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  • Department of Medicine AFRIMS, Bangkok, Thailand

Mucenski and colleagues reported the results of a DNA probe for P. falciparum (Am. J. Trop. Med. Hyg., 35: 912–920). Their study failed to demonstrate in humans sensitivity of the probe for low parasitemias (< 10 parasites per 200 WBC). In their discussion section they claim that the probe is certainly more appropriate … for “large scale epidemiological studies, eradication program surveillance and vaccine trials.” The levels of parasitemias which they examined are more typical of those seen on admission in treatment trials.

Results from longitudinal studies done in a malariaendemic area show that > 50% of the subjects had parasitemias < 5 parasites/200 WBC, performing weekly smears. Though not as high, a significant proportion of cases presented with similar levels from point prevalence surveys. Furthermore, I found collection of samples was much more difficult using their technique compared to conventional smears.