Bancroftian filariasis in a Philippine village: clinical, parasitological, immunological, and social aspects
Grove, D.I.; Valeza, F.S.; Cabrera, B.D.
Bulletin of the World Health Organization 56(6): 975-984
1978
ISSN/ISBN: 0042-9686 PMID: 367626 Document Number: 497003
Of the 555 inhabitants of Paraiso in Province of Catanduanes, a small island off the southeastern tip of Luzon, Philippines, the 535 people aged one year or more were included in this study. A history of acute lymphangitis or lymphadenitis was obtained from 57% of the males and 46% of the females. Approximately 25% of the children under 6 years old had a history of acute lymphatic inflammation. Inguinal lymphadenopathy, often very marked was found in 47% of males and 22% of females; the peak prevalence was in children between the ages of 5 and 10 years. No patient had gross elephantiasis. Hydrocele was found in 20 men. All nocturnal blood smears taken from 131 children were negative for Wuchereria bancrofti microfilariae. Of 328 people aged 6 years or more whose blood was examined by Nuclepore filtration, 46 males (37%) and 28 females (17%) were positive. Prevalence rose progressively with age, reaching a peak of 67% in males in the 6th decade and 29% in females in the 7th decade. The intensity of infection did not change with age in women, but increased with age in men. There was no relationship between the presence or absence of microfilaraemia and either a history of acute lymphatic inflammation or the presence of inguinal lymphadenopathy. Similarly, microfilaraemia was present in 36% of males with obstructive disease compared with 35% of men without such disease. No microfilariae were found in the urine of 100 people examined. The prevalence of positive immediate hypersensitivity skin reactions to Brugia malayi microfilarial antigen and serum fluorescent antibodies against B. malayi adult worm antigen increased with age. 90% of adults over 30 years old had detectable fluorescent antibodies. Microfilaraemia and obstructive disease were more common in heads of households with the lowest socioeconomic score.