Tick-borne relapsing fever in central Tanzania

Between October 1985 and September 1986, 488 children aged less than 15 years, 45 pregnant women, 21 other women and 18 men with tick-borne relapsing fever (TBRF) were seen at Mvumi Hospital, Central Tanzania. 88% of the children were less than 5 years old and 36% were less than 1 year. Twelve children were less than 1 month old and some of the 10 infants diagnosed at between 4 and 12 days of age were cases of congenital infection. The clinical features of TBRF in the children and pregnant women were compared with 129 children with a similar age distribution and 52 pregnant women, respectively, who had blood smears positive for malaria but negative for spirochaetes. The common presenting features in children with TBRF were a high fever, splenomegaly, convulsions, and meningism. The difficulty of differentiation from malaria is described. Severe disease in both children and adults was associated with high density of spirochaetes in blood smears. Of the 45 infected pregnant women, 22 (49%) went into labour. One of the deliveries was an abortion and 10 were preterm infants, 4 of whom died. There were no maternal deaths. The estimated overall mortality for children was 1.6%, and 2.3% for those aged less than 1 years; for the 95 children admitted it was 8.4%. Penicillin was a satisfactory treatment for all ages, with a relapse rate of 4.7%. Recommendations for patient management are given.