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1.  Pneumococcal Nasopharyngeal Carriage following Reduced Doses of a 7-Valent Pneumococcal Conjugate Vaccine and a 23-Valent Pneumococcal Polysaccharide Vaccine Booster▿ †  
Clinical and Vaccine Immunology : CVI  2010;17(12):1970-1976.
This study was conducted to evaluate the effect of a reduced-dose 7-valent pneumococcal conjugate vaccine (PCV) primary series followed by a 23-valent pneumococcal polysaccharide vaccine (23vPPS) booster on nasopharyngeal (NP) pneumococcal carriage. For this purpose, Fijian infants aged 6 weeks were randomized to receive 0, 1, 2, or 3 PCV doses. Within each group, half received 23vPPS at 12 months. NP swabs were taken at 6, 9, 12, and 17 months and were cultured for Streptococcus pneumoniae. Isolates were serotyped by multiplex PCR and a reverse line blot assay. There were no significant differences in PCV vaccine type (VT) carriage between the 3- and 2-dose groups at 12 months. NP VT carriage was significantly higher (P, <0.01) in the unvaccinated group than in the 3-dose group at the age of 9 months. There appeared to be a PCV dose effect in the cumulative proportion of infants carrying the VT, with less VT carriage occurring with more doses of PCV. Non-PCV serotype (NVT) carriage rates were similar for all PCV groups. When groups were pooled by receipt or nonreceipt of 23vPPS at 12 months, there were no differences in pneumococcal, VT, or NVT carriage rates between the 2 groups at the age of 17 months. In conclusion, there appeared to be a PCV dose effect on VT carriage, with less VT carriage occurring with more doses of PCV. By the age of 17 months, NVT carriage rates were similar for all groups. 23vPPS had no impact on carriage, despite the substantial boosts in antibody levels.
PMCID: PMC3008188  PMID: 20943882
2.  Seroepidemiology of cryptosporidiosis in children in Papua New Guinea and Australia. 
Epidemiology and Infection  1994;113(3):491-499.
Enzyme immunoassays (EIA) were used to measure serum antibodies to Cryptosporidium in four immunocompetent adults with recent proven cryptosporidial infection, 379 healthy children and 73 adult volunteers in Melbourne, Australia, and 205 children in Papua New Guinea (PNG) (47 healthy children; 158 with pneumonia). Antibodies peaked 3-6 weeks after infection and fell to baseline within a few months. A high level (5000 EIA units/ml) or a significant change between paired sera, of IgG or IgM, were taken as evidence of recent infection and found in 24% of PNG children and in 8% of children and 5% of adults in Melbourne. Among PNG children with pneumonia who had high cryptosporidial antibody levels, those with measles (6/8) were significantly more likely (P = 0.002) to have diarrhoea than the remainder (4/28). Symptomatic cryptosporidiosis may be associated with transient immune suppression due to viral infection. This study indicates that serological surveys can contribute to an understanding of the epidemiology of cryptosporidosis.
PMCID: PMC2271320  PMID: 7995359
3.  The Nonserotypeable Pneumococcus: Phenotypic Dynamics in the Era of Anticapsular Vaccines ▿  
Journal of Clinical Microbiology  2009;48(3):831-835.
Nonserotypeable pneumococci (NSP) are commonly carried by Australian Indigenous children in remote communities. The purpose of this study was to characterize carriage isolates of NSP from Indigenous children vaccinated with the seven-valent pneumococcal conjugate vaccine (PCV7) and to use these data to guide decisions on reporting of NSP. A total of 182 NSP were characterized by BOX typing, antibiogram analysis, and multilocus sequence typing (MLST) of common BOX types. NSP positive for the wzg capsule gene were analyzed by a multiplex PCR-based reverse line blot hybridization assay (mPCR/RLB-H) targeting capsule genes to determine the serotype. Among 182 NSP, 49 BOX types were identified. MLST of 10 representative isolates found 7 STs, including ST448 (which accounted for 11% of NSP). Non-penicillin susceptibility was evident in 51% of the isolates. Pneumococcal wzg sequences were detected in only 23 (13%) NSP, including 10 that contained an ∼1.2-kb insert in the region. mPCR/RLB-H identified serotype 14 wzy sequences in all 10 NSP, and 1 also contained a serotype 3-specific wze sequence. Among the remaining 13 wzg-positive NSP, few belonged to the serotypes represented in PCV7. It appears that most NSP identified in Australian Indigenous children are from a true nonencapsulated lineage. Few NSP represented serotypes in PCV7 that suppress capsular expression. High rates of carriage and penicillin resistance and the occasional presence of capsule genes suggest a role for NSP in the maintenance and survival of capsulated pneumococci. To avoid the inflation of pneumococcal carriage and antibiotic resistance rates, in clinical trials, we recommend separate reporting of rates of capsular strains and NSP and the exclusion of data for NSP from primary analyses.
