In what was once a leading cause of death in the US, tuberculosis or TB is thankfully on the decline. With the emergence of effective antibiotic treatments, overall cases have shrunk dramatically here on American soil, while much of the world still suffers from its often fatal effects.
Being the cause of roughly 1.3 million deaths worldwide in 2022, TB is still a cause for concern, even if the US only tallied up 8,000 cases in that same year.
TB is typically contracted via the M. tuberculosis bacteria which is spread through the air by infected people. A recent study published in Clinical Infectious Diseases has uncovered another mycobacterium causing infection, linked to the most popular game animal on the planet.
The study, authored by James Sunstrum, who is the infectious disease specialist at Corewell Health Dearborn Hospital, has discovered that three confirmed cases and one suspected case in Michigan are leading back to infection by the M. bovis mycobacterium.
“This form of tuberculosis is called bovine tuberculosis, which used to be a major problem in cattle throughout North America,” Sunstrum said. “It was virtually eliminated, but there is a stubborn, small focus in Northern Michigan, near the city of Alpena, where it did not get eradicated and it got established in wild deer. We think that’s one of the potential sources for this popping back into people.”
The earliest detection of M. bovis in Michigan deer dates back to 1997, but was not found to have been transmitted to humans until a case developed in 2002. In that case a deer hunter contracted the disease, leading to seven more infections since. Of those, the study focused on four of the most recent cases, highlighting the contact the patients had with infected cervids.
Of those cases, one of the patients was described as a taxidermist and another is someone that had hand-fed deer. The third patient indicated that they did not have any contact with wild animals or deer and the fourth patient contracted TB from the third.
It was noted that those infected by the mycobacterium often develop latent TB, which is not contagious and often does not present typical TB symptoms. Leading often to misdiagnosis, Sunstrum stated that it was not a time to sound the alarms, but rather a time for educating both the medical community and the public on M. bovis and possible treatments.
“It’s not a cause for panic or alarm, but it is enough justification to educate the public, particularly on handling deer tissues,” Sunstrum said. “There is some effort at educating deer hunters on wearing gloves, for example, when they’re dressing a deer carcass, and also educating hunters on recognizing what might be TB lesions that they might see in the deer lungs.”
