Browsing by Author "Albert Picado"

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Arsenic Exposure and Outcomes of Antimonial Treatment in Visceral Leishmaniasis Patients in Bihar, India: A Retrospective Cohort Study
(Public Library of Science, 2015) Meghan R. Perry; Vijay K. Prajapati; Joris Menten; Andrea Raab; Joerg Feldmann; Dipankar Chakraborti; Shyam Sundar; Alan H. Fairlamb; Marleen Boelaert; Albert Picado
In the late twentieth century, emergence of high rates of treatment failure with antimonial compounds (SSG) for visceral leishmaniasis (VL) caused a public health crisis in Bihar, India. We hypothesize that exposure to arsenic through drinking contaminated groundwater may be associated with SSG treatment failure due to the development of antimony-resistant parasites.A retrospective cohort design was employed, as antimony treatment is no longer in routine use. The study was performed on patients treated with SSG between 2006 and 2010. Outcomes of treatment were assessed through a field questionnaire and treatment failure used as a proxy for parasite resistance. Arsenic exposure was quantified through analysis of 5 water samples from within and surrounding the patient’s home. A logistic regression model was used to evaluate the association between arsenic exposure and treatment failure. In a secondary analysis survival curves and Cox regression models were applied to assess the risk of mortality in VL patients exposed to arsenic. One hundred and ten VL patients treated with SSG were analysed. The failure rate with SSG was 59%. Patients with high mean local arsenic level had a non-statistically significant higher risk of treatment failure (OR = 1.78, 95% CI: 0.7–4.6, p = 0.23) than patients using wells with arsenic concentration <10 μg/L. Twenty one patients died in our cohort, 16 directly as a result of VL. Arsenic levels ≥ 10 μg/L increased the risk of all-cause (HR 3.27; 95% CI: 1.4–8.1) and VL related (HR 2.65; 95% CI: 0.96–7.65) deaths. This was time dependent: 3 months post VL symptom development, elevated risks of all-cause mortality (HR 8.56; 95% CI: 2.5–29.1) and of VL related mortality (HR 9.27; 95% CI: 1.8–49.0) were detected. This study indicates a trend towards increased treatment failure in arsenic exposed patients. The limitations of the retrospective study design may have masked a strong association between arsenic exposure and selection for antimonial resistance in the field. The unanticipated strong correlation between arsenic exposure and VL mortality warrants further investigation. © 2015 Perry et al.
Determinants for progression from asymptomatic infection to symptomatic visceral leishmaniasis: A cohort study
(Public Library of Science, 2018) Jaya Chakravarty; Epco Hasker; Sangeeta Kansal; Om Prakash Singh; Paritosh Malaviya; Abhishek Kumar Singh; Ankita Chourasia; Toolika Singh; Medhavi Sudarshan; Akhil Pratap Singh; Bhawana Singh; Rudra Pratap Singh; Bart Ostyn; Michaela Fakiola; Albert Picado; Joris Menten; Jenefer M. Blackwell; Mary E. Wilson; David Sacks; Marleen Boelaert; Shyam Sundar
Background: Asymptomatic Leishmania donovani infections outnumber clinical presentations, however the predictors for development of active disease are not well known. We aimed to identify serological, immunological and genetic markers for progression from L. donovani infection to clinical Visceral Leishmaniasis (VL). Methods: We enrolled all residents >2 years of age in 27 VL endemic villages in Bihar (India). Blood samples collected on filter paper on two occasions 6–12 months apart, were tested for antibodies against L. donovani with rK39-ELISA and DAT. Sero converters, (negative for both tests in the first round but positive on either of the two during the second round) and controls (negative on both tests on both occasions) were followed for three years. At the start of follow-up venous blood was collected for the following tests: DAT, rK39- ELISA, Quantiferon assay, SNP/HLA genotyping and L.donovani specific quantitative PCR. Results: Among 1,606 subjects enrolled,17 (8/476 seroconverters and 9/1,130 controls) developed VL (OR 3.1; 95% CI 1.1–8.3). High DAT and rK39 ELISA antibody titers as well as positive qPCR were strongly and significantly associated with progression from seroconversion to VL with odds ratios of 19.1, 30.3 and 20.9 respectively. Most VL cases arose early (median 5 months) during follow-up. Conclusion: We confirmed the strong association between high DAT and/or rK39 titers and progression to disease among asymptomatic subjects and identified qPCR as an additional predictor. Low predictive values do not warrant prophylactic treatment but as most progressed to VL early during follow-up, careful oberservation of these subjects for at least 6 months is indicated. © 2018, Public Library of Science. All rights reserved. https://creativecommons.org/publicdomain/zero/1.0/.
