Understanding Behavioural Temperament of Phlebotomus argentipes Under the Influence of DDT-IRS Versus SP-IRS for Scoping New Approaches for Maximum Control Over the VL-Vector Population in Bihar

Background:After the decades of Dichlorodiphenyltrichloroethane (DDT) use, Phlebotomus argentipesreportedly developed resistance against it affecting every aspect of vector control at grass-root level. Although DDT based Indoor Residual Spray (IRS) has been replaced with Alphacypermethrine-a Synthetic Pyrethroid (SP) based insecticide, since 2016 butits successful implementation at the Visceral Leishmaniasis (VL) endemic regime of Bihar doesn’t cause much effect upon VL vector density. Furthermore, the outcomes of existing operational research works, it Original ResearchArticle had been observed that VL vectors are continuously changing its behavior under the pressure of insecticides. Methods: For validating the hypothesis, present study has been carried out at Vaishali and Patna being highly and semi-endemic sites respectively for quantifying the oriental behavior among VL vectors persuaded by the IRS and enforce them to remain alive and get trapped in light trap even after changed chemical composition of IRS i.e., SP-IRS from routine DDT-IRS. Results:Following results, a significant reduction in sand fly density (i.e., 33.09% and 29.16%) was observed for outdoor and indoor caught sand flies, collected with light trap and aspirator respectively. Significant higher no. of sand fly collection in terms of per light traps per night was recorded from the outdoor sites than thosefrom indoor habitat for each village of Vaishali and Saran district of Bihar. Higher no. of male sand flies than to that of female ones were collected from outdoor sites and only unfed female sand flies (i.e., 100%) were caught following SP-IRS from each study villages of Vaishali and Saran districts of Bihar.Conclusions:The results of higher no. of sand flies collection from the outdoor sites as compared with the indoor habitat validate the hypothesis of gradual shifting of habitat of VL vectors from endophilic to exophilic which is undoubtedly followed due to the fact of developed resistance among them against chemical constituent of IRS. Results provide very useful information about the sand fly dynamics under the impact of IRS and accordingly, advocates the combined approach of IRS along with insecticidal fogging together at a same time that could be an effective dividend for maximum VL vector control along for negotiating VL cases at par for longer duration during the maintenance phase at the VL foci.

A Hospital Based Retrospective Study of Post Kala-Azar Dermal Leishmaniasis (PKDL) Cases

Post Kala-azar dermal leishmaniasis (PKDL) is a cutaneous form of leishmaniasis and usually occurs one to several years after apparent cure of visceral leishmaniasis (VL). Methods: The present work was designed as a retrospective tertiary urban hospital based, observational, clinico-epidemiological study during the period from February 2018 to January 2019. Results: A total of 24 PKDL patients, 16 males (66.66%) and 8 females (33.34%) were included in the study. The age of the patients ranged from 8 years to 56 years (mean age 30.6 years). Lesions in most of our patients (n=21, 87.50%) were located on the face, including the lip and nose. Most of our patients (n=20, 83.33%) were nodular (non-ulcerative), while two (08.33%) had nodulo ulcerative lesions and one (04.16%) had macular lesions. In the present study, 91.66.47 % (n = 22) of PKDL patients reported history of VL. The median time of manifestation of PKDL after VL treatment were 32 months (range = 5–286 months). Majority (n=20) of cases with history of VL had been treated with amphotericin B while the remaining (n=4,) had been treated with sodium stibogluconate. Conclusion: The present study highlights occurrence of PKDL in endemic area.Further epidemiological studies are required for identification of vector and strain of Leishmania involved.

