Prevalence of hepatitis C in tropical communities: The importance of confirmatory assays

Abstract

The prevalence of antibody to hepatitis C virus (HCV) was estimated in 3 tropical populations using 2 screening ELISAs to detect antibody to the c100-3 antigen and 2 supplementary assays designed to test the specificity of these tests. Two hundred and eighty-six of 385 (74.2%) sera from Kiribati, 17 of 138 (12.3%) sera from Vanuatu, and 39 of 173 (22.5%) sera from Zaire were reactive in the initial screening assay. The proportion of reactive sera which were also reactive in the second screening ELISA varied between populations (55.1% in Kiribati, 85.1% in Vanuatu, and 39.2% from Zaire). Reactive sera were selected at random for confirmatory testing. Only 3 of 49 (6.12%) of sera from Kiribati and 1 of 14 (4.76%) of sera from Vanuatu positive in the initial ELISA were reactive in the confirmatory assays. The proportion of confirmed positive sera from Zaire was higher 8 of 28 (28.5%). Based on the results of these supplementary assays the estimated prevalence of anti-HCV in these populations is 4.8% in Kiribati, less than 1% in Vanuatu, and 6.4% in Zaire. Reliance on a single screening ELISA to estimate the prevalence of anti-HCV in stored sera from tropical communities may lead to a gross over-estimate of the true prevalence in these populations.

Low prevalence of hepatitis C virus infection in Amerindians from Western Venezuela

“…HCV infection appears to be absent in two of the studied communities. The high false-reactivity with ELISA systems found by us has been reported in other studies and might result from cross-reactivity with tropical pathogens or the presence of interfering substances (Aceti et al 1990, Tibbs et al 1991. Malaria is highly endemic among these Amerindians (Pérez & Bracho 1993).…”

Age, gender, and local geographic variations of viral etiology of hepatocellular carcinoma in a hyperendemic area for hepatitis B virus infection

“…3,18,28,29 However, the prevalence is extremely high in some areas. For example, the rate is higher than 6% in Zaire, 30 6% in regions of Saudi Arabia, 31 and higher than 16% in isolated communities in Japan. 32 HCV is most efficiently transmitted by large or repeated percutaneous exposures, such as transfusions, transplantation from an infected donor, or sharing of contaminated needles among injection drug users.…”

Contrasting patterns of hepatitis C virus infection in two regions from Tunisia

“…Published studies suggest that it varies from 0.7% to 1.2% in East Africa [Hyams et al, 1993;Ilako et al, 1995;Tess et al, 2000]. In Central and Southern African countries, HCV prevalence ranges from less than 1% (e.g., Zambia and Zimbabwe) [World Health Organization, 1997] to 6% (e.g., Cameroon and Zaire) [Tibbs et al, 1991;Ndumbe and Skalsky, 1993]. In North Africa, HCV prevalences vary greatly between countries: in Egypt HCV infection is highly endemic (14%) [Rall and Dienstag, 1995], while significantly lower prevalences have been reported in Morocco, Algeria, and Tunisia: 1.1%, 0.18%, and 0.4-0.7%, respectively [Ayed et al, 1995;Benjelloun et al, 1996;Triki et al, 1997;Gorgi et al, 1998].…”