Effect of untreated bed nets on blood-fed Phlebotomus argentipes in kala-azar endemic foci in Nepal and India
(Fundacao Oswaldo Cruz, 2009) Albert Picado; Vijay Kumar; Murari Das; Ian Burniston; Lalita Roy; Rijal Suman; Diwakar Dinesh; Marc Coosemans; Shyam Sundar; Kesari Shreekant; Marleen Boelaert; Clive Davies; Mary Cameron
Observational studies in the Indian subcontinent have shown that untreated nets may be protective against visceral leishmaniasis (VL). In this study, we evaluated the effect of untreated nets on the blood feeding rates of Phlebotomus argentipes as well as the human blood index (HBI) in VL endemic villages in India and Nepal. The study had a "before and after intervention" design in 58 households in six clusters. The use of untreated nets reduced the blood feeding rate by 85% (95% CI 76.5-91.1%) and the HBI by 42.2% (95% CI 11.1-62.5%). These results provide circumstantial evidence that untreated nets may provide some degree of personal protection against sand fly bites.
Effect of village-wide use of long-lasting insecticidal nets on visceral Leishmaniasis vectors in India and Nepal: A cluster randomized trial
(2010) Albert Picado; Murari L. Das; Vijay Kumar; Shreekant Kesari; Diwakar S. Dinesh; Lalita Roy; Suman Rijal; Pradeep Das; Mark Rowland; Shyam Sundar; Marc Coosemans; Marleen Boelaert; Clive R. Davies
Background: Visceral leishmaniasis (VL) control in the Indian subcontinent is currently based on case detection and treatment, and on vector control using indoor residual spraying (IRS). The use of long-lasting insecticidal nets (LN) has been postulated as an alternative or complement to IRS. Here we tested the impact of comprehensive distribution of LN on the density of Phlebotomus argentipes in VL-endemic villages. Methods: A cluster-randomized controlled trial with household P. argentipes density as outcome was designed. Twelve clusters from an ongoing LN clinical trial - three intervention and three control clusters in both India and Nepal - were selected on the basis of accessibility and VL incidence. Ten houses per cluster selected on the basis of high pre-intervention P. argentipes density were monitored monthly for 12 months after distribution of LN using CDC light traps (LT) and mouth aspiration methods. Ten cattle sheds per cluster were also monitored by aspiration. Findings:A random effect linear regression model showed that the cluster-wide distribution of LNs significantly reduced the P. argentipes density/house by 24.9% (95% CI 1.80%-42.5%) as measured by means of LTs. Interpretation: The ongoing clinical trial, designed to measure the impact of LNs on VL incidence, will confirm whether LNs should be adopted as a control strategy in the regional VL elimination programs. The entomological evidence described here provides some evidence that LNs could be usefully deployed as part of the VL control program. Trial registration: ClinicalTrials.gov CT-2005-015374. © 2010 Picado et al.
Exposure to phlebotomus argentipes (diptera, psychodidae, phlebotominae) sand flies in rural areas of Bihar, India: The role of housing conditions
(Public Library of Science, 2014) Paritosh Malaviya; Epco Hasker; Albert Picado; Mukesh Mishra; Jean-Pierre Van Geertruyden; Murari Lal Das; Marleen Boelaert; Shyam Sundar
Background: Visceral Leishmaniasis (VL) is a vector-borne infectious disease, caused by the protozoan Leishmania donovani, which is transmitted by phlebotomine sand flies. In an earlier study in Bihar, India, we found an association between incidence of VL and housing conditions. In the current study we investigated the influence of housing structure and conditions in and around the house on the indoor abundance of Phlebotomus argentipes, the vector of VL in this area. Methods: In each of 50 study villages in Muzaffarpur district, we randomly selected 10 houses. Light traps were installed in each house for one night during three annual peaks of sand fly density over two successive years. Sand flies captured were morphologically identified and segregated by species, sex and feeding status. Data on housing conditions and socioeconomic status were also collected. We fitted a linear mixed-effects regression model with log-transformed P. argentipes counts as outcome variable and village as random effect. Results: P. argentipes was found in all but four of the 500 households. There was considerable variability between the years and the seasons. On bivariate analysis, housing structure, dampness of the floor, keeping animals inside, presence of animal dung around the house, and socio-economic status were all significantly associated with sand fly density. Highest sand fly densities were observed in thatched houses. In the multivariate model only the housing structure and socio-economic status remained significant. Conclusions: Better housing conditions are associated with lower sand fly densities, independent of other socio-economic conditions. However, in this area in Bihar even in the better-built houses sand flies are present. © 2014 Malaviya et al.
