Thick Blood Smear: Sensitivity and Specificity
this is for all infections. Obviously, greater parasitemia yields greater sensitivity. In addition, sensitivity is greatly dependent on laboratory experience. It is recommended that smears be repeated every 6-12 hours until the diagnosis is confirmed (if there is clinical suspicion); sensitivity is pretty good at >100 parasites/ul.
Finally - thick smears are more sensitive for detection of any malaria - while thin smears are generally used to better estimate parasitemia and identify the species.
similar results from three studies re: sensitivity (see citations).
50% sensitive, 100% specific
85% sensitive, 100% specific