Dr Tanya Melillo MD MSc

Principle Medical Officer at Disease Surveillance Unit, Department of Public Health.

As of 12 May 2006, there have been 208 cases with 115 deaths with a case fatality rate of 56%. People who have been infected with avian influenza virus might be especially susceptible to avian virus because they are genetically predisposed to it  There have been many family clusters involving blood relatives but not a single case of infection involving husband and wife NOT CLEAR.

Avian influenza may be capable of infecting people through the gut, not just the respiratory system, and diarrhea is sometimes the first symptom. Particles of the lethal H5N1 virus contained in the meat and blood of infected poultry may have been ingested by some patients, possibly causing their infection. In a number of patients the only exposure risk has been drinking raw duck blood, which could imply that the gastrointestinal tract is also a route of transmission or a route of first infection.

Both influenza A and B viruses survived for 24-48 hours on hard, nonporous surfaces such as stainless steel and plastic but survived for less than 8-12 hours on cloth, paper, and tissues. Studies have shown that influenza A virus present on stainless steel surfaces was transferred to hands for up to 24 hours and from tissues to hands for up to 15 minutes. This indicates the importance of disinfecting common surfaces during a pandemic with alcohol wipes and washing hands with soap and water very frequently. The virus survived on hands for up to 5 minutes after transfer from environmental surfaces. These observations suggest that the transmission of the virus from infected persons who are shedding large amounts could occur for 2-8 hours via stainless steel surfaces and for a few minutes via paper tissues.

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The list of animals that are likely to be infected with avian viruses and transmit it to others include:

Species Some influenza types that are infectious
Cats Type A/H5N1
Dogs Type A/H3N8
Horses Type A/H7N7 and H3N8
Humans (pandemic and seasonal influenza) Type A/H3N2 and H1N1 also Types B and C
Marine Mammals (seals) Type A/H7N7
Mustelids (including ferrets, mink and wild mustelids) Types A/H3N2, H10N4 and H5N1
Pigs (swine fever) Type A/H1N1, H1N2 and H3N2

 

Carnivores can become infected after consuming infected poultry that succumbed to the disease. The risk to humans from an H5N1 infected cat is hard to quantify. Cats naturally hunt wild birds, will choose sick birds and have close contact with humans as companion animals. Given that one cat can infect another, the risk to humans cannot be zero. However, since H5N1 remains poorly adapted to humans the cat’s infection will not cross over easily. The present evidence is that cats with infectious H5N1 are quite ill, so the risk of acquiring H5N1 from a well cat may be negligible. Also, risk will be minimal in areas where there  is no H5N1.

Below are the recommendations by the Food and Agriculture Organization with regards to domestic cats and dogs for areas where H5N1 has been confirmed or suspected:

FAO Recommended Actions in Areas where H5N1 HPAI has been diagnosed or is suspected in poultry or wild birds :
  • Report any evidence of significant bird mortality (both wild and domestic) to the local veterinary authority
  • Be especially vigilant for any dead or sick cats and report such findings to the local veterinarian
  • Make sure contact between cats and wild birds or poultry (or their faeces) is avoided and/or keep cats inside
  • If cats bring a sick or dead bird inside the house, put on plastic gloves and dispense of the bird in plastic bags for collection by local veterinary animal handlers
  • Keep stray cats outside the house and avoid contact with them
  • If cats show breathing problems or nasal discharge, a veterinarian should be consulted
  • Do not touch or handle any sick-looking or dead cat (or other animal) and report to the authorities
  • Wash hands with water and soap regularly and especially after handling animals and cleaning their litter boxes or coming in contact with faeces or saliva
  • Dogs can only be taken outside the premises if kept restraint
  • Do not feed any water birds
  • Disinfect (e.g. with bleach 2-3 %) cages or other hardware with which sick animals have been transported or been in contact with
  • Wash animal blankets with soap or any other commercial detergent

For further information check the Disease Surveillance Unit Web Portal on http://www.health.gov.mt/dsu/ and TheSYNAPSE Web Portal on http://www.thesynapse.net/

The information is correct as on 13/5/06.