Cost comparison of microscopy vs. empiric treatment for malaria in southwestern nigeria: a prospective study

BACKGROUND: Presumptive treatment for malaria is common in resource-limited settings, yet controversial given the imprecision of clinical diagnosis. The researchers compared costs of diagnosis and drugs for two strategies: (1) empirical treatment of malaria via clinical diagnosis; and (2) empirical diagnosis followed by treatment only with Giemsa smear confirmation. METHODS: Patients with a diagnosis of clinical malaria were recruited from a mission/university teaching hospital in southwestern Nigeria. The patients underwent free Giemsa thick (diagnosis) and thin (differentiation) smears, but paid for all anti-malarial drugs. Clinical diagnosis was made on clinicians' judgments based on symptoms, including fever, diarrhoea, headache, and body aches. The paediatric regimen was artesunate (6-9 tablets of 3 mg/kg on day one and 1.5 mg/kg for the next four days) plus amodiaquine (10 mg/kg day 1-2 and 5 mg/kg on day three in suspension). Adults were given two treatment options: option one (four and one-half 50 mg artesunate tablets on day one and nine tablets for the next four days, plus three 500 mg sulphadoxine/25 mg pyrimethamine tablets) and option two (same artesunate regimen plus nine 200 mg tablets of amodiaquine at 10 mg/kg day 1-2 and 5 mg/kg on day three). The researchers calculated the costs of smears/drugs from standard hospital charges. RESULTS: Doctors diagnosed 304 patients (170 adults ages >16 years and 134 pediatric) with clinical malaria, prescribing antimalarial drugs to all. Giemsa thick smears were positive in 115/304 (38%). The typical patient cost for a Giemsa smear was 550 Naira (US$3.74 in 2009). For children, the cost of testing all, but treating only Giemsa positives was N888 ($6.04)/child; the cost of empiric treatment of all who were clinically diagnosed was lower, N660 ($4.49)/child. For adults, the cost of testing all, but treating only Giemsa positives was N711 ($4.84)/adult for treatment option one (artesunate and sulphadoxine/pyrimethamine) and N730 ($4.97)/adult for option two (artesunate and amodiaquine). This contrasts to lower costs of empiric treatment for both options one (N610 = $4.14/adult) and two (N680=$4.63/adult). CONCLUSIONS: Empiric treatment of all suspected cases of malaria was cheaper (at the end of the dry to the beginning of the rainy season) than only treating those who had microscopy-confirmed diagnoses of malaria, even though the majority of patients suspected to have malaria were negative via microscopy. One can acknowledge that giving many malaria-uninfected Nigerians anti-malarial drugs is undesirable for both their personal health and fears of drug resistance with overuse. Therefore, funding of rapid diagnostic tests whose performance exceeds the Giemsa smear is needed to achieve an ideal of diagnostic confirmation before treatment.