Prevalence of asymptomatic parasitaemia in an urban and rural community in south western Nigeria.

The prevalence of malaria parasitaemia was investigated among secondary school students in Ibadan city and a neighbouring rural community in Nigeria. Of 343 urban and 249 rural seemingly healthy subjects examined, 8 pc and 27 pc respectively were found positive for malaria parasitaemia. This showed a significantly higher parasite rate in the rural area as compared to the urban areas (p < 0.05). Only P. falciparum was found in the urban subjects while 7.4 pc of the rural infection was due to P. malariae. All the different erythrocytic stages both sexual and asexual forms of P. falciparum were seen in the rural samples whereas no schizont was seen in the urban samples. The haemoglobin genotype did not affect the prevalence of parasitaemia in the two populations studied. However, a lower parasite rate was observed among G6PD deficient subjects in both populations. There was also a significantly lower parasite infection rate among those with the B-antigen in the two populations studied.