PMCID: PMC2832454  PMID: 20042626
4.  Subtyping of Mycobacterium avium complex (MAC) isolates by thin-layer chromatography--distribution of subtypes from patients with AIDS compared with clinically non-significant isolates. 
Epidemiology and Infection  1994;112(3):543-549.
Thin-layer chromatography (TLC) was compared with seroagglutination for subtyping of Mycobacterium avium complex (MAC) bacteria. Seventy-five significant MAC isolates from patients with AIDS were typed by both methods and 36 isolates, judged to be clinically non-significant, were examined by TLC only. Overall, 75% of isolates tested were typable by seroagglutination and 91% by TLC; the results correlated between the two except for minor discrepancies. Serovars 1, 8 and 21 and mixed serovars 1-21 and 1-8-21 were common among isolates from AIDS patients and together represented 83% of isolates compared with only 36% in the non-significant group (odds ratio 8.4; 95% confidence interval 3.4-23.3). This difference remained significant after exclusion of serovar 41 (M. scrofulaceum), which was the commonest isolate (28%) in the non-significant group but was not isolated from patients with AIDS. TLC is useful to supplement seroagglutination for subtyping of MAC. Further study is required to determine whether apparent differences between isolates from patients with AIDS and from other sources reflect differences in virulence or in environmental prevalence of MAC subtypes.
PMCID: PMC2271518  PMID: 8005220
5.  Successful treatment of epiglottitis with two doses of ceftriaxone. 
Archives of Disease in Childhood  1994;70(2):129-132.
Epiglottitis in childhood is caused by Haemophilus influenzae type b. The usual antibiotic treatment at the Royal Children's Hospital, Parkville, Victoria is a five day course of chloramphenicol. Increasingly, third generation cephalosporins are being used to treat invasive H influenzae type b infections and preliminary data suggest that they can be used successfully for epiglottitis. In a prospective, randomised trial, the efficacy of a short course (two days) of ceftriaxone was compared with that of five days of chloramphenicol for the treatment of epiglottitis. The ability of these treatment regimens to eradicate H influenzae type b from the throat was also studied. Fifty five children were enrolled over an 18 month period. Epiglottitis was diagnosed clinically and confirmed on inspection of the epiglottis at direct laryngoscopy. Fifty three (96%) of 55 patients had H influenzae type b detected from at least one site: 44/52 (85%) from blood cultures, 41/47 (87%) from throat swab, and 6/8 (75%) as H influenzae type b urinary antigen. Children were randomised to receive either ceftriaxone 100 mg/kg intravenously followed by a single dose of 50 mg/kg 24 hours later (28 patients), or chloramphenicol 40 mg/kg intravenously, then 25 mg/kg eight hourly for five days, intravenously then by mouth (27 patients). All household contacts and patients receiving chloramphenicol received rifampicin 20 mg/kg daily for four days. Index patients randomised to ceftriaxone were not treated with rifampicin. There was no significant difference in outcome between the two groups with respect to the mean duration of fever, the duration of intubation, or the length of hospital admission. The proportion of patients colonised with H influenzae type b four weeks after discharge was not significantly different between the two groups: ceftriaxone 5/22 (23%) versus chloramphenicol and rifampicin 3/23 (13%). A short course of ceftriaxone was successful in treating all patients with no significant side effects and no relapses. A short course of ceftriaxone is a safe, efficacious, and economic alternative to the standard treatment in children with epiglottitis.
