Estimation of the fecund life span of Wuchereria bancrofti in an endemic area.

A stochastic approach appropriate for general use in endemic communities was applied to estimate the average yearly instantaneous rate of loss of Wuchereria bancrofti microfilaraemia from infected individuals, and gain by uninfected individuals, from longitudinal data. This method was shown to give similar results (i.e., the rate of loss was independent of age, while the rate of gain differed significantly between age classes) to a previously used method based on transmision interruption, provided that the intersurvey interval was > 5 years. The method was used to estimate the fecund life span of W. bancrofti in an endemic area at 5 years. The results suggest that the life span is at the lower end of previous estimates.