Current status of Brugian filariasis in the Republic of the Philippines

ABSTRACT

Brugian filariasis in the Republic of the Philippines was first reported in 1964 or 63 years after Bancroftian filariasis was reported in this country. The etiologic agent is Brugian malayi with a nocturnal subperiodic type of microfilarial periodicity. The four endemic foci are Palawan, Sulu, Agusan and Eastern Samar, with prevalence rate of 30-64%;24%, 1.2% and 0.030% respectively. The mosquito vectors are Mansonia bonneae and Mansonia uniformis with infection rate and infective rate of 0.98% and 0.51% respectively from Quezon, Palawan. The biting activity of these mosquitoes is from about 1600 to 2200 which correspond to the rise in microfilarial density in the peripheral blood and takes approximately 10 days for the development of larvae to the infective stage within vector mosquito Diagnosis may be by the thick blood film method stained with Giemsa and/or Delafield hematoxylin, serologic method such as SAFA and intradermal test using B malayi antigen and by the use of nuclepore filter. Treatment of cases may b done with the use of Diethylcarbamazine (Hetrazan) 6 mg/kg. body weight daily for 12 days or a total dose of 72 mg/kg Brugian filariasis appears to be confined in areas where fresh water swamps are found which are ideal breeding sites for the mosquito vectors. Control may be achieved by reduction in the number of mosquito vectors; avoidance of bites of vector mosquitoes and elimination of microfilaremia by drug treatment. (Summary)