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1.  An observational study of malaria in British travellers: Plasmodium ovale wallikeri and Plasmodium ovale curtisi differ significantly in the duration of latency 
BMJ Open  2013;3(5):e002711.
Objectives
Ovale malaria is caused by two closely related species of protozoan parasite: Plasmodium ovale curtisi and Plasmodium ovale wallikeri Although clearly distinct genetically, there have been no studies comparing the morphology, life cycle or epidemiology of these parasites. We tested the hypothesis that the two species differ in the duration of latency prior to presentation with symptoms of blood-stage infection.
Design
PCR was used to identify P ovale curtisi and P ovale wallikeri infections among archived blood from UK malaria patients. Latency periods, estimated as the time between entry into the UK and diagnosis of malaria, were compared between the two groups.
Setting
UK National Reference Laboratory.
Participants
None. Archived parasite material and surveillance data for 74 P ovale curtisi and 60 P ovale wallikeri infections were analysed. Additional epidemiological data were taken from a database of 1045 imported cases.
Outcomes
None.
Results
No differences between the two species were identified by a detailed comparison of parasite morphology (N=9, N=8, respectively) and sex ratio (N=5, N=4) in archived blood films. The geometric mean latency period in P ovale wallikeri was 40.6 days (95% CI 28.9 to 57.0), whereas that for P ovale curtisi was more than twice as long at 85.7 days (95% CI 66.1 to 111.1; p=0.002). Further, the proportion of ovale malaria sensu lato which occurred in patients reporting chemoprophylaxis use was higher than for Plasmodium falciparum (OR 7.56; p<0.0001) or P vivax (OR 1.82; p<0.0001).
Conclusions
These findings provide the first difference of epidemiological significance observed between the two parasites which cause ovale malaria, and suggest that control measures aimed at P falciparum may not be adequate for reducing the burden of malaria caused by P ovale curtisi and P ovale wallikeri.
doi:10.1136/bmjopen-2013-002711
PMCID: PMC3657643  PMID: 23793668
Parasitology
3.  Clinical Evaluation of a Loop-Mediated Amplification Kit for Diagnosis of Imported Malaria 
The Journal of Infectious Diseases  2013;208(4):637-644.
Background. Diagnosis of malaria relies on parasite detection by microscopy or antigen detection; both fail to detect low-density infections. New tests providing rapid, sensitive diagnosis with minimal need for training would enhance both malaria diagnosis and malaria control activities. We determined the diagnostic accuracy of a new loop-mediated amplification (LAMP) kit in febrile returned travelers.
Methods. The kit was evaluated in sequential blood samples from returned travelers sent for pathogen testing to a specialist parasitology laboratory. Microscopy was performed, and then malaria LAMP was performed using Plasmodium genus and Plasmodium falciparum–specific tests in parallel. Nested polymerase chain reaction (PCR) was performed on all samples as the reference standard. Primary outcome measures for diagnostic accuracy were sensitivity and specificity of LAMP results, compared with those of nested PCR.
Results. A total of 705 samples were tested in the primary analysis. Sensitivity and specificity were 98.4% and 98.1%, respectively, for the LAMP P. falciparum primers and 97.0% and 99.2%, respectively, for the Plasmodium genus primers. Post hoc repeat PCR analysis of all 15 tests with discrepant results resolved 4 results in favor of LAMP, suggesting that the primary analysis had underestimated diagnostic accuracy.
Conclusions. Malaria LAMP had a diagnostic accuracy similar to that of nested PCR, with a greatly reduced time to result, and was superior to expert microscopy.
doi:10.1093/infdis/jit183
PMCID: PMC3719897  PMID: 23633403
malaria; diagnostics; LAMP
4.  Severe imported falciparum malaria among adults requiring intensive care: a retrospective study at the hospital for tropical diseases, London 
BMC Infectious Diseases  2013;13:118.
Background
Malaria is the commonest imported infection in the UK. Malaria requiring ICU admission has a reported mortality of up to 25%. The relationship between ethnicity, immunity, and risk of malaria is complex. The Malaria Score for Adults (MSA) and Coma Acidosis Malaria (CAM) score have recently been proposed to risk stratify patients with malaria.
Methods
Retrospective study of patients with WHO severe falciparum malaria admitted to ICU at the Hospital for Tropical Diseases, London, UK. The relationship between clinical variables and risk of death or a prolonged ICU stay were examined with logistic regression. The predictive value of the MSA and CAM score were calculated.
