Patterns of malaria indices across three consecutive seasons in children in a highly endemic area of West Africa: a three times-repeated cross-sectional study.

OBJECTIVES: To study the manifestations of Plasmodium infection, and its relations with the malaria disease, especially when comparing dry and rainy seasons in a hyperendemic area of West Africa. METHODS: The study was carried out in an area where malaria transmission is high, showing important seasonal variations. One thousand children, representing the total child population (1-12 year old), were observed transversally at the end of three consecutive seasons (dry/rainy/dry). The usual indicators, such as parasite density, splenomegaly, anaemia, or febrile disease were recorded and analysed. RESULTS: The prevalence of Plasmodium falciparum was high in all age groups and seasons, constantly around 60%. The high transmission season (rainy) showed higher rates of anaemia and spleen enlargement and, in the youngest children only, higher parasite densities. There were also differences between the two dry seasons: in the first one, there was a higher rate of fever than in the second one (p < 0.001). Low parasite density (<2,000 p/µl) was never associated with fever during any season, raising some concern with regard to the usefulness of parasite detection. The possible origins of fever are discussed, together with the potential usefulness of analyzing these indices on a population sample, at a time when fever incidence rises and malaria is one potential cause among others. The distinction to be made between the Plasmodium infection and the malaria disease is highlighted. CONCLUSIONS: These data confirm previous hypotheses of a strong difference in malaria infection and disease between dry and rainy seasons. The most relevant seasonal indicator was not mainly parasite rate and density but anaemia, spleen enlargement, prevalence and possible origin of fever. RECOMMENDATIONS: In any situation (i.e. fever or not) and especially during the dry season, one must consider that detection of parasites in the blood is only evidence of a Plasmodium infection and not necessarily of a malaria disease. In such a situation, it seems suitable to obtain, through national malaria teams, a well-defined situation of transmission and prevalence of Plasmodium infection following zones and seasons, in order to adapt control strategies. For researchers, a systematic management of data separately for dry and rainy season appears mandatory.

Serological and parasitological response in chronic Chagas patients 3 years after nifurtimox treatment.

BACKGROUND: With declining vectorial transmission, Chagas disease predominantly affects adults nowadays. The efficacy of nifurtimox in the chronic phase in adult patients is poorly known, particularly in regions where there is no risk of reinfection. Recommendations for treatment outcome assessment rely on serological follow-up. We evaluated the serological and parasitological response to nifurtimox in a cohort of adult patients three years post-treatment in Switzerland. METHODS: Patients treated with nifurtimox in 2008 during a cross-sectional study in Geneva, Switzerland, were contacted for follow-up in 2011. Two ELISAs and a rapid immunochromatographic test were used to test 2008 and 2011 serum samples simultaneously. In addition, conventional and real-time PCR were performed on 2011 samples. RESULTS: Thirty-seven (84.1%) of 44 eligible patients, predominantly female, middle-aged, Bolivians at the indeterminate stage, were enrolled. All 2011 ELISA and immunochromatographic tests were positive. Twenty-eight (75.7%) patients presented a lower optical density (OD) in 2011 compared to 2008. This OD difference was significant in both commercial (P < 0.001) and in-house (P = 0.002) ELISAs. Agreement between the two ELISAs was low (Kappa = 0.469). All patients had negative conventional PCR results but one (2.7%) was positive with real-time PCR. CONCLUSION: Our results highlight the inadequacy of serology for assessing response in adults, three years after treatment. In our cohort, 97.3% had results that could either indicate treatment failure or persistant humoral response despite treatment. The lack of accurate early post-treatment tests of cure prevents appropriate patients information and councelling. New follow-up tests are needed to assess treatments efficacy given the large adult population in need of antiparasitic therapy.

[Old World cutaneous leishmaniasis]. / Leishmaniose cutanée de l'Ancien Monde.

