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Surveillance of Mortality During a Refugee Crisis --- Guinea, January--May 2001

Since 1990, the republic of Guinea (2000 population: 7.5 million) has accepted 390,000--450,000 refugees from Sierra Leone and Liberia (1,2). During this 10-year period, refugees have lived in small villages scattered throughout rural southeastern Guinea (3). During September--December 2000, attacks by armed factions in Guinea led to the widespread displacement of refugees living in the southeastern camps; the refugees subsequently were transferred to safer camps in the northwest. Approximately 280,000 refugees initially were estimated to have been displaced (4). After the attacks, the number of refugees relocated was approximately 58,000. This report demonstrates methods used to calculate mortality rates when large populations are displaced. The findings indicate that the number of refugees in Guinea before the relocation probably was overestimated. The mortality rates calculated using conservative denominator numbers did not meet the definition of an emergency phase* of a complex emergency, and mortality rates were lower for refugees compared with baseline rates for the local population. Accurate methods are needed to estimate population size in complex emergencies to provide resources to vulnerable groups.

In camps that were accessible to site visits by international agencies, nongovernmental organizations (NGOs)§ collected and reported camp mortality data from NGOs and government health posts, camp health-care workers, the referral hospital, and burial workers. Deaths were line listed (i.e., one line for each death), and duplications of reported deaths were deleted. Estimates of camp populations were provided by the government of Guinea, the United Nations High Commissioner for Refugees (UNHCR), NGOs, and refugee and other organizations. Because these estimates varied widely, the lowest estimates for all camps were used to calculate mortality rates. Nutrition surveys could not be conducted in less accessible camps; the prevalence of acute malnutrition among children aged 6--49 months was estimated using nutrition screening data collected from all children entering new camps in northwestern Guinea. Monthly camp death rates usually are calculated by dividing the sum of all deaths in the camps by the sum of each camp's midpoint population size and then dividing by the number of days in the month or by the mean number of days the camps were open. However, using this approach would have underrepresented camps that were not open for the entire month.

Individual camp mortality rates were calculated based on the number of days each camp was open during the month. Several sites were transit camps; opening and closing of these camps depended on refugee migration patterns. The mean mortality rates weighted by population were used to calculate overall camp mortality rates by month; mortality rates of each camp were weighted using the overall population and totaled. Only camps reporting data for the entire time they were open during each month were included in the overall monthly mortality rates. The same weighting method was used to calculate the overall crude mortality rate (CMR) and the mortality rate for children aged <5 years (<5MR) during January--May 2001.

The number of camps included in the health information systems (HIS) during January--May 2001 varied from four to 15 camps sheltering approximately 34,000--89,500 persons because of large population movements and changing security conditions. Before relocation, an estimated 280,000 refugees were housed in approximately 43 camps. However, in three HIS camps, census or relocation numbers determined by UNHCR were 1.6--3.9 times higher than original estimates of 280,000. If the overestimation ratios of 1.6--3.9 are applied to the original population estimate, the actual refugee population in southeastern Guinea may have ranged from 72,000 to 175,000 persons. Camps represented in the HIS tended to be larger and more accessible to UN and NGO health workers. All children aged 6 months--15 years were vaccinated for measles on entry to the new camps.

During January--May 2001, a total of 304 deaths were reported; 173 (57%) were among children aged <5 years. The CMR and <5MR of 0.3 and 0.9 deaths per 10,000 per day, respectively, were well below the levels used to define the emergency phase of a complex emergency (5,6). These rates also were lower than the CMR and <5MR reported for the Guinean population (0.5 and 1.3 deaths per 10,000 per day, respectively) (7). The CMR and <5MR monthly trends were higher at the beginning of relocation in January and after most refugees had been transferred in May. Mortality rates decreased then stabilized from February to April as refugees who arrived in secure camps were provided with services. In May, however, mortality rates increased (Figure 1) (5). NGOs anecdotally reported an increase in malnutrition in some of the less accessible camps. However, of 4,771 children who were screened in the new camps using weight-for-height during February--May, 119 (2.5%) were acutely malnourished.

In response to the increase in mortality rates among refugees in Guinea during May, UN agencies and NGOs 1) accelerated efforts to move the refugees in the new camps from crowded temporary shelters to permanent family structures, 2) enhanced communicable disease surveillance, 3) improved water and sanitation provisions in the new camps, 4) stockpiled cholera-control supplies, and 5) increased the number of health posts.

Reported by: T Doumbia, MD, B Massakumbo, MD, A Barry, MD, M Deppner, MD, United Nations High Commissioner for Refugees, Geneva, Switzerland. International Emergency and Refugee Health Br, Div of Emergency Environmental Health Svcs, National Center for Environmental Health, CDC.

