Overdiagnosis of malaria hurts the patient (and you and me)

Much of the world still diagnoses malaria clinically (based on symptoms alone without testing for the presence of the parasite). Recently, a Liverpool team working in Mozambique examined the cost to individual patients resulting from the clinical diagnosis of malaria (Malaria Journal – open access). The findings were striking but certainly not surprising. 23 percent of children and 31 percent of adults were overdiagnosed with malaria which resulted in a greater number of healthcare visits and costs for the adult patients.

At a population level, overdiagnosis is expensive for the health system due to the increased wastage of antimalarials and increased demand on provider time. The former concern is more pronounced recently since many countries are now using expensive artemisinin-combination therapies. Increased drug pressure also facilities the emergence and spread of drug-resistant malaria. Drug-resistant malaria increases morbidity and mortality and in some regions of the world our therapeutic alternatives are alarmingly few. I research the epidemiology and mechanisms of antimalarial resistance, and thus the lack of emphasis on parasitogically confirmed treatment is particularly worrisome. A leading malaria researcher once wrote to me, “The problem is even key malaria scientists still have difficulty thinking about how to prevent drug resistance development and how important it is to improve diagnosis and health care infrastructure so that “rational drug use” can be reinforced. They only think about what alternative drugs should be now that this one fails….” Words to heed indeed.


4 Responses to “Overdiagnosis of malaria hurts the patient (and you and me)”

  1. 1 michael makler md May 18, 2010 at 2:18 pm

    My colleague Dr Robert Piper and I have been developing diagnostics for malaria for the last 30 years. We have developed a series of monoclonal antibodies (mabs) to Plasmodium lactate dehydrogenase. These mabs in well made rapid malaria tests (Carestartâ„¢ for example) are able to diagnose all five forms of human malaria to levels of 10-100 parasites/ul. We believe that these Rapid Malaria Tests should be used before treatment. They are designed to be used in the far field where microscopes, slides and staining reagents are not available.

    The mabs are also useful to diagnose animal malaria (see malariaantibodies.com).

    I am well over retirement age and both Dr Piper and I wish to sell all the clones that produce these mabs ( about 20). Any one seriously interested in the purchase of all the clones should contact one of us. Our mabs are able to monitor therapy as well as to diagnosis. As far as I am aware there have never been a significant deletion of pLDH in malaria parasites.


  2. 2 Roger Ball January 17, 2011 at 11:57 am

    I am a Physician Assistant serving in the military. My deployment experiences to Afghanistan and Iraq have offered me new perspectives to share with the United States (US) medical community. For example we should be prepared as providers to unexpectedly diagnose and treat malaria. I have treated twelve Soldiers during my deployment and three on re-deployment with malaria. All the patients I treated were healthy people between the ages of twenty and thirty-three. Albeit I had training on malaria, I had only seen one other case in twenty years of medicine. This may be a familiar situation for many providers, especially civilian.
    The cases that I diagnosed and treated were difficult due to a lab technician’s limited experience performing thick and thin prep slides. I took a stance of diagnosis from clinical symptoms along with a CBC. The patients I had consistently exhibited leukopenia, thrombocytopenia, followed by frank anemia. We continued to do thick and thin preps, every six hours, until species could be isolated and confirmed. I performed exams and reviewed symptoms with all patients twice daily.
    I am aware that many providers in the US have never seen a case of malaria. One of the three cases of malaria I treated since re-deploying was treated at a military emergency room. The patient informed the staff he may have malaria because he recognized symptoms mentioned in the briefing I gave the unit prior to re-deploying to the US. Emergency staff surmised he had a stomach bug that would go away. After the weekend emergency room visit he followed up with the clinic on Monday where I diagnosed him with malaria. All deployed Soldiers are on malaria prophylaxis doxycycline daily, even with this treatment up to one percent of Soldiers may still contract malaria.
    The large number of Soldiers deployed since the start of the war on terrorism impacts American providers’ diagnosis and treatment of malaria cases. Recognition of malaria is imperative because misdiagnosed cases have potentially devastating outcomes. This will become an issue that affects American medical communities due to a considerable number of citizens who have deployed to areas with malaria. This may be of notable issue in US medical communities with a population of National Guard Units because the potential of US providers overlooking a patient’s military deployment experience as a pertinent piece of background information gathered in the examination performed at an emergency room or clinic visit.

    The views expressed in this blog are those of the author and do not reflect the official policy or position of the Department of the Army, Department of Defense, or the U.S. Government.
    R. Ball
    Major, SP
    ILE Student

    • 3 naman January 22, 2011 at 10:33 am

      Roger, great points on limited provider experience with the clinical picture of malaria in non-endemic settings as well as the sensitivity of blood smears for diagnosis, particularly with inexperienced technicians. In such cases I agree it’s reasonable to treat, especially since treatment is short and fairly safe, but where presumptive treatment becomes a problem is when it’s applied across all patients in an entire health system. An aside – I’m not a big fan of doxycycline for prophylaxis. Thanks for sharing.

  1. 1 Containing artemisinin resistant malaria | topnaman | Malaria blog Trackback on February 1, 2009 at 4:35 pm
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