Challenges for maintaining post elimination phase of visceral leishmaniasis control programme in India: A field-based study.

BACKGROUND: India is going through the maintenance phase of VL elimination programme which may be threatened by the persistence of hidden parasite pools among asymptomatic leishmanial infection (ALI) and PKDL. The present work was designed to determine the burden of VL, PKDL, and ALI and to assess the role of treatment of ALI in maintaining post-elimination phase. METHODS AND FINDING: The study was undertaken in Malda district, West Bengal, India during October 2016 to September 2021. Study areas were divided into 'Study' and 'Control' arms. VL and PKDL cases of both the arms were diagnosed by three active mass surveys with an interval of one year and treated as per National guideline. ALI of 'Study' arm was treated like VL. ALI of 'Control' arm was followed up to determine their fate. Fed sand-fly pools were analysed for parasitic DNA. No significant difference was noted between the incidence of VL and PKDL in both the arms. Incidence of ALI declined sharply in 'Study' arm but an increasing trend was observed in 'Control' arm. Significantly higher rate of sero-conversion was noted in 'Control' arm and was found to be associated with untreated ALI burden. Parasitic DNA was detected in 22.8% ALI cases and 2.2% sand-fly pools. CONCLUSION: Persistence of a significant number of PKDL and ALI and ongoing transmission, as evidenced by new infection and detection of leishmanial DNA in vector sand-flies, may threaten the maintenance of post-elimination phase. Emphasis should be given for elimination of pathogen to prevent resurgence of VL epidemics.

Assessment of knowledge about malaria and LLIN ownership and its use in Bankura, West Bengal, India.

BACKGROUND & OBJECTIVES: Community participation is one of the key factors for implementation and success of a public health programme which depends upon knowledge about that disease. Therefore, understanding the community knowledge about malaria is important for designing sustainable control programmes. This study was conducted to assess the knowledge about malaria, to evaluate long lasting insecticidal nets (LLINs) distribution and their use by LQAS method in endemic areas of Bankura district, West Bengal state, India Methods: It was a community based cross-sectional survey conducted in Bankura during December 2019-March 2020. Structured questionnaire under four categories: socio-demographic variables, knowledge of malaria, owner ship of LLINs and its use were used for the interview. Ownership of LLINs and its use were analysed by LQAS method. Data were analysed by binary logistic regression model and chi-squared test. RESULTS: Out of 456 respondents, 88.59% had good knowledge, 97.37% had good ownership of LLIN and 78.95% used LLINs properly. The knowledge about malaria was significantly associated with education level (p-value<0.0001). Out of 24 lots studied, 3, 2, 4 lots were underperforming with respect to knowledge, ownership of LLIN and its use, respectively. INTERPRETATION & CONCLUSION: The study population had a good knowledge about malaria. In spite of good coverage of LLIN distribution, the use of LLINs was not up to the mark. LQAS analysis showed underperformance in few lots about knowledge, ownership of LLIN and its use. The IEC and BCC activities about LLIN should be done to achieve the impact of this intervention at the community level.

Assessment of Knowledge, Attitudes, and Practices about Visceral Leishmaniasis in Endemic Areas of Malda District, West Bengal, India.

Community participation is an important aspect for the success of kala-azar (KA) elimination program implemented in five Southeast Asian countries by the WHO. The participation of community depends on the level of knowledge of, attitude toward, and practice around risk factors associated with KA transmission among the population. We assessed the knowledge, attitude, and practice toward KA elimination in endemic areas of Malda district, West Bengal, India. A total of 709 individuals from different villages of 12 sub-centers were interviewed during April-July 2019. Data were recorded in a structured questionnaire under four categories: sociodemographic parameters, knowledge, attitude, and practice. The association of dependent variables such as knowledge, attitude, and practice with independent variables such as the economy and sociodemographic parameters was analyzed by binary logistic regression model and chi-square test using SPSS software. Despite the endemicity of the disease for a long time, the adequacy of knowledge about the disease was found to be poor that can be attributed to low education level and socioeconomic status, but the attitude and practices were good. So, there is a scope of improvement in knowledge of the disease through proper health education. This will further improve the level of attitude and practices that will be helpful for the smooth implementation of different activities of the program by more active participation of the community.

Seasonal variation of sand fly populations in Kala-azar endemic areas of the Malda district, West Bengal, India.

Vector control is one of the main aspects to reach the target of eliminating visceral leishmaniasis from Indian sub-continent as set by the World Health Organisation. Data on different aspects of vector like ecology, behaviour, population dynamics and their association with environmental factors are very important for formulating an effective vector control strategy. The present work was designed to study the species abundance and impact of environmental factors on population dynamics of vector P. argentipes in a visceral leishmaniasis endemic area of Malda district, West Bengal. Adult sand flies were collected using light traps and mouth aspirators from twelve kala-azar affected villages of Habibpur block of Malda district, on a monthly basis from January to December, 2018. Morphological and molecular methods were used for species identification. Population dynamics were assessed by man hour density and per night per trap collection. Data were analysed using SPSS software to determine the impact of environmental factors on vector population P. argentipes was found to the predominant species and prevalent throughout the year. A significantly higher number of sand flies were collected from cattle sheds than human dwellings and peri-domestic vegetation. A portion of the P. argentipes population was exophilic and exophagic as evidenced by their collection from peri-domestic vegetation. The highest population density was recorded during April to September. Population dynamics were mostly influenced by average temperature along humidity and rain fall. Resting behaviour of sand flies was not restricted to the lower portion of the wall but equally distributed throughout the wall and ceiling. Programme officials should consider management of outdoor populations of the sand flies and timings of indoor residual spray for chemical control purpose.