Avaliação da efetividade do uso de coleiras impregnadas com deltametrina no controle da leishmaniose visceral no município de Votuporanga, Estado de São Paulo, Brasil, 2014 – 2016 / Evaluation of the effectiveness of using deltamethrinimpregnated collars to control visceral leishmaniasis in the municipality of Votuporanga, State of São Paulo, Brazil, 2014 – 2016

O objetivo deste artigo é apresentar os principais resultados do Projeto de Inovação Tecnológica em Saúde realizado entre 2014 e 2015, destacando-se o uso de coleiras impregnadas com deltametrina a 4% em cães em uma região endêmica para leishmaniose visceral (LV), o município de Votuporanga, São Paulo, Brasil. Neste município, anterior à realização do projeto, eram registrados muitos casos caninos e humanos da doença, com elevada taxa de letalidade. Durante o projeto, foram monitorados cerca de 16,5 mil cães, examinadas 25.700 amostras de sangue, considerando-se as perdas e as entradas de novos animais durante os quatro inquéritos sorológicos. Após sua finalização, verificou-se uma diminuição da prevalência e incidência de LV canina, assim como do número de casos humanos. A diminuição dos casos caninos foi correlacionada positivamente aos casos humanos no período de 2011 a 2016 (Correlação de Pearson de 0.914, p-valor<0.05). Além disso, a análise espacial dos resultados corrobora a diminuição ou desaparecimento da concentração de casos caninos e, consequentemente, de fontes e de infecção nas áreas endêmicas à medida que avançaram no tempo e espaço as diferentes etapas de desenvolvimento do projeto. Apesar da drástica redução na incidência da LV canina, ainda permaneceram algumas áreas críticas. Os resultados delineados sugerem a revisão de protocolos e manuais demonstrando a efetividade do uso das coleiras como medida preventiva e potencial no controle da LV.

This paper aims to present the main results of the Health Technology Innovation Project carried out between 2014 and 2015, which evaluates the use of 4% deltamethrin-impregnated collars in dogs, in an endemic region for visceral leishmaniasis (VL), the municipality of Votuporanga, São Paulo, Brazil. Before this project, Votuporanga had notified canine and human cases of the disease, with a high case fatality rate. We monitored approximately 16.5 thousand dogs, 25,700 blood samples analyzed, considering losses and entrances of new animals during the four serological surveys. After the project, the prevalence and incidence of canine VL decreased as well as the number of human cases. We found a positive correlation between the decrease of infected dogs and human cases from 2011 to 2016 (Pearson correlation of 0.914, p-value <0.05). Furthermore, the spatial analysis of the results indicated areas with canine cases concentration that decreased its intensity or disappeared concomitantly to the project levels in the space-time. Despite the drastic reduction in the incidence of canine VL, some critical areas remain. The current results suggest the review of protocols and manuals demonstrating the effectiveness of the use of collars as a preventive measure and potential in the control of VL.

Analysing Host Preference Behavior of Phlebotomus argentipes (Diptera: Psychodidae) Under the Impact of Indoor Residual Spray.

Background: Present scenario of Bihar and neighboring Indian states reveals dichlorodiphenyltrichloroethane (DDT) being an insecticide of choice for controlling the vector of Indian Visceral Leishmaniasis (VL) i.e., Phlebotomus argentipes, that had reported to attain resistance/tolerance against it, leading to the behavioral transition including host preference and selection by them. The relationship between insecticidal resistance and host preference/ selection is not yet well understood. Objective: Exploring the host preference/selection behavior under the influence of insecticidal pressure in different biotopes of VL endemic regions in India Methods: For this, the engorged sand flies that were collected before and after Indoor Residual Spray (IRS) were subjected for feeding behavior analysis. The parameter studied were Host Feeding Index (HFI) and Forage Ratio (FR) by analyzing Blood Meal Identification (BMI). Results: The higher percentage of sand flies were recorded to be fed on cattle host (56.05%) with respect to the human host (30.35%) before IRS while a significant increase in cattle blood index (79.17%) in contrast to significant drop in human blood index (9.43%) was recorded during post IRS session at the study site. It establishes, cattle being potentially served as a preferred host for sand flies in contrast to other available hosts. The lowered value of FR during pre- and post-IRS respectively for human (0.77 and 0.24) as compared to the cattle (1.89 and 2.67) indicates cattle host being selectively preferred by the P. argentipes also corroborate with the results of BMI. Conclusion: Through the study we can conclude that instead of being killed by IRS, P. argentipes has attained resistance against DDT. Under the insecticidal pressure the host preference as well as selection tendency of P. argentipes for cattle host gets enhanced under the influence of IRS, as abrupt increment was observed in the FR’s post-IRS. While, the avoidance tendency of insects from the human hosts in favor of other available hosts’ viz., cattle, goat, pigs, etc. with slight decrement in the forage ratios for the human hosts during the IRS was also observed. Thus, under the impact of IRS, P. argentipes has changed its behavior from endophilic to exophilic and migrated from the human hosts at the periphery area of sprayed houses towards much safer zone, i.e., deserted houses, nearby gardens, bushes, etc for their survival for feeding cattle i.e., preferred host, lying in unsprayed horizon. Therefore, change in control strategy involving the proper management of insecticide resistance is very much needed to tackle the vector outbreak and hence menace caused by them.

