Sussex expert comments on swine flu

Dr Stefan Elbe, Reader in International Relations at the University of Sussex and an expert in health security and pandemic preparedness, comments on the global spread of swine flu.

What do we mean by a pandemic?

In simple terms, a pandemic means that many, if not most, countries around the world will experience cases of human infection with the new swine flu virus. Because there are always viruses of different types in circulation throughout the world, the World Health Organization has devised a scale of six different phases to indicate how severe the threat is at any point in time. That scale ranges from low (Stage 1) through to a generalised pandemic (Stage 6).

Why are there six stages of threat according to the WHO?

The Director General of the World Health Organization elevated the influenza pandemic alert level from Stage 4 to 5 (out of a possible 6) on April 29 after the WHO engaged in a scientific review in a rapidly evolving situation. The key difference between Stages 4 and 5 relates to how many countries are experiencing sustained outbreaks at community level. The latter are instances where infections are not simply imported directly by travellers, but are spreading to people within the community with no travel history to areas where the infection is prevalent (e.g. Mexico). If that is only occurring in one country, the threat level is determined to be at Stage 4. Stage 4 was declared on 27 April because of the community transmission of swine flu occurring in Mexico. Stage 5 is declared when such community level outbreaks are occurring in more than one country. Following confirmation that such community-level transmission was also taking place in the United States, the WHO decided to elevate the threat level to Stage 5.

What does Stage 5 mean in real terms?

The ramifications of the change to Stage 5 are predominantly for governments. It is important to bear in mind that the World Health Organization is technically not a medical nor a non-governmental organization. It is principally there to serve its member states in relation to public health matters of international concern. Elevating the status to Stage 5 is essentially intended as a strong signal to governments around the world to be on stand on stand-by to implement their pandemic preparedness plans. Several such preparedness plans are also informally linked to the WHO threat level and are designed in such a way that each time the WHO elevates its threat level, additional measures are taken.

What is the criterion for Stage 6 - the highest stage of threat?

The criterion for declaring Stage 6 (the highest stage, and effectively a pandemic) is that community level outbreaks must simultaneously occur in countries belonging to more than one WHO region. That factor is slightly arbitrary because it depends on the ways in which the WHO has carved up the world into regions for organizational purposes. There are six such regions (all served by a regional office of the World Health Organization): Africa, the Americas, South-East Asia, Europe, the Eastern Mediterranean, and the Western Pacific. Because the USA and Mexico (and Canada) are in the same WHO region, this currently makes the situation Stage 5 according to the WHO classification. However, if in the next couple of days and over the weekend we see wider community transmission, for example in the UK (or in Asia), then that would satisfy the criteria of having community outbreaks in two different WHO regions, and the WHO could technically elevate the threat level to the highest stage.

Is the UK well prepared?

The UK is comparatively well prepared. Together with France, it has been described by the World Health Organization as one of the best prepared countries. For five years the UK government has taken the threat of avian (H5N1) influenza very seriously (at times on par with the threat of terrorism). Those efforts will now also place the country well to respond to swine flu. The government has also been running simulation exercise to test these plans. Ultimately, however, you can never be sure how effective your plans are until they are put into practice. We are certainly better prepared than in previous times of human history, when many medicines that we take for granted today were not available.

Is Tamiflu effective against swine flu?

Tamiflu is not a vaccine; it is an anti-viral medication. It is therefore not a cure, but blocks the process through which viruses replicate in the human body. It has proved to be effective in the case of swine flu, as long as it is administered early on in the course of infection. Tamiflu (and Relenza) can therefore be used as a treatment to minimize the extent and symptoms of infection. It can also be used as a prophylactic to give to people who have been in contact with infected persons to minimize further spread.

How do Governments decide who will be given anti-viral medication?

The UK has stockpiles of anti-virals such as oseltamivir (brand name Tamiflu) for treating half of the population. Currently, individuals suspected of infection have no problem getting access to those anti-virals in the UK. If many more infections occur, the supply may be targeted at heath care workers and other critical professionals. It is important to bear in mind that many people who have become infected with swine flu outside of Mexico have recovered without the need for such medications. An eventual vaccine will have to be virus specific and will take at least 4-6 months to develop, and it will take even longer before it is widely available. It is likely that the UK will be amongst the first in line to secure access to vaccines once they become available.

Can we contain a pandemic?

At this stage no, but if we are lucky, it could contain itself. The single most important factor determining the extent of human infections with the swine flu virus probably has to do with the biological characteristics of the virus and how it evolves, which is why it is being studied so carefully right now. If it were easy to contain the spread of influenza viruses, we would not have the problem of seasonal influenza every year.

What is the likely effect on the global economy of a pandemic?

In terms of the economy, precedents in the case of SARS in 2003 indicate that the effect on the economy could be considerable, but will depend on how wide the virus spreads, how deadly it is outside of Mexico, and how long the outbreak lasts. Some industries such as tourism and airlines will (and have already) been adversely affected as people cancel trips. In Mexico, many other businesses will suffer because of social distancing measures whereby public gatherings are cancelled and minimized. That has an impact on retail as well as restaurants and so forth. Some businesses, especially pharmaceuticals, may also benefit, as their medicines are in wide demand.


Notes for editors

By: Jacqui Bealing
Last updated: Friday, 11 December 2009