Lymphatic filariasis (LF), a vector-borne parasitic disease, is endemic in several parts of India and mostly affects the poor or those with a low-income. The disease results in huge numbers of morbidities, disabilities, and deaths every year. Association of co-infection with other pathogens makes the condition more severe. Although co-infection is becoming a growing area of research, it is yet to emerge as a frontier research topic in filarial research specifically. This study reports the occurrence of a fungal infection in a large number of patients suffering from bancroftian filariasis in two districts of West Bengal, India.
India is accelerating efforts to eliminate kala-azar by aligning its National Kala-Azar Elimination Program with the World Health Organization’s (WHO) roadmap for Neglected Tropical Diseases (NTDs) 2021–2030. Elimination relies on comprehensive vector surveillance and integrated vector management. This study aimed to conduct nationwide entomological surveillance to detect Leishmania donovani in phlebotomine sand flies. A cross-sectional survey was conducted from January 2022 to December 2023 in five different biogeographical zones in India. Mechanical aspirator, light traps were used for sampling. The collected sand flies were identified to species level. Molecular xenomonitoring was conducted using kDNA qPCR, and parasite characterization targeting ITS1 gene sequencing and RFLP. Sand fly species was confirmed by DNA barcode. Molecular xenomonitoring revealed that Phlebotomus argentipes from Bihar, West Bengal, and Kerala exhibited high levels of L. donovani parasitic DNA. In Rajasthan, P. sergenti and P. papatasi and in Himachal Pradesh, P. longiductus, P. major, and P. bruneyi were positive. The high levels of L. donovani parasitic DNA detected in various Phlebotomus species, along with its presence in other sand fly species beyond the established vectors, underscore the urgent need for the National Kala-Azar Elimination Program to prioritize comprehensive and rigorous vector surveillance. Strengthening these efforts is crucial for achieving the program’s goal of eliminating the disease.
3 January 2024 in The American Journal of Tropical Medicine and Hygiene
: The tribal population in and around the Western Ghats region of India is affected by both cutaneous leishmaniasis (CL) and visceral leishmaniasis (VL) with typical clinical symptoms. In this study, we recorded and analyzed seven CL and three VL cases from this emerging belt. All the cases were found as autochthonous transmission. Multiple genetic markers (minicircle kinetoplast DNA polymerase chain reaction and restriction fragment length polymorphism of 3′untranslated region heat shock protein (HSP)70, a larger segment of HSP 70, and 6-phosphogluconate dehydrogenase [PGDH] gene sequences) were used to identify and characterize the parasite. It was found that both clinical manifestations are caused by zymodeme MON-37 of Leishmania donovani. We have investigated the detailed entomological and epidemiological aspects of disease transmission. An abundant population of the proven vector Phlebotomus argentipes was observed in the study villages.
Wolbachia, a Gram-negative intracellular bacterium, naturally infects many arthropods, including mosquito vectors responsible for the spread of arboviral diseases such as Zika, chikungunya, and dengue fever. Certain Wolbachia strains are involved in inhibiting arbovirus replication in mosquitoes, and this phenomenon is currently being studied to combat disease vectors. A study was conducted in four states in north-eastern India to investigate the presence of natural Wolbachia infection in wild-caught Aedes albopictus and Aedes aegypti mosquitoes, the established vectors of dengue. The detection of a Wolbachia infection was confirmed by nested PCR and sequencing in the two mosquito species Ae. aegypti and Ae. albopictus. Positivity rates observed in Ae. aegypti and Ae. albopictus pools were 38% (44 of 115) and 85% (41 of 48), respectively, and the difference was significant (chi-square = 28.3174, = 0.00000010). Sequencing revealed that all detected Wolbachia strains belonged to supergroup B. Although Wolbachia infection in Ae. aegypti has been previously reported from India, no such reports are available from north-eastern India. Data on naturally occurring Wolbachia strains are essential for selecting the optimal strain for the development of Wolbachia-based control measures. This information will be helpful for the future application of Wolbachia-based vector control measures in this part of the country.