The Associated Press is reporting the Centers for Disease Control (CDC) released a report on January 8, 2016, detailing the investigation and the findings.
In the CDC’s Morbidity and Mortality Weekly Report, the employees were described as having a latent form of the respiratory disease while experiencing no symptoms.
The investigation ultimately identified three bull elephants with active tuberculosis, and 118 human contacts. A total of 96 humans were evaluated with seven of those individuals being found to have latent TB infection. The three elephants were treated for the infection, with two of them subsequently dying from other causes, and not the TB, according to Fox News.
Dr. Jennifer Vines, the deputy health officer for Multnomah County, Oregon said the CDC report adds to our thin knowledge of the transmission of tuberculosis from elephants to man. The CDC also pointed out that tuberculosis is but one of a number of diseases that can be transmitted from animals to humans that include bird flu, mad cow disease, and West Nile virus.
The report also said that approximately five percent of captive Asian elephants in North America are infected with tuberculosis. Tuberculosis can be transmitted to humans by close contact with elephants, as well as through droplets released by coughing or sneezing.
In a discussion of the findings, the CDC says the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service has developed guidelines for the screening and diagnosis of TB in captive elephants, including annual trunk wash samples, but this method of diagnosing TB in elephants can sometimes lead to erroneous results.
The CDC is recommending that further studies be done into the modes of TB transmission between humans, elephants, and other animals, as well as establishing better collaboration between public health, veterinary medicine, and occupational health experts in better understanding the risks for and prevention of zoonotic transmission of M. tuberculosis. The World Health Organization (WHO) defines zoonosis as an infection “shared in nature by man and animals.”