Abstract:
This study was conducted in the medical laboratories in Dongola city. The laboratories comprised the governmental, nongovernmental and private sector labs, to evaluate the result of malaria diagnosis by microscopy. 500 samples were taken by different laboratories. From each individual, a duplicate was taken for follow up by investigator. From blood sample, thick and thin smears were prepared, stained by Giemsa and examined microscopically to compare the results of each laboratory. The smears were examined by the investigator, in addition some of the slide examined by the laboratories under survey were send to the reference laboratory of malaria administration in Dongola for further confirmation of the result. The result were as follows:
The rate of false positive in all laboratories reached 63%.
The highest false positive results 62%were reported by the private laboratories, while the non-governmental laboratories and governmental laboratories reported 60% and 47%false results respectively.
The difference was found to be statistically significant.
Although the collection of the samples was done properly, the percentage of the false positives reached 42%and when collection of the samples was done improperly, the percentage reached 43%.
The study showed that when blood smears were done properly, the false positive rate reached 39%, and when the blood smears were done improperly, the rate reached 46%.
When the smears were properly stained, the rate was 27% and when smears were improperly stained the rate was 66%.
When the general conditions of the laboratory (building, electricity and water supply, space and cleanness) were good the false positives reached 41% and when the general conditions were bad, the rate reached 43%.
Despite the use of good and efficient microscopes, the rate of false positives results reached 34% and 21% when inefficient microscopes were used.
The study showed that, when a good quality immersion oil, was used the false positives results was 36% and reached 60% when the quality of immersion oil is bad.
The study showed that the false positive results reached 51% among personnel who did not receive training in malaria and 30% in those who received training in malaria.
The result revealed that the false positive rate was 26% among those samples examined by university graduates, while it reached 58% among those holding diplomas. The rate reached 47% among the samples examined by mixed graduates.