PMCID: PMC1029716  PMID: 8129435
6.  Rifampicin prophylaxis for throat carriage of Haemophilus influenzae type b in patients with invasive disease and their contacts. 
BMJ : British Medical Journal  1991;302(6790):1432-1435.
OBJECTIVE--To determine rates of colonisation with Haemophilus influenzae type b among household contacts of children with invasive H influenzae type b disease; compliance among medical staff with recommendations for use of rifampicin prophylaxis; and effects of rifampicin treatment in H influenzae type b colonisation of patients and contacts. DESIGN--Prospective study of patients and their household contacts. SETTING--Royal Children's Hospital (the major paediatric hospital) in Victoria, Australia, with catchment population of 4.2 million, including 300,000 children aged under 5 years. SUBJECTS--234 patients (age range 6 weeks to 8 years) with 235 episodes of all types of invasive H influenzae type b disease admitted during 1988-9 and their contacts. MAIN OUTCOME MEASURES--Positive cultures of H influenzae type b from throat swabs taken at admission and six weeks subsequently; recording of rifampicin prophylaxis. RESULTS--The percentage of patients with positive throat cultures fell from 69% (33/48) on day 1 of admission to 9% (4/47) after three days' treatment; at six weeks' follow up 32% (32/99) of patients who had not received rifampicin and 8% (5/61) who had, had positive throat cultures. Among household contacts, 33% (62/190) of children and 7% (25/359) of adults were colonised, and the colonisation rates were similar in contacts of patients with all types of H influenzae type b disease. Rifampicin prophylaxis was indicated in 85 families; in 34% it was not prescribed at all for contacts and in 41% not as recommended. The colonisation rates at follow up were significantly less in siblings given rifampicin (12%, 9/78), particularly in families in which all members were treated (3%), than in those in which they were not (36%) (odds ratio 21.5; 95% confidence interval 3.0 to 103.4). CONCLUSIONS--The rate of throat colonisation with H influenzae type b was similar among siblings of children with all types of invasive H influenzae type b disease. Colonisation in contacts can be reduced by rifampicin prophylaxis, but some contacts remained colonised or were recolonised by the time of follow up. Medical staff complied poorly with current recommendations for rifampicin prophylaxis, which reduces its intrinsically limited value in preventing H influenzae type b disease.
PMCID: PMC1670130  PMID: 2070109
7.  Evaluation of Two Enzyme Immunoassays for Detection of Immunoglobulin G Antibodies to Mumps Virus 
Clinical and Vaccine Immunology  2006;13(7):764-767.
To determine suitability for national serosurveys, we compared two commercial enzyme-linked immunosorbent assays (ELISAs) for mumps antibody, Enzygnost Anti-Parotitis-Virus/IgG (which uses a whole-virus antigen) and Microimmune Mumps IgG Screen ELISA (which uses a recombinant nucleoprotein antigen), by testing 1,915 opportunistically collected sera submitted to diagnostic laboratories across Australia in 1997 to 1998. The proportion of positive results increased with age in both ELISAs but was significantly higher with the Microimmune than with the Enzygnost ELISA overall (88% versus 63%; P < 0.01) and in all age groups. However, the proportion of equivocal results was significantly higher with the Enzygnost than with the Microimmune ELISA (9% versus 4%; P < 0.01). Of the 572 sera with discrepant or equivocal results, 508 had sufficient sample remaining to perform the neutralization test (NT). A proportion with concordant results in both ELISAs were also tested by the NT. For sera with discrepant results, there was significantly better agreement between the NT and Microimmune than between the NT and Enzygnost (310/444 [70%] versus 135/348 [39%]; P < 0.01). Of 64 sera with equivocal Microimmune results, 45 (70%) were positive in the NT compared with 140 of 160 (88%) equivocal Enzygnost results (P < 0.01). Compared with the NT, the Microimmune ELISA is more sensitive (96% versus 80%) but apparently less specific (36% versus 85%) than the Enzygnost ELISA. However, this is likely to be due to the generally lower sensitivity of the NT, since the Microimmune results reflect expected seroprevalence, based on vaccine uptake in the age groups studied. We conclude that the Microimmune ELISA is a more appropriate assay than the Enzygnost ELISA for estimation of mumps seroprevalence.
