Strategies for expanding access to quality malaria diagnosis in south-central Asia where malaria incidence is low

[Project summary in Français / Português]

Scientific title: An examination of ACT strategy in south-central Asia on P. falciparum malaria in a context where P. vivax is the major species.

What did we know before this research?

With the exception of Sub-Saharan Africa, most areas that are endemic for malaria have a combination of two species: Plasmodium falciparum and P. vivax. P. vivax is often the dominant species, accounting for a greater proportion of malaria cases.

Each of these species has a different level of severity and reaction to common drugs, therefore it’s crucial to diagnose patients and treat them accordingly. For example, P. falciparum is often resistant to cheap malaria drugs (monotherapies like Chloroquine), whereas P. vivax is still sensitive to those drugs. Recommended drugs for P. falciparum (ACT) can be more than ten times as expensive as those that are effective against P.vivax. Therefore, if a case of falciparum is mistakenly diagnosed as vivax, there is a danger of prescribing ineffective drugs which puts the patient at risk, and if a case of vivax is mistakenly diagnosed as falciparum, expensive ACT drugs are wasted unnecessarily.

Moreover, malaria transmission levels are much lower in south-central Asia than in Africa. For this reason, most people who go to clinics with fever do not, in fact, have malaria. Consequently, without accurate diagnosis and treatment, many patients are treated with a malaria drug when they do not, in fact, have malaria. This wastes drugs and neglects the treatment of the true cause of fever.

What does this study add?

Diagnosis is unavailable in most places where fever is common. Community health workers are often the main source of healthcare and are able to provide malaria drugs. However, without diagnosis that is reliable, clinicians and community health workers cannot distinguish the symptoms of malaria from other causes of fever. This results in huge overtreatment of malaria.  Even when microscopy is available, many patients who are negative for malaria still receive an antimalarial drug.

One solution is the use of rapid diagnostic tests (RDT). The tests are seen as relatively cost-effective in diagnosing patients in areas where malaria transmission is low or mixed, but this only applies if health workers trust their result.

We conducted a series of studies to test how effective different diagnostic and treatment methods are under field conditions, and measured their impact in effectively treating malaria.

First, we tested the accuracy of a rapid test that can distinguish the two malaria species and accurately identify negative patients. We found that one brand was the most accurate, and this was subsequently introduced as the national standard in Afghanistan.

We then conducted two randomised trials, one in clinics and one amongst community health workers, comparing the use of rapid diagnostic tests and microscopy. These studies will provide robust evidence for the most effective diagnostic tool, and allow both clinicians and community health workers to apply malaria treatments according to diagnostic results.

The research team

Principal Investigators

• Prof. Mark Rowland, London School of Hygiene & Tropical Medicine 

Email: mark.rowland@lshtm.ac.uk

• Dr Toby Leslie - The Global Fund (previous: London School of Hygiene & Tropical Medicine)

Email: Toby.Leslie@lshtm.ac.uk

Other Investigators

• Prof Chris Whitty - London School of Hygiene & Tropical Medicine
• Dr. Ismail Mayan, Health Protection and Research Organization, Kabul, Afghanistan
• Ms Amy Mikhail - London School of Hygiene & Tropical Medicine
• Dr Ismail Mayan - Health Protection and Research Organization (HPRO), Kabul
• Dr Nader Mohammed - HealthNet-TPO, Kabul
• Dr Anwar Hasanzai – HealthNet-TPO, Jalalabad, Nangaher
• Dr Sayed Habib Baktash  - Medical Emergency Relief International (Merlin), Kunduz