI 1.1–3.5) and to have had a household member with MDR-TB (OR 5.1, 95% CI 2.1–12.5). These associations remained significant when separately controlled for being currently hospitalized or HIV-infection.
Conclusions
MDR-TB was associated with previous treatment for TB, previous hospitalization, and having had a household member with MDR-TB, suggesting that TB control practices have been inadequate. Strengthening basic TB control practices, including expanding laboratory confirmation, directly observed therapy, and infection control, are critical to the prevention of MDR-TB.
doi:10.1186/1471-2334-12-385
PMCID: PMC3547706  PMID: 23273024
3.  Genetic diversity and drug resistance among newly diagnosed and antiretroviral treatment-naive HIV-infected individuals in western Yunnan: a hot area of viral recombination in China 
BMC Infectious Diseases  2012;12:382.
Background
The emergence of an HIV-1 epidemic in China was first recognized in Dehong, western Yunnan. Due to its geographic location, Dehong contributed greatly in bridging HIV-1 epidemics in Southeast Asia and China through drug trafficking and injection drug use; and also extensively to the HIV genetic diversity in Yunnan and China. We attempt to monitor HIV-1 in this area by studying the HIV-1 genetic distribution and transmitted drug resistance (TDR) in various at-risk populations.
Methods
Blood samples from a total of 320 newly HIV-1 diagnosed individuals, who were antiretroviral therapy (ART)-naive, were collected from January 2009 to December 2010 in 2 counties in Dehong. HIV-1 subtypes and pol gene drug resistance (DR) mutations were genotyped.
Results
Among 299 pol sequences successfully genotyped (93.4%), subtype C accounted for 43.1% (n=129), unique recombinant forms (URFs) for 18.4% (n=55), CRF01_AE for 17.7% (n=54), B for 10.7% (n=32), CRF08_BC for 8.4% (n=25) and CRF07_BC for 1.7% (n=5). Subtype distribution in patients infected by different transmission routes varied. In contract to the previous finding of CRF01_AE predominance in 2002-2006, subtype C predominated in both injecting drug users (IDUs) and heterosexually transmitted populations in this study. Furthermore, we found a high level of BC, CRF01_AE/C and CRF01_AE/B/C recombinants suggesting the presence of active viral recombination in the area. TDR associated mutations were identified in 4.3% (n=13) individuals. A total of 1.3% of DR were related to protease inhibitors (PIs), including I85IV, M46I and L90M; 0.3% to nucleoside reverse transcriptase inhibitors (NRTIs), including M184I; and 2.7% to non-nucleoside reverse transcriptase inhibitors (NNRTIs), including K103N/S, Y181C, K101E and G190A.
Conclusion
Our work revealed diverse HIV-1 subtype distributions and intersubtype recombinations. We also identified a low but significant TDR mutation rate among ART-naive patients. These findings enhance our understanding of HIV-1 evolution and are valuable for the development and implementation of a comprehensive public health approach to HIV-1 DR prevention and treatment in the region.
doi:10.1186/1471-2334-12-382
PMCID: PMC3552723  PMID: 23270497
HIV-1; Genetic diversity; Drug resistance; Injecting drug use; Dehong; China
4.  Merkel cell polyomavirus and trichodysplasia spinulosa-associated polyomavirus DNAs and antibodies in blood among the elderly 
BMC Infectious Diseases  2012;12:383.
Background
Merkel cell polyomavirus (MCPyV) and trichodysplasia spinulosa-associated polyomavirus (TSPyV) are recently found pathogens causing two rare skin disorders, Merkel cell carcinoma (MCC) and trichodysplasia spinulosa (TS). MCC is proportionally common in the elderly and most often is associated with immunosuppression. TS is a folliculocentric infection seen in patients in an immunocompromised state. Little or no baseline information exists, however, on the prevalences of these two viruses among the elderly. Epidemiologic data on this population could help in understanding their natural biology. We wished to determine the occurrences and blood levels of MCPyV and TSPyV DNAs among the elderly and any association between the prevalences of their corresponding antiviral IgG antibodies.
Methods
From 394 hospitalized elderly individuals (age ≥65 years) with respiratory symptoms, cardiovascular, and other diseases, we studied 621 serum samples by four different real-time quantitative (q) PCRs, two for the DNAs of MCPyV and two for TSPyV. The IgG antibodies for both viruses among 481 serum samples of 326 subjects were measured with enzyme immunoassays (EIAs), using as antigen recombinant virus-like particles (VLPs).
Results
Of the 394 patients, 39 (9.9%) were positive at least once for MCPyV DNA by the LT PCR, and 33 (8.4%) by the VP1 PCR, while 6 (1.5%) were positive by both PCR assays. In general, the viral DNA copy numbers were low. In sharp contrast, no TSPyV DNA was detectable with qPCRs for the corresponding genomic regions. The IgG seroprevalence of MCPyV was 59.6% and of TSPyV, 67.3%.
Conclusions
MCPyV DNA, unlike TSPyV DNA, occurs in low copy number in serum samples from a notable proportion of aging individuals. Whether this reflects enhanced viral replication possibly due to waning immune surveillance, and is associated with increased MCC risk, deserves exploration.
doi:10.1186/1471-2334-12-383
PMCID: PMC3560236  PMID: 23270528
MCPyV; TSPyV; PCR; Serology; Serum; Elderly
5.  Altered serum microRNAs as biomarkers for the early diagnosis of pulmonary tuberculosis infection 
BMC Infectious Diseases  2012;12:384.
Background
Pulmonary tuberculosis (TB) is a highly lethal infectious disease and early diagnosis of TB is critical for the control of disease progression. The objective of this study was to profile a panel of serum microRNAs (miRNAs) as potential biomarkers for the early diagnosis of pulmonary TB infection.
Methods
Using TaqMan Low-Density Array (TLDA) analysis followed by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) validation, expression levels of miRNAs in serum samples from 30 patients with active tuberculosis and 60 patients with Bordetella pertussis (BP), varicella-zoster virus (VZV) and enterovirus (EV) were analyzed.