Health & demographic surveillance system profile: The muzaffarpur-tmrc health and demographic surveillance system
(Oxford University Press, 2014) Paritosh Malaviya; Albert Picado; Epco Hasker; Bart Ostyn; Sangeeta Kansal; Rudra Pratap Singh; Ravi Shankar; Marleen Boelaert; Shyam Sundar
The Muzaffarpur-TMRC Health and Demographic Surveillance System (HDSS), established in 2007, was developed as an enlargement of the scope of a research collaboration on the project Visceral Leishmaniasis in Bihar, which had been ongoing since 2005. The HDSS is located in a visceral leishmaniasis (VL)-endemic area in the Muzaffarpur district of Bihar state in India. It is the only HDSS conducting research on VL, which is a vectorborne infectious disease transmitted by female phlebotomine sandflies and is fatal if left untreated. Currently the HDSS serves a population of over 105 000 in 66 villages. The HDSS collects data on vital events including pregnancies, births, deaths, migration and marriages, as well as other socio-economic indicators, at regular intervals. Incident VL cases are identified. The HDSS team is experienced in conducting both qualitative and quantitative studies, sample collection and rapid diagnostic tests in the field. In each village, volunteers connect the HDSS team with the community members. The Muzaffarpur-TMRC HDSS provides opportunities for studies on VL and other neglected tropical diseases (NTDs) and their interaction with demographic events such as migration. © The Author 2014; all rights reserved.
Incidence of symptomatic and asymptomatic Leishmania donovani infections in High-Endemic foci in India and Nepal: A prospective study
(2011) Bart Ostyn; Kamlesh Gidwani; Basudha Khanal; Albert Picado; François Chappuis; Shri Prakash Singh; Suman Rijal; Shyam Sundar; Marleen Boelaert
Incidence of Leishmania donovani infection and Visceral Leishmaniasis (VL) was assessed in a prospective study in Indian and Nepalese high-endemic villages. DAT-seroconversion was used as marker of incident infection in 3 yearly surveys. The study population was followed up to month 30 to identify incident clinical cases. In a cohort of 9034 DAT-negative individuals with neither active signs nor history of VL at baseline, 42 VL cases and 375 asymptomatic seroconversions were recorded in the first year, giving an infection:disease ratio of 8.9 to 1. In the 18 months' follow-up, 7 extra cases of VL were observed in the seroconverters group (N = 375), against 14 VL cases among the individuals who had not seroconverted in the first year (N = 8570) (RR = 11.5(4.5
Insecticide susceptibility of Phlebotomus argentipes in visceral leishmaniasis endemic districts in India and Nepal
(2010) Diwakar Singh Dinesh; Murari Lal Das; Albert Picado; Lalita Roy; Suman Rijal; Shri Prakash Singh; Pradeep Das; Marleen Boelaert; Marc Coosemans
Objectives: To investigate the DDT and deltamethrin susceptibility of Phlebotomus argentipes, the vector of Leishmania donovani, responsible for visceral leishmaniasis (VL), in two countries (India and Nepal) with different histories of insecticide exposure. Methods: Standard WHO testing procedures were applied using 4% DDT and 0.05% deltamethrin impregnated papers. The effect of the physiological status (fed and unfed) of females on the outcome of the bioassays was assessed and the optimal time of exposure for deltamethrin was evaluated on a colony population. Field populations from both countries were tested. Results: Fed and unfed females responded in a similar way. For exposure time on field samples 60 min was adopted for both DDT and deltamethrin. In Bihar, knockdown and mortality with DDT was respectively 20 and 43%. In Nepal almost all sand flies were killed, except at the border with Bihar (mortality 62%). With 0.05% deltamethrin, between 96 and 100% of the sand flies were killed in both regions. Conclusions: Based on literature and present data 4% DDT and 0.05% deltamethrin seem to be acceptable discriminating concentrations to separate resistant from susceptible populations. Resistance to DDT was confirmed in Bihar and in a border village of Nepal, but the sand flies were still susceptible in villages more inside Nepal where only synthetic pyrethroids are used for indoor spraying. The low effectiveness of indoor spraying with DDT in Bihar to control VL can be partially explained by this resistance hence other classes of insecticides should be tested. In both countries P. argentipes sand flies were susceptible to deltamethrin. © 2010 Dinesh et al.
