Malaria in African Infants and Children in Southern Nigeria

Abstract

2 series of investigations into the incidence and degree of malarial infection in 551 African parturient women in Lagos an urban and semi urban area of Southern Nigeria and their newborn infants were carried out during 1948-50. The routine technique of the investigation consisted of taking blood slides from the peripheral circulation of the mother and her newborn within 6-24 hours of delivery. A blood slide was made from a deep layer of a piece of the maternal placenta excised near the center. The weight of all newborn infants was recorded and whenever possible the progress of the infants was followed up throughout the neonatal period. The weight of all newborn infants was recorded and whenever possible the progress of the infants was followed up throughout the neonatal period. The mean incidence of malarial parasitaemia (mainly due to Plasmodium falciparum) in the sample of 323 Africa parturient women was found to be 33% somewhat higher than the usual parasite rate of the adult indigenous population. The incidence of malarial infection of the placenta was 23.8%. There were no cases of congenital malaria in 332 babies born of these mothers. The mean weight at birth of 237 babies born of mothers whose placentae were noninfected was 145 mg higher than that of 73 babies born of mothers whose placentae were found to be infected. The difference was statistically significant. There was no apparent correlation between neonatal mortality and infection of the placenta. Periodic investigation of a sample of 138 African infants followed up from the age of about 1 month through the 1st year of life and through part of the 2nd year showed that the mean parasite rate due principally to P. falciparum increased from 2.2% during the 1st quarter year to 20% in the 2nd quarter to 60-70% during the 3rd and 4th quarters and to over 80% thereafter. The infection rate when calculated in relation to the known length of exposure to infection shows that an equally long exposure leads to different frequencies of infection in the various age groups of the sample of infants investigated and that in the age group 1-3 months the parasite rate was significantly lower than might have been expected. Periodic follow-up of the mean weight curves of infection and noninfected infants indicated that the curves of both groups showed a considerable flattening out at about 5 months of age and later and that the flattening out is more pronounced in the infected group than in the noninfected. Records of 3540 autopsies performed upon children in Lagos during the years 1933-50 revealed that acute malaria can be incriminated as the cause of death in 9% of infants in 14% of children aged 1-4 years in 9% of children aged 5-7 years in 4% of older children and in 2% of adolescents. The number of deaths due to direct effects of malaria in the Nigerian population under 15 years of age amount to 35000/annum.