WHO increases swine flu threat level to "phase 5"

Syed Akbar
Hyderabad, April 30: India is safe from swine flu thanks to the preparedness measures it had undertaken during the outbreak of bird flu a year ago, even as the World Health Organisation has increased the threat perception of the epidemic from "phase 4" to "phase 5".

As the Central government had initiated a number of preventive steps after bird flu cases were reported in the neighbourhood, monitoring of swine flu has become quite easier for health authorities. The preparedness measures in the last two years are now benefiting the country in the form of increased awareness and action plan to tackle swine flu, should there be an outbreak here.

The WHO's classification of present outbreak of swine flu as "phase 5" indicates that the disease is now transmitting from human to human. The highest level of threat perception for any disease, as per WHO standards, is "phase 6".

"Health experts, for the first time, could track the evolution of swine flu in real time. This is mainly because the government has been awake on the avian flu problem," said Dr MN Khaja, senior scientist.

Thousands of health workers have been on high alert ever since a few cases of bird flu were reported two years ago. They had undergone specialised training. Since the nature of bird flu and swine flu is similar, health workers may not find it difficult to meet any challenge posed by swine flu.

Influenza viruses, whether bird flu or swine flu, are notorious for fast mutation and unpredictable behaviour. The WHO's change to a higher phase of alert is a signal that certain actions should now be undertaken with increased urgency, and at an accelerated pace.

According to a WHO report, in nature, influenza viruses circulate continuously among animals, especially birds. Even though such viruses might theoretically develop into pandemic viruses, in Phase 1 no viruses circulating among animals have been reported to cause infections in humans.

"In Phase 2 an animal influenza virus circulating among domesticated or wild animals is known to have caused infection in humans, and is therefore considered a potential pandemic threat. In Phase 3, an animal or human-animal influenza virus has caused sporadic cases or small clusters of disease in people, but has not resulted in human-to-human transmission sufficient to sustain community-level outbreaks".

When a disease takes the "community level outbreaks", it is declared as having "phase 4" threat. Swine flu was declared as phase 4 till Wednesday. WHO updated the threat to phase 5 on Thursday because the virus is now characterised by human-to-human spread into at least two countries in one WHO region.

"While most countries will not be affected at this stage, the declaration of Phase 5 is a strong signal that a pandemic is imminent and that the time to finalise the organisation, communication, and implementation of the planned mitigation measures is short," the WHO report said. When it takes the pandemic phase with
community level outbreaks it is classified as phase 6.