Malaria commonly misdiagnosed and mistreated in Afghanistan

Jul 25 2012

By Helen Albert

Findings published in the BMJ suggest that malaria is being significantly misdiagnosed in Afghanistan, with many patients with fever alone being given antimalarial drugs and antibiotics despite having negative laboratory results for the disease.

In addition, the researchers report that rare but potentially fatal cases of Plasmodium falciparum malaria were not picked up by healthcare workers "emphasizing the potential role of rapid diagnostic tests."

Previous research has demonstrated that overdiagnosis of malaria and misprescription of antimalarial drugs is rife in Africa, leading to serious nonmalarial infections being missed, drugs being wasted, and the cost effectiveness of diagnostic tests being reduced.

However, less is known about the extent of this problem in Asian countries.

To assess the accuracy of malaria diagnosis in Afghanistan, Toby Leslie (London School of Hygiene and Tropical Medicine, UK) and colleagues investigated how many patients testing positive and negative for malaria in 22 clinics were given antimalarial drugs and antibiotics. They also assessed the accuracy of laboratory diagnosis and its influence on subsequent drug prescription. A double-read reference slide was used by Leslie and team to confirm clinic diagnoses.

In five clinics with no laboratory, 412 (99%) of 414 patients with suspected malaria received antimalarial drugs and 47 (11%) received an antibiotic despite only one patient being positive for malaria according to the reference slide.

In five clinics with newly established microscopy (less than 5 years), 37% and 60% of patients who were negative for malaria according to the reference slide were given antimalarial drugs and antibiotics, respectively.

The 12 clinics with established microscopy (more than 5 years) had the best results overall, but 50.8% of patients negative for malaria were still given antimalarial drugs and 27.0% were given antibiotics.

Patients who did test positive for malaria were correctly given an antimalarial drug in 94% of cases, but only one in six cases of P. falciparum malaria were correctly identified and treated.

"Our study shows that in this south Asian setting of low incidence of malaria, almost all of which is the relatively less serious vivax form, malaria is substantially overdiagnosed as a cause of infection and results in large numbers of patients with other causes of acute febrile illness being mistreated," write Leslie et al.

They conclude: "Because malaria is much less common and predominantly due to Plasmodium vivax, overtreatment of malaria presents a worse risk-benefit outcome to patients than it would in Africa, or some areas of South East Asia where a higher proportion of febrile illness is due to malaria and is mostly caused by the potentially fatal Plasmodium falciparum."

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