Some risk factors for transmission of malaria in a population where control measures were applied in Zambia.

A total of 224 patients living in Lusaka, the capital city of Zambia, were treated for malaria in the University Teaching Hospital (UTH) and surveyed to determine the relationship between parasitaemia, malaria antibodies and travel outside Lusaka. Comparisons of those with parasitaemia or antibodies with those without suggested an increased risk among those who travelled out of Lusaka to high transmission areas and also among those who live in areas of Lusaka where transmission is considered to be high. This study shows that even if there is transmission of malaria in Lusaka, much of the malaria is contracted outside the city. Specificity and positive predictive values for the variables considered showed that these variables may be useful in a clinical situation in determining whether the patient has malaria or not. It is also suggested that these variables should be taken into consideration in assessing possibilities of malaria transmission in towns where control measures were once applied.