Archive for the ‘Infectious diseases’ category

What is swine flu and how it originates?

May 17th, 2009

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Influenza caused by strains of influenza virus called swine influenza virus that usually affect pigs is known as swine flu. In Midwestern United States, Canada, South America, Mexico, Japan, eastern Asian countries, it is found in pigs. Properly cooked pork poses no risk of transmission of swine influenza virus from pig to human. When infected, virus shows the signs of infection in the presence of antibodies and does not always cause human influenza, detectable only by laboratory tests.

It is called zoonotic flu when transmission results in a human influenza. People with intensive exposure to pigs or those who work with pigs are at risk of catching flu. Mal Since the mid twentieth century only 50 such transmissions have been recorded. The strains of swine flu pass from one human to another, and show common symptoms like chills, fever, muscle pains, sore throat, coughing, severe headache, weakness and general discomfort. The 2009 flu outbreak which is also known as the 'swine flu' is caused due to new strain of influenza A virus subtype H1N1. This virus contains genes closely related to swine influenza. Its origin is not known but the world organization for animal health claims that this virus is not isolated to pigs, it can also pass from human to human to cause normal symptoms of influenza.

Out of the genera of influenza virus, influenza virus C is common in pigs and influenza virus A is rare. Humans and pigs are infected due to influenza virus C and not birds. Transmission between human and pigs occurred before: for instance, influenza C caused outbreak of mild among children in Japan, but due to its limited host range and lack of genetic diversity, it did not became pandemic. It is also caused by influenza subtypes like H1N1, H1N2, H3N1, H3N2 and H2N3.

The first case of swine flu was found on 1918, when pigs as well as human became ill at the same time. For the following next 60 years the common strain was H1N1. after that between 1997 and 2003, its different subtypes emerged. With only 12 cases in US since 2005, its direct transmission from pigs to humans is rare. For several times it has been reported as a zoonosis in humans, usually with limited distribution. These outbreaks cause significant losses in industry. The 1918 flu pandemic was related to H1N1 and flu appeared in pigs. In this case, human caught disease from pigs. The exact origin of 1918 outbreak remains unknown. On October 1, 1976 the immunization program began and by the start of November 40 million people are vaccinated. In 1988 one woman was killed due to swine flu in its outbreak. This outbreak proved the fact that pigs can serve as crucible where novel influenza viruses emerge as resentment of genes from different strains. The 2009 outbreak is due to new strain H1N1 which is not previously reported in pigs and it is reported at pigs' farm at Alberta, Canada.

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Swine flue – Precautionary measures

May 9th, 2009

Swine flue - Precautionary measures

Spread of influenza among swine can be prevented by the use of different methods like; facility management, hard management and vaccination. Control strategies that rely on vaccination may prove insufficient, as much of death and illness associated with swine flu involves secondary infection by pathogens. In recent decades, control of swine influenza has become more difficult. Evolution of the virus proved traditional vaccines to be inconsistent. When the virus strains match enough to have significant cross protection, then the standard commercial swine flu vaccines are effective. In more difficult cases custom vaccines are made from specific viruses isolated. Use of several bivalent SIV vaccines is included in the present vaccination strategies. 41 0ut of 97 H3N2 isolates examined had strong serologic cross reactions with antiserum to three commercial SIV vaccines.

Primarily, the protective status of the influenza vaccines depends on the closeness of the match between the vaccine virus and the epidemic virus. Current vaccine techniques may not effectively protect pigs from infection from majority of H3N2 viruses. Pig vaccination keeps pigs from getting sick but it doesn't block infection or shedding of the virus. Facility management comprises use of disinfectants and ambient temperature for controlling virus in the environment. Virus survives for more than two weeks outside the living cells, except in the cold conditions. Herd management comprises adding pigs, which carry influenza to herds that have not been exposed to virus. In healthy carrier pig virus survives up to 3 months and can be recovered from them between outbreaks.

In swine farms the transmission from swine to human occurs. The major method of limiting swine to human transmission includes use of vaccines to prevent their infection. Coughing and sneezing is the main reason for spreading this disease in human. Pork products can not spread swine, because this virus can not spread through food. During the first five days of illness, swine proves to be most contagious. Children can remain contagious for ten days. For preventing the spread of virus standard infection control against influenza is recommended. These measures include frequent washing of hands with soap and water. Alcohol based hand sterilizers can also be used, especially after being out in the public. The current trivalent influenza vaccine is unable to provide protection against the 2009 H1N1 strain. Vaccine may be ready by the end of June 2009. hand washing can prevent viral infections, ordinary influenza and swine flu virus. Droplets containing the virus can linger on tabletops, telephones and on other surfaces and help spreading the disease. They can be transferred via mouth, nose or eyes. To destroy viruses and bacteria alcohol based gel or foam hand sanitizers can be used. Sudden fever, muscle or aches are the symptoms of this disease. Another main tactic is the social distancing. Large gatherings should be avoided, spreading out a little at work and perhaps staying home are the other options. This disease can be prevented by using these simple techniques and to enjoy healthy life style.
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Infection in human beings and animals, and its treatment possibilities

May 8th, 2009

Swine flue - Infection in human beings and animals, and its treatment possibilities

Swine flue influenza is very common among pigs. About half of breeding pigs are exposed to the virus in the United States. The main cause for the transmission of this disease is transmission from infected to uninfected animals. During animal transport these close contacts are very common. The risk of transmission also increases due to intensive farming, because pigs are raised in very close proximity to each other. The direct transfer occurs through dried mucus or by pigs touching noses. Wild animals can also transmit this disease, like wild boar, which spreads disease in the farms.