Epidemiological aspects of visceral leishmaniasis in Jaciara, Mato Grosso, Brazil, 2003 to 2012 / Aspectos epidemiológicos da leishmaniose visceral em Jaciara, Estado de Mato Grosso, Brasil, de 2003 a 2012

Visceral leishmaniasis (VL) is caused by Leishmania (L.) infantum chagasi in the Americas. In Brazil, it is transmitted by sandflies of the species Lutzomyia longipalpis and L. cruzi, and dogs are the main domestic reservoirs. The aim of this study was to analyze data relating to VL transmission in Jaciara, state of Mato Grosso, and discuss vector distribution, domestic reservoirs, and human cases that occurred between 2003 and 2012. The data for analysis were obtained from the Notifiable Diseases Information System (human), the State Health Department's Environmental Monitoring Agency (canine data) and the State Health Department's Entomology Laboratory (sandfly data). Over this period, Jaciara had 19 autochthonous human cases (12 males and seven females), with one death 2,273. Out of the 7,545 dogs tested by enzyme immunoassay and indirect immunofluorescence were positive. The sandflies collected comprised 5,015 individuals belonging to 24 species, with a predominance of L. whitmani followed by L. cruzi. The results showed that the parasite has frequent circulation and that the vector L. cruzi is widely distributed over all months, thus suggesting that transmission may occur at any time of the year.

A leishmaniose visceral (LV), causada nas Américas pelo protozoário Leishmania (L.) infantum chagasi, transmitida no Brasil por flebotomíneos das espécies Lutzomyia longipalpis e L. cruzi, tem os cães como principais reservatórios domésticos. O objetivo deste trabalho foi analisar os dados relacionados à transmissão da LV, em Jaciara (MT), e discutir a respeito da distribuição do vetor, reservatório doméstico e os casos humanos ocorridos no período de 2003 a 2012. Os dados para análise foram obtidos do Sistema de Informações de Agravos de Notificação (humanos), da Vigilância Ambiental da Secretaria Estadual de Saúde (caninos) e do Laboratório de Entomologia da Secretaria Estadual de Saúde (flebotomíneos). Jaciara apresentou 19 casos autóctones, 12 do sexo masculino e sete do sexo feminino, com um óbito. Dos 7.545 cães testados por imunoensaio enzimático e reação de imunofluorescência indireta, 2.273 foram reagentes. Os flebotomíneos coletados totalizaram 5.015 indivíduos pertencentes a 24 espécies com predomínio de L. whitmani seguido por L. cruzi. Os resultados demonstraram circulação frequente do parasito e a ampla distribuição do vetor L. cruzi com frequência em todos os meses, sugerindo que a transmissão possa ocorrer em qualquer época do ano.

