Schmallenberg virus harmless to humans

Animal disease by Schmallenberg virus no threat to humans

06/04/2012

After a large number of infections with the hitherto unknown Schmallenberg virus in cattle, sheep and goats had occurred in the past year, the Robert Koch Institute (RKI) has now investigated the risks of transmission to humans.

As the RKI reports, even in persons who were in close contact with infected herders, no infection by the Schmallenberg virus could be detected. There is no evidence that "infections or even human diseases could occur due to the Schmallenberg virus ", Says the current RKI communication.

More than 1,000 farms affected by infections with Schmallenberg virus
In the middle of last year more and more cattle, sheep and goats fell ill with a mysterious animal epidemic, which was accompanied by fever, loss of appetite and a strong milk decline. In November 2011, the Friedrich-Loeffler-Institut (FLI) as competent federal research institute for animal health was able to detect an infection with hitherto unknown viruses in the examined samples. After the origin of the samples the pathogen Schmallenberg virus was baptized. Although the infection in most animals was rather harmless and did not cause any long-term health problems, caution was warranted. Because with the infected animals the complaints piled up when they were pregnant. The offspring increasingly suffered from malformations and the probability of premature or stillbirths increased significantly. Also, the viruses could endanger the reproductive ability as a whole, the FLI explained after the virus was discovered. According to information from the Friedrich-Loeffler-Institut, the number of affected farms has risen to more than 1,000 since the first detection of the pathogens, more than 800 of them are sheep husbandry ", according to the latest release of the RKI.

Contagion risk in humans by the Schmallenberg virus checked
Therefore, the Robert Koch Institute has now examined to what extent a risk of infection by the Schmallenberg virus in humans exists. As a "precautionary measure", the RKI claims to carry out a "study on shepherds, as they have the most contact with the new pathogen." At the end of February, on the sidelines of an information event in North Rhine-Westphalia, 60 sheep farmers and one cattle farmer were questioned about possible disease symptoms , In addition, the RKI experts took blood samples from the volunteers, which were tested for antibodies against the Schmallenberg virus. "Such antibodies would have been evidence of infection with the virus," but none of the subjects could be detected, said the RKI in his press release "No indication of Schmallenberg virus in humans" (here). In order to exclude infection with the Schmallenberg virus also in the subjects who complained of nonspecific symptoms, such as fever or headache, they also carried out a so-called PCR test, with which the viruses can be detected directly. This was also negative, reports the RKI. Overall, "the results of the RKI study show that the new virus has not led to infection in people with much pathogen contact," said the President of the Robert Koch Institute, Reinhard Burger.

Very rare infectious events not recorded
However, the Robert Koch Institute limited that in the current study very rare infection events are not considered. Although "a comparatively high number of people with intensive contact with the pathogen were investigated", "very rare infection events can not be detected with such a study," according to the RKI. Overall, however, the risk of human infection based on the current study results and the genetic characteristics of the new virus can be estimated as extremely low. It is not to be feared that the pathogens will spill over to humans, such as swine flu or H5N1 virus infections (bird flu).

Virus with new genetic and animal characteristics
According to the Friedrich Loeffler Institute for Animal Health, the Schmallenberg virus belongs to the genus of the so-called Orthobunya viruses, which are widespread in "Oceania, Australia and Africa" ​​and "usually initially only cause a very mild clinical condition" whose symptoms usually go back after a relatively short time. In pregnant animals, however, threatened according to the FLI "significant congenital damage" of the offspring and "prematurity and disorders in fertility events." Since the "closest relatives" of the virus - three representatives of the Simbu serogroup - in humans do not trigger infections were Experts already convinced before the current investigation of the RKI that the viruses pose no threat to humans. However, the Schmallenberg virus has "new genetic and animal-related clinical epidemiological characteristics," which required a more detailed study to rule out any risks, the RKI said. (Fp)

Also read:
Schmallenberg virus metabolic mosquitoes discovered
Schmallenberg virus continues to spread
Schmallenberg virus: More and more lambs affected
Unknown virus discovered in cattle

Image: macro depilatory