In the first study of its kind in nearly a full century, researchers have found that rats in New York City are still hosting fleas that can carry dangerous plague pathogens. But don't panic just yet. The infamous Black Death, which still exists in the United States, was not found in these fleas, meaning that professionals simply need to be vigilant.

"If these rats carry fleas that could transmit the plague to people, then the pathogen itself is the only piece missing from the transmission cycle," Matthew Frye, an urban entomologist with Cornell University's New York State Integrated Pest Management (IPM) Program, explained in a recent statement.

This was discovered after Frye and his colleagues collected more than 6,500 specimens of five well-known species of fleas, lice and mites from 133 rats in the Big Apple. Among them, 500, or about eight percent, proved to be Oriental rat fleas - bugs notorious for their role in transmitting the bubonic plague. The results were published in the Journal of Medical Entomology.

[Nature World News recently reported how it was gerbils, not rats that likely were responsible for carrying these little pests and their deadly pathogens across seas. You can read more about that here.]

What's more, the researchers warn that while bubonic plague isn't prevalent in the eastern United States, it still exists in North America. The plague can be found most commonly in the American Southwest, circulating not among rats, but among ground squirrels, prairie dogs and the fleas they harbor. It even affects about 10 US citizens annually. (Scroll to read on...)

Thankfully, according to the World Health Organization (WHO), the same Black Death that killed up to 200 million people between 1346 and 1353 is now one of the most harmless and treatable 'fatal' illnesses today, as it is easily slain by common antibiotics. Health organizations even suspect that minor cases of plague often go unreported in developed countries, and are treated as a potential bacterial infection without ever being identified.

That means that even if the disease happens to make its way into NYC, physicians will be prepared. It won't even be the first major US city to host plague. According to the US Centers for Disease Control and Prevention (CDC), a flea-associated plague actually broke out in Los Angeles in 1924-1925, and has been circulating among local rodent populations ever since.

However, the plague wasn't the only disease of concern. Co-author Cadhla Firth and her colleagues used molecular screening methods to look for two other pathogenic bacteria the Oriental rat flea could vector: Rickettsia and several species of Bartonella.

And while they did not find evidence of Rickettsia, some versions of Bartonella, such as the common cat-scratch-fever, were identified.

"These pathogens can cause a wide range of clinical syndromes, some severe," she explained, warning that even city-folk should be wary of contracting illnesses often associated with road-kill or rural life.

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