Optimization of diagnostic procedures in primary health services to detect asymptomatic malaria

Background
The biggest challenge today is the accuracy of diagnostic tools to detect asymptomatic malaria. Up to the present, a microscopic examination procedure is only performed on patients with fever; thus, finding asymptomatic malaria is quite impossible. A serial microscopic examination (SME) procedure on patients who are at risk of malaria would make it possible to detect asymptomatic malaria.

Objectives
This study was done to find cases of asymptomatic malaria through the optimization of malaria diagnostic procedures at the primary health care facilities in the Batubara District, North Sumatera Province of Indonesia.

Material and methods
SME was conducted for three consecutive days once a microscopic examination provided a negative result. A diagnosis of malaria is confirmed by optimization of routine microscopic examination (ORME). SME is then carried out on the 2nd day (first SME), the 8th day (second SME) and the 15th day (third SME). An examination was declared negative once Plasmodium sp. is not found up to 500 high power field.

Results
SME of 1,597 patients who had negative results on the first microscopic examination revealed that 95 had submicroscopic malaria (5.9%). This study found asymptomatic malaria in 20.3% of the study subjects (188 persons) at first microscopic examination, 3.7% (34 persons) at first SME and 3% (28 persons) at second SME.

Conclusions
ORME and SME performed on people at risk of malaria provide the possibility to detect asymptomatic malaria.