Maintaining Laboratory Capacity for Malaria Diagnosis in Low-Incidence Settings

A quality assurance system was developed to enhance the expertise of microscopists in reading thick and thin blood smears. This system aimed to ensure that personnel maintain their skills and capacities to properly diagnose malaria. Low incidence of malaria can lead to several challenges, including community health workers and health professionals mistaking signs and symptoms of malaria for other febrile illnesses. Health professionals may fail to confirm clinical diagnosis of malaria with proper laboratory diagnosis, resulting in personnel losing the skills required to make a diagnosis and provide treatment. Additionally, malaria incidence and prevalence may be under-reported to national surveillance systems, increasing the probability of cases of severe malaria, as well as re-introduction and outbreaks. The World Health Organization (WHO) recommends quality-assured rapid diagnostic tests (RDTs) and microscopy as the primary diagnostic tools for confirmation and management of cases of suspected clinical malaria in all epidemiological situations, including areas of low transmission. RDTs and microscopy are suitable for routine malaria surveillance due to their good performance in detecting clinical malaria, widespread availability, and relatively low cost. Nucleic acid amplification techniques (NAA), such as PCR, are available and more sensitive in detecting malaria than RDTs and microscopy. However, the use of highly sensitive diagnostic tools should be considered only in low-transmission settings where there is already widespread malaria diagnostic testing and treatment, and low parasite prevalence rates. NAA-based methods should not divert resources from malaria prevention and control or from strengthening of health care services and surveillance systems. Sub-microscopic P. falciparum and P. vivax infections are common in both low- and high-transmission settings. The use of NAA methods in malaria programmes should be considered for epidemiological research and surveys to map sub-microscopic infections in low-transmission areas. NAA methods might also be used for identifying foci for special interventions in elimination settings. Common standards should be set for nucleic acid-based assays, and a standard operating procedure should be prepared for sample collection and extraction.