Results
124 patients were included. Cerebral malaria and acute kidney injury occurred earlier (median day 1) than acute respiratory distress syndrome (median day 3). Six patients had community acquired bacterial co-infection. Eight patients were co-infected with HIV, five of whom were newly diagnosed. The positive predictive value of a CAM score ≥2 or an MSA ≥5 for death were 12% and 22% respectively. Five patients died. No variable was significantly associated with risk of death. There were no significant differences between individuals raised in endemic countries compared to non-endemic countries.
Conclusions
Mortality in patients managed in a specialist centre was low. Patients who died succumbed to complications associated with a prolonged stay on ICU rather than malaria per se. The clinical usefulness of the MSA and CAM score was limited. Co-infection with HIV was relatively common but compared to studies in children, bacteraemia was uncommon. The relationship between ethnicity and immunity to severe disease is complex.
doi:10.1186/1471-2334-13-118
PMCID: PMC3599148  PMID: 23497139
5.  Gametocyte carriage in Plasmodium falciparum-infected travellers 
Malaria Journal  2013;12:31.
Background
Gametocytes are the sexual stage of Plasmodium parasites. The determinants of gametocyte carriage have been studied extensively in endemic areas, but have rarely been explored in travellers with malaria. The incidence of gametocytaemia, and factors associated with gametocyte emergence in adult travellers with Plasmodium falciparum malaria was investigated at the Hospital for Tropical Diseases in London.
Methods
Clinical, parasitological and demographic data for all patients presenting with P. falciparum malaria between January 2001 and December 2011 were extracted from a prospective database. These data were supplemented by manual searches of laboratory records and patient case notes.
Results
Seven hundred and seventy three adult patients with laboratory-confirmed P. falciparum malaria were identified. Four hundred and sixty five (60%) were born in a country where malaria is endemic. Patients presented to hospital a median of four days into their illness. The median maximum parasite count was 0.4%. One hundred and ninety six patients (25%) had gametocytes; 94 (12%) on admission, and 102 (13%) developing during treatment. Gametocytaemia on admission was associated with anaemia and a lower maximum parasitaemia. Patients with gametocytes at presentation were less likely to have thrombocytopenia or severe malaria. Patients who developed gametocytes during treatment were more likely to have had parasitaemia of long duration, a high maximum parasitaemia and to have had severe malaria. There was no apparent association between the appearance of gametocytes and treatment regimen.
Conclusions
The development of gametocytaemia in travellers with P. falciparum is associated with factors similar to those reported among populations in endemic areas. These data suggest that acquired immunity to malaria is not the only determinant of patterns of gametocyte carriage among patients with the disease.
doi:10.1186/1475-2875-12-31
PMCID: PMC3582526  PMID: 23347669
Falciparum malaria; Gametocytes; Adult travellers
6.  Epidemiology of Imported Cutaneous Leishmaniasis at the Hospital for Tropical Diseases, London, United Kingdom: Use of Polymerase Chain Reaction to Identify the Species 
This study reviewed all patients diagnosed with imported cutaneous leishmaniasis (CL) at the Hospital for Tropical Diseases in London, United Kingdom, over an 11-year period. Diagnostic and epidemiologic information was collected prospectively for all patients with imported CL to this hospital during 1998–2009. A total of 223 patients were given a diagnosis of CL. Ninety patients were diagnosed with Old World CL, which was caused most commonly by Leishmania donovani complex (n = 20). A total of 71% were tourists to the Mediterranean region, 36% were migrants or visiting friends and relatives, and 17% were soldiers. One hundred thirty-three patients were given a diagnosis of New World CL. The Leishmania subgenus Viannia caused 97 of these cases; 44% of these were in backpackers and 29% were in soldiers. Polymerase chain reaction was more sensitive and faster for detecting Leishmania DNA (86% for Old World CL and 96% for New World CL) than culture. This is the largest study of imported leishmaniasis, and demonstrates that tourists to the Mediterranean and backpackers in Central and South America are at risk for this disease.
doi:10.4269/ajtmh.2012.10-0558
PMCID: PMC3247118  PMID: 22232460
7.  Geographical concentration of falciparum malaria treated in the UK and delay to treatment with artesunate in severe cases: an observational study 
BMJ Open  2012;2(6):e001854.
