Clinical diagnosis of malaria: can we improve?
Most cases of malaria in Zimbabwe are diagnosed on the basis of clinical suspicion, without laboratory tests. Of patients treated, between 10 and 30% have malaria parasites on blood slide examination. Can diagnosis be improved by a systematic history? We examined this question in 287 patients treated for malaria in an area of year-round transmission in Zimbabwe. The most common complaints were 'headache' (85.7%), 'bodily weakness' (79.0%) and 'fever/feeling hot' (73.2%). Eighty patients (28%) had malaria parasites on blood smear. Using the blood slide as the standard, we calculated the sensitivity, specificity and positive predictive value of a variety of clinical symptoms and signs. None had a positive predictive value substantially higher than the unknown diagnostic criteria used by health workers (28%). Multivariate analysis showed that 15 different demographic and clinical variables did not significantly predict a positive blood slide result. We conclude that, in this setting, clinical history alone will not improve the diagnosis of malaria.
Bassett
M T
MT
Department of Community Medicine, Medical School, Avondale, Zimbabwe.
Taylor
P
P
Bvirakare
J
J
Chiteka
F
F
Govere
E
E
D002738:Chloroquine / Q000627:therapeutic use; D006801:Humans; D008288:Malaria / Q000175:diagnosis* / Q000469:parasitology; D008487:Medical History Taking / Q000379:methods*; D010274:Parasitology / Q000379:methods; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D015030:Zimbabwe
D002738:Chloroquine