Mass chemotherapy with diethylcarbamazine for the control of bancroftian filariasis: a 12-year follow-up in North Trinidad including observations on mansonella ozzardi microfilaraemia - abstract

ABSTRACT

A microfilaria survey was conducted in Blanchisseuse, North Trinidad in 1992 twelve years after mass treatment with spaced doses of diethylcarbamazine citrate (DEC-C) for the control of Bancroftian filariasis; 348 persons were examined, including 104 who had participated in the mass-chemotherapy campaign in 1980. No W. bancrofti microfilarie were detected among 66 percent of the population examined. In 1980, 86 persons were found with W. bancrofti, 140 with M. ozzardi and 44 with mixed infections while in 1992 only Mansonella ozzardi infections persisted despite DEC-C treatment. From the 104 persons re-examined, 46 persons had M.ozzardi, of which 5 were new cases but none had W. bancrofti infections in 1992. During both the 1980 and 1992 surveys, low microfilariae rates of M.ozzardi were observed among the 1-4, 5-9 and 10-19-year age groups. From the 302 persons examined in 1992, 29 were infected, with significantly (p<0.001) more males (79.3 percent) than females (20.7 percent) being microfilaraemic. The combined results showed similar prevalence rates of M.ozzardi from 23.3 percent to 21.6 percent in 1980 and 1992, respectively. A good correlation was found between the results observed from Nucleopore membrane filtration and thick blood films. The usefulness of thes methods and spaced treatment using DEC-C is also discussed (AU)