Latent Infection with Leishmania donovani in Highly Endemic Villages in Bihar, India
(Public Library of Science, 2013) Epco Hasker; Sangeeta Kansal; Paritosh Malaviya; Kamlesh Gidwani; Albert Picado; Rudra Pratap Singh; Ankita Chourasia; Abhishek Kumar Singh; Ravi Shankar; Joris Menten; Mary Elizabeth Wilson; Marleen Boelaert; Shyam Sundar
Introduction: Asymptomatic persons infected with the parasites causing visceral leishmaniasis (VL) usually outnumber clinically apparent cases by a ratio of 4-10 to 1. We describe patterns of markers of Leishmania donovani infection and clinical VL in relation to age in Bihar, India. Methods: We selected eleven villages highly endemic for Leishmania donovani. During a 1-year interval we conducted two house to house surveys during which we collected blood samples on filter paper from all consenting individuals aged 2 years and above. Samples were tested for anti-leishmania serology by Direct Agglutination Test (DAT) and rK39 ELISA. Data collected during the surveys included information on episodes of clinical VL among study participants. Results: We enrolled 13,163 persons; 6.2% were reactive to DAT and 5.9% to rK39. Agreement between the tests was weak (kappa = 0.30). Among those who were negative on both tests at baseline, 3.6% had converted to sero-positive on either of the two tests one year later. Proportions of sero-positives and sero-converters increased steadily with age. Clinical VL occurred mainly among children and young adults (median age 19 years). Discussion: Although infection with L. donovani is assumed to be permanent, serological markers revert to negative. Most VL cases occur at younger ages, yet we observed a steady increase with age in the frequency of sero-positivity and sero-conversion. Our findings can be explained by a boosting effect upon repeated exposure to the parasite or by intermittent release of parasites in infected subjects from safe target cells. A certain proportion of sero-negative subjects could have been infected but below the threshold of antibody abundance for our serologic testing.
Long-lasting Insecticidal Nets to Prevent Visceral Leishmaniasis in the Indian Subcontinent; Methodological Lessons Learned from a Cluster Randomised Controlled Trial
(Public Library of Science, 2015) Albert Picado; Bart Ostyn; Suman Rijal; Shyam Sundar; Shri Prakash Singh; François Chappuis; Murari Lal Das; Basudha Khanal; Kamlesh Gidwani; Epco Hasker; Jean Claude Dujardin; Veerle Vanlerberghe; Joris Menten; Marc Coosemans; Marleen Boelaert
[No abstract available]
Longlasting insecticidal nets for prevention of Leishmania donovaniinfection in India and Nepal: Paired cluster randomised trial
(2011) Albert Picado; Shri Prakash Singh; Suman Rijal; Shyam Sundar; Bart Ostyn; François Chappuis; Surendra Uranw; Kamlesh Gidwani; Basudha Khanal; Madhukar Rai; Ishwari Sharma Paudel; Murari Lal Das; Rajiv Kumar; Pankaj Srivastava; Jean Claude Dujardin; Veerle Vanlerberghe; Elisabeth Wreford Andersen; Clive Richard Davies; Marleen Boelaert
Objective: To test the effectiveness of large scale distribution of longlasting nets treated with insecticide in reducing the incidence of visceral leishmaniasis in India and Nepal. Design: Paired cluster randomised controlled trial designed to detect a 50% reduction in incidence of Leishmania donovani infection. Setting: Villages in Muzaffarpur district in India and Saptari, Sunsari, and Morang districts in Nepal. Participants: 13 intervention and 13 control clusters. 12 691 people were included in the analysis of the main outcome (infection), and 19 810 were enrolled for the secondary (disease) end point. Intervention: Longlasting insecticidal nets (treated with deltamethrin) were distributed in the intervention clusters in December 2006. Main outcome measures: Infection was determined by direct agglutination test at 12 and 24 months after the intervention in those who had negative results (titre <1:1600) at baseline. The effect estimate was computed as the geometric mean of the risk ratios for seroconversion for each cluster pair (net/no net), with its 95% confidence interval. Formal tests of effect of no intervention were obtained with a paired t test. Results: There was no significant difference in the risk of seroconversion over 24 months in intervention (5.4%; 347/6372) compared with control (5.5%; 345/6319 people) clusters (risk ratio 0.90, 95% confidence interval 0.49 to 1.65) nor in the risk of clinical visceral leishmaniasis (0.99, 0.46 to 1.40). Adjustment for covariates did not alter these conclusions. Conclusions: There is no evidence that large scale distribution of longlasting insecticidal nets provides additional protection against visceral leishmaniasis compared with existing control practice in the Indian subcontinent. The observed effect was small and not significant, though the confidence intervals did not exclude a 50% change in either direction. Trial registration: Clinical Trials NCT 2005-015374.
