Avian flu: Virus with an Eggshell.

Avian flu: Virus with an Eggshell. Avian flu can be transmitted from birds to humans; transmission among humans, however, is limited. The reason may be an eggshell-like mineral layer that the virus acquires due to the high calcium concentration in the intestines of birds. As reported by Chinese researchers in the journal Angewandte Chemie, these mineralized viruses are significantly more infectious and, in addition, more robust and heat stable than the native viruses. Avian flu is a highly infectious disease among birds that has developed into a serious threat to human health. Close contact with diseased birds or their feces is considered to be the primary source of infections in humans. Transmission between humans is limited, however, which indicates that these viruses cannot directly infect humans. Previously it was assumed that these viruses crossed the species barrier as a result of mutation or recombination with another pathogen. More recent results demonstrate that avian flu viruses isolated from infected humans have the same gene sequences as those from birds.Avian flu: Virus with an Eggshell. So how is it that humans catch the disease from birds? Researchers working with Ruikang Tang at Zhejiang University (Hangzhou, China) claim that it is because the viruses acquire a mineral "shell" in the bird intestines. They discovered that viruses can become mineralized under calcium-rich conditions. Naturally, the digestive tract of birds--the primary location of avian flu viruses--provides just such a calcium-rich environment, so that the birds can make egg shells.Avian flu: Virus with an Eggshell. Experiments with a solution that imitates the bird intestine environment allowed the researchers to demonstrate that 5 to 6 nm shells of a calcium phosphate mineral form around H9N2 and H1N1 viruses. In both cell cultures and mice, these mineralized viruses proved to be significantly more infectious--and deadly--than the native viruses. In humans, avian flu viruses infect the airways and are then found in bodily fluids, where the calcium concentration is too low for mineralization.

Breeding Resistant Chickens for Improved Food Safety.

Breeding Resistant Chickens for Improved Food Safety. A recent test developed by Agricultural Research Service (ARS) scientists in College Station, Texas, could make it easier to breed pathogen-resistant chickens. The test identifies roosters whose blood contains naturally high levels of two key chemicals, cytokines and chemokines. These chemicals mobilize the birds' innate immune response, according to ARS microbiologist Christi Swaggerty, in ARS's Food and Feed Safety Research Unit. Using the new test, commercial poultry breeders can single out roosters that have a strong immune response and use them to selectively breed a more robust flock. Such resistance, especially during the birds' first week of life, may lower costs related to animal well-being and food safety. Protecting chickens from pathogens involves sanitation, vaccination, biosecurity and use of antibiotics and other medications. But some chickens have an especially robust and efficient immune response and can resist pathogens, notes Swaggerty.

TB a leading cause of death among children worldwide.

TB a leading cause of death among children worldwide. Tuberculosis ranks among the top 10 causes of death among children around the world, a mathematical modeling study showed. Researchers wrote that the disease represents a “key omission” from analyses of mortality in children aged younger than 5 years. “The UN Inter-agency Group on Child Mortality Estimation tracks overall under-5 mortality, and breakdowns by cause of death have been estimated by the study group formerly known as the Child Health Epidemiology Reference Group, most recently in 2016,” Peter J. Dodd, PhD, of the University of Sheffield, UK, and colleagues wrote. “These estimates have been important in assessing progress toward targets, directing public health funding and spending and for advocacy. However, tuberculosis has never been explicitly mentioned in these reports. The researchers used a mathematical model to estimate deaths of children aged younger than 5 years in 217 countries and territories. Dodd and colleagues disaggregated WHO pediatric TB estimates by age, as well as treatment status and HIV status, using pediatric TB notification data and pediatric ART estimates. Most deaths –more than 70% – occurred in southeast Asia and Africa (n = 182,000; 95% CI, 140,000-239,000), the researchers reported. Seventeen percent (n = 39,000; 95% CI, 23,000-73,000) of children who died had HIV, with 31,000 of those children living in Africa (36%; 95% CI, 19,000-59,000). The vast majority of children who died (96%; n = 230,000; 95% CI, 185,000-289,000) did not receive treatment for TB, Dodd and colleagues wrote. The large mortality burden of undiagnosed pediatric tuberculosis should … not spur hopelessness, but action; these new estimates identify a prime opportunity to address an under-recognized and preventable cause of child deaths.

Surge in human H7N9 cases caused by poultry, not people.

Surge in human H7N9 cases caused by poultry, not people. New study findings indicate that the recent surge in human influenza A(H7N9) cases in China is probably due to increased spread from poultry to people and not because of a swell in human-to-human transmission. With a case fatality rate of around 40%, experts consider H7N9 to be one of the most troubling infectious disease threats in the world because of its potential to cause a deadly pandemic. So far, most of the more than 1,500 human cases since 2013 have been transmitted from poultry, not people. Since 2013, China has been struck by five epidemics of H7N9, the most recent one being by far the largest and most widespread. In addition to a record number of human cases, the fifth epidemic produced evidence that the virus had split into two strains, including one that was no longer susceptible to the old vaccine and was becoming harder to treat. The CDC developed a new vaccine, replacing the old one that was based on viruses taken after H7N9 emerged in 2013.

Many health care workers do not know correct influenza precautions.

Many health care workers do not know correct influenza precautions. In a small survey conducted at a St. Louis hospital, many health care personnel could not describe the correct transmission-based precautions for patients with influenza, and some even said they had reservations about the safety and effectiveness of the influenza vaccine. Hilary M. Babcock, MD, MPH, associate professor of medicine in the division of infectious diseases at Washington University School of Medicine, and colleagues surveyed 170 full- and part-time health care personnel (HCP) at a long-term care (LTC) facility with a mandatory influenza vaccination policy. Just 73 people responded to the survey. Among those, 42 reported closer contact with patients — including many nurses — and 21 said they had less patient contact working in jobs such as food service worker and administrator. Skip to main content

What PED taught us about handling future disease outbreaks.

What PED taught us about handling future disease outbreaks. The porcine epidemic diarrhea virus (PEDV) outbreak that devastated many US hog farms over the past 4 years served as a wake-up call for the pork industry to be more vigilant against foreign animal diseases.

 “We know what to do in the case of foreign animal diseases, like foot-and-mouth disease, classical swine fever and African swine fever,” Dustin Oedekoven, DVM, South Dakota state veterinarian, said. He thinks the industry also has a “fairly clear direction” about how to handle future investigations and where to submit diagnostic samples.

 A gap that became evident with the PEDV outbreak is we weren’t working in a coordinated manner to control the spread of the disease. As a result, it spread very rapidly because the swine industry was very naïve to the virus.

 Veterinarians worked with producers to identify the critical problems. Samples were submitted to diagnostic labs for routine workup.  When the expected diseases weren’t found, the labs initiated additional diagnostic tests and were able to identify PEDV.

 Other diagnostic labs worked collaboratively to develop a rapid test to identify the virus. However, a break in communications caused a gap in timely response to the disease.

PEDV and other pathogens survive in feed for weeks.

PEDV and other pathogens survive in feed for weeks.In 2013-2014, infection of pig farms with porcine epidemic diarrhea virus (PEDV) was a frequent event, even on farms using the highest level of biosecurity. Investigations into the occurrence showed one common denominator across many of these farms which was feed outage in a specific subpopulation of animals, requiring an emergency feed delivery to a specific bin onsite. The pigs consuming the feed from the emergency delivery were the first to become infected. Samples from inside the suspect feed bins were collected and sent to a diagnostic lab for testing. The results showed the feed did contain live PEDV, an outcome that had not been confirmed before.