PMCID: PMC1489562  PMID: 16829613
8.  Australian Isolates of Legionella longbeachae Are Not a Clonal Population 
Journal of Clinical Microbiology  1999;37(10):3249-3254.
Legionella longbeachae is almost as frequent a cause of legionellosis in Australia as Legionella pneumophila, but epidemiological investigation of possible environmental sources and clinical cases has been limited by the lack of a discriminatory subtyping method. The purpose of this study was to examine the genetic variability among Australian isolates of L. longbeachae serogroup 1. Pulsed-field gel electrophoresis (PFGE) of SfiI fragments revealed three distinct pulsotypes among 57 clinical and 11 environmental isolates and the ATCC control strains of L. longbeachae serogroups 1 and 2. Each pulsotype differed by four bands, corresponding to <65% similarity. A clonal subgroup within each pulsotype was characterized by >88% similarity. The largest major cluster was pulsotype A, which included 43 clinical isolates and 9 environmental isolates and was divided into five subgroups. Pulsotypes B and C comprised smaller numbers of clinical and environmental isolates, which could each be further divided into three subgroups. The ATCC type strain of L. longbeachae serogroup 1 was classified as pulsotype B, subtype B3, while the ATCC type strain of L. longbeachae serogroup 2 was identified as a different pulsotype, LL2. SfiI macrorestriction analysis followed by PFGE showed that the Australian L. longbeachae strains are not a single clonal population as previously reported.
PMCID: PMC85541  PMID: 10488187
9.  Helicobacter westmeadii sp. nov., a new species isolated from blood cultures of two AIDS patients. 
Journal of Clinical Microbiology  1997;35(5):1144-1150.
A slowly growing anaerobic Helicobacter species was isolated from the blood cultures of two human immunodeficiency virus-positive patients admitted to Westmead Hospital, Westmead, Australia, with fevers. The morphology of the isolates was consistent with Helicobacter cinaedi or Helicobacter fennelliae. The results of culture growth conditions, biochemical tests, gas chromatography data, ribotyping, and 16S rDNA sequencing showed that these isolates represent a new Helicobacter species, for which the name Helicobacter westmeadii has been proposed.
PMCID: PMC232719  PMID: 9114397
10.  Invasive Haemophilus influenzae type b disease in elderly nursing home residents: two related cases. 
Emerging Infectious Diseases  1997;3(2):179-182.
We investigated two fatal cases of invasive Haemophilus influenzae type b (Hib) infection in a community nursing home in western Sydney, Australia. Two elderly women had lived in the same room, and the onset of their illness was 5 days apart. Hib isolates from blood cultures showed identical profiles by pulsed field gel electrophoresis. These findings suggest that Hib infection was transmitted within this nursing home. Serious Hib disease may be underrecognized in this setting. Continued surveillance and serotyping of invasive H. influenzae disease is essential for identifying groups at increasing risk that may benefit from immunization against Hib.
PMCID: PMC2627616  PMID: 9204300
11.  Rapid diagnosis of Legionella pneumophila serogroup 1 infection with the Binax enzyme immunoassay urinary antigen test. 
Journal of Clinical Microbiology  1997;35(4):954-956.
The Binax legionella urinary antigen (LUA) enzyme immunoassay (Binax, Portland, Maine) was evaluated in 159 patients with suspected or proven legionellosis and 209 controls. A positive LUA test was found in 37% of patients with suspected legionellosis overall and in 83% of those with proven Legionella pneumophila serogroup 1 infection. The sensitivity of the LUA test was significantly greater than that of the direct fluorescent-antigen test (83 versus 42%; P < 0.0001) but not significantly different from that of culture (85%) or serology (91%); specificity was at least 99.5%.
PMCID: PMC229708  PMID: 9157160
12.  Differing antibody responses to Haemophilus influenzae type b after meningitis or epiglottitis. 
Epidemiology and Infection  1996;116(1):21-26.
