antibiotic Drug-resistant 'super typhoid' now spreading globally

Drug-resistant 'super typhoid' now spreading globally

(NaturalNews) A multi-antibiotic-resistant strain of deadly typhoid fever has spread from Asia to Africa, where it might have reached epidemic proportions, warned an international research team in a study published in the journal Nature Genetics on May 11.

The 74 researchers from nearly two dozen countries, who performed one of the most comprehensive genetic analyses ever conducted on a human infectious agent, concluded that a strain of Salmonella Typhi known as H58 poses an "ever-increasing public health threat."

"H58 is displacing other typhoid strains, completely transforming the genetic architecture of the disease and creating a previously underappreciated and on-going epidemic," the researchers said in a statement.

Nearly half of samples resistant to multiple drugs

People contract typhoid fever through food or beverages contaminated with urine or fecal matter from infected people, some of whom may be asymptomatic carriers. The disease's symptoms are vague, including fever, chills, headaches, and constipation, which can make diagnosis difficult. When left untreated, it leads to death in about 20 percent of cases.

Although there is a vaccine against the disease, its high cost prevents its use in the poorer countries where typhoid fever is more common. Instead, people in those countries typically treat the disease with antibiotics or even seek to prevent it by taking antibiotics before they become ill.

This widespread antibiotic use has favored the evolution of a potent strain of S. Typhi that is resistant to all frontline antibiotics as well as many newer drugs such as ciprofloxacin and azithromycin, the researchers found. They genetically sequenced 1,832 separate samples of the bacteria collected from 63 countries from 1992 to 2013. A full 47 percent of the samples came from the H58 multidrug resistant strain. The data showed that in recent years, H58 has actually been pushing out other strains, some of which had been dominant in their regions for hundreds of years.

"We were all amazed at what we saw," said researcher Gordon Dougan of the Sanger Institute. "When you see the data, it's pretty stark. It's very convincing that it's becoming the dominant strain. This is one of the first pictures we've had of how antimicrobial resistance is impacting on the way we treat infectious diseases, and how we will have to tackle them."

Unrecognized epidemic

The analysis showed that H58 emerged in South Asia approximately 30 years ago and spread from there to the rest of Asia as well as Fiji and eastern and southern Africa. The strain has apparently crossed to Africa from Asia several times in the past few years, and it appears to have already have caused previously unreported epidemics in several African nations.

"The most striking thing to me is that typhoid was previously considered a disease of Asia, not Africa," Dougan said. "This has transformed the global epidemiology. This beast can get into a new area and it's at an advantage, because a lot of competition is wiped out by antibiotics.

Various S. Typhi strains have always been able to trade genetic material as they pass from person to person, and this process has led to antibiotic resistance since at least the 1970s, said researcher Kathryn Holt of the University of Melbourne. In the past, however, these traits were short-lived. In H58, they seem to have become permanent, "which means multiple antibiotic resistant typhoid is here to stay," she said.

Even conventional typhoid is already a major global killer, the researchers warned.

"This is killing 200,000 people a year and no one is really noticing," said co-author Nick Feasey of the Liverpool Tropical School of Tropical Diseases.

Typhoid fever spreads readily following major disasters, and the researchers expressed concern that H58, which is found in Kathmandu, could cause a wave of new infections following the recent massive earthquake in Nepal.


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