Measurement of recent exposure to Phlebotomus argentipes, the vector of indian visceral leishmaniasis, by using human antibody responses to sand fly saliva
(2010) Meredith F. Clements; Kamlesh Gidwani; Rajiv Kumar; Jitka Hostomska; Diwakar S. Dinesh; Vijay Kumar; Pradeep Das; Ingrid Müller; Gordon Hamilton; Vera Volfova; Marleen Boelaert; Murari Das; Suman Rijal; Albert Picado; Petr Volf; Shyam Sundar; Clive R. Davies; Matthew E. Rogers
Antibody (IgG) responses to the saliva of Phlebotomus argentipes were investigated using serum samples from regions of India endemic and non-endemic for visceral leishmaniasis (VL). By pre-adsorbing the sera against the saliva of the competing human-biting but non-VL vector P. papatasi, we significantly improved the specificity of a P. argentipes saliva enzyme-linked immunosorbent assay. Using this method, we observed a statistically significant correlation between antibodies to P. argenitpes saliva and the average indoor density of female sand flies. Additionally, the method was able to detect recent changes in vector exposure when sera from VL patients were assayed before, during, and after hospitalization and protected from sand fly bites under untreated bed nets. Collectively, these results highlight the utility of antibodies to P. argentipes saliva as an important tool to evaluate VL vector control programs. Copyright © 2010 by The American Society of Tropical Medicine and Hygiene.
Model-Based Investigations of Different Vector-Related Intervention Strategies to Eliminate Visceral Leishmaniasis on the Indian Subcontinent
(Public Library of Science, 2014) Anette Stauch; Hans-Peter Duerr; Albert Picado; Bart Ostyn; Shyam Sundar; Suman Rijal; Marleen Boelaert; Jean-Claude Dujardin; Martin Eichner
The elimination of infectious diseases requires reducing transmission below a certain threshold. The Visceral Leishmaniasis (VL) Elimination Initiative in Southeast Asia aims to reduce the annual VL incidence rate below 1 case per 10,000 inhabitants in endemic areas by 2015 via a combination of case management and vector control. Using a previously developed VL transmission model, we investigated transmission thresholds dependent on measures reducing the sand fly density either by killing sand flies (e.g., indoor residual spraying and long-lasting insecticidal nets) or by destroying breeding sites (e.g., environmental management).Model simulations suggest that elimination of VL is possible if the sand fly density can be reduced by 67% through killing sand flies, or if the number of breeding sites can be reduced by more than 79% through measures of environmental management.These results were compared to data from two recent cluster randomised controlled trials conducted in India, Nepal and Bangladesh showing a 72% reduction in sand fly density after indoor residual spraying, a 44% and 25% reduction through the use of long-lasting insecticidal nets and a 42% reduction after environmental management.Based on model predictions, we identified the parameters within the transmission cycle of VL that predominantly determine the prospects of intervention success. We suggest further research to refine model-based predictions into the elimination of VL. © 2014 Stauch et al.
