Transmission timing and containment risk in human Andes virus outbreaks
- 1The University of Texas at Austin
Abstract
The 2026 multinational Andes virus (ANDV) outbreak linked to cruise-ship travel from Argentina triggered extensive contact tracing and quarantine. Whether intervention on this scale was necessary or sufficient depends on the risk of onward transmission, which can be difficult to estimate early in an outbreak. Using transmission-pair data from the 2018-2019 outbreak in Epuyen, Argentina, and a mechanistic model linking viral growth, symptom onset, and transmission, we estimated that 42.4% (95% CrI: 18.2-69.7%) of transmission occurs before symptom onset and that the median incubation period is 18.5 days (95% CrI: 16.5-19.5). We simulated outbreaks under an Epuyen-calibrated estimate (R = 2.12, k = 0.316) and a pooled estimate from 15 prior ANDV investigations (R = 0.24, k = 0.39), with intervention beginning after two generations, as in the cruise-associated event. Under the higher-transmission scenario, missing 10% of exposed individuals or downstream contacts resulted in a 29.9% probability of continued spread and a 20.6% probability that at least 5,000 ultimately uninfected people would be quarantined. Under lower transmission, continued spread stayed below 8%. However, the risk of onward transmission could not be estimated precisely from the first several detected cases. These findings therefore support rapid, comprehensive contact tracing and quarantine after large international exposure events despite substantial costs.
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BibTeX
@misc{jamieson2026transmission,
title = {{Transmission timing and containment risk in human Andes virus outbreaks}},
author = {N. Jamieson and R. Pasco and S. Abbott and J. Lessler and L. A. Meyers},
howpublished = {medRxiv},
year = {2026},
month = oct,
doi = {10.64898/2026.10.10.26365227},
url = {https://www.medrxiv.org/content/10.64898/2026.10.10.26365227v1},
note = {CC BY-NC-ND},
}
RIS
TY - UNPB
TI - Transmission timing and containment risk in human Andes virus outbreaks
AU - N. Jamieson
AU - R. Pasco
AU - S. Abbott
AU - J. Lessler
AU - L. A. Meyers
PY - 2026
DA - 2026/10/10
PB - medRxiv
DO - 10.64898/2026.10.10.26365227
UR - https://www.medrxiv.org/content/10.64898/2026.10.10.26365227v1
AB - The 2026 multinational Andes virus (ANDV) outbreak linked to cruise-ship travel from Argentina triggered extensive contact tracing and quarantine. Whether intervention on this scale was necessary or sufficient depends on the risk of onward transmission, which can be difficult to estimate early in an outbreak. Using transmission-pair data from the 2018-2019 outbreak in Epuyen, Argentina, and a mechanistic model linking viral growth, symptom onset, and transmission, we estimated that 42.4% (95% CrI: 18.2-69.7%) of transmission occurs before symptom onset and that the median incubation period is 18.5 days (95% CrI: 16.5-19.5). We simulated outbreaks under an Epuyen-calibrated estimate (R = 2.12, k = 0.316) and a pooled estimate from 15 prior ANDV investigations (R = 0.24, k = 0.39), with intervention beginning after two generations, as in the cruise-associated event. Under the higher-transmission scenario, missing 10% of exposed individuals or downstream contacts resulted in a 29.9% probability of continued spread and a 20.6% probability that at least 5,000 ultimately uninfected people would be quarantined. Under lower transmission, continued spread stayed below 8%. However, the risk of onward transmission could not be estimated precisely from the first several detected cases. These findings therefore support rapid, comprehensive contact tracing and quarantine after large international exposure events despite substantial costs.
ER -