THE swine flu (Influenza A H1N1) epidemic is leveling off, but the world may not be out of the woods just yet. Scientists calculate that the number of laboratory-confirmed swine flu cases has reached 5,251 in some 30 countries around the world, with 61 deaths recorded, according to the World Health Organisation.

Other experts say at least one third of the world's population could become infected because this latest flu has a "full pandemic potential" and is spreading readily between people with the possibility of going global in the next six to nine months.

In Mexico, epicenter and origin of the swine flu outbreak, health officials are optimistic that the most lethal outbreak may be leveling off. Already, restaurants and cafes in Mexico City are scheduled to reopen with other public institutions to follow suit. The President, Felipe Calderon assumed new powers to isolate infected people. He ordered government offices and private businesses not crucial to the economy to stop work to avoid further infections from the new virus.

Working in collaboration with the WHO and public health agencies in Mexico, researchers assessed the Mexico epidemic using data to the end of April and taking into account factors like international spread and viral genetic diversity.

They say it may be too early to say whether the virus will cause deaths on a massive scale, or prove little more lethal than normal seasonal flu. Analysis of Mexico's swine flu outbreak however suggests that the H1N1 virus is about as dangerous as the virus behind a 1957 pandemic that killed two million people worldwide, but it's not nearly as lethal as the bug that caused the 1918 Spanish flu pandemic, which caused an estimated 50 million deaths.

A member of the World Health Organisation's emergency committee for the outbreak, confirmed that "This virus really does have full pandemic potential. It is likely to spread around the world in the next six to nine months and when it does so it will affect about one-third of the world's population. His study suggests swine flu could kill four in every 1,000 infected people and that decisions must be taken swiftly on vaccine production.

But some African governments such as Gabon and Ghana are not taking chances and have suspended all pork imports while increasing health checks at border entry points. The authorities have banned imports of pork and pork products. Ghana has drugs available and a quarantine system in place should any cases be identified.

In Morocco, the African country closest to Spain, the worst-hit country in Europe, health and airport workers have been issued with equipment such as gloves and masks. Official stocks of Tamiflu are reportedly sufficient for one million of the 34 million people who live there.

Although one in three persons who come in contact with the virus is likely become infected, experts are wary of predicting any possible death toll.

Nigeria is not banning pork products, even as Health Minister Babatunde Osotimehin assures that there is increased surveillance, and government is providing information about the disease to the public and medical centers while making sure there are sufficient supplies of anti-viral drugs. Already, the government had alerted all borders to be on alert for potential carriers of the disease. Nigeria was badly hit by bird flu three years ago. Government is also encouraging citizens to wash their hands and avoid large groups.

South Africa has stockpiled about 100,000 doses of Tamiflu and has access to more if needed, while thermal scanners have been installed at major entry ports. All passengers on flights from affected countries must complete questionnaires about possible symptoms and their travel patterns.

The Sudanese government has also banned any person arriving directly from Mexico from entering the country. It has set up offices at the airport and at Port Sudan to examine people exhibiting flu-like symptoms. Transit passengers arriving from countries with problems relating to the disease were kept in a room at the airport for four to seven days. The country says it has the capability to treat 45,000 cases.

In the Americas, Argentina has suspended flights to and from Mexico and immigration authorities have been asked to provide information about passengers who arrived from Mexico in the last 15 days. The authorities have installed a field hospital at the main international airport where heat sensors are already operating to attend to passengers arriving with flu-like symptoms. Health authorities have been ordered to watch for an increase in respiratory illnesses and to promote vaccinations and preventative hygiene habits among health workers and the public.

Importation of meat products from the US and Mexico has been temporarily banned in Kyrgyzstan. In Malaysia, there is no stockpile of personal protection equipment such as masks for the general population yet, but there is a supply for health staff who will be dealing with any outbreak. There are thermal scanners at airports and there is Tamiflu stockpile covering more than two million people out of a population of 27 million.

With the first confirmed cases in the region, public health officials in New Zealand say they have "ample stocks" of anti-flu drugs. The government has raised the level of the national pandemic plan and is screening all flights from the US. The country built up a stockpile after the bird flu scare sufficient to cover 25-30 per cent of the 4.3 million population.

However, Bolivia has gone a step ahead and declared a "state of health alert". It is gathered that the control mechanisms for swine flu are based on what was done to prevent bird flu. If a case of swine flu were found in Bolivia, health-service workers would be transferred to all airports and border areas, he said. Officials are checking for people with flu symptoms arriving from affected countries. Bolivia's health minister says it has only 100 doses of Tamiflu, but adds that the WHO has promised an emergency shipment of 12,000 more.

On its own, Brazil is authorising a $67m emergency funding to combat swine flu. Most of the funds will be directed to public information campaigns. Monitoring of passengers, initially restricted to those arriving from Mexico and US, has been extended to all international flights. It has started to distribute medication giving priority to Rio de Janeiro and Sao Paulo, states which receive the highest number of passengers from abroad.

In Japan, passengers from Mexico, Canada and the US are being checked at international airports. Officials are inspecting all imported pigs across the country (about 420 pigs were imported in 2008). The central government has Tamiflu and Relenza combined stockpiles which would cover nearly 20 per cent of the population. New supplies of anti-viral drugs to treat 8.3 million people have been ordered.

After cases were confirmed in Canada - all involving only mild illness- the government is stepping up surveillance for possible new cases and urged people to take precautions like frequent hand washing. The government has advised against non-essential travel to Mexico and two major airlines have said they will suspend flights to Mexican resorts.

The bottom line is that the world really needs to be prepared. At the moment, the swine flu virus is not spreading fast in the northern hemisphere, but a really major epidemic cannot be ruled out.

Indeed, one of the key decisions which has to be made this week by the world community is how much is required to switch over current vaccine production to make a vaccine against the new threat. The implication is that those decisions need to be made quickly.