Evidence for Human-to-Human Transmission of Hantavirus: A Systematic Review

Background: Hantavirus is known to be transmitted from rodents to humans. However, some reports from Argentina and Chile have claimed that the hantavirus strain Andes virus (ANDV) can cause human-to-human transmission of the disease. The aim of this systematic review was to assess the evidence for human-to-human transmission of hantavirus. Methods: We searched PubMed (inception to 28 February 2021), Cochrane Central, Embase, LILACS and SciELO (inception to 3 July 2020), and other sources. We included studies that assessed whether interpersonal contact with a person with laboratory-confirmed hantavirus infection led to human-to-human transmission. Two reviewers conducted screening, selection, data extraction, and risk of bias assessment. Results: Twenty-two studies met the inclusion criteria. Meta-analysis was not possible due to heterogeneity. With the exception of 1 prospective cohort study of ANDV in Chile with serious risk of bias, evidence from comparative studies (strongest level of evidence available) does not support human-to-human transmission of hantavirus infection. Noncomparative studies with a critical risk of bias suggest that human-to-human transmission of ANDV may be possible. Conclusions: The balance of the evidence does not support the claim of human-to-human transmission of ANDV. Well-designed cohort and case-control studies that control for co-exposure to rodents are needed to inform public health recommendations.