Diagnostico de la Leishmaniasis visceral canina mediante las técnicas western blot e inmunofluorescencia indirecta / Diagnóstico de leishmaniose visceral canina através da técnicade western blot e imunofluorescencia / Canine visceral leishmaniasis diagnosis by means of western blot and indirect immunofluorescence test

Objetivo: un estudio epidemiológico transversal fue desarrollado para establecer la seroprevalencia de la Leishmaniasis Visceral (LV) en caninos localizados en la zona endémica del departamento del Tolima por medio de las pruebas de Inmunofluorescencia Indirecta (IFI) y Western Blot (WB). Materiales y métodos: se incluyeron en el estudio 211 caninos mestizos procedentes de seis municipios de la zona endémica de leishmaniasis visceral del departamento del Tolima. Se utilizó como antígeno la cepa colombiana de Leishmania infantum MHOM/COL/CL044B para IFI y WB. Resultados: se estableció una seroprevalencia de la Leishmaniasis Visceral Canina en el grupo de animales evaluados del 41,7 y22, 2% por medio de IFI y WB, respectivamente. La concordancia entre las dos técnicas fue negativa (k= -0,102; p = 0,084). Se detectaron 12 fracciones antigénicas en la prueba WB entre los 13 y 91 kDa, de las cuales la de 14 kDa se considera valiosa en el diagnóstico precoz de la infección, para evaluar la resolución de la enfermedad y la evolución del tratamiento. Se sugiere desarrollar un constructo de pruebas diagnósticas directas e indirectas que permitan confirmar el estado real de la infección de los caninos, para orientar eficientemente los programas de control de la enfermedad en zonas endémicas de leishmaniasis visceral.

Objective: a cross-sectional epidemiological study was carried out in order to establish the prevalence of canine visceral leishmaniasis in the endemic area of Tolima department by means of Indirect Immunofluorescence (IFAT) and Western Blotting (WB) tests. Materials and Methods: the study included 211 mongrel dogs from six municipalities of the endemic area of visceral leishmaniasis (VL) of the Tolima department. The Colombian Leishmania infantum MHOM/CO/CL044B strain was used as antigen for IFI and WB. Results: The seroprevalence in the group tested was 41.7% and 22.2% by IFAT and WB, respectively. The agreement between the two techniques was negative (k = -0.102; p = 0.084). 12 antigenic fractions were detected between 13 and 91 kDa, of which 14 kDa is considered valuable in early diagnosis of the infection, in order to evaluate the resolution of the disease and treatment progress. The article suggests developing a construct of direct and indirect diagnostic tests for confirming the real state of the animals’ infection to guide disease control programs in endemic areas of visceral leishmaniasis.

Objetivo: uma pesquisa epidemiológica transversal foi desenvolvida para estabelecer a soroprevalência da Leishmaniose Visceral (LV) canina localizados na zona endêmica do Estado do Tolima por médio das provas de Imunofluorescência indireta (IFI) e Western Blot (WB). Materiais e Métodos se incluíram na pesquisa 211 canina mestiça procedente de seis prefeituras da zona endêmica de Leishmaniose visceral do Estado de Tolima. Utilizou-se como antígeno a cepa Colombiana de Leishmania infantum MHOM/COL/CL044B para IFI e WB...

Evaluación de factores de riesgo de la leishmaniasis visceral en seis municipios endémicos colombianos / Evaluation of risk factors of visceral leishmaniasis in six endemic Municipalities in Colombia / Avaliação de fatores de risgo da leishmaniasis visceral em seis municipios endemicos colombianos

Objetivo: un estudio epidemiológico descriptivo fue desarrollado para identificar condiciones socio-económicas y medidas implementadas para el control de la Leishmaniasis Visceral en la población indígena, localizada en diez veredas de los municipios de Coyaima, Natagaima, Purificación, Coello, Ataco y Purificación. Materiales y métodos: se estructuró un instrumento epidemiológico que fue aplicado durante los meses de marzo a septiembre de 2007, enfocado a evaluar variables sociales y económicas, características de la vivienda, conocimiento de la enfermedad y actitudes frente a las medidas de prevención contra la picadura del artrópodo vector. La población estuvo conformada por 527 viviendas con 2.454 personas (56,6% población adulta y 43,4% niños). Resultados: se evidenció la presencia de una infraestructura sanitaria pobre de las viviendas y deficientes condiciones de saneamiento básico. El 78,7% de las familias reciben menos de un salario mínimo mensual legal vigente, para dar soporte a un promedio de 4,7 habitantes por residencia. El 64,1% de las familias no usan ningún tipo de protección contra las picaduras. El conocimiento básico sobre la enfermedad es deficiente (11%). Las condiciones socioeconómicas, el bajo conocimiento de la enfermedad por la población y las medidas de control individual específicas y colectivas, requieren de intervención mediante la aplicación de medidas sostenibles.

