How Far Are We from Reaching Universal Malaria Testing of All Fever Cases?

Abstract

Universal malaria diagnostic testing of all fever cases is the first step in correct malaria case management. However, monitoring adherence to universal testing is complicated by unreliable recording and reporting of the true number of fever cases. We searched the literature to obtain gold-standard estimates for the proportion of patients attending outpatient clinics in sub-Saharan Africa with malarial and non-malarial febrile illness. To correct for differences in malaria transmission, we calculated the proportion of patients with fever after excluding confirmed malaria cases. Next, we analyzed routine data from Guinea and Senegal to calculate the proportion of outpatients tested after exclusion of confirmed malaria cases from the numerator and denominator. From 12 health facility surveys in sub-Saharan Africa with gold-standard fever screening, the median proportion of febrile illness among outpatients after exclusion of confirmed malaria fevers was 57% (range: 46-80%). Analysis of routine data after exclusion of confirmed malaria cases demonstrated much lower testing proportions of 23% (Guinea) and 13% (Senegal). There was substantial spatial and temporal heterogeneity in this testing proportion, and testing in Senegal was correlated with malaria season. Given the evidence from gold-standard surveys that at least 50% of non-malaria consultations in sub-Saharan Africa are for febrile illness, it appears that a substantial proportion of patients with fever are not tested for malaria in health facilities when considering routine data. Tracking the proportion of patients tested for malaria after exclusion of the confirmed malaria cases could allow programs to make inferences about malaria testing practices using routine data.

Figure 1.

Corrected fever testing proportion, defined as the proportion of all-cause outpatients tested for malaria after exclusion of confirmed malaria cases, by district in Guinea and Senegal during low malaria transmission season (March) and high malaria transmission season (September). Gray represents districts with missing data for the given month.

Figure 2.

(A) Test positivity rate, crude fever testing proportion, and corrected fever testing proportion, defined as the proportion of all-cause outpatients tested after exclusion of confirmed malaria cases, by age group in Senegal for the period 2013–2017. (B) The crude and corrected fever testing proportion, stratified by transmission zone, Senegal, 2013–2017.

Figure 3.

Breakdown of all-cause outpatient consults into confirmed malaria cases (blue), patients testing negative for malaria (green), and non-tested patients (red) for two districts with good apparent malaria testing practices: Forecariah in Guinea and Salamata in Senegal. Dashed line represents the crude fever testing proportion, defined as the proportion of all-cause outpatients tested for malaria, and solid line indicates corrected fever testing proportion indicator, defined as the proportion of all-cause outpatients tested after exclusion of confirmed malaria cases. Data retrieved from routine information systems in Guinea and Senegal.

Figure 4.

Breakdown of all-cause outpatient consults into confirmed malaria cases (blue), patients testing negative for malaria (green), and non-tested patients (red) for four districts with poor apparent malaria testing practices: Siguiri in Guinea, and Kebemer, Keur Momar Sarr, and Tambacounda in Senegal. Dashed line represents the crude fever testing proportion, defined as the proportion of all-cause outpatients tested for malaria, and solid line indicates corrected fever testing proportion indicator, defined as the proportion of all-cause outpatients tested after exclusion of confirmed malaria cases. Data retrieved from routine information systems in Guinea and Senegal.

Figure 5.

The relationship between the crude fever testing proportion, defined as the proportion of all-cause outpatients tested for malaria, and the corrected fever testing proportion, defined as the proportion of all-cause outpatients tested after exclusion of confirmed malaria cases, for 2015 for each of Guinea’s 38 districts. The five districts comprising low-transmission Conakry are marked in blue, and high-transmission Dabola is marked in red.