In Northern Nigeria some 11 000 blood films taken from infants were examined for the presence of malaria parasites during the course of WHO field trials of new insecticides. A first film was taken, in most cases, within the first month and the subsequent ones at monthly intervals thereafter. Analyses of the results obtained from these longitudinal studies were made according to the malaria transmission season, and infant parasite incidences were calculated.The incidences thus obtained were found to be valuable in investigating the epidemiological situation in a particular locality, in assessing the effect of congenital immunity and in evaluating the efficacy of insecticidal attack.

Humans↗

PubMed1968

The dynamics of malaria.

Previous studies on dynamic systems of transmission of malaria, and of eradication of infection following the interruption of transmission, have now been adapted for advanced techniques using the facilities offered by computers.The computer programmes have been designed for a deterministic model suitable for a large community and also for a stochastic model relevant to small populations in which infections reach very low finite numbers. In this model, new infections and recoveries are assessed by the daily inoculation rate and are subject to laws of chance. Such a representation is closer than previous models to natural happenings in the process of malaria eradication. Further refinements of the new approach include the seasonal transmission and simulation of mass chemotherapy aimed at a cure of P. falciparum infections.These programmes present models on which the actual or expected results of changes due to various factors can be studied by the analysis of specific malaria situations recorded in the field. The value of control methods can also be tested by the study of such hypothetical epidemiological models and by trying out various procedures.Two specific malaria situations (in a pilot project in Northern Nigeria and in an outbreak in Syria) were studied by this method and provided some interesting results of operational value. The attack measures in the pilot project in Northern Nigeria were carried out according to the theoretical model derived from the basic data obtained in the field.

Disease Outbreaks↗