Molecular and serological markers of Leishmania donovani infection in healthy individuals from endemic areas of Bihar, India
(2013) Pankaj Srivastava; Kamlesh Gidwani; Albert Picado; Gert Van der Auwera; Puja Tiwary; Bart Ostyn; Jean-Claude Dujardin; Marleen Boelaert; Shyam Sundar
Objectives: Recent epidemiological reports indicate that asymptomatic human infections with Leishmania donovani, the causative agent of visceral leishmaniasis or Kala-azar (KA), occur frequently in India. We explored markers of infection. Methods: Blood samples were collected from 286 healthy subjects from 16 villages in the Muzaffarpur district of Bihar. These individuals were classified into three groups: (i) persons with no history of KA and living in a house where no KA cases were previously reported, (ii) persons with no history of KA but living in a house where KA cases were diagnosed at the time of sampling or in the past, and (iii) successfully treated KA patients. Each sample was tested using a Leishmania-specific PCR to detect Leishmania DNA, and two serological tests to demonstrate anti-Leishmania antibodies: the Direct Agglutination Test and rK39 ELISA. Results: PCR positivity was similar among the three groups (20-25%). In contrast, among treated patients, the percentage of serologically positive individuals was roughly five times that of healthy individuals with no KA history, as measured with either test. Living in a house where KA had been reported did not affect seropositivity. Conclusion: A significant proportion of asymptomatic infections of Leishmania exist in endemic regions. Using a combination of molecular and serological tests increases the capacity to detect infections at different stages. Further work is required to understand the kinetics of the markers. © 2013 Blackwell Publishing Ltd.
Persistence of Leishmania donovani antibodies in past visceral leishmaniasis cases in India
(2011) Kamlesh Gidwani; Albert Picado; Bart Ostyn; Shri Prakash Singh; Rajiv Kumar; Basudha Khanal; Veerle Lejon; François Chappuis; Marleen Boelaert; Shyam Sundar
The persistence of anti-Leishmania donovani antibodies in past visceral leishmaniasis (VL) cases was retrospectively assessed by means of the direct agglutination test (DAT) and the rK39 enzyme-linked immunosorbent assay (ELISA). Antibody titers remained high for an extended period of time in past cases of VL. These results highlight the need to carefully elicit the history of patients with VL symptoms. Copyright © 2011, American Society for Microbiology. All Rights Reserved.
Phlebotomus argentipes seasonal patterns in India and Nepal
(2010) Albert Picado; Murari Lal Das; Vijay Kumar; Diwakar S. Dinesh; Suman Rijal; Shri P. Singh; Pradeep Das; Marc Coosemans; Marleen Boelaert; Clive Davies
The current control of Phebotomus argentipes (Annandale and Brunetti), the vector of Leishmania donovani (Laveran and Mesnil), on the Indian subcontinent is base on indoor residual spraying. The efficacy of this method depends, among other factors, on the timing and number of spraying rounds, which depend on the P. argentipes seasonality. To describe P. argentipes' seasonal patterns, six visceral leishmaniasis (VL) endemic villages, three in Muzaffarpur and three in Sunsari districts in India and Nepal, respectively, were selected based on accessibility and VL incidence. Ten houses per cluster with the highest P. argentipes density were monitored monthly for 1516 mo using Center for Disease Control and Prevention light traps. Minimum and maximum temperature and rainfall data for the months January 2006 through December 2007 were collected from the nearest available weather stations. Backwards stepwise regression was used to generate the minimal adequate model for explaining the monthly variation in P. argentipes populations. The seasonality of P. argentipes is similar in India and Nepal, with two annual density peaks around May and October. Monthly P. argentipes density is positively associated with temperature and negatively associated with rainfall in both study sites. The multivariate climate model explained 57% of the monthly vectorial abundance. Vector control programs against P. argentipes (i.e., indoor residual spraying) should take into account the seasonal described here when implementing and monitoring interventions. Monitoring simple meteorological variables (i.e., temperature, rainfall) may allow prediction of VL epidemics on the Indian subcontinent. © 2010 Entomological Society of America.
Post-kala-azar dermal leishmaniasis in visceral leishmaniasis-endemic communities in Bihar, India
(2012) Rudra Pratap Singh; Albert Picado; Shahnawaz Alam; Epco Hasker; Shri Prakash Singh; Bart Ostyn; François Chappuis; Shyam Sundar; Marleen Boelaert
We assessed the prevalence of post-kala-azar dermal leishmaniasis (PKDL), a late cutaneous manifestation of visceral leishmaniasis (VL), in 16 VL-endemic communities in Bihar, India. The prevalence of confirmed PKDL cases was 4.4 per 10000 individuals and 7.8 if probable cases were also considered. The clinical history and treatment of the post-kala-azar dermal leishmaniasis cases are discussed. © 2012 Blackwell Publishing Ltd.
