Outbreaks of H5N1 bird flu virus re-occurred in Indonesia. Some cases, whether suspected (suspect) or that has been confirmed (confirmed) have been reported. According to WHO data as of January 15, 2007, this year has occurred in Indonesia and 4 cases of which 3 died (www.who.int).
From the same data, in the case of accumulative in Indonesia, numbering 79 and 61 of them died. If seen from the number of cases died, Indonesia was ranked first after Vietnam, with 42 deaths.
However, unlike in Indonesia, so far no reports from Vietnam and other Southeast Asian countries before the H5N1 virus that is endemic. In fact, in Vietnam, which is the country with the highest accumulative cases (93 cases and 42 of whom died), since 2006 until now, there has been no reports of H5N1 cases in humans. Why did this happen? Maybe we should learn how to do prevention in Vietnam.
Bird Flu Pandemic
Is the return of outbreaks of H5N1 bird flu virus in Indonesia is a sign of pandemic start? At least, there are three things that make a bird flu pandemic could occur. The first is the ability of the H5N1 virus to infect humans. H5N1 is the bird flu virus, which originally could only infect birds. This virus then mutated into a virus that can infect humans.
Both are supporting the occurrence of a pandemic is the lack of human immunity to the H5N1 virus. Because humans have not previously been exposed to the virus, almost all men do not have antibodies that can neutralize the H5N1 virus that infects the virus freely human cells and damage it. Thus, the virus infection will cause a fatal effect on humans who are infected.
Third is the nature of the pathogenic H5N1 virus is high. Based on WHO data, globally have occurred in 267 cases of human H5N1 and 161 of them died (www.who.int). If calculated, the fatality / mortalita s of this virus is 60 percent.
Especially for Indonesia, fatality rates even higher at 77 percent (61/79). This figure is much higher than the fatality rate of SARS virus, a virus that we fear and outbreaks in various parts of the world a few years ago with a fatality rate of about 10 percent.
Another factor is the key to the ability of a pandemic virus to spread from human to human. Although until now has not proven the existence of transmission between humans, several cases indicate transmission from human to human. One of the results of research by taking a sample of one family in Thailand has shown the possibility of human transmission within a family (Ungchusak et al, 2005).
The research showed the mother and aunt that nurse H5N1-infected children are also infected by the H5N1 virus. The mother even until death. From the results of Reverse transcriptase Polymerase Chain Reaction (RT-PCR) organ nasopharynx and throat swab (throat) of the mother discovered the H5N1 virus. Both the mother and aunt had never contact with birds.
In fact, his mother came from a distance that is not endemic bird flu, and only came to look after her son who suffered from H5N1 infection. Similarly in Indonesia, suspected there was some H5N1I cluster in families.
Therefore, we need to remain vigilant due to be transmitted between humans, the H5N1 virus may only require a single mutation in the genome. Need to be recognized that the world was not ready for a pandemic of H5N1 avian influenza. The reason is not only due to lack of vaccines, but also the health monitoring system as a whole.
1918 pandemic
Influenza experts have warned that historically, flu pandemics occur every 11 to 42 years. The worst influenza pandemic in history was the "Spanish Flu" (H1N1) that occurred in 1918-1919. The last pandemic was the "Hong Kong flu" (H3N2) that occurred in 1968-1969.
The question is whether H5N1 will become the next pandemic? The ability to spread the virus between humans is the key to the occurrence of H5N1 flu pandemic. Changed the character to be transmitted between humans may occur in two ways. First, through mutation, as happened in the virus that causes "Spanish Flu".
Second, by recombination (reassortment) between the bird influenza virus with human influenza, as happened in the case of "Hong Kong Flu" in 1968. Analysis showed that the H5N1 bird flu virus is still (avian influenza). Many experts argue that the genetic changes that facilitate human transmission does not occur in H5N1. This can be seen from the fact that in nearly 10 years, since infect humans in 1997 until now, the H5N1 virus has not turned into a virus that can be transmitted between humans.
If they guess correctly, especially pathogenic H5N1 strain of bird and accidentally infect humans who have direct contact with infected birds.
Do we believe in the optimistic scenario that? This is a difficult thing that people are generally considered opinion that we must be prepared for the worst scenario. Experience the 1918 flu pandemic could be the basis for the preparation of H5N1 pandemic. This is because of the similarity of the virus.
Spanish flu virus strain has resulted in 3 waves and the death of about 50 million people, including 675 thousand inhabitants in the U.S.. Characters that are not common in this virus is a high mortality rate at age 15-35. Cases of influenza in the U.S. generally attacks the elderly aged more than 85 years.
This phenomenon is similar to H5N1 infection in humans is happening right now. Most patients are young or children. Genetic analysis showed that both H1N1 viruses are endemic in 1918 and the H5N1 virus gene still has the bird flu virus (avian influenza), rather than human flu viruses (human influenza).
What can be done?
In addition to interventions to reduce the number of infected birds, there are three main weapons to control the spread of human viruses, namely vaccines, antiviral drugs, and isolation of patients from the community (Bartlett, 2006). The first weapon (vaccine) difficult to apply because we are not ready with the H5N1 vaccine. This is due to the H5N1 vaccine production can not currently meet the needs of the world. Global vaccine production capacity is about 1 billion doses per annum with 15 micrograms of antigen content.
Therefore, we can not expect much. Moreover, the Indonesian state, as a third country, can certainly not be a priority to get the vaccine. Weapons to-2, in the form of anti-viral drugs, it is possible to do. Although require substantial funds, if any attention from the government, still allow way it is. Oseltamivir is a component of Tamiflu is proven effective against influenza, including H5N1.
Currently, we have imported Tamiflu, even domestic companies have been granted permission to produce Tamiflu. Moreover, these drugs can be stored up to 10 years so we can prepare now for the inventory until the year 2017. The third strategy is the isolation of patients.
According to a 1918 pandemic model, 1 / 3 of the transmission occurs within the family, 1 / 3 occurs at work or school, and 1 / 3 occurs in the general community (Ferguson et al, 2006). Therefore, if in the case, the separation of the patient should immediately be done to prevent a wider spread.
Main Andi PhOleh: D, virolog on Biotechnology-LIPI Research Center
Source: http://www.jawapos.co.id
Related Posts :
0 comments:
Post a Comment