Avian Influenza Virus Infection In Humans

Avian influenza virus does not normally infection to outside the poultry and pig species. Case first avian influenza infection in humans in Hong Kong show in 1997. At that time, H5N1 strain caused respiratory disease in a heavy 18 patients, of which 6 of them died. Infection in humans is coinsidension from the avian influenza epidemic that is very infectious (H5N1) that occurred in farm animals and cattle.

Extensive investigation of outbreaks that reflects the close contact with live infected cattle is a source of infection in humans. Study on the genetic level further go to that reflects the virus from poultry to humans. Of health workers in some (limited) appears, but does not cause a serious case of the disease.

Influenza Virus Antigen Variation

All type A influenza virus, including the cause seasonal epidemic in humans, the genetic extremely unstable and can quickly adapt to avoid the body's defense mechanisms (antibody) the (host). Virus-influenza virus have less mechanism for the "proofreading" or "repair the damage the structure" and improve the disability / differences that arise during replication. As a result of the differences that are not repaired, then the genetic composition of virus when the virus replicated change in humans and animals, and strain before antigenik replaced with new variants. Small changes that are constant and permanent, in the composition of influenza A virus antigenik known seb aga i "antigenic drift". Antigenik This drift can occur in the influenza virus types A and B.

virus-influenza virus antigenic changes in the permanent and quite often this causes a situation to monitor the WHO influenza program in the world in the WHO Global Influenza Program began in th. 1947. Every years after the monitoring on 4 WHO collaborative research centers that receive data from 112 institutions from 83 countries. WHO provides a reference to the influenza vaccine manufacturers to make the vaccine with the appropriate subtipe-subtipe the influenza virus circulation in the world. (Influenza vaccine recommendations)

Influenza viruses have characteristics of both the trigger sad very very health of the community. Influenza virus type A, including subtipe-subtipe from a different species (Avian and human), may change or the genetic material can be arranged and exchange new "reassort". The process of re-drafting of this genetic material known as "antigenic shift". Antigenik this shift will result in a new type of subtipe different from the second parent. Because the human population does not have any immunity against subtipe new, and there is no vaccine available to provide protection, antigenic shift in the history of the pandemic (epidemic highway), which is death. This especially appears when subtipe have new genes from the human influenza virus can spread from person to person during the period of ongoing.

Conditions that enable the emergence of antigenic shift have long known that involves human life, or live near cattle and domestic pigs. Easy because pigs are infected either from virus or from avian virus-mammals, including human influenza virus, the pig could act aga i seb media blender "mixing vessel" to confuse genetic material from human and avian viruses, which result in the emergence of new virus subtipe. Data that identify possible new second. Evidence that the learned, at least some of the 15 types of avian influenza virus that bersirkulasi in poultry populations could provide an infection in humans and humans can

Reservoir and Transmission H5N1

This disease is carried by all types of poultry, the chicken, duck, goose, birds etc.. Avian influenza (H5N1) can spread rapidly among the poultry population in the death of livestock and cause a very quick and high. Even spread between the farms of a region to another. This disease can also attack humans through the air tercemar by the virus, which originated from sekret poultry or feces that are suffering from bird flu.

Until this time there is no evidence to indicate the manner of transmission from human to human. People who have high risk for contracting is that people often relate directly (direct contact) with the birds, for example, workers in the poultry farm, cutting chicken and other poultry products penjamah.

Waterfowl that migrate, such as grouse, heron and wild duck (there are only four seasons the country) is the natural reservoir of avian influenza virus, it is more resistant to infection. Domestic livestock, including chickens and turkeys, is the most easily infected with the fatal impact of rapid influenza epidemic.

Influenza Virus Type

Consisting of influenza virus type A, B and C. Fifteen subtipe of influenza virus known to menginfeksi birds-poultry, s aat up to this, all forms of influenza outbreaks of the highly patogenik derived from virus-influenza virus type A with subtipe (Haemaglutinin) H5 and H7. Type A influenza subtipe views of Neuraminidase also, s aat this subtipe Type 9 is based on Neuramanidase. Avian influenza virus of the aat s s aat this bersirkulasi in Asia and cause many deaths in poultry is H5N1.

Birds with H5N1 influenza virus can be issued with a large amount in kotorannya. The virus can survive in water up to 4 hours at a temperature of 22 C and more than 30 days in the temperature 30C. In poultry feces and poultry in the patient's body can survive longer, but will die on the heating 60C for 30 minutes.

Aat s research on this virus has been found that the influenza-virus was not pathogenic after several bersirkulasi s aat on livestock population, can be bermutasi virus-virus that is infectious. S elama epidemic in the United States in the year. 1983-1984, H5N2 virus initially caused death in a small amount, but in the next six months turned into highly infectious, with a mortality rate approaching 90%. Level of prevention against epidemics depopulasi produce 17 million poultry with the cost of almost U.S. $ 65 million. S elama th epidemic in Italy. 1999-2001, H7N1 virus, initially not very infectious, but time in 9 months bermutasi virus becomes highly contagious. Cause 13 million birds dead or destroyed.

Introduction About H5N1

Avian influenza is an infection of the disease in poultry caused by influenza virus strain type A. The disease first identified in Italy more than 100 years ago, now appear in the world.

All poultry be susceptible to avian influenza infection, although some species more resistant to this virus than others. This infection causes symptoms that spectrum is very knowledgeable on the birds-poultry, ranging from mild symptoms to spread to a very high and fast into a fatal disease resulting in a serious epidemic.

WHO's latest report dated 18 February 2004 said that influenza A (H5N1) have caused outbreaks of avian influenza in Thailand, Viet Nam, China, Japan, Korea, Cambodia, Laos and Indonesia S IA. Even in Thailand has bird flu infect people with the number of cases of 9 people, 7 of them died. Vietnam fell ill a more severe outbreak of 22 reported cases in humans, 15 of them died. Nyatalah that outbreaks of bird flu is not the only cause of death in the animals but also in humans.

In January 2004, in several provinces in Indonesia, especially in Bali, Lombok, Jabotabek, East Java, Central Java, West Kalimantan, and West Java, there are reported cases of death of chickens livestock performance. Death was initially suspected to be because the virus New Castle, but the final confirmation by the Ministry of Agriculture, caused by a virus of bird flu or Avian influenza (AI). Although up to this s aat in Indonesia have still not report the occurrence of transmission to humans, but caution must always be enhanced by the nature of these influenza viruses that can be turned into violent in a relatively quick time.