Results
The Low-Density Array data showed that 97 miRNAs were differentially expressed in pulmonary TB patient sera compared with healthy controls (90 up-regulated and 7 down-regulated). Following qRT-PCR confirmation and receiver operational curve (ROC) analysis, three miRNAs (miR-361-5p, miR-889 and miR-576-3p) were shown to distinguish TB infected patients from healthy controls and other microbial infections with moderate sensitivity and specificity (area under curve (AUC) value range, 0.711-0.848). Multiple logistic regression analysis of a combination of these three miRNAs showed an enhanced ability to discriminate between these two groups with an AUC value of 0.863.
Conclusions
Our study suggests that altered levels of serum miRNAs have great potential to serve as non-invasive biomarkers for early detection of pulmonary TB infection.
doi:10.1186/1471-2334-12-384
PMCID: PMC3568404  PMID: 23272999
Tuberculosis; MicroRNA; Biomarker; Low-Density Array; qRT-PCR
6.  Hepatitis B Infection among high risk population: a seroepidemiological survey in Southwest of Iran 
BMC Infectious Diseases  2012;12:378.
Background
Hepatitis B virus (HBV) infection remains a major global health problem. This study aimed to assess the prevalence and risk behaviors for HBV infection among high risk groups in Kohgiloyeh and Boyerahmad province, in Southwest of Iran.
Methods
Blood samples were collected from 2009 subjects, between 2009 and 2010 in Kohgiloyeh and Boyerahmad province, in southwest of Iran. Recruited subjects were the high risk groups for HBV infection, including inmates, injecting drug users, health care workers, patients on maintenance haemodialysis, hemophilic patients and patients with a history of blood transfusion. Their serum samples were tested for the presence of antibodies to hepatitis B core antigen (HBc IgM, IgG) by enzyme-linked immunosorbent assay (ELISA). Seropositive specimens were tested for HBsAg. Demographic features of participants were recorded during sample collecting.
Results
HBsAg was detected in 24 of the 2009 subjects, giving an overall prevalence of 1.2%. All HBsAg positive cases were males. The prevalence of HBsAg among injection drug users was 3.2%. Significant correlation was found between HBV infection and drug abuse, level of education and place of residence (p<0.05), while no significant correlation was found between HBV infection and previous history of blood transfusion, unprotected sexual behavior, and thalassemia.
Conclusion
Based on the findings of this study, incarceration and drug abuse are the most important risk factors for acquiring HBV infection in this region. Modifying behavior, improving the individual education and expanding the HBV vaccination coverage may reduce the rate of infection in the region.
doi:10.1186/1471-2334-12-378
PMCID: PMC3543710  PMID: 23270391
Seroprevalence; HBV; High risk group; Prevalence; Iran
7.  Negative effect of smoking on the performance of the QuantiFERON TB gold in tube test 
BMC Infectious Diseases  2012;12:379.
Background
False negative and indeterminate Interferon Gamma Release Assay (IGRA) results are a well documented problem. Cigarette smoking is known to increase the risk of tuberculosis (TB) and to impair Interferon-gamma (IFN-γ) responses to antigenic challenge, but the impact of smoking on IGRA performance is not known. The aim of this study was to evaluate the effect of smoking on IGRA performance in TB patients in a low and high TB prevalence setting respectively.
Methods
Patients with confirmed TB from Denmark (DK, n = 34; 20 smokers) and Tanzania (TZ, n = 172; 23 smokers) were tested with the QuantiFERON-TB Gold In tube (QFT). Median IFN-γ level in smokers and non smokers were compared and smoking was analysed as a risk factor for false negative and indeterminate QFT results.
Results
Smokers from both DK and TZ had lower IFN-γ antigen responses (median 0.9 vs. 4.2 IU/ml, p = 0.04 and 0.4 vs. 1.6, p < 0.01), less positive (50 vs. 86%, p = 0.03 and 48 vs. 75%, p < 0.01) and more false negative (45 vs. 0%, p < 0.01 and 26 vs. 11%, p = 0.04) QFT results. In Tanzanian patients, logistic regression analysis adjusted for sex, age, HIV and alcohol consumption showed an association of smoking with false negative (OR 17.1, CI: 3.0-99.1, p < 0.01) and indeterminate QFT results (OR 5.1, CI: 1.2-21.3, p = 0.02).
Conclusions
Cigarette smoking was associated with false negative and indeterminate IGRA results in both a high and a low TB endemic setting independent of HIV status.
doi:10.1186/1471-2334-12-379
PMCID: PMC3546031  PMID: 23270417
Tuberculosis; IGRA; HIV; Quantiferon; Smoking
8.  Cytokine profile, proliferation and phosphorylation of ERK1/2 and Akt in circulating mononuclear cells from individuals during the chronic intestinal phase of Schistosomiasis mansoni infection 
BMC Infectious Diseases  2012;12:380.
Background
The immune response to Schistosoma mansoni is characterized by a granulomatous reaction around the parasite eggs that are trapped in the host liver, and this reaction modulates the immune response during the chronic phase of the disease. The typical peripheral blood mononuclear cell (PBMC) response of patients during the chronic intestinal phase of infection is characterized by a decreased response to an S. mansoni soluble egg antigen. To obtain a greater understanding of Schistosoma infections, this study investigated the effects of the soluble egg antigen (SEA) and soluble adult worm antigen (SWAP) of S. mansoni on cellular proliferation, cytokine production, and ERK1/2 and Akt phosphorylation in PBMCs from infected (XTO) and egg-negative (NI) individuals living in the same endemic area.
Methods
The activation status was evaluated by cell immunophenotypic staining (cytometry). The cell proliferation assay was by CFSE method. Cytokine detection assay (Th1 and Th2) was by Cytometric Bead and Array phosphorylation status was by ELISA.
Results
The XTO, NI and BD (blood donor) individuals from an area not endemic for schistosomiasis were compared. The CD4+ T lymphocyte proliferation rate was lower in the XTO group, but not the NI group, after SEA stimulation compared to the BD group. The CD8+ T cell proliferation rate was lower in the XTO group in the unstimulated cultures and after both SEA and SWAP stimulation compared to the BD group. Cytokine analysis after either SEA or SWAP stimulation showed a balanced cytokine pattern in the XTO and NI groups. ERK1/2 and Akt phosphorylation were only marginally detected in all groups; however, a decrease in ERK 1/2 phosphorylation was observed in the SWAP-stimulated XTO group compared to both the NI and BD groups.
