Revista do Instituto de Medicina Tropical de São Paulo
On-line version ISSN 1678-9946
PILGER, Daniel; KHAKBAN, Adak; HEUKELBACH, Jorg and FELDMEIER, Hermann. Self-diagnosis of active head lice infestation by individuals from an impoverished community: high sensitivity and specificity. Rev. Inst. Med. trop. S. Paulo [online]. 2008, vol.50, n.2, pp.121-122. ISSN 1678-9946. http://dx.doi.org/10.1590/S0036-46652008000200011.
To compare sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of self-diagnosis for head lice infestation with visual inspection, we conducted a study in an urban slum in Brazil. Individuals were asked about active head lice infestation (self-diagnosis); we performed visual inspection and thereafter wet combing (gold standard). Of the 175 individuals included, 77 (44%) had an active head lice infestation. For self-diagnosis, sensitivity (80.5%), specificity (91.8%), PPV (88.6%) and NPV (85.7%) were high. Sensitivity of visual inspection was 35.1%. Public health professionals can use self-diagnosis as a diagnostic tool, to estimate accurately prevalence of pediculosis in a community, and to monitor ongoing intervention strategies.
Keywords : Head lice; Epidemiology; Diagnosis; Sensitivity; Specificity; Predictive values.