Here’s why — and how much — we should worry about the plague today

The plague – alias the black Death, alias the Great Pestilence – is rarely contracted today, but it recently infected a resident of South Lake Tahoe. But before putting your “purifying” beak from the 17th century, let’s discover experts why this disease is still there and how dangerous it is now.

Most people associate the term “scourge” with the massive and destructive event that killed 25 million Europeans in the Middle Ages, said Professor John Swartzberg of the UC Berkeley Public Health School. In the 14th century, the plague killed up to 50% of the European population.

“The plague is really a specific disease that has … in our human history [reared] His ugly head and caused massive deaths, “said Swartzberg, who works in the university’s disease and vaccinology division.

This can be a threat from the past, but it continues to be a very serious illness, with a small number of cases each year.

In the recent case of the South Lake Tahoe resident, it is believed that the person contracted rare disease after being bitten by an infected chip during camping in the region, according to health officials of the County of El Dorado.

The most recent case in front of it was reported in the county of El Dorado in 2020 and was also transmitted in the same area, officials said. Two cases of plague were reported in California in 2015, suspected of having been caused by bites of a chip or a rodent infected in Yosemite National Park.

Even if medical progress has made deadly disease treatable, it has not been eliminated.

Contract the plague, even today

The plague is caused by the bacteria Yersinia Pestis And mainly affects small animals or rodents in the United States, said Swartzberg.

There are three types of plague:

• Bubonic plague, with the brand swollen lymph nodes from the brand;
• Septicemic plague, when the infection spreads throughout the body;
• Plague pneumonic, which infects the lungs.

It can spread to humans and pets from the bite of an infected chip or to come into close contact or manipulation of an infected rodent.

The plague was introduced in the United States at the beginning of the 20th century from steam infested with rats arriving in California from Asia, with the first case identified in the San Francisco region, said Swartzberg.

To date, the latest known case of the plague associated with rats occurred in Los Angeles in the 1920s, according to public health officials.

Today, the main source of plague in the County of Los Angeles is wild rodents in rural areas.

Most people who contract the plague do this during hiking or camping, and in these areas, they are unconsciously bitten by an infected chip, said Ashok Chopra, professor of microbiology and immunology at the medical branch of the University of Texas.

Animals live in much higher concentrations in rural areas, where they are closest to other creatures and habitats, which facilitates the prosperity of the bacteria, said Swartzberg.

Wooded creatures that could carry the disease and should be avoided include tamias, wooden rats, mice and marmots.

Where the plague could be contracted in Socal

In California, public health officials say that the plague takes place in the buttresses, the sets, the mountains and along the coast. It is largely absent from the southeast desert region and the central valley.

There is the potential for exposure in the County of Los Angeles, but the areas where the risk is the highest are the recreational areas and rural wilderness of the National Forest of Angeles and the Mountains of San Gabriel, said county officials.

People and their pets can get the plague if they visit or live in areas where wild rodents are naturally infected, according to the Los Angeles Public Health Service. People who live in close contact with rats are also more likely to get rodent disease possibly infected.

It is not uncommon for dogs and cats to be infected because pets have fleas. An infected chip, although rare, can weaken pets, which are vulnerable to the disease, said Chopra.

Why the plague remained

The United States has only eradicated one human infectious disease, which is varied, and this has been done by vaccination, according to the centers for Disease Control and Prevention.

There have been several vaccination candidates to ward off the plague, but at that time there are no inoculations approved by the Food and Drug Administration for the disease, said Chopra.

“We do not know how to eradicate an infection in a population of mammals which is propagated by a vector like the chips,” said Swartzberg, “so I do not see us being able to eradicate this at the moment of our history.”

But the plague is not an absolute priority for experts in infectious disease or public health officials because it is under control.

“Elimination means that the infection has disappeared in a geographical area and that there is no localized transmission,” added Swartzberg, “we have almost eliminated the plague as a serious problem.”

So how much should we worry? If we receive a timely treatment, there is little to fear, according to experts.

The plague can be treated with antibiotics, said Chopra, but if it is not treated, it can be fatal.

“If the infection is overwhelming,” he said, “then bacteria can spread fairly quickly in the blood circulation, then it becomes very dangerous.”

The staff writer Clara Harter contributed to this report.