Conclusions
The data indicate that SEA-stimulated CD4+ T cells from infected patients have a lower proliferation rate than the same cells from the NI group. Furthermore, we observed that SWAP stimulation influences ERK1/2 phosphorylation in the XTO group.
doi:10.1186/1471-2334-12-380
PMCID: PMC3549743  PMID: 23270458
Schistosomiasis mansoni; PBMC; Th1 and Th2 cytokines; ERK1/2; Akt
9.  The effectiveness of retreatment with peginterferon alfa and ribavirin in patients with chronic viral hepatitis C genotype 2 and 3: a prospective cohort study in Brazil 
BMC Infectious Diseases  2012;12:377.
Background
More than 50% of patients infected with chronic hepatitis C virus (HCV) do not respond to treatment with conventional interferon (IFN) combined with ribavirin (RBV). The aim of our study was to evaluate the effectiveness of retreatment with peginterferon alfa-2a or 2b (PEG-IFN 2a or 2b) concomitantly with RBV in patients with HCV genotype 2 and 3, which were non-responders or relapsers to initial treatment with IFN / RBV and to identify possible predictors of sustained virological response (SVR).
Methods
From September 2003 to March 2009 a cohort of 216 patients who had previously failed therapy with a regimen of standard interferon and ribavirin, were followed in a specialized service implemented in the Brazilian Unified Health System, Rio Grande do Sul. All patients were retreated with PEG-IFN 2a or 2b per week, associated with RBV, through oral route, with doses determined according to weight (1,000 mg if weight ≤ 75 Kg and 1,250 mg if ≥ 75 Kg) per day for 48 weeks. The HCV-RNA was tested by Polymerase Chain Reaction (PCR). Virological Response (VR) within 48 weeks and SVR in the 72 weeks was considered for evaluation of treatment efficacy. Analyses were performed in patients who received at least one dose of PEG-IFN.
Results
The SVR rate for non-responders to previous treatment was 34.4% and for relapsers was 50% (p = 0.031). As predictive factors that contribute to improve SVR, were identified the age (p = 0.005), to be relapsers to previous treatment (p = 0.023) and present liver biopsy examination Metavir F0-F2 (p = 0.004). In assessing the safety profile, 51 patients (23.6%) discontinued treatment prematurely.
Conclusions
This alternative retreatment for patients who have failed prior therapies for anti-HCV, has demonstrated promising SVR rate, provided that it includes a careful selection of patients with predictors of response and adverse events monitored.
doi:10.1186/1471-2334-12-377
PMCID: PMC3548710  PMID: 23270376
Hepatitis C; Retreatment; Peginterferon alpha; Ribavirin
10.  Virologic versus immunologic monitoring and the rate of accumulated genotypic resistance to first-line antiretroviral drugs in Uganda 
BMC Infectious Diseases  2012;12:381.
Background
Viral load monitoring (VLM) to identify individuals failing antiretroviral therapy (ART) is not widely available in resource-limited settings. We compared the genotypic resistance patterns between clients with VLM versus immunological monitoring (IM).
Methods
Between 2004–2008, 559 ART naïve clients were enrolled in a prospective cohort, initiated on ART, and monitored with viral load (VL) and CD4+ cell counts every 6 months (VLM group). From February 2008 through June 2009, 998 clients on ART for 36–40 months (corresponding to the follow-up time of the VLM group) at the same clinic and monitored with CD4+ cell counts every 6 months were recruited into a cross sectional study (IM group). Samples from VLM clients at 12, 24 and 36 months and IM clients at 36–40 months with VL > 2000 copies/ml underwent genotypic drug resistance testing.
Results
Baseline characteristics were similar. Virologic failure (VL > 400 copies/ml) at 12, 24 and 36 months in the VLM group were 12%, 6% and 8% respectively, and in the IM group 10% at 36–40 months. Samples from 39 VLM and 70 IM clients were genotyped. 23/39 (59%) clients in the VLM group (at 12, 24 or 36 months) compared to 63/70 (90%) in the IM group, (P < 0.0001) had at least 1 non-nucleoside reverse transcriptase mutation. 19/39 (49%) of VLM clients had an M184V mutation compared to 61/70 (87%) in the IM group (P < 0.0001). Only 2/39 (5%) of VLM clients developed thymidine analogue mutations compared to 34/70 (49%) of IM clients (P < 0.0001).
Conclusions
Routine VL monitoring reduced the rate of accumulated genotypic resistance to commonly used ART in Uganda.
doi:10.1186/1471-2334-12-381
PMCID: PMC3548731  PMID: 23270482
HIV-1; Antiretroviral therapy; Drug resistance
11.  A case–control study of risk factors for HIV-negative children with cryptococcal meningitis in Shi Jiazhuang, China 
BMC Infectious Diseases  2012;12:376.
Background
Although cryptococcal meningitis (CM) is an emerging disease worldwide, there have been few studies of the characteristics and risk factors of CM in children.
Methods
We used data collected from May 2007 through April 2012 in the Acute Meningitis-Encephalitis Syndrome Surveillance project in Shi Jiazhuang, China to describe the epidemiologic, clinical, and laboratory findings in children with CM. Furthermore, a matched case–control study was used to determine risk factors of CM.
Results
Overall 23 HIV-negative children with CM (median age: 10.91 years; range: 5 months-17 years) were enrolled in our study. The average annual incidence of CM was 0.43/100,000 with a fatality rate of 1.7%. Most patients were males (60.87%) and rural children (73.91%). Common clinical symptoms included increased intracranial pressure, such as headaches (78.3%), nausea (60.9%), altered mental status (56.5%), vomiting (52.2%), and seizures (43.5%), and frequent laboratory findings consisted of blood leukocytosis (87.0%), decreased CSF glucose (87.0%), pleocytosis (82.6%), increased intracranial pressure (73.9%) and elevated CSF proteins (65.2%). Epidemiologic, clinical, and laboratory findings were similar between patients with and without underlying diseases. Multivariate logistic regression analysis showed that children who had contact with birds/bird droppings or saprophytes were more likely to be infected than those without such contact (odds ratio(OR) =11.82; 95% confidence interval (CI), 2.21-62.24; P = 0.004). Patients with an interval of ≥20 days from onset to admission were at high risk for CM (OR= 5.31; 95%CI, 1.58-17.89; P = 0.007).
