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| An urban rat emerges from its hole at a New York City subway stop. Experts believe that if monkeypox spreads to rats or other wild animals, it will be eradicated. (Julie Jacobson) |
Maureen Miller, a Columbia University infectious disease epidemiologist and medical anthropologist, was not surprised to learn this week that an Italian greyhound in Paris had become the first dog to catch monkeypox from a human.
Since the outbreak's inception, the Centers for Disease Control and Prevention and the World Health Organization have warned that the disease could spread to pets. Many of the common ways dogs express affection for their owners — licking their faces, nuzzling their skin, leaping up into their bedding — are potential viral transmission pathways.
The CDC provides specific instructions for keeping household animals separate from infected people and potentially infected pets separate from one another. Dogs, like humans, should be able to recover from the virus.
Miller is concerned about the human-to-animal transmission scenario.
"I'm afraid of rodents," she explained.
If the virus spreads to wild animals such as rats or squirrels, eradication becomes exponentially more difficult. Rather than being limited to humans, it would infect countless tiny vectors, which could then infect other animals, pets, and people.
Miller feels "horrible" for the greyhound, but "there are clear protocols on how to manage infected pets... I would only be concerned about it if it spreads to rodents."
She is not by herself.
The prospect of monkeypox becoming endemic in rodents — a mammal order notorious for its hardiness, mobility, and effectiveness at spreading pathogens — is "the thing that keeps me awake at night," according to Anne Rimoin, a UCLA epidemiologist who has studied it for the last two decades.
"It's certainly a possible scenario," Rimoin said, "and the more opportunity the virus has to spread, the more likely it becomes."
Since the first case of monkeypox was reported in Boston on May 19, the United States has recorded over 13,500 cases. The disease is spread primarily through sustained skin-to-skin contact, with infected clothing or sheets being less effective.
The current outbreak in Europe and North America has seen the vast majority of cases among men who have sex with men. "There's no reason, no biological reason, why they're the only risk group," Miller said. "And they're not."
If the virus spreads beyond that specific demographic, non-human mammals may play an important role.
Unlike smallpox, which only infected humans, this orthopoxvirus is less picky about which mammal hosts it infects. Anteaters, hedgehogs, and chinchillas can all contract it, and many species of rats and mice are also thought to be susceptible.
There are several relatively simple ways for the virus to spread to the rodent population. Infected pets may spread it through bites, scratches, feces, or urine. Rodents digging in garbage may come into contact with contaminated bedsheets, clothing, or bandages.
Animals, particularly rodents, have been the primary source of transmission to humans in previous outbreaks involving this poxvirus.
The disease is most prevalent in rural areas of western and central Africa. It spreads through close contact with infected animals, most commonly while hunting, farming, or, in the case of many children, playing with squirrels.
Although scientists have not confirmed which wild animal species are the virus's natural hosts, the World Health Organization has identified rodents as the most likely candidate.
Other orthopoxviruses, which include monkeypox and its far deadlier cousin smallpox, do not appear to be dangerous to birds, reptiles, or amphibians.
The WHO announced this month that it will rename the virus and its two primary strains, which were previously labeled based on where they circulated in Africa.
The disease's previous outbreak in the United States was caused by rodents. A Texas animal distributor kept prairie dogs in the same cages and bedding as exotic animals imported from Africa that tested positive for the virus in 2003. All 72 suspected or confirmed cases had contact with those animals, beginning with a 3-year-old Wisconsin girl who was bitten by her pet prairie dog.
That outbreak was brought under control in two months, before the virus had a chance to infect the local animal population. There are currently no known animal reservoirs for this virus outside of western and northern Europe.
Veterinarians and epidemiologists warn that this could change quickly. The CDC's recommendations for isolating pets with confirmed or suspected infections are intended to protect the animals' health while also preventing the virus from spreading to wild mammals.
According to the CDC, pets exposed to a person with the disease should be quarantined from other animals for 21 days. In a warning reminiscent of the early days of the COVID-19 pandemic, the agency warns concerned pet owners not to use household cleaners or chemical disinfectants on their animals.
"The longer the virus remains with us, and the more species become infected, the more likely it will circulate in other animals," said Eman Anis, a veterinary microbiologist at the University of Pennsylvania School of Veterinary Medicine.
Humans and their pets can be vaccinated, but "once it gets into the wild, it will be difficult to control," she says.
Thanks to the Los Angeles Times.
Nice article
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