1996 - Rwanda

28 November 1996

Disease Outbreak Reported

Summary:

From 15 to 21 November 1996 an estimated 500 000 refugees returned from East Zaire to Rwanda across the border at Gisenyi, a small Rwandese town next to the Zairian town of Goma. More than 90% of them crossed the border during the first three days. The massive and rapid influx of returnees occurred on an unexpectedly large scale and could have had very serious public health consequences. About 14 000 consultations and 47 deaths were registered by the epidemiological sentinel stations in place. Diarrhoeal diseases accounted for two-thirds of all consultations. The crude mortality rate was estimated to 0.1/ 10 000/day (based on a denominator of 500 000). In view of the potential risks associated with such a massive population movement, this figure can be considered a success.

The first groups of returnees arrived in Goma on 15 November 1996. They were held in the Petite Barrière camp and released to relieve the pressure created by a massive influx of new arrivals. "Way stations" were installed every 5 to 6 km on the route according to a preestablished plan as soon as these arrivals were announced. Water, protein biscuits and some basic care, essentially oral and intravenous rehydration, were provided. Two transit centres were opened for further health care. Local health centres were also contributing, particularly those along the route of the returnees. Food distribution was limited to protein biscuits since any slowdown could have caused panic and stampedes, and would also worsen the risk of epidemics.

Epidemiological surveillance

Simple and practical forms for surveillance were developed mainly to detect illness with epidemic potential. The forms were distributed in advance to health centres concerned and to non-governmental organizations involved health care and working in the Gisenyi Prefecture.

Medical coordination was established in the regional health directorate under the chairmanship of the medical director of the health region concerned with technical support of the representative from WHO on site. Members of the health directorate, medical representatives of the UN agencies and NGOs involved met formally on a daily basis.

The epidemiological information presented below was collected in the "way stations" on the transit route, the transit centres and local health units. The NGOs such as AHA, COOPI, Merlin, MDM and MSF provided epidemiological data collected in the districts they had been allocated. Crude morbidity and mortality rates were calculated on a denominator of 500 000 population although the exact number is not known.

In addition to medical coordination and data collection, a plan of action in the event of a cholera epidemic was established with the health authorities.

Results:

A total of 14 160 consultations were registered from 16 to 21 November 1995. The peak of the consultations was on the third day of the migration. On this day, almost all returnees were still within the District of Gisenyi. Acute diarrhoeal disease was the main complaint and amounted to 9,407 or 66% of all registered consultations. The peak of the consultations for diarrhoea also occurred on the third day of the migration and then decreased (see table 1).

Only 319 cases of bloody diarrhoea were reported, with no deaths. In 23 cases of watery diarrhoea, Vibrio cholerae 01 El Tor was isolated from faecal samples by the laboratory in the central hospital in Kigali. None of the confirmed cases of cholera was severe or needed antibiotic treatment. This was fortunate as the V.cholerae strains isolated were resistant to doxycycline, tretracyline and cotrimoxazole. There were 38 deaths from diarrhoeal disease (CFR=0.4%). One case of measles and a case of suspected meningitis were registered.

It seems likely that many patients who consulted for acute diarrhoea were in reality exhausted and dehydrated after their long and sustained effort. Many presented with vomiting and stomach cramp and many complained of muscular cramp. No blood tests were done to investigate but it seems likely they suffered from hypoglycaemia and hypokalaemia. The patients recovered after receiving perfusion (Ringer's lactate) and a few protein biscuits and could continue their route.

Comment

The public health indicators are surprisingly good considering the massive repatriation taking place in a short time. A crude mortality rate of 0.1 per 10,000/day compares well with the mortality rate of 0.3/10 000/day estimated in the Mugunga camp where the refugee population stayed earlier. However, further steps need to be taken to strengthen preparedness in case of future massive population movements. This is particularly true if the health status of the population concerned continues to be precarious. The lessons learnt have served as a basis for recommendations for the future.