In an update on a report late last week concerning a “probable” plague-related death in a 52-year-old Santa Fe County woman, New Mexico health officials tell Outbreak News Today that the case has been confirmed positive for Yersinia pestis, the first human plague case and death in 2015.

Oriental rat flea, Xenopsylla cheopis/CDC

Details on how the woman contracted the lethal bacterial disease has not been disclosed and the investigation is ongoing.

In New Mexico, there were two human plague cases in 2014, four human plague cases in 2013 with one fatality, one human plague case in 2012, two human cases of plague in 2011, and no cases in 2010.

The Centers for Disease Control and Prevention (CDC) says an average of seven human plague cases have been reported each year (range: 1–17 cases per year) in recent decades. Over 80% of United States plague cases have been the bubonic form. It is not noted the form of plague the Santa Fe County woman had.

Most human cases in the United States occur in two regions: Northern New Mexico, northern Arizona, and the southern Colorado region and the California, southern Oregon, and far western Nevada region.

Plague is a disease that affects humans and other mammals. It is caused by the bacterium, Yersinia pestis. Humans usually get plague after being bitten by a rodent flea that is carrying the plague bacterium or by handling an animal infected with plague.

New Mexico has reported eight animal plague cases as of June 27–3 in dogs, 3 in cats and 2 in wild animals.

There are three forms of plague:

  • Bubonic plague: Patients develop sudden onset of fever, headache, chills, and weakness and one or more swollen, tender and painful lymph nodes (called buboes). This form is usually the result of an infected flea bite. The bacteria multiply in the lymph node closest to where the bacteria entered the human body. If the patient is not treated with appropriate antibiotics, the bacteria can spread to other parts of the body.
  • Septicemic plague: Patients develop fever, chills, extreme weakness, abdominal pain, shock, and possibly bleeding into the skin and other organs. Skin and other tissues may turn black and die, especially on fingers, toes, and the nose. Septicemic plague can occur as the first symptoms of plague, or may develop from untreated bubonic plague. This form results from bites of infected fleas or from handling an infected animal.
  • Pneumonic plague: Patients develop fever, headache, weakness, and a rapidly developing pneumonia with shortness of breath, chest pain, cough, and sometimes bloody or watery mucous. Pneumonic plague may develop from inhaling infectious droplets or from untreated bubonic or septicemic plague that spreads to the lungs. The pneumonia may cause respiratory failure and shock. Pneumonic plague is the most serious form of the disease and is the only form of plague that can be spread from person to person (by infectious droplets).

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