Chinese officials believe the unidentified male became infected after handling and eating a wild hare on Nov. 5 in the Inner Mongolia, according to state news site XinhuaNet.
As a precaution, officials quarantined the people who had since come in contact with the man. None of them have exhibited fever or other symptoms of the plague, infamous for the Black Death pandemic during the Middle Ages.
Two cases of pneumonic plague, a highly contagious form of the disease, were confirmed in China by local health officials last week. The two patients, who also were from Inner Mongolia, were diagnosed in Beijing and are currently being treated for the condition in the Chaoyang District.
No epidemiological association has been found between the two cases, according to officials.
The plague is caused by Yersinia pestis — a common bacteria carried by rats, rabbits and squirrels, according to the U.S. Center for Disease Control and Prevention. Humans can contract the bubonic plague when bitten by infected fleas. Handling infected animals directly also can cause infection.
Ryan Miller of USA Today reports a Mongolian couple died from the bubonic plague after eating raw marmot meat, sparking a quarantine that trapped tourists for days, officials said Monday.
According to AFP, the couple died May 1 in a remote area of the country’s Bayan-Ölgii province, which borders China and Russia.
A six-day quarantine of 118 people who had come in contact with the couple, including locals and a number of foreign tourists, had been lifted as of Tuesday, Ariuntuya Ochirpurev, a World Health Organization official, told the BBC.
Ochirpurev told BBC that the couple ate the rodent’s raw meat and kidney, which is believed to be good for health in the area.
“After the quarantine (was announced) not many people, even locals, were in the streets for fear of catching the disease,” Sebastian Pique, an American Peace Corps volunteer in the area, told AFP.
Between 1340 and 1400, the Black Death spread throughout Europe, killing more than 20 million people. For hundreds of years, it was thought that fleas carried by black rats spread the deadly disease. But new research suggests that the “vermin” might not be to blame.
Kristin Hugo of Newsweek reports a study published in the Proceedings of the National Academy of Sciences on Monday illustrates how the plague might have spread. Researchers at the University of Oslo ran computerized mathematical simulations of disease spread by human-to-human fleas and lice, by human-to-rat-to-human fleas, and by airborne pathogens.
The researchers compared those computerized simulations to nine examples of the actual spread of the Black Death. They found that the simulations of human-to-human models most closely resembled the actual spread patterns in the nine real studies that they investigated, indicating that rats might not have been involved at all.
A study published in 2011 supports this conclusion. Authors say that the spread of the plague was too fast for rats to have been an intermediary, and furthermore, researchers should have found more dead rats that had succumbed if they were such important disease-carriers.
Another study in 2015 criticized the idea of rats as reservoirs of disease, claiming that the weather was too cold and rainy for rats to thrive and spread the disease widely. And an ecological review in 1986 cited a general lack of evidence for rats as the carriers of the disease.
However, exonerating the rats is likely to prove controversial among historians, who believe that the bacteria must have at least come from rats, or some other animal carrying fleas, at some point. The researchers at Oslo admit that their computer simulations could use more data, according to National Geographic. The more data a program has, the more accurate simulations it can run.
Notably, the Black Death lost its grip when people started improving sanitation and cleaning themselves regularly, and covering sewers.
The U.S. Centers for Disease Control and Prevention reports in May 2015, Yersinia pestis, the bacterium that causes plague, was identified in dead Piute ground squirrels (Urocitellus mollis) reported through the Idaho Department of Fish and Game’s wildlife mortality monitoring program; in June 2015, the Idaho Division of Public Health (DPH) sent an advisory to veterinarians in four southwestern Idaho counties requesting that they notify their local public health officials of suspected plague in animals.* Y. pestis was not confirmed in any pets during 2015.
During May 30–July 26, 2016, local veterinarians notified public health officials that five dogs and 12 cats were being evaluated for possible plague. Local veterinarians also performed necropsies, when applicable, to establish the diagnosis. Idaho’s Central District Health Department and Eastern Idaho Public Health coordinated with DPH on submission of specimens to the DPH Bureau of Laboratories for Y. pestis testing and interviewed veterinary staff and pet owners. Specimens from blood, spleen, liver, and lymph nodes were screened using real–time polymerase chain reaction and confirmed by culture and phage lysis testing.
Among evaluated animals, Y. pestis was isolated from six of 12 cats; five of the six were from areas in southwestern Idaho where dead ground squirrels with confirmed Y. pestis had been reported in May 2016, and one was from from eastern Idaho. Among these six cats, specimen collection occurred during May 31–July 12, 2016; cats ranged in age from 10 months to 14.5 years (median = 4 years), four (67%) were male, five (83%) resided both indoors and outdoors, and one resided outdoor only. All six cats were domestic shorthair breed and had been neutered or spayed. Fever and lymphadenopathy (n = 4, 67%) were the most commonly reported signs of illness. None of the cats had known pulmonary involvement. Three of the six cats were treated with appropriate antibiotics (1); of these, two survived and one was euthanatized. The three other cats had died or had been euthanatized. All six cats reportedly had contact with ground squirrels and other wild rodents or rabbits before becoming ill; one had flea control administered before illness onset.
Cat owners, their household members, and veterinary staff were advised to be alert for fever and other plague symptoms (2) in themselves and other pets that might have had contact with the ill cats. Veterinary staff members were reminded about methods to prevent occupational exposure when managing pets suspected of having plague (1). In June 2016, an updated plague advisory was sent to veterinarians in four southwestern Idaho counties and eight eastern Idaho counties.† Local public health districts used the Idaho Health Alert Network to enhance situational awareness among health care providers and issue guidance on management and reporting of plague cases. Public communication strategies to raise awareness about the risk for and prevention of Y. pestistransmission to persons and pets included an online map of plague-affected areas, warnings posted in affected public areas, and press releases advising residents about preventive measures. No human plague cases were reported.
Cat-associated human plague cases, including fatalities, have been reported in the western United States since 1977 (3). Compared with dogs, cats are highly susceptible to plague illness and can transmit disease to humans directly through exposure to respiratory droplets and infectious body fluids associated with bites or scratches (1). Cats could also carry infected fleas into households. Y. pestis–infected cats usually develop fever, anorexia, lethargy, and lymphadenitis (submandibular in approximately 75% of cases); approximately 10% of cases are pneumonic (4) and present the most risk to pet owners and veterinary staff members. During 1926–2012, six (43%) of all primary pneumonic cases of human plague that occurred in the United States had contact with domestic cats (5). No plague vaccine for pets is available.
Veterinarians should consider the diagnosis of plague in pets, including cats, with compatible signs and exposure to rodent habitats, rodents, or ill pets in areas where plague is endemic or epizootic. Suspicion of plague should trigger the following actions by veterinary staff: 1) implementation of personal protective measures, including wearing masks and gloves; 2) isolation of the ill pet; 3) assessment of pulmonary involvement; 4) initiation of diagnostic testing for Y. pestis; 5) prompt administration of antibiotic therapy; 6) implementation of flea control for affected animals and the hospital environment; 7) provision of advice on household flea control to pet owner; and 8) notification of public health officials (1). Pet owners can reduce the risk for plague in pets by controlling pet roaming, implementing a flea control program, and minimizing rodent habitats and food sources inside and outside the home. Additional information on prevention of plague is available at http://www.cdc.gov/plague/prevention/index.html.