People who work on poultry farm, having intensive exposures are more prone to get zoonotic infection. So important public health care measures should be taken which include vaccination of these workers and surveillance for new influenza strains among this population. The study shows that people whose job involves handling of poultry should be the focus of public health surveillance. Swine influenza strains usually have three different species; pigs, birds and humans. In this pigs act as host and virus may produce new and dangerous strains by exchanging genes. In china avian influenza virus H3N2 is endemic in pigs and also detected in pigs in Vietnam. H3N3 is evolved from H2N2 as a result of antigenic shift. New strain known as H5N1 was found in china in 2004. infection due to H5N1 is very common.

Little treatment beyond rest and supportive care is required, as swine flu is rarely fatal to pigs. The spread of the virus through the farm can be prevented by implying veterinary efforts. These efforts include vaccination and animal management techniques. To these disease antibiotics are used, but they don't have any effect against the influenza virus. They only help with bacterial pneumonia and secondary infections. Antiviral drugs can be used if person becomes sick, which make the illness milder and make patient feel better. Serious flu complications can also be prevented by using them. Antiviral drugs work best for treatment, if started soon after getting sick. Other measures include; palliative care focuses on controlling fevers and maintaining fluid balance. Use of Tamiflu and Relenza ia recommended by the US centre for disease control and prevention for the treatment of swine influenza viruses. However people make full recovery without use of medical attention or antiviral drugs. In the 2009 outbreak the virus was found resistant to the rimantadine and amantadine. On april 27, 2009, FDA issued emergency use authorizations so that Tamiflu antiviral drugs and Relenza can be made available to treat the swine flu influenza virus. The agency issued EUAs sso that treatment of the patients younger than the current approval should be allowed, and also for the widespread distribution of the drugs, which also includes non licensed volunteers. Proper care and maintenance of hygienic conditions will result in the prevention of this disease and good health conditions, and the use of various medicines can be avoided.

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Impact of swine flu

May 8th, 2009

Impact of swine flu

Scientists predicted nearly a year ago, that Mexico and other tropical hotspots are emerging as the growing areas for genetic diseases. And now the newly originated swine flu is originated from these areas. The events caused by zoonotic diseases are correlated with the socio-economic, environmental and ecological factors. With the help of these conditions scientists made predictive map of emerging diseases pointing to Latin America, tropical Africa and Asia. Search team also focused on richer developed countries of Europe, North America, parts of Asia and Australia rather than in developing countries.

Along the recent developments, some Asian countries have set up quarantines for passengers who arrive their. The United States of America is one of the swine flu infected regions, where new swine flu virus or is suspected of spreading. A person can carry a virus from one country to another and can be contagious before symptoms appear. It is also found that a virus has evolved new ways to exploit human contact as a way of spreading. If the contact is reduced then the outbreak of this disease can also be reduced. Mexico, Brazil and Canada are the most likely routes of entry for avian influenza into the United States. Study showed that the bird flu was most likely to be introduced to United States and other countries of the western hemisphere through the infected poultry trade. The H5N1 avian influenza virus was also brought by migratory birds to the United States from Mexican countries. Biodiversity also contributed in spreading the zoonosis. Disease emergence is also affected by climate change by shifting animal habitats and by increasing range of known disease carriers like mosquitoes. Few years ago, researchers and policy makers placed their bets on H5N1 strain of bird flu virus emerging in Asia. Work on vaccine for the new swine flu to protect us from getting sick has started by the centers for the disease control and prevention. It will take four to six months to be ready, once researchers and manufacturers commit to making a vaccine for the new swine flu virus. Scientists can now better identify the movement of many new diseases causing agents before they move to people by identifying the links between wildlife, livestock and humans.

The recent outbreak in 2009, in humans is due to new strain known as influenza A virus subtype H1N1, which contains genes closely related to the swine influenza. Though the origin of this strain is not known, world organization for animal health reports that strain has not been isolated in pigs. This strain causes normal symptoms of influenza and can pass from human to human. Swine outbreaks are very common and cause high economic losses in industry. So, necessary steps should be taken to stop spreading of this disease as it is influencing the social and economic structure of the states. Various precautionary and preventive steps should be taken to avoid this pandemic disease.

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