Study Selection and Inclusion/Exclusion Criteria

Search results were imported into Endnote (a reference manager), where duplicate publications were identified and excluded. Titles and abstracts of remaining records were screened for relevance, and full texts of relevant and potentially relevant publications were retrieved for additional screening. References of articles and reviews were also checked to identify further publications that could have been missed.

The inclusion criteria were met for any publication that reported HSV-1 seroprevalence measure(s), based on primary data using type-specific diagnostic assays such as Western blot or type-specific (glycoprotein-G-based) enzyme-linked immunosorbent assays (ELISAs). The inclusion criteria were also met for any publication that reported a proportion of HSV-1 detection by standard viral detection and subtyping methods in GUD or genital herpes—to estimate the “etiological” (or “associative”) fraction for HSV-1 in these clinical conditions. Included studies had to have a sample size of ≥10, regardless of outcome measure.

Exclusion criteria included case reports, case series, reviews, editorials, letters to editors, commentaries, and qualitative studies. Measures reporting seroprevalence in <3-month-old infants were excluded because of maternal antibodies.

For terminology, a “publication” is a document containing a relevant outcome measure, and a “study” or a “measure” indicates all details pertaining to a specific outcome measure—a single publication may contribute multiple measures, and multiple publications of the same data set are deemed a single study.