Low Prevalence of Anti-Hepatitis C Virus Antibodies in Mexico: A Systematic Review

Background: The prevalence of reactive tests to anti-hepatitis C virus (HCV) antibodies in Mexico is unknown, though estimated to be 1%. There is no single nation-wide study or comprehensive literature review addressing the epidemiology of HCV infection in Mexico. Methods: We did a systematic review of English- and Spanish-language literature reporting on the frequency of anti-HCV antibodies in asymptomatic persons at low risk, of studies performed in Mexico. An exhaustive search in MEDLINE, IMBIOMED, MedicLatina, ARTEMISA and MEDIGRAPHIC databases was undertaken. Weighted mean prevalence (WMP) was calculated after combining the results of each study. Results: 22 studies involving 825,377 persons at low risk, mainly blood donors, were identified. Crude seroprevalence reported in each study ranged from 0.1 to 2%, with 16 (73%) studies reporting below 1%. Overall, WMP of anti-HCV antibodies (tested by enzyme immunoassay) was 0.37% (95% CI, 0.36–0.38%), differing by country region and immunoassay generation (p< 0.01). The most frequent risk factor reported was blood transfusion. Confirmation of specific anti-HCV antibodies by recombinant immunoblot assay ranged from 30 to 100%, whereas confirmation of viremia by PCR ranged from 16 to 80%. In 3 studies on HCV genotype frequency, genotype 1 had crude prevalence ranging from 63 to 70%, subtype 1b being the most prevalent (21–47%). Conclusions: The prevalence of anti-HCV antibodies in Mexico might be lower than previously estimated. Transfusion of blood products is the main risk factor. HCV subtype 1b is the most prevalent among persons with confirmed viremia. Information of a nation-wide survey is mandatory.