KETERANGAN MENGENAI VIRUS H1N1

VIRUS H1N1

1.Versi Bahasa Melayu

Sah babi punca H1N1
WASHINGTON 23 Mei – Pusat Kawalan dan Pencegahan Penyakit Amerika Syarikat (AS) mendapati virus baru influenza A (H1N1) yang menyebabkan wabak selesema babi telah tersebar tanpa dikesan sejak beberapa tahun lepas, sebahagian besarnya berpunca daripada babi.

Ketua Bahagian Influenza di pusat tersebut, Dr. Nancy Cox berkata, berdasarkan satu kajian yang dijalankan pihaknya, babi adalah punca jelas yang membawa kepada pandemik tersebut.

‘‘Keputusan kajian itu menunjukkan keperluan global untuk menjalankan pengawasan yang lebih bersistematik berkenaan virus tersebut pada babi,’’ katanya kepada pemberita melalui telefon.

Laporan oleh Cox bersama sekumpulan penyelidik antarabangsa dalam jurnal sains itu menyebut virus berkenaan ‘mungkin telah tersebar tanpa dikesan di kalangan kawanan babi di suatu kawasan di dunia ini’.

Kumpulan penyelidik itu turut mengesahkan campuran gen manusia, babi dan burung dalam virus terbabit yang telah menjangkiti lebih 11,000 orang di 42 buah negara, serta membunuh 86 orang.

Pertubuhan Kesihatan Sedunia (WHO) sebelum ini hampir mengumumkan status pandemik penuh terhadap virus tersebut.

Penyelidik berkata, campuran gen itu sama seperti campuran pelik lain yang menjangkiti babi, namun ia memang tidak pernah dilihat sebelum ini.

Mereka turut menyusun secara jujukan kod genetik 70 sampel berasingan virus terbabit yang diperoleh dari AS dan Mexico.

‘‘Kami boleh mengenal pasti dari mana setiap gen itu berasal,’’ kata Cox.

Virus baru itu merupakan satu campuran yang terhasil daripada campuran-campuran lain termasuklah sejenis virus yang ditemui pada 1998 yang mengandungi elemen manusia, burung dan babi.

Ia turut mengandungi sedikit selesema Eurasian termasuk satu segmen yang mempunyai kaitan dengan sampel yang diperoleh daripada seorang pesakit di Hong Kong yang dijangkiti selesema babi pada 1999.

Bagaimanapun, penyelidik berkata, kemunculan campuran baru virus itu masih menjadi satu misteri.

*sumber:
http://www.utusan.com.my/utusan/info.asp?y=2009&dt=0524&pub=Utusan_Malaysia&sec=Luar_Negara&pg=lu_01.htm
ARKIB : 24/05/2009


2.Versi Bahasa Inggeris

2009 H1N1 Influenza A Virus

Soon after the emergence of the H1N1 virus in April 2009, ARS scientists at the National Animal Disease Center in Ames, Iowa, began research using virus samples provided by the Centers for Disease Control and Prevention (CDC). The first step was to evaluate whether current U.S H1N1 swine influenza vaccines can protect pigs from infection with the 2009 H1N1 influenza virus circulating in people. This research study also evaluated whether pre-existing titers in pigs previously infected with endemic H1N1 swine influenza viruses circulating in the U.S could protect against the 2009 H1N1 influenza virus. Second was to address whether meat, blood and tissue from pigs infected with the new 2009 H1N1 Influenza A Virus would be free of infectious virus.

Classical swine influenza virus infections are enzootic among pigs in North America. Sporadic cases of human infection with swine influenza virus have been reported in the United States and elsewhere. Worldwide, more than 50 human cases of swine influenza virus infection, mostly due to classical swine influenza virus, have been documented in the past 35 years, with the greatest risk of infection among people with occupational exposure to live pigs.
Experts believe pigs can act as a "mixing vessel" for the reassortment of avian, swine and human influenza viruses, and might play an important role in the emergence of novel influenza viruses that could be capable of causing a human pandemic similar to the virus in the current outbreak.

Between the 1930s and the 1990s, the most commonly circulating swine influenza virus among pigs-classical swine influenza A, known as H1N1-underwent little change.

However, by the late 1990s, multiple strains and subtypes of triple reassortant swine influenza viruses-whose genomes include combinations of avian, human and swine influenza virus gene segments-had emerged and became predominant among North American pigs. The 2009 H1N1 influenza virus is also a triple reassortent, but its lineage is different than the H1N1 influenza viruses currently circulating in U.S. pigs.

Background

The genetic makeup of swine influenza viruses is identical to other influenza A viruses and consists of 8 segments of RNA that code for different proteins. Influenza viruses have the ability to exchange these segments, creating new genetically different viruses. Two major surface glycoproteins (proteins with a carbohydrate attached), called hemagglutinin (H) and neuraminidase (N), are how influenza A viruses are identified. These glycoproteins also determine the host range, antigenicity and the pathogenicity of the viruses. The hemagglutinin and neuraminidase proteins are important targets for diagnostics and used to designate the subtype of the virus.

Currently 16 different hemagglutinins and 9 neuraminidases have been identified. The majority of these viral subtypes are found in waterfowl, with only a few combinations being found in humans and swine.

Swine influenza virus (SIV) is one of the primary causes of respiratory disease in growing pigs and can lead to major economic losses. Currently, only H1N1, H1N2, and H3N2 subtypes are circulating in the U.S. swine population.

Pigs have long been considered a potential source for new and novel influenza viruses that infect humans, as they have receptors on their cells that bind both mammalian and avian influenza viruses, increasing the opportunity for the exchange of genetic segments of the virus.

Previously, the CDC have reported approximately one case of human infection with a swine influenza virus every one to two years.

*By:
http://www.ars.usda.gov/2009H1N1/