Residual activity and integrity of PermaNet® 2.0 after 24 months of household use in a community randomised trial of long lasting insecticidal nets against visceral leishmaniasis in India and Nepal
(2012) Albert Picado; Shri Prakash Singh; Veerle Vanlerberghe; Surendra Uranw; Bart Ostyn; Harparkash Kaur; Murari Lal Das; Shyam Sundar; Suman Rijal; Patrick Tungu; Marleen Boelaert; Mark Rowland
The World Health Organization (WHO) recommends several brands of long lasting insecticidal net (LN) for protection against insect vectors but also advises national programmes to monitor and evaluate performance under local conditions to help them select the most suitable LN for their setting. During the course of a community randomised trial of LNs against visceral leishmaniasis in northern India and Nepal, opportunity arose to assess the efficacy of PermaNet 2.0 (Vestergaard-Frandsen, Denmark) after two years of use against sandfly vectors. Between 63% (India) and 78% (Nepal) of LNs became holed over the course of two years, deltamethrin residues fell from 55mg/m2 to an average of 11.6mg/m2 (India) and 27.9mg/m2 (Nepal), but on the basis of bioassay criteria all LNs tested still met the WHO Pesticide Evaluation Scheme standard for LN effectiveness. Nets had on average only been washed 2.5 times (India) and 0.6 times (Nepal) by householders over the course of two years. The loss of insecticide was attributed to factors which had little or nothing to do with washing, such as handling, friction and torsion during daily use. Under conditions pertaining in this region of south Asia, and for two years at least, this brand of net continues to meet the criteria established by WHO for LNs. © 2011 Royal Society of Tropical Medicine and Hygiene.
Risk factors for visceral leishmaniasis and asymptomatic Leishmania donovani infection in India and Nepal
(Public Library of Science, 2014) Albert Picado; Bart Ostyn; Shri Prakash Singh; Surendra Uranw; Epco Hasker; Suman Rijal; Shyam Sundar; Marleen Boelaert; François Chappuis
There is increasing interest in the role of asymptomatic infection in transmission of Visceral Leishmaniasis (VL). We studied the individual, household and environmental factors associated with asymptomatic Leishmania donovani infected individuals and VL. 7,538 individuals living in VL endemic villages in India and Nepal were divided into three mutually exclusive groups based on their VL history and Direct Agglutination Test (DAT) results in yearly serosurveys over a two-year period. The groups were (1) VL cases, (2) asymptomatically infected individuals (seroconverters) and (3) seronegative individuals. VL cases and seroconverters were compared to seronegative individuals in mixed logistic regression models. The risk of seroconversion and disease was significantly increased in individuals aged 14 to 24 years old and by the presence of other DAT-positive, asymptomatically infected individuals and VL cases in the house. The risk of seroconversion was higher in Indian than in Nepalese villages and it increased significantly with age, but not so for VL. This study demonstrates that, when risk factors for leishmanial infection and VL disease are evaluated in the same population, epidemiological determinants for asymptomatic infection and VL are largely similar. © 2014 Picado et al.
Serological markers for Leishmania donovani infection in Nepal: Agreement between direct agglutination test and rK39 ELISA
(2010) Basudha Khanal; Suman Rijal; Bart Ostyn; Albert Picado; Kamlesh Gidwani; Joris Menten; Diane Jacquet; Veerle Lejon; François Chappuis; Marleen Boelaert
Visceral leishmaniasis (VL) is an important vector-borne disease caused by Leishmania donovani in the Indian subcontinent. The actual incidence and role of asymptomatic infections in the region are not well known. We used the direct agglutination test (DAT) and the rK39 ELISA as L. donovani infection markers in 10 VL endemic villages in Nepal. DAT titre distribution showed two subgroups in the population (infected and non-infected individuals), while rK39 did not. The agreement between both tests was moderate (κ=0.53; 95% CI 0.49-0.57). More research is needed to develop validated markers for Leishmania infection. © 2010 Blackwell Publishing Ltd.