Cutaneous leishmaniasis is a parasitic disease that causes various clinical features depending on the infecting Leishmania species and the host immune response. Transmission occurs through the bite of an infected sand fly (subfamily of Phlebotominae). Leishmaniasis must be part of the differential diagnosis of persistent cutaneous lesions in travellers returning from an endemic area. The disease is most frequently characterized by one or more ulcerative lesions, which are predominant on the exposed parts of the body. The diagnosis is confirmed by microscopical observation of the parasite on a scraping or biopsy of the lesion, or by PCR, the latter allowing an identification of the Leishmania species. Treatment is dependent on the clinical presentation, the species of Leishmania and the comorbidities of the patient.

Validation of a rapid immunochromatographic assay for diagnosis of Trypanosoma cruzi infection among Latin-American Migrants in Geneva, Switzerland.

Chagas' disease is a global public health problem due to the recent exchange of population between Latin America and other regions, including Europe. The recent development of rapid diagnostic tests (RDTs) for Trypanosoma cruzi infection may improve patient access to diagnosis and care worldwide. We evaluated the diagnostic accuracy of the Chagas Stat-Pak RDT in a cohort of undocumented Latin-American migrants living in Geneva, Switzerland. Study participants were enrolled in a primary health care center. The Chagas Stat-Pak test was performed independently on blood and serum samples. A combination of two commercialized enzyme-linked immunosorbent assay (ELISA)-based serological tests was used for comparison (reference standard). A total of 999 adults (median age, 36 years) were included in the study; the majority were women (83%) and originally from Bolivia (47%) or Brazil (25%). A total of 125 participants (12.5%) were diagnosed with T. cruzi infection; with the exception of three individuals, all individuals diagnosed with T. cruzi were originally from Bolivia. The sensitivity and specificity of the Chagas Stat-Pak test on blood samples were 95.2% (95% confidence interval [95% CI], 89.2% to 97.9%) and 99.9% (95% CI, 99.3% to 100%), respectively. When the test was performed on serum samples, the sensitivity was 96% (95% CI, 91% to 98.3%), and the specificity was 99.8% (95% CI, 99.2% to 99.9%). The concordance of test results for blood and serum samples was 99.7%. Both negative and positive predictive values were above 98%. The Chagas Stat-Pak is an accurate diagnostic test for T. cruzi infection among Latin-American migrants living in Europe. The mild deficit in sensitivity should be interpreted in light of its ease of use and capacity to provide immediate results, which allow more people at risk to have access to diagnosis and care both in countries where Chagas' disease is endemic and in countries where this disease is not endemic.

External quality control results of urine dip-slide devices.

Urinary tract infections are frequently diagnosed by using urine dip-slide devices, especially in medical practices and small laboratories. We performed a retrospective analysis of more than 3000 results obtained by several urine dip-slide devices during external quality control surveys. We found that an underestimation of bacterial counts and a difficulty in identifying mixed flora were relatively more frequent in medical practices than in specialized laboratories, and that regular participation in external quality control surveys correlates with better performances.

Malaria cases in Switzerland from 2005 to 2015 and recent rise of imported Plasmodium vivax malaria.

Reporting cases of malaria to the Federal Office of Public Health has been mandatory in Switzerland since 1974. We analysed notifications of imported confirmed malaria cases between 2005 and 2015 in Switzerland or Liechtenstein. Data for previously visited countries, nationality and reason for travelling were analysed. In contrast with the impressive drop of malaria cases reported worldwide since 2000, we found that the number of malaria cases imported yearly in Switzerland doubled in 2014 and 2015 compared to the average for the preceding decade. Since 2014, Plasmodium vivax infection represented 36% of all diagnosed malaria cases in Switzerland, compared to 11% in the decade leading to 2013. Most of the vivax malaria patients originated from the Horn of Africa, especially from Eritrea. This rise in cases was a consequence not only of an increase in the number of Eritrean refugees, but also their vivax malaria incidence rate, which jumped from 1-3‰ previously to 12‰ in 2014. This is a trend that is not matched by national statistics in Eritrea. An unreported increased incidence in the country of origin (Eritrea) might be the cause of the rise of Pv cases imported into Switzerland, but infections are also likely to occur along the harsh and long migration journey. This epidemiology highlights the need to register and use primaquine for the treatment of latent-phase P. vivax malaria in Switzerland, a medicine currently neither marketed nor systematically reimbursed. Moreover, general practitioners should be aware of this specific epidemiological situation in order to avoid misdiagnosis of febrile Eritreans even months after they reach Switzerland.

