Swine flu science update: 12 June 2009
The WHO has declared the global spread of swine flu — influenza A(H1N1) — to be a pandemic. Director-general Margaret Chan confirmed yesterday (11 June) that the organisation had raised the virus's threat level to phase six.
"Spread in several countries can no longer be traced to clearly-defined chains of human-to-human transmission," Chan said. "Further spread is considered inevitable."
It is the first time in 41 years that a virus has reached pandemic levels.
On a more positive note researchers have adapted a widespread and relatively simple laboratory method to diagnose both seasonal influenza virus and influenza A(H1N1). The test could help developing countries quickly and easily diagnose the virus.
Co-author Xavier de Lamballerie, from the Institute of Research for Development, France, told SciDev.Net that the test is very sensitive but robust and cheap.
"This is crucial for our partners in developing countries: this test will be soon used in Gabon, Bolivia, Mali, Laos, in the Indian Ocean [countries] where we have collaborators."
"The first comments we have from our colleagues in these countries are extremely positive and enthusiastic. It will be useful for clinical diagnostics, epidemiology and will allow the inclusion of results from different origins in comparative studies," says Lamballerie.
BBC Online reported that a US nongovernmental organisation, the Pew Charitable Trust, funded a study published last year which warned of the potential spread of viruses from animals.
The study concluded that: "The continued cycling of viruses and other animal pathogens in large herds or flocks increases opportunities for the generation of novel viruses through mutation ... that could result in more efficient human-to-human transmission."
Meanwhile, scientists report in Nature this week (11 June) that influenza A(H1N1) was derived from several viruses circulating in swine [1.08MB] Using evolutionary analysis, they estimate that the initial swine– human transmission occurred "several months" before the outbreak was detected.
"Our results highlight the need for systematic surveillance of influenza in swine and provide evidence that the mixing of new genetic elements in swine can result in the emergence of viruses with pandemic potential in humans," they write.
Nature also reports that the biggest challenge facing the international scientific community lies ahead as the developing nations in the southern hemisphere enter their flu season.
"In general, the developing countries are not prepared," said Hitoshi Oshitani, a virologist with the Tohoku University Graduate School of Medicine in Sendai, Japan.
According to the article, the World Bank has released substantial funds to prepare these regions. Many people in poorer countries suffer from HIV/AIDS and malnutrition making them more vulnerable to A(H1N1).
"In addition, they are likely to be left out of the global scramble for a vaccine, which has already started as nations such as the United States and Britain rush to tie up vaccine contracts," says the article.