Conclusions
Our findings show that CM is an uncommon disease with a high mortality rate in children. Although additional studies are needed to find effective prevention and treatments for CM, clinicians should consider CM as a potential cause for pediatric meningitis in children, particularly boys from rural areas, who had contact with birds/bird droppings or saprophytes and in children who did not receive prompt medical attention.
doi:10.1186/1471-2334-12-376
PMCID: PMC3560247  PMID: 23267689
Cryptococcosis; Cryptococcal meningitis; Epidemiologic characteristics; Clinical features; Bird droppings and sacrophytes; Risk factors; Children
12.  Additional risk factors for infection by multidrug-resistant pathogens in healthcare-associated infection: a large cohort study 
BMC Infectious Diseases  2012;12:375.
Background
There is a lack of consensus regarding the definition of risk factors for healthcare-associated infection (HCAI). The purpose of this study was to identify additional risk factors for HCAI, which are not included in the current definition of HCAI, associated with infection by multidrug-resistant (MDR) pathogens, in all hospitalized infected patients from the community.
Methods
This 1-year prospective cohort study included all patients with infection admitted to a large, tertiary care, university hospital. Risk factors not included in the HCAI definition, and independently associated with MDR pathogen infection, namely MDR Gram-negative (MDR-GN) and ESKAPE microorganisms (vancomycin-resistant Enterococcus faecium, methicillin-resistant Staphylococcus aureus, extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella species, carbapenem-hydrolyzing Klebsiella pneumonia and MDR Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter species), were identified by logistic regression among patients admitted from the community (either with community-acquired or HCAI).
Results
There were 1035 patients with infection, 718 from the community. Of these, 439 (61%) had microbiologic documentation; 123 were MDR (28%). Among MDR: 104 (85%) had MDR-GN and 41 (33%) had an ESKAPE infection. Independent risk factors associated with MDR and MDR-GN infection were: age (adjusted odds ratio (OR) = 1.7 and 1.5, p = 0.001 and p = 0.009, respectively), and hospitalization in the previous year (between 4 and 12 months previously) (adjusted OR = 2.0 and 1,7, p = 0.008 and p = 0.048, respectively). Infection by pathogens from the ESKAPE group was independently associated with previous antibiotic therapy (adjusted OR = 7.2, p < 0.001) and a Karnofsky index <70 (adjusted OR = 3.7, p = 0.003). Patients with infection by MDR, MDR-GN and pathogens from the ESKAPE group had significantly higher rates of inadequate antibiotic therapy than those without (46% vs 7%, 44% vs 10%, 61% vs 15%, respectively, p < 0.001).
Conclusions
This study suggests that the inclusion of additional risk factors in the current definition of HCAI for MDR pathogen infection, namely age >60 years, Karnofsky index <70, hospitalization in the previous year, and previous antibiotic therapy, may be clinically beneficial for early diagnosis, which may decrease the rate of inadequate antibiotic therapy among these patients.
doi:10.1186/1471-2334-12-375
PMCID: PMC3566942  PMID: 23267668
Healthcare-associated infections; Multidrug resistant pathogens infection; Multidrug resistant gram negatives infection; ESKAPE microorganisms’ infection; Independent risk factors; Inadequate antibiotic therapy
13.  Epidemic of Klebsiella pneumoniae ST11 Clone Coproducing KPC-2 and 16S rRNA Methylase RmtB in a Chinese University Hospital 
BMC Infectious Diseases  2012;12:373.
Background
Emergence of rmtB-positive Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae (KPC-KP) poses a great threat to antimicrobial treatment options.
Methods
From January 2010 to December 2010, non-duplicate KPC-KP isolates from our hospital were screened for rmtB and multiple other resistance determinants with PCR. Subsequent studies included MIC determination, PFGE, and multilocus sequence typing. Records from patients with KPC-KP isolated were retrospectively reviewed. Comparisons of molecular and clinical characteristics between rmtB-positive and rmtB–negative isolates were systematically performed, as well as the environmental colonization study in ICU wards.
Results
A total of 84 KPC-KP strains were collected, including 48 rmtB-positive KPC-KP (RPKP) and 36 rmtB-negative KPC-KP (RNKP) isolates. All KPC-KP isolates were multidrug resistant, with colistin and tigecycline being the most active agents. Compared with RNKP, RPKP displayed a much severer resistance phenotype. Susceptibility rates for amikacin (0% for RPKP versus 88.9% for RNKP, p < 0.01), fosfomycin (8.5% for RPKP versus 88.9% for RNKP, p < 0.01), and minocycline (6.7% for RPKP versus 52.8% for RNKP, p < 0.01), were all significantly lower in RPKP strains. Isolates belonging to PFGE pulsetype A and sequence type 11 were predominant in both groups, including 39 (81.3%) RPKP and 22 (61.1%) RNKP isolates. Nevertheless, RNKP showed more complex genetic backgrounds compared with RPKP. Diverse clinical characteristics were found in both cohorts, however, no significant differences were observed between RPKP and RNKP patients.
Conclusions
RPKP strains have spread widely and gradually replaced RNKP in our hospital. They seemed to show much severer resistance phenotypes compared with RNKP and had a bigger dissemination potential. Prudent use of available active agents combined with good control practices is therefore mandatory.
doi:10.1186/1471-2334-12-373
PMCID: PMC3543704  PMID: 23259910
Carbapenem; Aminoglycoside; KPC; rmtB; Epidemic
14.  Lack of evidence to support the association of a single IL28B genotype SNP rs12979860 with the HTLV-1 clinical outcomes and proviral load 
BMC Infectious Diseases  2012;12:374.
Background
The Interleukin 28B (IL28B) rs12979860 polymorphisms was recently reported to be associated with the human T-cell leukemia virus type 1 (HTLV-1) proviral load (PvL) and the development of the HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP).
