Winter has arrived in the southern hemisphere and health ministers all over the world are waiting to see if the pandemic H1N1 virus that spread around the globe last year and this year has receded or whether it will mutate into yet another “novel” influenza virus.
Even if the news is good, we will likely have to face the emergence of another strain of the virus somewhere down the line. The question is whether we have learned enough to make this a less daunting prospect.
Certainly, we have learned a number of crucial lessons that will prove decisive in any global effort to tackle a coming epidemic. First, border quarantine is of limited effectiveness, although it can retard the spread of a disease within a country in the short term if strictly implemented, buying precious time for better pandemic preparation to be made.
Second, local infectious disease surveillance is important, but there is also a need for cooperation and integration between local, central and global surveillance systems for influenza, which can then provide instant feedback to each other.
Third, the implementation of prevention measures in places where outbreaks of influenza occur such as hospitals, schools and public spaces, was more efficient in those countries or areas that experienced the 2003 outbreak of severe acute respiratory syndrome (SARS) than in tropical countries.
Fourth, health policies have to be closely integrated with findings through epidemiological investigation and surveillance systems.
In the most recent scenario, for example, we were fortunate that the US Centers for Disease Control and Prevention (CDC) detected the novel triple reassortant pandemic H1N1 virus early on, and that several states implemented timely syndromic surveillance systems. This made it possible to determine the nucleotide sequence of the virus, develop rapid laboratory diagnosis reagents and conduct an epidemiological investigation on risk/protection factors, information that was shared with public health decisionmakers in other countries as soon as it became available.
Finally, countries have experienced large-scale outbreaks of influenza primarily due to inadequate surveillance systems and ineffective epidemiological investigation.
The most effective strategy to cope with the early stages of an epidemic of a newly emerged infectious disease would be to take a three-pronged approach. This would consist of more effective surveillance and health information systems, which would then reveal clinical manifestations and epidemiological characteristics. The results of virological surveillance and rapid laboratory tests could then help to verify the etiological agent. This would enable us to come up with a three-level definition scheme to determine suspected, possible and confirmed cases, providing us with a scientific basis to assess the risk factors for both the infection and the disease.
It is especially important that we quickly identify possible causes for severe and fatal cases and simultaneously monitor any possible increases in the virus’ pathogenicity and virulence (the case fatality rate).
Effective monitoring of the severity of an epidemic or a pandemic and the way in which it develops is dependent on cooperation between infectious disease epidemiologists, statisticians and health policy makers. During the SARS outbreak back in 2003 the Department of Life Sciences at the National Science Council and the Center for Disease Control (CDC) in Taiwan assigned the majority of their infectious disease experts to the research effort. This time, however, there was a lack of systematic integration of research between hospitals and clinics, local health bureaus and academic institutions on what needed to be taken into account and what risks were involved, particularly professional considerations and risk communication in dispensing anti-viral treatment or implementing mass vaccinations.
RSS