Objectives
To quantify geographical concentration of falciparum malaria cases in the UK at a hospital level. To assess potential delay-to-treatment associated with hub-and-spoke distribution of artesunate in severe cases.
Design
Observational study using national and hospital data.
Setting and participants
3520 patients notified to the Malaria Reference Laboratory 2008–2010, 34 patients treated with intravenous artesunate from a tropical diseases centre 2002–2010.
Main outcome measures
Geographical location of falciparum cases notified in the UK. Diagnosis-to-treatment times for intravenous artesunate.
Results
Eight centres accounted for 43.9% of the UK's total cases; notifications from 107 centres accounted for 10.2% of cases; 51.5% of hospitals seeing malaria notified 5 or fewer cases in 3 years. Centres that saw <10 cases/year treat 26.3% of malaria cases; 6.1% of cases are treated in hospitals seeing <2 cases/year. Concentration of falciparum malaria was highest in Greater London (1925, 54.7%), South East (515, 14.6%), East of England (402, 11.4%) and North West (192, 5.4%). The North East and Northern Ireland each notified 5 or fewer cases per year. Median diagnosis-to-treatment time was 1 h (range 0.5–5) for patients receiving artesunate in the specialist centre; 7.5 h (range 4–26) for patients receiving it in referring hospitals via the hub-and-spoke system (p=0.02); 25 h (range 9–45) for patients receiving it on transfer to the regional centre from a referring hospital (p=0.002).
Conclusions
Most UK hospitals see few cases of falciparum malaria and geographical distances are significant. Over 25% of cases are seen in hospitals where malaria is rare, although 60% are seen in hospitals seeing over 50 cases over 3 years. A hub-and-spoke system minimises drug wastage and ensures availability in centres seeing most cases but is associated with treatment delays elsewhere. As with all observational studies, there are limitations, which are discussed.
doi:10.1136/bmjopen-2012-001854
PMCID: PMC3533059  PMID: 23148346
Infectious Diseases; Parasitology
8.  Management of imported malaria in Europe 
Malaria Journal  2012;11:328.
In this position paper, the European Society for Clinical Microbiology and Infectious Diseases, Study Group on Clinical Parasitology, summarizes main issues regarding the management of imported malaria cases. Malaria is a rare diagnosis in Europe, but it is a medical emergency. A travel history is the key to suspecting malaria and is mandatory in patients with fever. There are no specific clinical signs or symptoms of malaria although fever is seen in almost all non-immune patients. Migrants from malaria endemic areas may have few symptoms.
Malaria diagnostics should be performed immediately on suspicion of malaria and the gold- standard is microscopy of Giemsa-stained thick and thin blood films. A Rapid Diagnostic Test (RDT) may be used as an initial screening tool, but does not replace urgent microscopy which should be done in parallel. Delays in microscopy, however, should not lead to delayed initiation of appropriate treatment. Patients diagnosed with malaria should usually be hospitalized. If outpatient management is preferred, as is the practice in some European centres, patients must usually be followed closely (at least daily) until clinical and parasitological cure. Treatment of uncomplicated Plasmodium falciparum malaria is either with oral artemisinin combination therapy (ACT) or with the combination atovaquone/proguanil. Two forms of ACT are available in Europe: artemether/lumefantrine and dihydroartemisinin/piperaquine. ACT is also effective against Plasmodium vivax, Plasmodium ovale, Plasmodium malariae and Plasmodium knowlesi, but these species can be treated with chloroquine. Treatment of persistent liver forms in P. vivax and P. ovale with primaquine is indicated after excluding glucose 6 phosphate dehydrogenase deficiency. There are modified schedules and drug options for the treatment of malaria in special patient groups, such as children and pregnant women. The potential for drug interactions and the role of food in the absorption of anti-malarials are important considerations in the choice of treatment.
Complicated malaria is treated with intravenous artesunate resulting in a much more rapid decrease in parasite density compared to quinine. Patients treated with intravenous artesunate should be closely monitored for haemolysis for four weeks after treatment. There is a concern in some countries about the lack of artesunate produced according to Good Manufacturing Practice (GMP).
doi:10.1186/1475-2875-11-328
PMCID: PMC3489857  PMID: 22985344
9.  Gnathostomiasis: An Emerging Imported Disease 
Emerging Infectious Diseases  2003;9(6):647-650.
