An assessment of accuracy of mothers' presumptive diagnosis of fever at home in southwest Nigeria: evidence for switch to parasite-based diagnostic test

Abstract

Objective: Home management of malaria (HMM) strategy was based on presumptive diagnosis of malaria and use of correct dose of chloroquine. However, the development of chloroquine resistant parasites in most endemic areas necessitated the recommendation of artemisinin combination therapy (ACT); and this has been demonstrated to be effective in HMM. However, the recommendation that ACT should be dispensed only to laboratory confirmed cases underscores the need to review the accuracy of mothers' presumptive diagnosis and provide evidence for a switch to parasite based diagnostic test.

Methods: This was a follow-up study nested to a larger controlled intervention study carried out to assess the effect of malaria treatment guideline on mothers' adherence to correct treatment of malaria in children. In a subset, thick blood smears were prepared from finger prick blood samples of febrile children who have been presumptively diagnosed to have malaria by mothers on Days 0, 1, 2, 3, 7 and 14 to detect parasitaemia. The presumed diagnosis was compared with the presence of parasitaemia.

Results: A total of 162 children with febrile illness (88 and 74 in intervention and control groups respectively) were studied. Sixty-four (72.7%) and 62 (83.8%) of the febrile cases presumed to have malaria in the intervention and control groups respectively had parasitaemia on Day 0. The sensitivity and specificity of mothers' diagnoses was 78.1% and 29.2%; 82.3% and 8.3%; in the intervention and control groups respectively.

Conclusion: The low specificity of presumptive diagnosis has implication for the deployment of ACT at the community level in Nigeria. This supports current views on the need for a more sensitive and specific parasite-based diagnosis of malaria before ACT treatment. Further study to compare presumptive diagnosis of malaria with malaria diagnostic test carried out at the community level is needed to inform policy on the adoption of parasite based malaria diagnosis at community level.