Editorial Note:

During complex emergencies, agencies must resolve immediate health questions affecting tens of thousands of refugees, despite the uncertainty of population size and the inaccuracy of data. This report used methods to calculate rates that suggest an effective response to the 2001 Guinea refugee crisis in which large populations were displaced. Mortality rates might have been kept below emergency threshold rates because of the prompt engagement of international agencies together with sufficient resources and coping mechanisms developed by the refugees during the 10 years in Guinea preceding the latest crisis. The increase in mortality after most refugees were relocated into the new camps might have occurred because some refugees were not relocated to individual family shelters as quickly as planned, causing overcrowding of temporary shelters and overburdening of existing facilities. This increase demonstrates the need to ensure that adequate human and material resources and programs are in place before large transfers of persons occur.

Lower mortality rates among refugees than among host populations have been . documented in postemergency settings (8,9); in Guinea during the displacement, the refugee population had lower mortality rates than those of the baseline population in Guinea. The lack of mortality data for the local and internally displaced populations during the refugee crisis suggests that organizations whose mandates cover nonrefugee populations need to be included early in the process of emergency response.

Despite all refugees being offered transportation, far fewer relocated to the new camps than had been anticipated. Populations commonly are overestimated in refugee crises because food distribution is linked to camp size. In Guinea, internally displaced and local persons sought to be counted as refugees to receive food aid and other services; distinguishing among the three groups, where refugees came from the same ethnic group and lived among the local population, was particularly difficult.

The findings in this report are subject to at least five limitations. First, data were unavailable from inaccessible camps where mortality rates may have been higher than in more accessible camps. Second, population denominators for camps that did not have a recent census probably overestimated population sizes. Third, underreporting and underestimates of mortality might have occurred in camps with limited access. Fourth, only camps with data for 1 month were included in the monthly HIS calculations. The changing number of camps with data available for an entire month and the opening and closing of some transit camps make the comparison of monthly rates difficult, because the same sites and populations were not represented each month. Finally, midpoint rather than the mean population size was used as the denominator in calculating mortality rates. The preferred method is unclear because of the constant changes in population throughout this period (10).

Difficulties arise when estimating mortality and nutrition rates among displaced populations that are moving at different rates in areas with varying accessibility (10). In Guinea, some approaches to these challenges were 1) including mortality data only for the days in which individual camps were open for each month throughout the 5-month reporting period, 2) using the lowest population estimates and applying them retrospectively when appropriate, and 3) calculating overall mortality rates using population-weighted mean rates to allow for an unbiased estimate from camps being open for different numbers of days within a month.


  1. US Committee for Refugees. World refugee survey 2001. New York, New York: US Committee for Refugees, 2001.
  2. United Nations High Commissioner for Refugees. The state of the world's refugees 2000. Geneva, Switzerland: Oxford University Press, 2000.
  3. Van Damme W, De Brouwere M, Van Lerberghe W. Effects of a refugee-assistance program on host population in Guinea as measured by obstetric interventions. Lancet 1998;231:1609--13.
  4. Rostrup M, Ford N. Aid and safety for Guinea's refugees. Lancet 2001;357:1123.
  5. CDC. Famine-affected, refugee, and displaced populations: recommendations for public health issues. MMWR 1992;41(no. RR-13).
  6. Steering Committee for Humanitarian Response and InterAction. The Sphere Project: humanitarian charter and minimum standards in disaster response. Oxford, England: Oxford Publishing, 1998.
  7. UNICEF. State of the world's children. New York, New York: Oxford University Press, 2001.
  8. Elias CJ, Alexander BH, Sokly T. Infectious disease control in a long-term refugee camp: the role of epidemiologic surveillance and investigation. Am J Public Health 1990;80: 824- -8.
  9. Mercer A. Mortality and morbidity in refugee camps in eastern Sudan: 1985--90. Disasters 1992;16:28--42.
  10. Burkholder BT, Spiegel P, Salama P. Methods of determining mortality in the mass displacement and return of emergency-affected populations in Kosovo, 1998--99. In: Forced migration and mortality. Washington, DC: National Academy Press, 2001:86--101.

* Crude mortality rate of >1 death per 10,000 population per day or a mortality rate of >2--4 deaths per 10,000 children aged <5 years per day.

Relatively acute situations affecting large civilian populations, usually involving a combination of war or civil strife, food shortages, and population displacement, resulting in excess mortality.

§ Action Against Hunger, American Refugee Committee, International Federation of the Red Cross and Crescent, Doctors of the World, and Doctors Without Borders.

Provided by United Nations Children's Fund and the government of Guinea.

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