Diagnosis &Treatment Bill Brieger | 06 Nov 2008 06:42 am
Treatment without disease
A discrepancy “between the perceived and actual level of transmission intensity” has been observed in the ‘Mosquito River’ area of Tanzania near Arusha by Mwanziva and colleagues. Specifically, they found …
Malaria transmission intensity by serological assessment was equivalent to < 1 infectious bites per person per year. Despite low transmission intensity, >40% of outpatients attending the clinics in 2006-2007 were diagnosed with malaria. Prospective data demonstrated a very high overdiagnosis of malaria. Microscopy was unreliable with <1% of slides regarded as malaria parasite-positive by clinic microscopists being confirmed by trained research microscopists. In addition, many ‘slide negatives’ received anti-malarial treatment. As a result, 99.6% (248/249) of the individuals who were treated with ACT were in fact free of malaria parasites.
A similar experience was found in urban Lagos, Nigeria ten years ago*:
- Blood film investigation of 916 children between the ages of 6 months and 5 years yielded a parasite prevalence rate of 0.9%.
- Night knockdown collections of mosquitoes in rooms yielded only C. quinquefasciatus and A. aegypti
- Very low densities of A. gambiae larvae were found in breeding sites (between 0.3 and 0.7)
- Community members, during focus group discussion identified malaria, in it various culturally defined forms, as a major health problem.
- Among the children examined clinically, 186 (20.3%) reported an illness, which they called “malaria” in the previous two weeks, and 180 had sought treatment for this illness.
- Data obtained from 303 shops in the area documented that a minimum of US $4,000 was spent on purchases of antimalarial drugs in the previous week.
This contrasts with a report from Médecins Sans Frontières (MSF) that “ weak distribution and health systems and a lack of qualified staff” are reasons why poor people in many malaria endemic areas do not receive appropriate treatment.
During a recent visit to Mozambique I observed that antenatal clinic staff had Rapid Diagnostic tests. Some explained that if the test was negative, they would send the client to the lab. If the lab results were negative, they would still treat to be on the sfae side. This reinforces the conclusion by Mwanziva that “rational drug-prescribing behaviour” must be reinforced. Of course as seen in Lagos, this concern goes well past the behavior of orthodox prescribers.
This malaria treatment gap poses serious threats to both lives and resources. The shame is that health workers and program planners bear as much of the responsibility as the patients themselves, if not more. This is a challenge may be met through development and enforcement of better treatment performance standards.
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*Brieger WR, Sesay HR, Adesina H, Mosanya ME, Ogunlade PB, Ayodele JO, Orisasona SA. Urban malaria treatment behaviour in the context of low levels of malaria transmission in Lagos, Nigeria. African Journal of Medicine and Medical Sciences 2002; 30(suppl): 7-15.