Methods
In an attempt to examine this hypothesis, we assessed the association of the rs12979860 genotypes with HTLV-1 PvL levels and clinical status in 112 unrelated Brazilian subjects (81 HTLV-1 asymptomatic carriers, 24 individuals with HAM/TSP and 7 with Adult T cell Leukemia/Lymphoma (ATLL)).
Results
All 112 samples were successfully genotyped and their PvLs compared. Neither the homozygote TT nor the heterozygote CT mutations nor the combination genotypes (TT/CT) were associated with a greater PvL. We also observed no significant difference in allele distribution between asymptomatic carriers and patients with HTLV-1 associated HAM/TSP.
Conclusions
Our study failed to support the previously reported positive association between the IL28B rs12979860 polymorphisms and an increased risk of developing HAM/TSP in the Brazilian population.
doi:10.1186/1471-2334-12-374
PMCID: PMC3547796  PMID: 23259930
HTLV-1; ILB 28 polymorphisms; HAM/TSP; Proviral load
15.  Ciprofloxacin-resistant Escherichia coli in Central Greece: mechanisms of resistance and molecular identification 
BMC Infectious Diseases  2012;12:371.
Background
Fluoroquinolone resistant E. coli isolates, that are also resistant to other classes of antibiotics, is a significant challenge to antibiotic treatment and infection control policies. In Central Greece a significant increase of ciprofloxacin-resistant Escherichia coli has occurred during 2011, indicating the need for further analysis.
Methods
A total of 106 ciprofloxacin-resistant out of 505 E. coli isolates consecutively collected during an eight months period in a tertiary Greek hospital of Central Greece were studied. Antimicrobial susceptibility patterns and mechanisms of resistance to quinolones were assessed, whereas selected isolates were further characterized by multilocus sequence typing and β-lactamase content.
Results
Sequence analysis of the quinolone-resistance determining region of the gyrA and parC genes has revealed that 63% of the ciprofloxacin-resistant E. coli harbored a distinct amino acid substitution pattern (GyrA:S83L + D87N; ParC:S80I + E84V), while 34% and 3% carried the patterns GyrA:S83L + D87N; ParC:S80I and GyrA:S83L + D87N; ParC:S80I + E84G respectively. The aac (6’)-1b-cr plasmid-mediated quinolone resistance determinant was also detected; none of the isolates was found to carry the qnrA, qnrB and qnrS.
Genotyping of a subset of 35 selected ciprofloxacin-resistant E. coli by multilocus sequence typing has revealed the presence of nine sequence types; ST131 and ST410 were the most prevalent and were exclusively correlated with hospital and health care associated infections, while strains belonging to STs 393, 361 and 162 were associated with community acquired infections. The GyrA:S83L + D87N; ParC:S80I + E84V substitution pattern was found exclusively among ST131 ciprofloxacin-resistant E. coli. Extended-spectrum β-lactamase-positive ST131 ciprofloxacin-resistant isolates produced CTX-M-type enzymes; eight the CTX-M-15 and one the CTX-M-3 variant. CTX-M-1 like and KPC-2 enzymes were detected in five and four ST410 ciprofloxacin-resistant E. coli isolates, respectively.
Conclusions
Our findings suggest that, ST131 and ST410 predominate in the ciprofloxacin resistant E. coli population.
doi:10.1186/1471-2334-12-371
PMCID: PMC3548683  PMID: 23259844
Escherichia coli; Quinolones,MLST; Beta lactamases
16.  Genetic diversity of Mycobacterium tuberculosis isolates from Beijing, China assessed by Spoligotyping, LSPs and VNTR profiles 
BMC Infectious Diseases  2012;12:372.
Background
Tuberculosis is one of the most infectious diseases in the world. Molecular typing methods such as spoligotyping, and VNTR (variable number tandem repeats), IS6110 in the NTF region and LSP (large sequence polymorphisms) analysis are generally useful tools for the resolution of various issues related to the classical epidemiology of Mycobacterium tuberculosis (M. tuberculosis).
Methods
To determine the transmission characteristics of M. tuberculosis strains isolated in Beijing, China, and their genetic relationships, especially those among Beijing family strains, 260 M. tuberculosis strains isolated from patients presenting pulmonary tuberculosis were analyzed by spoligotyping, and by examining 22 VNTR loci and the presence/absence of IS6110 in the NTF region, RD105 and RD181.
Results
81% (211 strains) of the isolates studied were Beijing family strains, 174 (82.5%) of which were identified as modern Beijing strains based on the presence of IS6110 upstream of the NTF region. RD181 was intact in 9 of the other 37 (17.5%) ancestral Beijing strains. The percentage of Beijing family strains in this study was consistent with previous reports. There are many differences, however, in allele diversity among VNTR loci between reports on strains from different areas.
Conclusions
The Beijing family is the most prevalent genotype in Beijing city and the predominance of Beijing family strains has not altered in almost twenty years. Differences in the alleles and discrimination ability of VNTR loci between different regions is likely due to population differences in the regions where these M. tuberculosis strains were isolated or to differences in sampling times.
doi:10.1186/1471-2334-12-372
PMCID: PMC3583687  PMID: 23259861
M. tuberculosis; Beijing family; Genotyping
17.  Comparison between the BACTEC MGIT 960 system and the agar proportion method for susceptibility testing of multidrug resistant tuberculosis strains in a high burden setting of South Africa 
BMC Infectious Diseases  2012;12:369.
Background
The increasing problem of multi-drug-resistant (MDR) tuberculosis (TB) [ie resistant to at least isoniazid (INH) and rifampicin (RIF)] is becoming a global problem. Successful treatment outcome for MDR-TB depends on reliable and accurate drug susceptibility testing of first-line and second-line anti-TB drugs.
Method
Consecutive M. tuberculosis isolates identified as MDR-TB during August 2007 to January 2008 using the BACTEC MGIT 960 systems and the agar proportion method were included in this study. Susceptibility testing of MDR-TB isolates against ethambutol (EMB) and streptomycin (STR) as well as two second-line anti-TB drugs, kanamycin (KAN) and ofloxacin (OFX) was performed using the BACTEC MGIT 960 systems at a routine diagnostic laboratory. The results were compared to those obtained by the agar proportion method.
