[ad_1]
The first known case of rats is a long-standing patient who has a long-standing mystery of how the cryptic viruses spread and bounce between humans and animal reservoirs.
Last Friday, September 28, Researchers at the University of Hong Kong revealed that a 56-year-old-man had contracted a strain of hepatitis. Hepatitis E viruses, generally, causes inflammation in humans that is usually self-limiting but can be severe or even fatal to some, including organ transplant patients and pregnant women.
Researchers spotted the man's infection back in September of last year, after he had undergone a liver transplant in May. They reported that the virus was infected by this virus, which they verified the presence of the unexpected virus and its source.
In the course of their work, the researchers ruled out the possibility that the man was infected with his organ or blood donors. Instead, the researchers noted evidence of an infestation near the man's home garbage chute. Testing of at least one rat in the neighborhood in recent years had positive hepatitis E, the researchers reported.
Yuen Kwok-yung, of the University of Hong Kong, describes the case of "a wake-up call" in a press conference. He said some of the city's rats had become larger and better off.
While the suggestion may not be a bad idea, there is no need to panic, yet, according to hepatitis E expert X.J. Meng of the VA-MD College of Veterinary Medicine. "This has never happened before," Meng noted of the virus jumping from a rat to a human. It's "unprecedented" he went on to say in an interview with Ars. "Regardless, I do not personally think this [case] is a major public health issue. "
Still, the news does spotlight the lingering mystery around the little-known form of hepatitis.
Enigmatic infections
Meng notes hepatitis E from rats could spread to humans-it has been a piece of the long-standing puzzle surrounding how the virus spreads. Generally, the transmission tests were done by the virus from rats to non-human primates or pigs in labs. So far, all of the attempts have failed. And, Meng explains, we know that rat hepatitis E-like the rest of its ilk-spreads through a fecal-oral route, which works exactly as it sounds. Essentially, for the rat virus to become a major source of infection, it is likely to be a significant amount of a contaminating source of drinking water, he speculated.
In the case of the 56-year-old man in Hong Kong, Meng speculates it was just an unlucky twist of fate that he got the "first infected" title. His immune system has been transplanted following the liver, making him much more susceptible. And it seems he just happened to have a high chance of exposure from his environment.
Still, the rare rat case has not been treated for many years.
Researchers have long documented that human viruses cause outbreaks of acute liver inflammation in developing countries, typically in cases where fecal contamination seeps into water sources. The human viruses cause an estimated 20 million infections in the world, according to the World Health Organization.
But in the late 1990s, researchers started noticing that surprisingly high numbers of blood donors in the US and other countries were shown with anti-hepatitis in their blood (which is typically evidence of a past infection). The researchers could not figure out why they are being exposed to the viruses, absent international travel.
The findings may have somehow come down with subclinical infections that are clear on their own, Meng said. But if they did have the infection, it was unlikely we would be able to figure it out. When they are treating inflammation or other viral illnesses, they tend to think of the other hepatitis viruses first, A, B, and C-but not E, he said. "This disease is grossly under-diagnosed in many countries," and "we do not have an FDA-approved diagnostic test" for it, he added. If we did, "I'm sure you're going to see more cases reported in the clinics."
The lack of diagnosis is part of a larger problem, Meng notes. "This is a very important public health pathogen, but it is extremely under-studied. There are very few labs that study this virus. "
Germ germ
The few researchers, however, have shown that there are at least four types of hepatitis that infect humans, aka HEVs. They are HEV genotypes 1, 2, 3, and 4. Researchers have collected genetic evidence that these HEVs can also infect a variety of animals, including pigs, wild boar, deer, rabbits, mongoose, chickens, camels, ferrets, greater bandicoots Asian musk shrew, mink, moose, and fish. HEV G3 and G4, in particular, have been found to spread directly from pigs and wild boar to humans.
There are other strains (HEV-like strains) that infect rats and ferrets. These are genetically different from the HEVs, Meng points out, and there has been no evidence (except for the new case) that rat hepatitis can spread from rats to humans. The genetic analysis of the strain of infecting the patient in Hong Kong has not been published yet, but reported that it was "highly divergent" from the strains that infected humans.
Yet, in recent years, there have been numerous controversial reports of rats being able to catch-up and potentially spread-the HEVs themselves. This would be a problem of how humans, particularly in rural areas of developed countries, may be exposed to HEVs.
In 2010, researchers reported molecular evidence of HEV infections in wild rats in Hamburg, Germany. In subsequent years, HEV in wild rats in Los Angeles and more specifically, HEV G3 in wild rats from various places in the US. Still, researchers' attempts to infect rats in labs with HEV have been hit or miss. And-except for the new case in Hong Kong – no one has gone through the hops from rats to humans.
In a 2016 article, Meng noted that we can not know enough about hepatitis E viruses to figure out what's going on. We may only have a glimpse of their genetic diversity in the wild, and we still do not understand their life cycles. "Significant progress in HEV research," Meng concluded, "but many important questions remain."
Source link
