Hathshya M.  Munasigha, Ananda  Amarasinghe, Neelika G. Malavige  , Nalini  Sathiakumar, 
    Predictive Value of Self-reported History of Varicella in Colombo
District, Sri Lanka,
    International Journal of Tropical Medicine,
    Volume 14,Issue 1,
    2019,
    Pages 5-10,
    ISSN 1816-3319,
    ijtmed.2019.5.10,
    (https://makhillpublications.co/view-article.php?doi=ijtmed.2019.5.10)
    Abstract: To determine whether self-reported history of previous varicella infection is an accurate predictor of
immunity to varicella. A population-based cross-sectional study of 1258 participants was conducted in
Colombo District, Sri Lanka. Using interviewer-administered questionnaire, information on sociodemographic
characteristics and previous history of varicella infection were obtained. A commercial enzyme-linked
immunosobent assay kit was used to detect varicella zoster virus antibody IgG from serum samples.
Self-reported varicella infection by the overall study group and by subgroups of adolescents, adults and
women of childbearing age had a high positive predictive value (overall group, 92%; subgroups, 91-95%) for
immunity to VZV. Whereas, a negative history of varicella infection was not an accurate predictor of
nonimmune status, the negative predictive values were low for the overall group (76%) and subgroups
(64-84%). For persons who are not at high risk of varicella infection, a positive history of varicella may be used
to indicate positive immune status in lieu of serological testing. For those at high risk for varicella infection and
a negative history of varicella infection, serological testing is required to determine immune status. For all those
determined to the non-immune by serological testing, varicella vaccine should be offered.
    Keywords: Colombo;predictive value;self-reported;Sero-prevalence;varicella;serological testing