Result
The agreement between the BACTEC MGIT 960 system and the agar proportion method was 44% for EMB, 61% for STR and 89% for both KAN and OFX. The sensitivity and specificity of the BACTEC MGIT 960 system using the agar proportion method as a gold standard was 92% and 37% for EMB, 95% and 37% for STR, 27% and 97% for KAN and 84% and 90% for OFX, respectively.
Conclusions
The BACTEC MGIT 960 system showed acceptable sensitivity for EMB, STR, and OFX; however, the BACTEC MGIT 960 system was less specific for EMB and STR and demonstrated a low sensitivity for KAN. The lower agreement found between the two methods suggests the unreliability of the BACTEC MGIT 960 system for the drugs tested. The reasons for the lower agreement between the two methods need to be investigated and further studies are needed in this setting to confirm the study finding.
doi:10.1186/1471-2334-12-369
PMCID: PMC3543708  PMID: 23259765
BACTEC MGIT 960; MDR-TB; TB; XDR-TB
18.  Clostridium difficile 027 infection in Central Italy 
BMC Infectious Diseases  2012;12:370.
Background
Clostridium difficile (CD) has increasingly become recognised as a significant international health burden, often associated with the healthcare environment. The upsurge in incidence of CD coincided with the emergence of a hypervirulent strain of CD characterized as 027.
In 2010, 8 cases of CD 027 infections were identified in Italy. Since then, no further reports have been published. We describe 10 new cases of CD 027 infection occurring in Italy.
Methods
Since December 2010, stool samples of patients with severe diarrhea and clinical suspicion of the presence of a hypervirulent strain, were tested for CD 027 by the Xpert C. difficile PCR assay (Cepheid, Sunnyvale, CA). Clinical, epidemiological and laboratory data were collected.
Results
From December 2010 to April 2012, 24 faecal samples from 19 patients who fit the above criteria were submitted to our laboratory. Samples were collected from 7 different hospitals.
Of these, 17 had a positive PCR for CD and 10 were the epidemic 027 strain (59%). All PCR positive samples had a positive EIA toxin A/B test. Nine of 10 patients were recently exposed to antimicrobials and were healthcare-associated, including 4 with a history of long term care facility (LTCF) admission; the remaining case was community-associated, namely the wife of a patient with hospital-acquired CD 027 infection. Five patients experienced at least one recurrence of CD associated diarrhea (CDAD) with a total of 12 relapsing episodes. Of these, two patients had 5 and 6 relapses respectively.
We compared the 10 patients with 027 CDAD versus the 7 patients with non-027 CDAD. None of the 7 patients with non-027 CDAD had a recent history of LTCF admission and no subsequent relapses were observed (p = 0.04).
Conclusions
Our study shows that CD 027 is emerging in healthcare facilities in Italy. Whilst nosocomial acquisition accounted for the majority of such cases, 4 patients had history of a recent stay in a LTCF. We highlight the substantial risks of this highly transmissible organism in such environments. Moreover, 50% of our patients with CDAD from the 027 strain had high relapse rates which may serve to further establish this strain within the Italian health and social care systems.
doi:10.1186/1471-2334-12-370
PMCID: PMC3549759  PMID: 23259814
Clostridium difficile; CDAD; NAP1; 027; Italy
19.  Prevalence of low-risk HPV types and genital warts in women born 1988/89 or 1983/84 -results of WOLVES, a population-based epidemiological study in Wolfsburg, Germany 
BMC Infectious Diseases  2012;12:367.
Background
Wolfsburg HPV Epidemiological Study (WOLVES) is a population-based cohort study on HPV infections and associated diseases in the pre-vaccination era in young women in Wolfsburg, Germany.
Methods
Women born 1983/84 or 1988/89 were invited to participate. Participants were recruited in gynecology practices, and completed a questionnaire with socioeconomic, sexual and medical data including vaccination status. Pelvic examination with Pap smear and HPV testing (HC2 = Hybrid Capture 2) was obligatory. HC2-positive and 10% of HC2-negative samples were tested for specific HPV types with SPF-10-PCR, and in inconclusive cases with DNA sequencing. Women with genital warts (GW) and those with atypical Pap smears were transferred for colposcopy. GWs were classified as typical condylomata acuminata (TCA), flat condyloma (FC) and seborrheic wart-like (SWL).
Results
In total, 1258 subjects were recruited from the target population of 2850 (44.1%). Overall the prevalence of HC2 low-risk (LR) types was 8.5%. HPV6 was the most frequent LR type (2.1%), followed by HPV42 (1.1%), HPV11 and HPV44 (each 0.4%). LiPA showed a low sensitivity for HPV types 42, 90 and 91, which were detected only by HC2 and HPV sequencing. Nine women (0.7%) were transferred with incident GW: five TCA, two FC and two SWL. All TCA were associated with HPV6 in corresponding cervical swabs and warts. Tissues of SWL contained HPV6 (n = 1) and HPV16 (n = 1). The cumulative life-risk for GW was 1.4% in the 1988/89 and 4.8% in the 1983/84 cohort. Eight of 107 HC2-LR + and five of nine cases of GW had concomitant abnormal Pap smears. All CIN lesions could be linked to high-risk HPV types but borderline and low-grade abnormal smears were explained by vaginal and cervical TCA in four cases.
Conclusions
HC2 was a specific test for the detection of established and potential LR types. In this first WOLVES analysis, HPV6 was the most frequent HPV type and the single LR type linked to disease. The observed GW incidence of 715 per 100,000 fits well with estimates of healthcare providers. Although life risks for GW were lower than in Scandinavian analyses, the societal burden within the WOLVES populations was considerable.
doi:10.1186/1471-2334-12-367
PMCID: PMC3536688  PMID: 23259726
20.  Association between early bacterial carriage and otitis media in Aboriginal and non-Aboriginal children in a semi-arid area of Western Australia: a cohort study 
BMC Infectious Diseases  2012;12:366.
