“Rabbit fever” cases rise in US as CDC warns of zoonotic bacterial disease

Cases of tularemia, also known as “rabbit fever,” are on the rise in the U.S., according to a new report from the Centers for Disease Control and Prevention (CDC).

Caused by bacteria Francisella tularensisthe disease commonly infects rabbits, hares and rodents.

However, it is zoonotic, meaning it can spread from animals to humans.

The bacterium is a “Tier 1 select agent,” a classification given to agents and toxins that “pose the greatest risk of intentional misuse with significant potential for mass casualties or devastating effects on the economy, critical infrastructure, or public trust , and pose a serious threat to public health and safety,” according to the CDC.

Although tularemia is relatively rare, with only 2,462 diagnoses between 2011 and 2022, cases have increased 56% compared to the previous decade (2001-2010), as reported in the CDC’s Morbidity and Mortality Weekly Report.

“The increase in reporting of possible cases may be associated with an actual increase in human infection, improved detection of tularemia, or both,” the report states.

Daniel Ruderfer, MD, chief of the Division of Pediatric Infectious Diseases at Hackensack Meridian K. Hovnanian Children’s Hospital in New Jersey, believes the increase in cases is largely due to improved microbiology detection methods.

“The traditional method of confirming cases has historically been through culture growth and antibody testing,” he told Fox News Digital.

“However, newer detection methods, such as PCR testing, are likely to be a major contributor to the increase in reported cases.”

People can contract the disease through bites from deer flies or ticks, contact with infected animals or exposure to contaminated water or aerosols, the same source said.

Symptoms of tularemia can vary depending on the type of disease.

Common symptoms include chills, headache, malaise, fatigue, anorexia, myalgia, chest discomfort, cough, severe sore throat, vomiting, diarrhea and abdominal pain, according to Ruderfer.

“Depending on the location of the infected bit or scratch, people can develop localized lymphadenopathy (enlarged lymph nodes) and a skin ulcer at the site of infection,” he said.

Other manifestations include conjunctivitis, pneumonia, and potentially bloodstream infections.

The death rate from the disease is usually low, less than 2%, but the CDC noted that it can be as high as 24% in rare and severe cases.

Tularemia can be treated with antibiotics, but there is currently no vaccine.

“The infection is absolutely dangerous and potentially life-threatening if not treated with appropriate antibiotics,” Ruderfer said.

According to the report, those most at risk include children ages 5 to 9, older men, American Indians and Alaska Natives, and those living in the central US states.

The general population is not at a “significant” risk of infection unless they come into physical contact with an infected rabbit, tick or deer fly, the expert noted.

Those who routinely hunt or interact with rabbits should see a doctor if they develop any worrisome symptoms, he advised.

“Many factors may contribute to the higher risk of tularemia in this population, including the concentration of Native American reservations in the central states and sociocultural or occupational activities that may increase contact with wildlife or infected arthropods,” the CDC wrote. .