10th Meeting of Global Alliance to Eliminate Lymphatic Filariasis

• India is hosting the 10th meeting of Global Alliance to Eliminate Lymphatic Filariasis. India has highest burden of Lymphatic Filariasis and there is need of taking leadership role to Eliminate lymphatic filariasis.

About Lymphatic Filariasis:

• Lymphatic filariasis (LF) is caused by infection with threadlike worms called nematodes of the family Filarioidea: 90% of infections are caused by Wuchereria bancrofti and the remainder by Brugia spp. .
• Humans are the exclusive host of infection with W. bancrofti.
• Although certain strains of B. malayi can also infect some animal species (felines and monkeys), the life cycle in these animals is perceived as epidemiologically distinct from that in humans.

Transmission

• The major vectors of W. bancrofti are mosquitoes of the genus Culex (in urban and semi-urban areas), Anopheles (in rural areas of Africa and elsewhere) and Aedes (in islands of the Pacific).
• The parasites of B. malayi are transmitted by various mosquito species of the genus Mansonia; in some areas, anopheline mosquitoes are responsible for transmitting infection. Brugian parasites are confined to areas of east and south Asia, notably India, Indonesia, Malaysia and Thailand.
• Transmission in a community is influenced by the number of infected persons (prevalence), the density of microfilaria in the blood of infected persons, the density of vector mosquitoes, characteristics of the vector that affect development of infective larvae and frequency of human-vector contact.

Elimination strategy

• Elimination of lymphatic filariasis is possible by interrupting the transmission cycle. Providing treatment on a large-scale to entire communities where the infection is present can stop the spread of infection.
• This strategy of preventive chemotherapy, called mass drug administration (MDA), involves a combined dose of 2 medicines given.
• Adult worms can remain viable for years. Therefore it is necessary to deliver several rounds of MDA. At least five rounds are recommended to reduce infections in the community to levels below a threshold at which mosquitoes are unable to continue spreading the parasites from person to person and new infections are prevented.
• Vector control is supplemental to the core strategy of MDA and can enhance elimination efforts by reducing the mosquito density and preventing human-mosquito contact. Malaria control interventions such as residual spraying and sleeping under long-lasting insecticidal nets have collateral benefits in reducing transmission of LF.

By: Vishal