Objective: A descriptive epidemiological study was conducted in order to identify socioeconomic conditions and measures implemented to control Visceral Leishmaniasis in the indigenous population located in ten villages in the municipalities of Coyaima, Natagaima, Coello, Ataco and Purificación. Materials and Methods: An epidemiological questionnaire was applied from March to September (2007), focusing on social and economic variables, housing characteristics, disease knowledge, and attitudes towards arthropod bites prevention. The population consisted of 527 households with 2.454 individuals (56.6% adult population and 43.4% children). Results: The results showed the presence of a poor sanitary infrastructure of housing and basic sanitation conditions. 78.7% of the families earnless than one minimum wage, to support an average of 4.7 residents per household. 64.1% of families do not use any protection against bites. Basic knowledge on the disease is poor (11%). The socioeconomic conditions, low population awareness of the disease and the specific individual and collective control measures require intervention by means of implementing sustainable measures.

Objetivo: uma pesquisa epidemiológica descritiva foi desenvolvida para identificar condições socioeconômicas e medidas realizadas para o control da Leishmaniasis Visceral na povoação indígena, localizada em dez veredas dos municípios de Coyaima, Natagaima, Purificação, Coello, Ataco. Materiais e métodos: se estruturou um instrumento epidemiológico que foi aplicado durante os meses de março a setembro de 2007, enfocado avaliar variáveis sociais e econômicas, características da vivenda, conhecimento da enfermidades e atitudes frente à medidas de prevenção contra a picadura do artrópode vector. A povoação esteve conformada por 527 vivendas com 2.454 pessoas (56,6% povoação adulta e 43,4% crianças). Resultados: se evidenciou a presença duma infra-estrutura sanitária pobre das vivendas e deficientes condições de saneamento básico. O 78,7% das famílias recebem menos dum salário mínimo mensal legal vigente, para dar suporte para um meio de 4,7 habitantes por residência. O 64,1% das famílias não usam nenhum tipo de proteção contra as picaduras. O conhecimento básico sobre a enfermidade é deficiente (11%). As condições socioeconômicas, o baixo conhecimento da enfermidade pela povoação e as medidas de control individual especificas e coletivas, requerem de intervenção mediante a aplicação das medidas para que sustentem.

Knowledge About Sandflies in Relation to Public and Domestic Control Activities of Kala-azar in Rural Endemic Areas of Bihar.

Visceral Leishmaniasis (VL) control is a global cause of concern. To identify the gaps in People's knowledge/ awareness about sand flies and control activities of kala-azar in rural endemic areas of Bihar, this study consisting of 450 respondents with 288 male and 162 female was carried out. The result showed that 95% respondents had heard about the disease up to some extent, but majority respondents were neither aware about the vector of kala-azar, nor they had any idea about transmission of the disease. About 61% had wrong impression that mosquitoes were causing kala-azar. Regarding knowledge about breeding and resting sites of vectors, 20% reported cattle shed, 16% crevices in the household followed by 15% damp dark places. The attitude of respondents towards vector control programme was poor, as 99% lost faith in the DDT spraying because of ineffectiveness, like no reduction in mosquito nuisance. Bed net was considered the best protection method against sand fly or mosquito nuisance but the cost was considered the major constraint in its use. Proper health education programme in Simple and local language along with visual demonstration should be promoted to enhance the awareness and co-operation at community level.