Update on Cholera in Pohnpei — descriptive data, 4 September 2000
Source: Pacific Public Health Surveillance Network, 11 September 2000

This summary has been compiled from inpatient and outpatient data from the Pohnpei Hospital and community-based dispensaries, provided by the Pohnpei Hospital Medical Records through the National Health Statistician. It updates the description of the outbreak of cholera on Pohnpei island that public health authorities recognised on 17th April 2000. The Pohnpei Hospital Laboratory isolated Vibrio cholerae, as the cause of this outbreak and the serotype has been confirmed as serotype Ogawa by Guam Public Health laboratory. The biotype, established by Pasteur Institute of New Caledonia, is El Tor.

Up to 4 September, there have been 2 886 cases of acute watery diarrhoea reported since the beginning of the outbreak, which includes cases less than 5 years of age and many for which age was not determined (Figure 1). There have been nineteen deaths reported in association with the outbreak.

In the data for which the ages are reported up to the beginning of July, approximately 85% of the suspected cholera cases are meeting the World Health Organization case definition[1].

The inpatients data are the most reliable of the three possible data sources and were the most complete. Daily admissions for suspected cholera are shown in Figure 2.

Both graphs (Figures 1 & 2) show the highest peak mid-June (weeks 23-25), followed by another high peak in the first half of July (weeks27-28), and a subsequent decrease in the daily and weekly number of cases.

There are still a number of limitations that must be considered in the interpretation of these data, particularly for outpatients and emergency departments, including:

  • age was not available for many outpatients,
  • patients may have presented more than once for the same episode,
  • the case definition for suspected cholera was not rigorously applied, and
  • there may be errors due to recording, or data entry.

More frequent updates are also available on PACNET. They include a description of control measures taken by Pohnpei State and a preparedness advice.


Figure 1: Cases of acute watery diarrhoea by week of presentation to inpatients, outpatients and emergency departments at the Pohnpei hospital, and community-based dispensaries, 4 Sept 2000

Figure 2: Cases of suspected cholera, by day of admission, Inpatient Data, Pohnpei Hospital, 4 Sept 2000


CONFIDENTIAL – Copyright PPHSN

[1] The World Health Organization guidelines for cholera control indicate that for surveillance purposes, the case definition for suspected cholera in an epidemic situation should be a person 5 years of age or greater develops acute watery diarrhoea.