Background
Streptococcus pneumoniae (Pnc), nontypeable Haemophilus influenzae (NTHi) and Moraxella catarrhalis (Mcat) are the most important bacterial pathogens associated with otitis media (OM). Previous studies have suggested that early upper respiratory tract (URT) bacterial carriage may increase risk of subsequent OM. We investigated associations between early onset of URT bacterial carriage and subsequent diagnosis of OM in Aboriginal and non-Aboriginal children living in the Kalgoorlie-Boulder region located in a semi-arid zone of Western Australia.
Methods
Aboriginal and non-Aboriginal children who had nasopharyngeal aspirates collected at age 1- < 3 months and at least one clinical examination for OM by an ear, nose and throat specialist before age 2 years were included in this analysis. Tympanometry to detect middle ear effusion was also performed at 2- to 6-monthly scheduled field visits from age 3 months. Multivariate regression models were used to investigate the relationship between early carriage and subsequent diagnosis of OM controlling for environmental factors.
Results
Carriage rates of Pnc, NTHi and Mcat at age 1- < 3 months were 45%, 29% and 48%, respectively, in 66 Aboriginal children and 14%, 5% and 18% in 146 non-Aboriginal children. OM was diagnosed at least once in 71% of Aboriginal children and 43% of non-Aboriginal children. After controlling for age, sex, presence of other bacteria and environmental factors, early nasopharyngeal carriage of NTHi increased the risk of subsequent OM (odds ratio = 3.70, 95% CI 1.22-11.23) in Aboriginal children, while Mcat increased the risk of OM in non-Aboriginal children (odds ratio = 2.63, 95% CI 1.32-5.23). Early carriage of Pnc was not associated with increased risk of OM.
Conclusion
Early NTHi carriage in Aboriginal children and Mcat in non-Aboriginal children is associated with increased risk of OM independent of environmental factors. In addition to addressing environmental risk factors for carriage such as overcrowding and exposure to environmental tobacco smoke, early administration of pneumococcal-Haemophilus influenzae D protein conjugate vaccine to reduce bacterial carriage in infants, may be beneficial for Aboriginal children; such an approach is currently being evaluated in Australia.
doi:10.1186/1471-2334-12-366
PMCID: PMC3546895  PMID: 23256870
Otitis media; Aboriginal; Streptococcus pneumoniae; Haemophilus influenzae; Moraxella catarrhalis
21.  HIV-1 integrase resistance among antiretroviral treatment naive and experienced patients from Northwestern Poland 
BMC Infectious Diseases  2012;12:368.
Background
HIV integrase inhibitor use is limited by low genetic barrier to resistance and possible cross-resistance among representatives of this class of antiretrovirals. The aim of this study was to analyse integrase sequence variability among antiretroviral treatment naive and experienced patients with no prior integrase inhibitor (InI) exposure and investigate development of the InI drug resistance mutations following the virologic failure of the raltegravir containing regimen.
Methods
Sequencing of HIV-1 integrase region from plasma samples of 80 integrase treatment naive patients and serial samples from 12 patients with observed virologic failure on raltegravir containing treatment whenever plasma vireamia exceeded >50 copies/ml was performed. Drug resistance mutations were called with Stanford DB database and grouped into major and minor variants. For subtyping bootstrapped phylogenetic analysis was used; Bayesian Monte Carlo Marcov Chain (MCMC) model was implemented to infer on the phylogenetic relationships between the serial sequences from patients failing on raltegravir.
Results
Majority of the integrase region sequences were classified as subtype B; the remaining ones being subtype D, C, G, as well as CRF01_AE , CRF02_AG and CRF13_cpx recombinants. No major integrase drug resistance mutations have been observed in InI-treatment naive patients. In 30 (38.5%) cases polymorphic variation with predominance of the E157Q mutation was observed. This mutation was more common among subtype B (26 cases, 54.2%) than non-B sequences (5 cases, 16.7%), p=0.00099, OR: 5.91 (95% CI:1.77-22.63)]. Other variants included L68V, L74IL, T97A, E138D, V151I, R263K. Among 12 (26.1%) raltegravir treated patients treatment failure was observed; major InI drug resistance mutations (G140S, Q148H and N155H, V151I, E92EQ, V151I, G163R) were noted in four of these cases (8.3% of the total InI-treated patients). Time to the development of drug resistance ranged from 2.6 to 16.3 months with mean increase of HIV viral load of 4.34 (95% CI:1.86-6.84) log HIV-RNA copies/ml at the time of emergence of the major mutations. Baseline polymorphisms, including E157Q were not associated with the virologic failure on raltegravir.
Conclusions
In InI treatment naive patients polymorphic integrase sequence variation was common, with no major resistance mutants. In the treatment failing patients selection of drug resistance occurred rapidly and followed the typical drug resistance pathways. Preexisting integrase polymorphisms were not associated with the treatment failure.
doi:10.1186/1471-2334-12-368
PMCID: PMC3547692  PMID: 23259737
HIV-1; Integrase inhibitors; Raltegravir; Antiretroviral treatment failure; Drug resistance mutations
22.  Associated factors for recommending HBV vaccination to children among Georgian health care workers 
BMC Infectious Diseases  2012;12:362.
Background
Most cases of hepatitis B virus (HBV) infection and subsequent liver diseases can be prevented with universal newborn HBV vaccination. The attitudes of health care workers about HBV vaccination and their willingness to recommend vaccine have been shown to impact HBV vaccination coverage and the prevention of vertical transmission of HBV. The purpose of this study was to ascertain the factors associated with health care worker recommendations regarding newborn HBV vaccination.
Methods
A cross-sectional study of prevalence and awareness of hepatitis B and hepatitis B vaccine was conducted among randomly selected physicians and nurses employed in seven hospitals in Georgia in 2006 and 2007. Self-administered questionnaires included a module on recommendations for HBV, HCV and HIV.
Results
Of the 1328 participants included in this analysis, 36% reported recommending against hepatitis B vaccination for children, including 33% of paediatricians. Among the 70.6% who provided a reason for not recommending HBV vaccine, the most common concern was an adverse vaccine event. Unvaccinated physicians and nurses were more likely to recommend against HBV vaccine (40.4% vs 11.4%, PR 3.54; 95% CI: 2.38, 5.29). Additionally, health care worker age was inversely correlated with recommendations for HBV vaccine with older workers less likely to recommend it.
