Navigation Links
Avian influenza virus in mammals spreads beyond the site of infection to other organ systems

Researchers at Erasmus Medical Center have demonstrated systemic spread of avian influenza virus in cats infected by respiratory, digestive, and cat-to-cat contact. The paper by Rimmelzwaan et al., "Influenza A virus (H5N1) infection in cats causes systemic disease with potential novel routes of virus spread within and between hosts," appears in the January issue of The American Journal of Pathology and is accompanied by a commentary.

Avian influenza (H5N1) is of great concern because of the current outbreaks in Asia and the potential for pandemic spread. This virus is highly contagious in birds and spreads easily due to the agricultural and migratory nature of the bird species infected, including poultry, water fowl, and other migratory species (See commentary by Brown for more information). While spread of avian influenza from bird to man is known to occur, as first reported during the 1997 Hong Kong outbreak, human-to-human spread is extremely rare. Thus, the disease events that take place during mammal-to-mammal spread are not well characterized.

To assess the spread of H5N1 influenza virus in mammalian hosts, Rimmelzwaan et al. examined cats infected via the respiratory tract, via the digestive tract (by feeding on infected chicks), or by close contact with respiratory-infected cats. The researchers, led by Dr. Thijs Kuiken, then examined mucous membranes (throat, nasal, and rectal swabs) and organ systems (respiratory, digestive, nervous, cardiovascular, urinary, lymphoid, and endocrine) for the presence of virus and viral protein.

As expected, all cats were infected with H5N1 virus and exhibited clinical signs of disease (fever, lethargy, labored breathing, etc.), and virus was detected in throat, nasal, and rectal swabs, regardless of the original site of infection. Most interesting, virus spread throughout the organ systems with virus being found in respiratory and digestive tracts, liver, kidney, heart, brain, and lymph node s. Furthermore, examination of infected tissues revealed cellular damage at sites containing viral proteins, providing an explanation for the increased severity of disease in humans.

These data underscore the potential for influenza virus to spread not only from the respiratory tract but also from the digestive and urinary tracts, greatly increasing the possible routes of mammalian transmission. Systemic disease has long been known to occur in birds, with the fecal-oral route of transmission being most important. However, this is the first demonstration of systemic replication in cats, providing a cautionary tale for humans regarding how influenza is spread and how the disease presents itself.

Rimmelzwaan and colleagues caution that because of the systemic nature of avian influenza, "H5N1 virus infection needs to be included in the differential diagnosis of a broader range of clinical presentations than is currently done." In addition better understanding of the mechanisms of spread, including possible fecal-oral route in humans, "may limit the risk of H5N1 virus developing into a pandemic influenza virus."


Source:American Journal of Pathology

Related biology news :

1. NIAID Initiates Trial of Experimental Avian Flu Vaccine
2. Avian flu transmission to humans may be higher than thought
3. Avian flu modeled on supercomputer, explores vaccine and isolation options for thwarting a pandemic
4. Computers to be used to find blueprint for new influenza drug
5. Less virulent strains of avian influenza can infect humans
6. Drug resistant avian influenza viruses more common in Southeast Asia than North America
7. New vaccine platform may fight infections with causes from influenza to bioterrorism
8. First big influenza genome study reveals flu evolution
9. Web model of influenza-host lifecycles will aid scientists in creating anti-viral drugs
10. New influenza vaccine takes weeks to mass produce
11. Study outlines genetic differences between potential pandemic influenza strains
Post Your Comments:

(Date:11/18/2015)... , Nov. 18, 2015  As new scientific ... children, doctors and other healthcare providers face challenges in ... families and patients. In addition, as more children continue ... a patient,s adulthood and old age. John ... The Children,s Hospital of Philadelphia (CHOP) . ...
(Date:11/17/2015)... 2015 Paris from 17 ... Paris from 17 th until 19 ... innovation leader, has invented the first combined scanner in the ... same scanning surface. Until now two different scanners were required: one ... capture both on the same surface. This innovation is ...
(Date:11/17/2015)...  Vigilant Solutions announces today that Mr. Dick ... --> --> Mr. ... partnership at TPG Capital, one of the largest global ... in revenue.  He founded and led TPG,s Operating Group, ... from 1997 to 2013.  In his first role, he ...
Breaking Biology News(10 mins):
(Date:11/24/2015)... 2015 --> ... released by Transparency Market Research, the global non-invasive prenatal ... of 17.5% during the period between 2014 and 2022. ... Industry Analysis, Size, Volume, Share, Growth, Trends and Forecast ... market to reach a valuation of US$2.38 bn by ...
(Date:11/24/2015)... ... November 24, 2015 , ... In harsh industrial ... points for in-line sensors can represent a weak spot where leaking process media ... of retractable sensor housings , which are designed to tolerate extreme process conditions. ...
(Date:11/24/2015)... Nov. 24, 2015 Capricor Therapeutics, Inc. ... on the discovery, development and commercialization of first-in-class therapeutics, ... Executive Officer, is scheduled to present at the 2015 ... 10:50 a.m. EST, at The Lotte New York Palace ... . --> ...
(Date:11/24/2015)... ... November 24, 2015 , ... Whitehouse Laboratories is pleased ... The new stand-alone facility will be strictly dedicated to basic USP 61, USP 62 ... clients the chance to have complete chemistry and micro testing performed by one supplier. ...
Breaking Biology Technology: