AUSTRALIA is experiencing the biggest outbreak of the highly virulent Hendra virus since the disease was identified in 1994. Worse, a change in the symptoms in horses suggests that new strains may have emerged. The big worry is that a strain capable of spreading from human-to-human will follow.

Hendra virus originated in fruit bats but passed to horses and then people, where it tends to affect the nervous system, causing headaches, convulsions and coma. It can be fatal. As New Scientist went to press, the latest outbreak had infected two people, who remain in hospital, while 50 more are being tested.

Classic horse symptoms are laboured breathing, frothy nasal discharge, a swollen muzzle and death within days. This time, however, horses have mainly suffered neurological symptoms such as paralysis and loss of balance. This, along with "very preliminary sequencing data", suggests that "there is a cluster of strains that differ in their pathogenesis and infectivity", says Hume Field of the Australian Biosecurity Cooperative Research Centre for Emerging Infectious Disease. Such a cluster makes it more likely that a strain that can pass between humans will arise.

comment: well there you have it and just as I thought. We get all hyped about H1N1 and here comes a newbie.

And it has jumped into people. And they are in the hospital and others are being testing. Well..you read it here. When this becomes the next Pandemic- we have yet to see if it will kill those infected. If it does- we may be looking at what Piggy Flu is not yet- highly virulent.

not if, but when

Medclinician

The Hendra virus was first recognised in Queensland in 1994, and since then, infection in horses has sporadically occurred with at least two outbreaks recorded in four of the past five years.

Of the 11 equine outbreaks, four have also led to infection of humans with three of the six known human cases being fatal, the most recent of these in August 2008.

In a project led by Dr Deborah Middleton, from CSIRO’s Australian Animal Health Laboratory, a number of infected horses were studied to determine the early signs of infection and establish how best to manage infected horses and prevent further spread of the disease.

In this podcast Dr Middleton explains how the virus is transmitted from horse to horse and from horse to human, and also the methods for early detection that are being investigated.

  :)        http://www.youtube.com/watch?v=G5dHXzmV24U&feature=related

Nipah As a Biological Weapon

Nipah virus is important as a potential biological weapon (targeted to animals, humans, or both) for the following reasons:

• Even a small outbreak in pigs could result in mass culling of affected herds, thereby causing substantial economic loss to the industry or to the national economy of the affected country.
• Nipah virus can infect humans and the case-fatality rate may be as high as 50%.
• There is no effective treatment or vaccine for the disease in either pigs or humans (although ribavirin may reduce mortality in humans with encephalitis).
• Little is known about Nipah virus, so an outbreak in animals or humans could cause substantial fear and social disruption.

The Centers for Disease Control and Prevention (CDC) has listed Nipah virus as a critical biological agent, Category C. Category C agents are emerging pathogens that could be engineered for mass dissemination in the future because of:

• Availability
• Ease of production and dissemination
• Potential for high morbidity and mortality rates and major health impact

Definition of Encephalitis, Nipah virus

Encephalitis, Nipah virus: Brain inflammation (encephalitis) due to the Nipah virus that infects pigs and people. Nipah is the name of the first village the virus struck near Kuala Lumpur in Malaysia. (The Nipah virus is similar to Hendra virus that was discovered in Australia in 1994.) Sorry Aussies- we are looking at Brisbane 10- and stuff coming out of the Land Down Under- the Equine stuff happened int he last few years and is significant.  Nipah virus caused a severe outbreak of viral encephalitis in Malaysia in 1998-1999.

The main risk factor for Nipah virus encephalitis is recent contact with pigs. Most patients have had direct contact with pigs in the two weeks preceding the onset of the illness. The infection may spread to people through contact with pig secretions such as feces or saliva or through contact with infected dogs.

The spread of the Nipah virus illustrates a problem due to trends in livestock production -- large-scale production and international commerce. Huge hog farms can have tens of thousands of animals. Some infectious agents such as the Nipah virus are associated with intensity of production and concentration of animals in limited spaces. International commerce in meat and poultry now increases the chance of the worldwide dissemination of exotic infectious agents like the Nipah virus.

Bats are believed to be the natural host of Nipah virus. The virus is similar but not identical to Hendra virus, another agent of zoonotic viral disease in which bats are the usual host.

Comment: there has been an almost religious commentary that humans could not be infected with viruses from pigs which are fatal and everything passed was from human to human.

Nipah is MUCH more deadly than the must moaned about by the pork indiustry- Swiine Flu. Despite the fact that some scientists say it carries on 3 strains - two swine and one human- the big push to include an Avian Strain is so it could be given the name

Novel Influenza A- How much Avian is in it? According to several virogists, one in Scotland- none.

The reason I brought these threads up is because we are in the process of making probably hundreds of millions of doses of vaccine from samples of California virus which has already mutated and with ABSOLUTELY no solid evidence that it even works in humans.

However, these other two viruses and several prions- a fairly new type of pathogen - and one also know to be actively worked on in weapons research (even though the weapons reserach is formally denied)

Nipah and Hendra are killers. If they spread- we will have another Pandemic.  And this one won't be a yawn Pandemic with few deaths.

Medclinician

Nipah As a Biological Weapon

Nipah virus is important as a potential biological weapon (targeted to animals, humans, or both) for the following reasons:

• Even a small outbreak in pigs could result in mass culling of affected herds, thereby causing substantial economic loss to the industry or to the national economy of the affected country.
• Nipah virus can infect humans and the case-fatality rate may be as high as 50%.
• There is no effective treatment or vaccine for the disease in either pigs or humans (although ribavirin may reduce mortality in humans with encephalitis).
• Little is known about Nipah virus, so an outbreak in animals or humans could cause substantial fear and social disruption.

The Centers for Disease Control and Prevention (CDC) has listed Nipah virus as a critical biological agent, Category C. Category C agents are emerging pathogens that could be engineered for mass dissemination in the future because of:

• Availability
• Ease of production and dissemination
• Potential for high morbidity and mortality rates and major health impact

Nipah virus - Med from Wiki

[edit] Emergence

Pteropus vampyrus (Malayan flying fox), one of the natural reservoirs of Nipah virus

Nipah virus was identified in 1999 when it caused an outbreak of neurological and respiratory disease on pig farms in peninsular Malaysia, resulting in 105 human deaths and the culling of one million pigs.^[7] In Singapore, 11 cases including one death occurred in abattoir workers exposed to pigs imported from the affected Malaysian farms. The Nipah virus has been classified by the Centers for Disease Control and Prevention as a Category C agent (http://www.bt.cdc.gov/agent/agentlist-category.asp).

The outbreak was originally mistaken for Japanese encephalitis (JE), however, physicians in the area noted that persons who had been vaccinated against JE were not protected, and the number of cases among adults was unusual ^[16] Despite the fact that these observations were recorded in the first month of the outbreak, the Ministry of Health failed to react accordingly and instead launched a nationwide campaign to educate people on the dangers of JE and its vector, Culex mosquitoes.

Symptoms of infection from the Malaysian outbreak were primarily encephalitic in humans and respiratory in pigs. Later outbreaks have caused respiratory illness in humans, increasing the likelihood of human-to-human transmission and indicating the existence of more dangerous strains of the virus.

Based on seroprevalence data and virus isolations, the primary reservoir for Nipah virus was identified as Pteropid fruit bats including Pteropus vampyrus (Malayan flying fox) and Pteropus hypomelanus (Island flying fox), both of which occur in Malaysia.

The transmission of Nipah virus from flying foxes to pigs is thought to be due to an increasing overlap between bat habitats and piggeries in peninsular Malaysia. At the index farm, fruit orchards were in close proximity to the piggery, allowing the spillage of urine, faeces and partially eaten fruit onto the pigs.^[17] Retrospective studies demonstrate that viral spillover into pigs may have been occurring in Malaysia since 1996 without detection.^[7] During 1998, viral spread was aided by the transfer of infected pigs to other farms where new outbreaks occurred.

[edit] Outbreaks

Eight more outbreaks of Nipah virus have occurred since 1998, all within Bangladesh and neighbouring parts of India. The outbreak sites lie within the range of Pteropus species (Pteropus giganteus). As with Hendra virus, the timing of the outbreaks indicates a seasonal effect.

Locations of henipavirus outbreaks (red stars–Hendra virus; blue stars–Nipah virus) and distribution of henipavirus flying fox reservoirs (red shading–Hendra virus ; blue shading–Nipah virus)

• 2001 January 31 – February 23, Siliguri, India: 66 cases with a 74% mortality rate.^[18] 75% of patients were either hospital staff or had visited one of the other patients in hospital, indicating person-to-person transmission.

