The Ministry of Health has been working closely with the World Health Organization (WHO) to respond to the current outbreak of severe acute watery diarrhoea in which a number of people have tested positive to the cholera bacteria. This collaboration first began when the first wave of cases was reported in October 2007.
Several reports in the media have expressed concern about the use of the term 'Severe Acute Watery Diarrhoea' to describe cases in this outbreak.
"During large outbreaks it is not practical to test every person with severe acute watery diarrhoea. What is more important in an outbreak setting is that everyone with severe acute watery diarrhoea be treated as if they had tested positive for cholera" said Vice Minister of Health, Trinh Quan Huan. This is what is happening in Viet Nam and this probably explains why there have been no deaths reported.
The total number of cases for which cholera treatment is being given (i.e. severe acute watery diarrhoea cases) should be reported, as well as the number of these cases for which laboratory confirmation has been completed (i.e. confirmed cholera cases). "Although this approach can lead to some confusion, it is still one of the best ways to classify and report these cases" said Dr Jean-Marc Olivé, WHO Representative in Viet Nam.
The Ministry of Health is continuing to respond actively to the outbreak and has requested technical assistance from WHO.
It is often difficult to identify the source of infection during an outbreak of food-borne or water-borne illness. Even in the best of settings, the source of infection is identified in only 30% of these outbreaks.
The National Institute of Hygiene and Epidemiology, with assistance from WHO technical advisors, has been very active in their search for the source of the outbreak, and they have provided a high level of expertise in both their epidemiological and laboratory investigations.
These investigations have identified the nature of the cholera strain in the outbreak and have identified key high risk activities for becoming infected with cholera in this outbreak. The activity with the highest risk for cholera infection remains eating meals containing dog meat, shrimp paste, and raw herbs and vegetables.
The National Institute of Hygiene and Epidemiology has begun additional investigations to provide further information for action, and stronger surveillance and monitoring activities will further reduce the risk of outbreaks in the future.
The Ministry of Health and the World Health Organization have agreed to continue the following measures to stop this outbreak:
- Rapid identification and treatment of cases
- Increased inspections of commercial food vendors to improve food safety standards and to identify and take action against high-risk premises
- Disinfection of the household environment of cases
- Maintaining the supply of safe water
- Public information campaigns with key messages on reducing personal risk through improved food safety and personal hygiene
As the risk of outbreaks with cholera is highest during the rainy season, new outbreaks are possible in the near future in Viet Nam.
WHO recommends that the measures introduced in response to this outbreak be continued in the future and become routine practice. In particular, WHO recommends the widespread promotion and adoption of the five keys to safer food which remain important for the prevention of food-borne and water-borne diseases. These are:
- Keep clean – particularly by hand washing with soap before handling food and after going to the toilet.
- Separate raw and cooked food – particularly high risk foods like raw meat, poultry and seafood.
- Cook food thoroughly.
- Keep food at safe temperatures – particularly keeping cooked foods above 60oC or cold below 5oC.
- Use safe water (chlorinated or boiled) for consumption and for cleaning of raw foods, such fruit and vegetables.