Conclusion
Vaccinating health care workers against HBV may provide a dual benefit by boosting occupational safety as well as strengthening universal coverage programs for newborns.
doi:10.1186/1471-2334-12-362
PMCID: PMC3544730  PMID: 23256746
Hepatitis B; Vaccine; Safety; Health Care Worker; Newborns
23.  Correlation of anti-fungal susceptibility with clinical outcomes in patients with cryptococcal meningitis 
BMC Infectious Diseases  2012;12:361.
Background
This study aimed to investigate the correlation of minimum inhibiting concentrations (MICs), obtained by broth micro-dilution, and clinical response in patients with cryptococcal meningitis.
Methods
Using retrospective analyses covering the period 2001–2010, factors affecting clinical therapeutic cure in patients with cryptococcal meningitis 10 weeks after the start of anti-fungal therapy were identified. Specific emphasis was placed on the role of anti-fungal susceptibility.
Results
Of 46 patients with cryptococcal meningitis identified, 21 were cured after 10 weeks of treatment. Overall, 12 strains (26.1%) were resistant to fluconazole (>8 μg/ml) and 8 (17.4%) had an MIC >1 μg/ml for amphotericin B. Twenty-three patients received combination amphotericin B and fluconazole as their initial antifungal therapy, 17 were given amphotericin B only, five received fluconazole only, and one received a combination of amphotericin B and flucytosine. After 2 weeks, all patients received fluconazole (400–600 mg daily for 8 weeks at least, then 200 mg daily thereafter). The presence of isolates resistant to fluconazole (MIC >8 μg/ml; 4.8% vs. 44%, p < 0.01) were statistically significant among patients who were cured. Anti-fungal susceptibility, reflected by fluconazole MIC >8 μg/ml, was an independent predictor of therapeutic cure at 10-week evaluation (OR = 15.7; 95% CI: 1.8-135.9; p = 0.01), but higher MIC of amphotericin B (>1 μg/ml) was not.
Conclusions
The MICs of fluconazole, determined by the CLSI method, may be a potential predictor of therapeutic cure in patients with cryptococcal meningitis.
doi:10.1186/1471-2334-12-361
PMCID: PMC3546060  PMID: 23253817
Cryptococcal meningitis; Fluconazole; Outcome; Susceptibility
24.  Occurrence of AH1N1 viral infection and clinical features in symptomatic patients who received medical care during the 2009 influenza pandemic in Central Mexico 
BMC Infectious Diseases  2012;12:363.
Background
In 2009 a new influenza serotype (AH1N1) was identified in Mexico that spread rapidly generating worldwide alarm. San Luis Potosi (SLP) was the third state with more cases reported in that year. The clinical identification of this flu posed a challenge to medical staff. This study aimed at estimating the AH1N1 infection, hospitalization and mortality rates, and at identifying related clinical features in persons who received medical care during the influenza pandemic.
Methods
Retrospective study with persons with flu-like illness who received public or private medical care in SLP from 15.03.09 to 30.10.09. Physicians purposely recorded many clinical variables. Samples from pharyngeal exudate or bronchoalveolar lavage were taken to diagnose AH1N1 using real-time PCR. Clinical predictors were identified using multivariate logistic regression with infection as a dependent variable. Odds ratios (OR) with 95% confidence intervals (CI) were computed. Analyses were stratified by age group based on the distribution of positive cases.
Results
From the 6922 persons with flu symptoms 6158 had available laboratory results from which 44.9% turned out to be positive for AH1N1. From those, 5.8% were hospitalized and 0.7% died. Most positive cases were aged 5–14 years and, in this subgroup, older age was positively associated with A H1N1 infection (95% CI 1.05-1.1); conversely, in patients aged 15 years or more, older age was negatively associated with the infection (95% CI 0.97-0.98). Fever was related in those aged 15 years or more (95% CI 1.4-3.5), and headache (95% CI 1.2-2.2) only in the 0–14 years group. Clear rhinorrhea and cough were positively related in both groups (p < 0.05). Arthralgia, dyspnea and vaccination history were related to lesser risk in persons aged 15 years or more, just as dyspnea, purulent rhinorrhea and leukocytosis were in the 0–14 years group.
Conclusion
This study identified various signs and symptoms for the clinical diagnosis of AH1N1 influenza and revealed that some of them can be age-specific.
doi:10.1186/1471-2334-12-363
PMCID: PMC3553033  PMID: 23256776
25.  Coronavirus infections in hospitalized pediatric patients with acute respiratory tract disease 
BMC Infectious Diseases  2012;12:365.
Background
Acute viral respiratory infections are an important cause of morbidity and mortality in humans worldwide. The etiological backgrounds of these infections remain unconfirmed in most clinical cases. The aim of this study was to estimate the prevalence of human coronavirus infections in a series of children hospitalized with symptoms of acute respiratory tract disease in a one-year period in Slovenia.
Methods
The 664 specimens from 592 children under six years of age hospitalized at the University Children’s Hospital in Ljubljana were sent for the routine laboratory detection of respiratory viruses. Respiratory viruses were detected with a direct immunofluorescence assay and human coronaviruses were detected with a modified real-time RT–PCR.
Results
HCoV RNA was detected in 40 (6%, 95% CI: 4.3%–8.1%) of 664 samples. Of these specimens, 21/40 (52.5%) were identified as species HKU1, 7/40 (17.5%) as OC43, 6/40 (15%) as 229E, and 6/40 (15%) as NL63. Infection with HCoV occurred as a coinfection with one or more other viruses in most samples (70%). Of the HCoV-positive children, 70.3% had lower respiratory tract infections.
Conclusion
The results of our study show that HCoV are frequently detected human pathogens, often associated with other respiratory viruses and acute respiratory tract infections in hospitalized children. An association between age and the viral load was found. The highest viral load was detected in children approximately 10 months of age.
doi:10.1186/1471-2334-12-365
PMCID: PMC3557153  PMID: 23256846
Hospitalized children; Human coronavirus; Respiratory viral infection

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