Overuse of artemisinin-combination therapy in Mto wa Mbu (river of mosquitoes), an area misinterpreted as high endemic for malaria.
BACKGROUND
Adequate malaria diagnosis and treatment remain major difficulties in rural sub-Saharan Africa. These issues deserve renewed attention in the light of first-line treatment with expensive artemisinin-combination therapy (ACT) and changing patterns of transmission intensity. This study describes diagnostic and treatment practices in Mto wa Mbu, an area that used to be hyperendemic for malaria, but where no recent assessments of transmission intensity have been conducted.


METHODS
Retrospective and prospective data were collected from the two major village health clinics. The diagnosis in prospectively collected data was confirmed by microscopy. The level of transmission intensity was determined by entomological assessment and by estimating sero-conversion rates using anti-malarial antibody responses.


RESULTS
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.


CONCLUSIONS
Transmission intensity has dropped considerably in the area of Mto wa Mbu. Despite this, most fevers are still regarded and treated as malaria, thereby ignoring true causes of febrile illness and over-prescribing ACT. The discrepancy between the perceived and actual level of transmission intensity may be present in many areas in sub-Saharan Africa and calls for greater efforts in defining levels of transmission on a local scale to help rational drug-prescribing behaviour.
Mwanziva
Charles
C
Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands. cmwanziva@yahoo.com
Shekalaghe
Seif
S
Ndaro
Arnold
A
Mengerink
Bianca
B
Megiroo
Simon
S
Mosha
Frank
F
Sauerwein
Robert
R
Drakeley
Chris
C
Gosling
Roly
R
Bousema
Teun
T
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000818:Animals; D000852:Anopheles / Q000469:parasitology; D000913:Antibodies, Protozoan / Q000097:blood; D037621:Artemisinins / Q000008:administration & dosage*; D002648:Child; D002675:Child, Preschool; D004359:Drug Therapy, Combination; D019353:Endemic Diseases; D004983:Ethanolamines / Q000008:administration & dosage*; D005260:Female; D005449:Fluorenes / Q000008:administration & dosage*; D006801:Humans; D007223:Infant; D000078102:Lumefantrine; D008288:Malaria / Q000175:diagnosis* / Q000188:drug therapy* / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D018512:Parasitemia / Q000175:diagnosis* / Q000188:drug therapy*; D011891:Rain; D019035:Rural Health Services; D016036:Seroepidemiologic Studies; D013636:Tanzania / Q000453:epidemiology; D055815:Young Adult
D000913:Antibodies, Protozoan; D037621:Artemisinins; D004983:Ethanolamines; D005449:Fluorenes; C031327:artemisinin; D000078102:Lumefantrine