Two common forms of invasive disease due to Haemophilus influenzae type b (Hib) are epiglottitis and meningitis. It is not known why some children develop epiglottitis and others meningitis. To examine the hypothesis that epiglottitis occurs in children who may have been previously exposed to Hib, and who would therefore exhibit a more vigorous antibody response in convalescence, we measured levels of antibody to Hib capsule in 92 children. Geometric mean convalescent-phase IgG, IgA, IgM and total antibody levels were significantly higher in 45 children with epiglottitis than in 47 with meningitis, even after adjustment for age differences (mean total antibody, 95% confidence intervals: meningitis 0.38, 0.34-0.43; epiglottitis: 2.25, 2.0-2.54 micrograms/ml). However, contrary to previous reports, a poor antibody response was only observed in a minority of children with meningitis; the antibody response of the majority was indistinguishable from that observed in children with epiglottitis.
PMCID: PMC2271250  PMID: 8626000
13.  Genetic characterization of Mycobacterium avium isolates recovered from humans and animals in Australia. 
Epidemiology and Infection  1996;116(1):41-49.
Genetic relationships amongst 115 mainly Australian isolates of Mycobacterium avium were assessed using multilocus enzyme electrophoresis (MEE). The isolates were divided into 58 electrophoretic types (ETs), with a mean genetic diversity of 0.29. Isolates from humans were closely related to but distinct from those cultured from birds, whilst some porcine isolates belonged to the same ETs as certain human isolates. Pulsed field gel electrophoresis (PFGE) was used to differentiate related isolates, and those from birds and some from other animals, including pigs, were distinguished from the human isolates. The results of MEE and PFGE suggested that certain strains of M. avium may be transmitted between birds and pigs, but there was no clear evidence of transmission to humans. The serovar of the M. avium isolates was not obviously related to their ET assignment or their PFGE type.
PMCID: PMC2271235  PMID: 8626003
14.  Comparison of cell culture, mouse inoculation, and PCR for detection of Toxoplasma gondii: effects of storage conditions on sensitivity. 
Journal of Clinical Microbiology  1996;34(6):1572-1575.
The sensitivity of detection of a wild-type strain of Toxoplasma gondii by cell culture, mouse inoculation, and PCR was determined following sample storage under conditions to which clinical specimens may be subjected during transport to the testing laboratory. Sample storage at -20 degrees C significantly decreased the sensitivity of mouse inoculation. The sensitivity of cell culture decreased with sample storage at 4 and -20 degrees C. The sensitivity of PCR was reduced by storage at 4 degrees C for 48 h, freezing, and heating. These findings have implications for the selection of appropriate methods for the direct detection of T. gondii organisms in suboptimally transported clinical samples.
PMCID: PMC229067  PMID: 8735123
15.  Sporadic invasion of cultured epithelial cells by Haemophilus influenzae type b. 
Infection and Immunity  1996;64(3):1051-1053.
While working with an in vitro invasion assay, we observed that Haemophilus influenzae type b occasionally exhibits highly invasive behavior. The phenomenon is not inhibited by colchicine or cytochalasin but is dependent on the presence of supplemental CO2. We propose that sporadic invasiveness may correlate with the unknown events that precede Haemophilus influenzae type b bacteremia.
PMCID: PMC173880  PMID: 8641759
16.  Serological cross-reaction between Legionella spp. and Capnocytophaga ochracea by using latex agglutination test. 
Journal of Clinical Microbiology  1994;32(12):3054-3055.
Cross-reactivity between Legionella spp. and Capnocytophaga ochracea was noted by latex agglutination tests (Serobact Legionella; Disposable Products, Adelaide, Australia). Four of 11 (36%) C. ochracea isolates agglutinated with latex reagents designed to identify Legionella pneumophila serogroups. C. ochracea isolated on buffered charcoal yeast extract media may give false-positive results in this Legionella latex agglutination assay.
PMCID: PMC264227  PMID: 7883900
17.  Antibodies to Haemophilus influenzae type b outer membrane proteins in children with epiglottitis or meningitis and in healthy controls. 
Infection and Immunity  1993;61(4):1531-1537.
