Socio-economic factors contributing to endemic filariasis in Kerala, India: Exploring xenomonitoring studies to evaluate the efficacy of therapeutic practices for disease control

Lymphatic filariasis causes a wide spectrum of clinical and subclinical disease manifestations. The disease is prevalent in various parts of the state of Kerala, India and various factors are contributing to its endemicity in the state. The objective of the present study is to examine various socio-economic and occupational characteristics of filarial patients residing at endemic locations in 10 districts of Kerala. The results revealed that most of the victims are males falling in the age group 61-75 years (56.55%±18). Data on the pre-infection history of patients revealed that 95.8% (±8.53) of people are residents. Details on the post-infection status revealed that most of them (77.05%±17.27) are leading a sedentary sort of life and are unemployed. 97.92% (±3.23) of the victims are suffering from clinical manifestations in the form of swelling in the legs. 58.72% (±13.64) of the patients are not following any treatment practice and 98.75% (±3.75) are not aware of the disease-causing parasite. The study as a whole concluded that a congested pattern of lifestyle, poor knowledge of disease, parasites, and vectors along with poor disease management practices are the prime reasons for the disease endemicity. Xenomonitoring of mosquitoes for parasites during pre-MDA and post-MDA periods has also been carried out in two disease-endemic districts (Thirunellayi of Palakkad and Ponnani of Malappuram) of Kerala. The disease infection rates during the pre-MDA period were estimated to be 2.97% in Palakkad and 0.88% in Malappuram districts. No parasites were observed in mosquitoes collected from the two districts during the post-MDA period, which is an indication of the efficiency of the disease control programs undertaken in the community level.