• 2001 April – May, Meherpur district, Bangladesh: 13 cases with nine fatalities (69% mortality).^[19]

• 2003 January, Naogaon district, Bangladesh: 12 cases with eight fatalities (67% mortality).^[19]

• 2004 January – February, Manikganj and Rajbari provinces, Bangladesh: 42 cases with 14 fatalities (33% mortality).

• 2004 19 February – 16 April, Faridpur district, Bangladesh: 36 cases with 27 fatalities (75% mortality). Epidemiological evidence strongly suggests that this outbreak involved person-to-person transmission of Nipah virus, which had not previously been confirmed.^[20] 92% of cases involved close contact with at least one other person infected with Nipah virus. Two cases involved a single short exposure to an ill patient, including a rickshaw driver who transported a patient to hospital. In addition, at least six cases involved acute respiratory distress syndrome which has not been reported previously for Nipah virus illness in humans. This symptom is likely to have assisted human-to-human transmission through large droplet dispersal.

• 2005 January, Tangail district, Bangladesh: 12 cases with 11 fatalities (92% mortality). The virus was probably contracted from drinking date palm juice contaminated by fruit bat droppings or saliva.^[21]

• 2007 February – May, Nadia District, India: up to 50 suspected cases with 3-5 fatalities. The outbreak site borders the Bangladesh district of Kushtia where eight cases of Nipah virus encephalitis with five fatalities occurred during March and April 2007. This was preceded by an outbreak in Thakurgaon during January and February affecting seven people with three deaths.^[22] All three outbreaks showed evidence of person-to-person transmission.

• 2008 February - March, Manikganj and Rajbari provinces, Bangladesh: Nine cases with eight fatalities.^[23]

Eleven isolated cases of Nipah virus encephalitis have also been documented in Bangladesh since 2001.

Nipah virus has been isolated from Lyle's flying fox (Pteropus lylei) in Cambodia^[24] and viral RNA found in urine and saliva from P. lylei and Horsfield's roundleaf bat (Hipposideros larvatus) in Thailand.^[25] Infective virus has also been isolated from environmental samples of bat urine and partially-eaten fruit in Malaysia.^[26] Antibodies to henipaviruses have also been found in fruit bats in Madagascar (Pteropus rufus, Eidolon dupreanum)^[27] and Ghana (Eidolon helvum)^[28] indicating a wide geographic distribution of the viruses. No infection of humans or other species have been observed in Cambodia, Thailand or Africa.

[edit] Pathology

In humans, the infection presents as fever, headache and drowsiness. Cough, abdominal pain, nausea, vomiting, weakness, problems with swallowing and blurred vision are relatively common. About a quarter of the patients have seizures and about 60% become comatose and might need mechanical ventilation. In patients with severe disease, their conscious state may deteriorate and they may develop severe hypertension, fast heart rate, and very high temperature.

Nipah virus is also known to cause relapse encephalitis. In the initial Malaysian outbreak, a patient presented with relapse encephalitis some 53 months after his initial infection. There is no definitive treatment for Nipah encephalitis, apart from supportive measures, such as mechanical ventilation and prevention of secondary infection. Ribavirin, an antiviral drug, was tested in the Malaysian outbreak and the results were encouraging, though further studies are still needed.

In animals, especially in pigs, the virus causes porcine respiratory and neurologic syndrome also known as barking pig syndrome or one mile cough.

[edit] Causes of emergence

The emergence of henipaviruses parallels the emergence of other zoonotic viruses in recent decades. SARS coronavirus, Australian bat lyssavirus, Menangle virus and probably Ebola virus and Marburg virus are also harbored by bats and are capable of infecting a variety of other species. The emergence of each of these viruses has been linked to an increase in contact between bats and humans, sometimes involving an intermediate domestic animal host. The increased contact is driven both by human encroachment into the bats’ territory (in the case of Nipah, specifically pigpens in said territory) and by movement of bats towards human populations due to changes in food distribution and loss of habitat.

There is evidence of habitat loss for flying foxes both in South Asia and Australia (particularly along the east coast) as well as encroachment of human dwellings and agriculture into the remaining habitats, creating greater overlap of human and flying fox distributions.

[edit] See also

• Animal viruses
• Paramyxovirus

[edit] References

[edit] External links

• ViralZone: Henipavirus
• Hendra virus CSIRO FAQ
• Nipah virus CSIRO FAQ
• Henipavirus Henipavirus Ecology Research Group (HERG) INFO
• Animal viruses
• Queensland vet dies from Hendra virus—accessed 21Aug08
• Treatment : Virus's Achilles' Heel Revealed - Science, Feb 2009