As the scope of international travel expands, an increasing number of travelers are coming into contact with helminthic parasites rarely seen outside the tropics. As a result, the occurrence of Gnathostoma spinigerum infection leading to the clinical syndrome gnathostomiasis is increasing. In areas where Gnathostoma is not endemic, few clinicians are familiar with this disease. To highlight this underdiagnosed parasitic infection, we describe a case series of patients with gnathostomiasis who were treated during a 12-month period at the Hospital for Tropical Diseases, London.
doi:10.3201/eid0906.020625
PMCID: PMC3000140  PMID: 12781003
Gnathostoma; helminthiasis; imported disease; research
10.  Increased sensitivity for detecting malaria parasites in human umbilical cord blood using scaled-up DNA preparation 
Malaria Journal  2012;11:62.
Background
All mothers donating umbilical cord blood units to the NHS cord blood bank undergo an assessment for the likelihood of prior exposure to malaria infection. Those deemed at risk due to a history of travel to, or residence in, malaria endemic regions are screened serologically to detect anti-malaria antibodies. A positive result excludes the use of the cord blood for transplant therapy unless a risk assessment can ensure that malaria transmission is extremely unlikely. This paper details the screening of cord blood units from malaria serology positive mothers to detect malaria parasite DNA using a highly sensitive nested PCR.
Methods
Uninfected blood from a healthy volunteer was spiked with known quantities of malaria parasites and 5 millilitre and 200 microlitre aliquots were subjected to DNA extraction using QIAamp DNA maxi and DNA mini kits respectively. Nested PCR, to detect malarial SSU rRNA sequences, was performed on the purified DNA samples to determine the limit of detection for this assay with both extraction methodologies. Following assay validation, 54 cord blood units donated by mothers who were positive for anti-malaria antibodies were screened by this approach.
Results
When DNA was purified from 5 millilitres of blood it was possible to routinely detect as few as 50 malaria parasites per millilitre using nested PCR. This equates to a significant increase in the sensitivity of the current gold standard nucleic acid amplification technique used to detect malaria parasites (routinely performed from > 200 microlitre volumes of blood). None of the 54 donated cord blood units from serology positive mothers tested positive for malaria parasites using this scaled up DNA preparation method.
Conclusion
Serological testing for malaria parasites may be overly conservative, leading to unnecessary rejection of cord blood donations that lack malaria parasites and which are, therefore, safe for use in stem cell therapy.
doi:10.1186/1475-2875-11-62
PMCID: PMC3325849  PMID: 22390576
11.  African Trypanosomiasis in Travelers Returning to the United Kingdom 
Emerging Infectious Diseases  2002;8(1):74-76.
Two returning safari tourists with African trypanosomiasis were admitted to the Hospital for Tropical Diseases, London, in a 3-day period, compared with six cases in the previous 14 years. We describe the clinical features, diagnosis, and problems encountered in accessing appropriate therapy, and discuss the potential for emergence of this disease in increasingly adventurous international travelers.
doi:10.3201/eid0801.010130
PMCID: PMC2730280  PMID: 11749752
trypanosomiasis; African; Trypanosoma brucei; therapy; travel
12.  Mitochondrial DNA Targets Increase Sensitivity of Malaria Detection Using Loop-Mediated Isothermal Amplification ▿  
Journal of Clinical Microbiology  2010;48(8):2866-2871.
Loop-mediated isothermal amplification (LAMP) of DNA offers the ability to detect very small quantities of pathogen DNA following minimal tissue sample processing and is thus an attractive methodology for point-of-care diagnostics. Previous attempts to diagnose malaria by the use of blood samples and LAMP have targeted the parasite small-subunit rRNA gene, with a resultant sensitivity for Plasmodium falciparum of around 100 parasites per μl. Here we describe the use of mitochondrial targets for LAMP-based detection of any Plasmodium genus parasite and of P. falciparum specifically. These new targets allow routine amplification from samples containing as few as five parasites per μl of blood. Amplification is complete within 30 to 40 min and is assessed by real-time turbidimetry, thereby offering rapid diagnosis with greater sensitivity than is achieved by the most skilled microscopist or antigen detection using lateral flow immunoassays.
doi:10.1128/JCM.00355-10
PMCID: PMC2916605  PMID: 20554824
14.  Anaphylaxis from intravascular rupture of Hydatid disease following liver trauma 
Cystic Echinococcosis also known as cystic hydatid disease is a parasitic infection endemic in many parts of the world. Humans are accidental intermediate hosts with cysts most commonly developing in the liver. This case describes a rare presentation of hydatid disease following trauma to the liver. Intraparenchymal cyst rupture led to haemodynamic instability with release of the parasites protoscolices into hepatic venules producing severe life threatening anaphylaxis.
doi:10.1093/jscr/2010.7.1
PMCID: PMC3649144
15.  Gnathostomiasis, Another Emerging Imported Disease 
Clinical Microbiology Reviews  2009;22(3):484-492.
Gnathostomiasis is a food-borne zoonosis caused by the late-third stage larvae of Gnathostoma spp. It is being seen with increasing frequency in countries where it is not endemic and should be regarded as another emerging imported disease. Previously, its foci of endemicity have been confined to Southeast Asia and Central and South America, but its geographical boundaries appear to be increasing, with recent reports of infection in tourists returning from southern Africa. It has a complex life cycle involving at least two intermediate hosts, with humans being accidental hosts in which the larvae cannot reach sexual maturity. The main risks for acquisition are consumption of raw or undercooked freshwater fish and geographical exposure. Infection results in initial nonspecific symptoms followed by cutaneous and/or visceral larva migrans, with the latter carrying high morbidity and mortality rates if there is central nervous system involvement. We review the literature and describe the epidemiology, life cycle, clinical features, diagnosis, treatment, and prevention of gnathostomiasis.
doi:10.1128/CMR.00003-09
PMCID: PMC2708391  PMID: 19597010
16.  Novel pfdhps Haplotypes among Imported Cases of Plasmodium falciparum Malaria in the United Kingdom ▿  
Treatment of acute malaria caused by Plasmodium falciparum may include long-half-life drugs, such as the antifolate combination sulfadoxine-pyrimethamine (SP), to provide posttreatment chemoprophylaxis against parasite recrudescence or delayed emergence from the liver. An unusual case of P. falciparum recrudescence in a returned British traveler who received such a regimen, as well as a series of 44 parasite isolates from the same hospital, was analyzed by PCR and direct DNA sequencing for the presence of markers of parasite resistance to chloroquine and antifolates. The index patient harbored a mixture of wild-type and resistant pfdhfr and pfdhps alleles upon initial presentation. During his second malaria episode, he harbored only resistant parasites, with the haplotypes IRNI (codons 51, 59, 108, and 164) and SGEAA (codons 436, 437, 540, 581, and 613) at these two loci, respectively. Analysis of isolates from 44 other patients showed that the pfdhfr haplotype IRNI was common (found in 81% of cases). The SGEAA haplotype of pfdhps was uncommon (found only in eight cases of East African origin [17%]). A previously undescribed mutation, I431V, was observed for seven cases of Nigerian origin, occurring as one of two haplotypes, VAGKGS or VAGKAA. The presence of this mutation was also confirmed in isolates of Nigerian origin from the United Kingdom Malaria Reference Laboratory. The presence of the pfdhps haplotype SGEAA in P. falciparum parasites of East African origin appears to compromise the efficacy of treatment regimens that include SP as a means to prevent recrudescence. Parasites with novel pfdhps haplotypes are circulating in West Africa. The response of these parasites to chemotherapy needs to be evaluated.
doi:10.1128/AAC.00024-09
PMCID: PMC2715629  PMID: 19433569
17.  Inter-rater reliability of malaria parasite counts and comparison of methods 
Malaria Journal  2009;8:267.
Background
The introduction of artemesinin-based treatment for falciparum malaria has led to a shift away from symptom-based diagnosis. Diagnosis may be achieved by using rapid non-microscopic diagnostic tests (RDTs), of which there are many available. Light microscopy, however, has a central role in parasite identification and quantification and remains the main method of parasite-based diagnosis in clinic and hospital settings and is necessary for monitoring the accuracy of RDTs. The World Health Organization has prepared a proficiency testing panel containing a range of malaria-positive blood samples of known parasitaemia, to be used for the assessment of commercially available malaria RDTs. Different blood film and counting methods may be used for this purpose, which raises questions regarding accuracy and reproducibility. A comparison was made of the established methods for parasitaemia estimation to determine which would give the least inter-rater and inter-method variation
Methods
Experienced malaria microscopists counted asexual parasitaemia on different slides using three methods; the thin film method using the total erythrocyte count, the thick film method using the total white cell count and the Earle and Perez method. All the slides were stained using Giemsa pH 7.2. Analysis of variance (ANOVA) models were used to find the inter-rater reliability for the different methods. The paired t-test was used to assess any systematic bias between the two methods, and a regression analysis was used to see if there was a changing bias with parasite count level.