Prevalence of chronic infections and susceptibility to measles and varicella-zoster virus in Latin American immigrants.

BACKGROUND: Large numbers of Latin American immigrants recently arrived in Western Europe. Curative and preventive programmes need to take account of their risk of suffering and transmitting imported chronic infections and of their susceptibility to cosmopolitan infections. We aimed to assess the prevalence and co-occurrence of imported chronic infections among Latin American immigrants, and their susceptibility to highly prevalent cosmopolitan infections. METHODS: Adult participants were recruited in the community and in a primary health centre in Geneva in 2008. Serological tests were performed on stored sera for HIV, HBV, syphilis, Strongyloides stercoralis, Trypanosoma cruzi, varicella and measles. We considered only chronic active infections in the analysis. RESULTS AND DISCUSSION: The 1 012 participants, aged 37.2 (SD 11.3) years, were mostly female (82.5 %) and Bolivians (48 %). Overall, 209 (20.7 %) had at least one and 27 (2.7 %) two or more chronic infections. T. cruzi (12.8 %) and S. stercoralis (8.4 %) were the most prevalent chronic active infections compared to syphilis (0.4 %), HBV (0.4 %) and HIV (1.4 %). Concomitant infections affected 28.2 and 18.5 % of T. cruzi and S. stercoralis infected cases. Bolivian origin (aOR: 13.6; 95 % CI: 3.2-57.9) was associated with risk of multiple infections. Susceptibilities for VZV and measles were 0.7 and 1.4 %, respectively. Latin American immigrants are at risk of complications and possible reactivation of chronic parasitic infections but have overall low risks of chronic viral and syphilitic active infections. CONCLUSIONS: Systematic screening for chronic active parasitic infections is therefore necessary especially among Bolivians. The high protection rate against measles and VZV doesn't require specific preventive interventions.

Prevalence, clinical staging and risk for blood-borne transmission of Chagas disease among Latin American migrants in Geneva, Switzerland.

BACKGROUND: Migration of Latin Americans to the USA, Canada and Europe has modified Chagas disease distribution, but data on imported cases and on risks of local transmission remain scarce. We assessed the prevalence and risk factors for Chagas disease, staged the disease and evaluated attitudes towards blood transfusion and organ transplant among Latin American migrants in Geneva, Switzerland. METHODOLOGY/PRINCIPAL FINDINGS: This cross-sectional study included all consecutive Latin American migrants seeking medical care at a primary care facility or attending two Latino churches. After completing a questionnaire, they were screened for Chagas disease with two serological tests (Biomérieux ELISA cruzi; Biokit Bioelisa Chagas). Infected subjects underwent a complete medical work-up. Predictive factors for infection were assessed by univariate and multivariate logistic regression analysis.1012 persons (females: 83%; mean age: 37.2 [SD 11.3] years, Bolivians: 48% [n = 485]) were recruited. 96% had no residency permit. Chagas disease was diagnosed with two positive serological tests in 130 patients (12.8%; 95%CI 10.8%-14.9%), including 127 Bolivians (26.2%; 95%CI 22.3%-30.1%). All patients were in the chronic phase, including 11.3% with cardiac and 0.8% with digestive complications. Predictive factors for infection were Bolivian origin (OR 33.2; 95%CI 7.5-147.5), reported maternal infection with T. cruzi (OR 6.9; 95%CI 1.9-24.3), and age older than 35 years (OR 6.7; 95%CI 2.4-18.8). While 22 (16.9%) infected subjects had already donated blood, 24 (18.5%) and 34 (26.2%) considered donating blood and organs outside Latin America, respectively. CONCLUSIONS: Chagas disease is highly prevalent among Bolivian migrants in Switzerland. Chronic cardiac and digestive complications were substantial. Screening of individuals at risk should be implemented in nonendemic countries and must include undocumented migrants.