Friday, April 04, 2008

Updating influenza pages

Just updated the links in our avian and pandemic flu pages. Have not done this for some time, so a few to change. Can't get the PubMed RSS feed to work. Also discovered that if I edit the page generated by MyIntute, using Contribute, and then try to publish it, it has terrible trouble. I ended up creating all sorts of rubbish with variant filenames. Fortunately, none of this junk actually seems to have been published. Have made mental note not to edit that page again!

1 comment:

Dipl.-Ing. Wilfried Soddemann said...

Spread of avian flu by drinking water can explain small clusters in households
Proved awareness to ecology and transmission is necessary to understand the spread of avian flu. For this it is insufficient exclusive to test samples from wild birds, poultry and humans for avian flu viruses. Samples from the known abiotic vehicles also have to be analysed. There are plain links between the cold, rainy seasons as well as floods and the spread of avian flu. That is just why abiotic vehicles have to be analysed. The direct biotic transmission from birds, poultry or humans to humans can not depend on the cold, rainy seasons or floods. Water is a very efficient abiotic vehicle for the spread of viruses - in particular of fecal as well as by mouth, nose and eyes excreted viruses.
Infected birds and poultry can everywhere contaminate the drinking water. All humans have very intensive contact to drinking water. To prove viruses in water is difficult because of dilution. If you find no viruses you can not be sure that there are not any. On the other hand in water viruses remain viable for a long time. Water has to be tested for influenza viruses by cell culture and in particular by the more sensitive molecular biology method PCR.
There is a widespread link between avian flu and water, e.g. in Egypt to the Nile delta or Indonesia to residential districts of less prosperous humans with backyard flocks and without central water supply as in Vietnam:
http://www.cdc.gov/ncidod/EID/vol12no12/06-0829.htm.
See also the WHO web side:
http://www.who.int/water_sanitation_health/emerging/h5n1background.pdf and
http://www.umg-verlag.de/umwelt-medizin-gesellschaft/407_m_s.html
“Influenza: Initial introduction of influenza viruses to the population via abiotic water supply versus biotic human viral respirated droplet shedding” and
http://www.thelancet.com/journals/laninf/article/PIIS1473309907700294/abstract?iseop=true
“Transmission of influenza A in human beings”.
Avian flu infections may increase in consequence to increase of virus circulation. Transmission of avian flu by direct contact to infected poultry is an unproved assumption from the WHO. There is no evidence that influenza primarily is transmitted by saliva droplets.
In hot climates/the tropics flood-related influenza is typical after extreme weather and floods. Virulence of influenza viruses depends on temperature and time. Special in cases of local water supplies with “young” and fresh H5N1 contaminated water from low local wells, cisterns, tanks, rain barrels, ponds, rivers or rice paddies this pathway can explain small clusters in households. At 24°C e.g. in the tropics the virulence of influenza viruses in water amount to 2 days.
Human to human and contact transmission of influenza occur - but are overvalued immense. In the course of influenza epidemics in Germany, recognized clusters are rare, accounting for just 9 percent of cases e.g. in the 2005 season.
In temperate climates for “older” water from central water supplies cold water is decisive to virulence of viruses. At 7°C the virulence of influenza viruses in water amount to 14 days. In temperate climates the lethal H5N1 virus will be transferred to humans via cold drinking water, as with the birds in February and March 2006, strong seasonal at the time when drinking water has its temperature minimum.
The performance to eliminate viruses from the drinking water processing plants regularly does not meet the requirements of the WHO and the USA/USEPA. Conventional disinfection procedures are poor, because microorganisms in the water are not in suspension, but embedded in particles. Even ground water used for drinking water is not free from viruses.

Dipl.-Ing. Wilfried Soddemann - Free Science Journalist - soddemann-aachen@t-online.de