Results
The thin blood film gave parasite counts around 30% higher than those obtained by the thick film and Earle and Perez methods, but exhibited a loss of sensitivity with low parasitaemia. The thick film and Earle and Perez methods showed little or no bias in counts between the two methods, however, estimated inter-rater reliability was slightly better for the thick film method.
Conclusion
The thin film method gave results closer to the true parasite count but is not feasible at a parasitaemia below 500 parasites per microlitre. The thick film method was both reproducible and practical for this project. The determination of malarial parasitaemia must be applied by skilled operators using standardized techniques.
doi:10.1186/1475-2875-8-267
PMCID: PMC2789092  PMID: 19939271
18.  East African Trypanosomiasis in a Pregnant Traveler 
Emerging Infectious Diseases  2009;15(11):1866-1867.
doi:10.3201/eid1511.090384
PMCID: PMC2857228  PMID: 19891893
Human African trypanosomiasis; Africa; pregnancy; parasites; travelers; letter
19.  Imported Human Fascioliasis, United Kingdom 
Emerging Infectious Diseases  2009;15(11):1876-1877.
doi:10.3201/eid1511.090511
PMCID: PMC2857236  PMID: 19891898
Fasciola spp.; fascioliasis; zoonosis; khat; parasites; eosinophilia; United Kingdom; letter
20.  Gnathostomiasis Acquired by British Tourists in Botswana 
Emerging Infectious Diseases  2009;15(4):594-597.
Infection with Gnathostoma spinigerum has been generally confined to Southeast Asia and Central and South America. However, gnathostomiasis was recently found in British tourists who had visited Botswana. Consequently, travel to Africa should now be considered a risk factor for gnathostomiasis.
doi:10.3201/1504.081646
PMCID: PMC2671435  PMID: 19331741
Gnathostoma sp.; gnathostomiasis; eosinophilia; Botswana; United Kingdom; tourists; bream; albendazole; ivermectin; dispatch
21.  Establishment of the 1st World Health Organization International Standard for Plasmodium falciparum DNA for nucleic acid amplification technique (NAT)-based assays 
Malaria Journal  2008;7:139.
Background
In order to harmonize results for the detection and quantification of Plasmodium falciparum DNA by nucleic acid amplification technique (NAT)-based assays, a World Health Organization (WHO) collaborative study was performed, evaluating a series of candidate standard preparations.
Methods
Fourteen laboratories from 10 different countries participated in the collaborative study. Four candidate preparations based upon blood samples parasitaemic for P. falciparum were evaluated in the study. Sample AA was lyophilized, whilst samples BB, CC and DD were liquid/frozen preparations. The candidate standards were tested by each laboratory at a range of dilutions in four independent assays, using both qualitative and quantitative NAT-based assays. The results were collated and analysed statistically.
Results
Twenty sets of data were returned from the participating laboratories and used to determine the mean P. falciparum DNA content for each sample. The mean log10 "equivalents"/ml were 8.51 for sample AA, 8.45 for sample BB, 8.35 for sample CC, and 5.51 for sample DD. The freeze-dried preparation AA, was examined by accelerated thermal degradation studies and found to be highly stable.
Conclusion
On the basis of the collaborative study, the freeze-dried material, AA (NIBSC code No. 04/176) was established as the 1st WHO International Standard for P. falciparum DNA NAT-based assays and has been assigned a potency of 109 International Units (IU) per ml. Each vial contains 5 × 108 IU, equivalent to 0.5 ml of material after reconstitution.
doi:10.1186/1475-2875-7-139
PMCID: PMC2518157  PMID: 18652656
22.  Imported malaria and high risk groups: observational study using UK surveillance data 1987-2006 
BMJ : British Medical Journal  2008;337(7661):103-106.
Objective To examine temporal, geographic, and sociodemographic trends in case reporting and case fatality of malaria in the United Kingdom.
