In which stage of filariasis are microfilaria seen in peripheral blood:

Ans. (c) Early adenolymphangitis stage* Filariasis is a parasitic disease that is caused by thread- like nematodes (roundworms) belonging to the family known as "filariae".* These are transmitted from host to host by blood-feeding arthropods, mainly black flies and mosquitoes.* The adult worms, which usually stay in one tissue, release early larval forms known as microfilariae into the hosts bloodstream. Person is infective once microfilaria presents in the peripheral blood.* The inflammatory phase is characterised by Lymphangitis, lymphadenitis and adenolymphangitis.* It lasts for a few days, then subsides spontaneously & recurs at irregular intervals for a period of weeks to months.* These circulating microfilariae can be taken up with a blood meal by the arthropod vector; in the vector, they develop into infective larvae that can be transmitted to a new host.* Filariasis is diagnosed in microfilaraemic cases primarily through direct observation of microfilariae in the peripheral blood.* Remember: W. bancrofti is nocturnally periodic i.e. micro filariae are scarce in peripheral blood by day and increase at night.