The two most common manifestations of Haemophilus influenzae type b (Hib) infection in Western communities are meningitis and epiglottitis. The role of antibodies against outer membrane proteins (OMP) in the pathogenesis of these diseases was investigated by Western blotting (immunoblotting) with an OMP antigen prepared from a local Hib strain. Acute- and convalescent-phase serum samples from 25 children with epiglottitis and 20 with meningitis and single serum samples from 19 control children in the same age group were tested. Western blots were evaluated quantitatively by use of graphs generated from a densitometer. OMP antibody was detected in all sera from patients and controls. There was no significant difference between the mean antibody level in acute-phase sera from children with meningitis (336 +/- 143 arbitrary units) and those from children with epiglottitis (286 +/- 134 arbitrary units). However, the mean OMP antibody level in sera from healthy controls, with no known history of Hib disease, was significantly higher than that in sera from patients with Hib disease within 2 days of admission to the hospital (patients [n = 35], 282 +/- 144; controls [n = 19], 425 +/- 236; P = 0.007). The difference was due mainly to higher levels, in control sera, of antibody against four proteins, one of which is either P1 or a comigrating protein of 49 kDa. The finding of higher levels of OMP antibody in healthy controls suggests a protective role for antibodies directed against one or more OMP. This information could be exploited in future vaccine development.
PMCID: PMC281396  PMID: 8454359
18.  Outer membrane protein subtypes of Haemophilus influenzae type b isolates causing invasive disease in Victoria, Australia, from 1988 to 1990. 
Journal of Clinical Microbiology  1992;30(7):1879-1881.
Outer membrane protein subtyping of 187 isolates of Haemophilus influenzae type b (Hib), isolated from children with invasive Hib disease in Victoria, Australia, showed that a single outer membrane protein subtype (1VA) was responsible for 83% of the infections. It was identical to that responsible for the majority of cases of invasive Hib disease in Europe.
PMCID: PMC265399  PMID: 1629347
19.  Chickenpox during pregnancy. 
BMJ : British Medical Journal  1993;306(6885):1079-1080.
PMCID: PMC1677489  PMID: 8495148
20.  Rapid diagnosis of herpes simplex virus infections by enzyme-linked immunosorbent assay. 
Journal of Clinical Microbiology  1984;19(6):865-869.
A total of 457 clinical specimens were tested for the presence of herpes simplex virus (HSV) by isolation in cell culture and by enzyme-linked immunosorbent assay. HSV antigen was detected by enzyme-linked immunosorbent assay in 94% of the clinical specimens from which the virus was isolated. The detection rate was improved to 100% when specimens were either assayed within 24 h or stored frozen at a constant temperature (-20 degrees C) for up to 14 days. Type-specific HSV antigen was also detected in 6% of culture-negative specimens. The assay can be completed in 5 h or less, and commercially available immunoglobulins are used. Enzyme-linked immunosorbent assay is a rapid and sensitive method for the diagnosis of HSV infection and can be used to improve the management of pregnant women with a history of genital herpes and of neonates and others with serious HSV infection which may require specific antiviral therapy. It also offers an alternative to cell culture for routine diagnosis of HSV infections.
PMCID: PMC271200  PMID: 6088571
21.  Enzyme-linked immunosorbent assay for rubella immunoglobulin G: new method for attachment of antigens to microtiter plates. 
Journal of Clinical Microbiology  1983;17(5):738-743.
Many of the enzyme-linked immunosorbent assay (ELISA) techniques previously described for detection of rubella-specific antibodies employ complex technology not available in routine diagnostic laboratories. The method described allows the use of commercially available rubella hemagglutination inhibition (HI) antigen. Passive adsorption of these antigens to plastic is variable, but with the use of albumin as a bridge, it is possible to attach the antigen reliably to the plastic wells. Over 1,500 sera were tested by both HI and ELISA techniques to detect the presence of rubella antibodies. These sera were selected with a bias towards those with low levels of rubella-specific antibody, since it has been demonstrated that it is in this range that discrepancies are more likely to occur between HI and ELISA techniques. In 99% of the sera tested, the results of both techniques were in agreement. On the basis of these results, the technique offers a useful alternative to the routine rubella HI test and other ELISA techniques which need sophisticated antigen preparations.
PMCID: PMC272734  PMID: 6863497

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