Experimental Biology 2010: A Prospective Study And Cost Analysis Of Malaria Testing And Empiric Treatment

Purpose of Study: To compare the cost of empirical treatment for all clinically diagnosed with malaria to the costs of testing all and treating only those with positive Giemsa thick blood smears at a major medical center in southwestern Nigeria. We also assessed the test performance of the Leishman thin blood smear (compared to Giemsa) since the Leishman is often used in Nigeria to diagnose malaria.

Methods Used: All patients in our study with the clinical diagnosis of malaria received free Leishman thin smears, Giemsa thick (diagnosis) and thin (differentiation) smears, and antimalarial treatment. Clinical malaria was diagnosed per medical center doctors’ judgments involving symptoms of malaria. Direct patient costs (drugs and smears) were calculated from the medical center’s charges. The cost for the pediatric treatment regimen of artesunate 6-9 tablets and amodiaquine suspension was 660 naira (N660=US$4.41 in mid-2009). Adults were given two treatment options: option one (12 tablets of artesunate and 3 tablets of sulfadoxine pyrimethamine) cost N610 ($4.07) and option two (12 tablets of artesunate and 8 tablets of amodiaquine) cost N680 ($4.54).

Summary of Results: Doctors diagnosed and treated 304 patients (170 adult and 134 pediatric) with clinical malaria. Of the 304 tests, Giemsa thick smears were positive in 115 (38%), while and Leishman thin smear were positive in 52 (17%). The sensitivity of the Leishman was 52/115=45% and the specificity is 189/189= 100%. The patient cost of one Giemsa smear was 550 Naira (N550=US$3.67 in 2009). The cost of testing all and treating only Giemsa positive children was N119,000 ($793.65); their empiric treatment cost N88,440 ($598.84). The cost of testing all and treating only Giemsa positive adults was N120,950 ($806.61) for option one and N124,100 ($827.61) for option two. The respective costs for empiric treatment of all adult patients was N103,700 ($691.57) and N115,600 ($770.93).

Conclusions: In southwestern Nigeria, the most cost-effective approach to malarial management was empiric treatment, though many uninfected children and adults will receive antimalarial drugs. The widely used Leishman thin smear was insensitive compared to the Giemsa smear which should be the preferred diagnostic approach.