No new cases of filariasis have been reported in the second phase of the transmission assessment survey (TAS) among students in the district. Officials say that the first part of the survey was conducted among 3,000 students in Classes 1 and 2 sometime back.
According to World Health Organisation (WHO) guidelines, TAS is used as a surveillance tool to ensure that infection levels remain below target thresholds.
Three surveys
“We are conducting three transmission assessment surveys. The result of the first survey was negative. Now, we have completed the first phase of the second survey, the result of which also is negative. We will conduct the second phase of the second survey after the reopening of schools. TAS is conducted to study the transmission of filariasis among students and to evaluate whether the disease is transmitted to the next generation,” says a Health Department official.
A recent spurt
A parasitic disease caused by mosquitoes which infects the human body through tiny filarial worms, filariasis has been under check in the district following a Mass Drug Administration (MDA) programme.
However, the disease that the district successfully curbed in the past reared its ugly head recently with floating migrant population acting as microfilaria carrier. Several fresh cases were reported in the district between 2015 and 2018.
The recent filariasis was caused by Wuchereria bancrofti, a human parasitic roundworm, largely unknown to this part of the region.
In the past, Brugia malayi roundworm was largely responsible for the disease.
Campaigns
The Brugia malayi is transmitted by Mansonia mosquitoes, resulting in swelling of the lower limbs. However, Wuchereria bancrofti, transmitted by Culex mosquitoes, affects the scrotum, legs, and arms in males and breast, genital organs, legs, and arms in females.
After the reappearance of the disease, the Health Department has conducted campaigns for distributing DEC and Albendazole tablets to the vulnerable sections. The department also organised screening of the migrant workers.