Setting National malaria reference laboratory surveillance data in the UK.
Design Observational study using prospectively gathered surveillance data and data on destinations from the international passenger survey.
Participants 39 300 cases of proved malaria in the UK between 1987 and 2006.
Main outcome measures Plasmodium species; sociodemographic details (including age, sex, and country of birth and residence); mortality; destination, duration, and purpose of international travel; and use of chemoprophylaxis.
Results Reported cases of imported malaria increased significantly over the 20 years of the study; an increasing proportion was attributable to Plasmodium falciparum (P falciparum/P vivax reporting ratio 1.3:1 in 1987-91 and 5.4:1 in 2002-6). P vivax reports declined from 3954 in 1987-91 to 1244 in 2002-6. Case fatality of reported P falciparum malaria did not change over this period (7.4 deaths per 1000 reported cases). Travellers visiting friends and relatives, usually in a country in Africa or Asia from which members of their family migrated, accounted for 13 215/20 488 (64.5%) of all malaria reported, and reports were geographically concentrated in areas where migrants from Africa and South Asia to the UK have settled. People travelling for this purpose were at significantly higher risk of malaria than other travellers and were less likely to report the use of any chemoprophylaxis (odds ratio of reported chemoprophylaxis use 0.23, 95% confidence interval 0.21 to 0.25).
Conclusions Despite the availability of highly effective preventive measures, the preventable burden from falciparum malaria has steadily increased in the UK while vivax malaria has decreased. Provision of targeted and appropriately delivered preventive messages and services for travellers from migrant families visiting friends and relatives should be a priority.
doi:10.1136/bmj.a120
PMCID: PMC2453297  PMID: 18599471
23.  Imported malaria and high risk groups: observational study using UK surveillance data 1987-2006 
Objective To examine temporal, geographic, and sociodemographic trends in case reporting and case fatality of malaria in the United Kingdom.
Setting National malaria reference laboratory surveillance data in the UK.
Design Observational study using prospectively gathered surveillance data and data on destinations from the international passenger survey.
Participants 39 300 cases of proved malaria in the UK between 1987 and 2006.
Main outcome measures Plasmodium species; sociodemographic details (including age, sex, and country of birth and residence); mortality; destination, duration, and purpose of international travel; and use of chemoprophylaxis.
Results Reported cases of imported malaria increased significantly over the 20 years of the study; an increasing proportion was attributable to Plasmodium falciparum (P falciparum/P vivax reporting ratio 1.3:1 in 1987-91 and 5.4:1 in 2002-6). P vivax reports declined from 3954 in 1987-91 to 1244 in 2002-6. Case fatality of reported P falciparum malaria did not change over this period (7.4 deaths per 1000 reported cases). Travellers visiting friends and relatives, usually in a country in Africa or Asia from which members of their family migrated, accounted for 13 215/20 488 (64.5%) of all malaria reported, and reports were geographically concentrated in areas where migrants from Africa and South Asia to the UK have settled. People travelling for this purpose were at significantly higher risk of malaria than other travellers and were less likely to report the use of any chemoprophylaxis (odds ratio of reported chemoprophylaxis use 0.23, 95% confidence interval 0.21 to 0.25).
Conclusions Despite the availability of highly effective preventive measures, the preventable burden from falciparum malaria has steadily increased in the UK while vivax malaria has decreased. Provision of targeted and appropriately delivered preventive messages and services for travellers from migrant families visiting friends and relatives should be a priority.
doi:10.1136/bmj.a120
PMCID: PMC2453297  PMID: 18599471
24.  Plasmodium malariae in Haitian Refugees, Jamaica 
Emerging Infectious Diseases  2007;13(6):931-933.
Since 1963, reported malaria transmission in Haiti has been restricted to Plasmodium falciparum. However, screening of Haitian refugees in Jamaica in 2004, by microscopic examination, identified P. falciparum, P. vivax, and P. malariae. PCR confirmed the P. malariae and P. falciparum but not P. vivax infections. DNA sequencing and rRNA gene sequences showed transmission of P. malariae. This report confirms that P. malariae is still being transmitted in Haiti.
doi:10.3201/eid1306.061227
PMCID: PMC2792841  PMID: 17553241
Plasmodium malariae; Plasmodium brasilianum; Haiti; refugees; Jamaica; dispatch

Results 1-25 (31)