Credit CDC
#18,744
While I may be slightly biased due to an early-teenage exposure to George R. Stewart's groundbreaking 1949 post-apocalyptic novel Earth Abides, the subject of rats and rat-borne diseases comes up in this blog fairly often.
I even borrowed a blog title five years ago (see COVID-19: The Rat Abides?) after numerous reports of rat sightings during the early weeks of the COVID shutdown.
But in recent years we've seen the number of recognized rat (and rodent) borne diseases increase markedly.
Last March, in Experimental Infection of Rats with Influenza A Viruses: Implications for Murine Rodents in Influenza A Virus Ecology, we saw that rats could be experimentally infected - and carry - a wide variety of influenza A viruses (including H5, H7, H9, & H10 subtypes).
Similar studies have found natural IAV infection in rats around the world, including Emer. Microbe & Inf.: HPAI Virus H5N1 clade 2.3.4.4b in Wild Rats in Egypt during 2023. The role of mice and rats in spreading avian flu - particularly in agricultural settings - is likely underestimated.
Rats are also capable of carrying coronaviruses, including SARS-CoV-2 (see mBio: SARS-CoV-2 Exposure in Norway Rats (Rattus norvegicus) from New York City). In Preprint: SARS-CoV-2 Infection in Domestic Rats After Transmission From Their Infected Owner, we saw further evidence of the susceptibility of rodents to COVID, with the author's writing:In yet another example, last March in Viruses: Novel Rodent Coronavirus-like Virus Detected Among Beef Cattle with Respiratory Disease in Mexico, we looked at the detection of an novel alphacoronavirus in Monterrey Cattle.We report the transmission of SARS-CoV-2 Omicron variant from a COVID-19 symptomatic individual to two domestic rats, one of which developed severe symptoms. Omicron carries several mutations which permit rodent infection. This report demonstrates that pet, and likely wild, rodents could therefore contribute to SARS-CoV-2 spread and evolution.
One that most closely resembled a rodent-coronavirus isolated in China in 2021(see Nature: Virus Diversity, Wildlife-Domestic Animal Circulation and Potential Zoonotic Viruses of Small Mammals, Pangolins and Zoo Animals).
The Hidden Threat: Rodent-Borne Viruses and Their Impact on Public Health
by Awad A. Shehata 1,*, Rokshana Parvin 2, Shadia Tasnim 2, Phelipe Magalhães Duarte 3,
Alfonso J. Rodriguez-Morales 4,5 and Shereen Basiouni 6
Abstract
Rodents represent the most diverse order of mammals, comprising over 2200 species and nearly 42% of global mammalian biodiversity. They are major reservoirs of zoonotic pathogens, including viruses, bacteria, protozoa, and fungi, and are particularly effective at transmitting diseases, especially synanthropic species that live in close proximity to humans. As of April 2025, approximately 15,205 rodent-associated viruses have been identified across 32 viral families. Among these, key zoonotic agents belong to the Arenaviridae, Hantaviridae, Picornaviridae, Coronaviridae, and Poxviridae families.Due to their adaptability to both urban and rural environments, rodents serve as efficient vectors across diverse ecological landscapes. Environmental and anthropogenic factors, such as climate change, urbanization, deforestation, and emerging pathogens, are increasingly linked to rising outbreaks of rodent-borne diseases.This review synthesizes current knowledge on rodent-borne viral zoonoses, focusing on their taxonomy, biology, host associations, transmission dynamics, clinical impact, and public health significance. It underscores the critical need for early detection, effective surveillance, and integrated control strategies. A multidisciplinary approach, including enhanced vector control, improved environmental sanitation, and targeted public education, is essential for mitigating the growing threat of rodent-borne zoonoses to global health.
