Communicable Diseases

Measles, diarrheal diseases, ARIs, and in some cases, malaria are the primary causes of morbidity and mortality among refugee and displaced populations (1,16,41). (Figure 4), (Figure 5), and (Figure 6) illustrate patterns of mortality typical among those found in refugee camps. Other communicable diseases, i.e., meningococcal meningitis, hepatitis, typhoid fever, and relapsing fever have also been observed among refugee populations; however, the contribution of these illnesses to the overall burden of disease among refugees has been relatively small.

Densely populated camps with poor sanitation, inadequate clean water supplies, and low-quality housing all contribute to the rapid spread of disease in refugee settings. In addition, the interaction between malnutrition and infection in these populations, particularly among young children, has contributed to the high rates of morbidity and mortality from communicable diseases. Available and affordable technology could prevent much of this morbidity and mortality either through primary prevention (e.g., immunization, adequate planning, and sanitation) or through appropriate case management (e.g., treatment of dehydration caused by diarrhea with oral rehydration salts and continued feeding).

Measles

Outbreaks of measles within refugee camps have been common and have caused many deaths. Low levels of immunization coverage, coupled with high rates of undernutrition and vitamin A deficiency, have played a critical role in the spread of measles and the subsequent mortality within some refugee camps. Measles has been one of the leading causes of death among children in refugee camps. In addition, measles has contributed to high malnutrition rates among those who have survived the initial illness. Measles infection may lead to or exacerbate vitamin A deficiency, compromising immunity and leaving the patient susceptible to xerophthalmia, blindness, and premature death (42). In early 1985, the crude, measles-specific death rate in one eastern Sudan camp reached 13/1,000/month; among children less than 5 years of age, the measles-specific death rate was 30/1,000/month. Over 2,000 measles deaths were reported in this camp from February through May 1985. (Figure 9) illustrates the proportion of all deaths that were due to measles in this camp during the course of the outbreak (16). The CFR was reported to be 33% during this outbreak; however, mild cases may have been underreported. Large numbers of measles deaths have been reported in camps in Somalia, Bangladesh, Sudan, and Ethiopia (1). Mass immunization campaigns were effective in reducing the measles morbidity and mortality rates in camps in both Somalia and Thailand (16). Measles outbreaks probably did not occur during certain other major refugee emergencies (e.g., Somalis in Ethiopia in 1989; Iraqis in Turkey in 1991), because immunization coverage rates were already high in those refugee populations before their flight (9,10).

Diarrheal diseases

Diarrheal diseases are a major cause of morbidity and mortality among refugee and displaced populations, primarily because of the inadequacy of the water supply (both in terms of quality and quantity), and the insufficient and poorly maintained sanitation facilities. In eastern Sudan in 1985, between 25%-50% of all deaths in four major camps were attributed to diarrheal diseases. In Somalia (1980), Malawi (1988), and Ethiopia (1989), between 28%-40% of all deaths in refugee camps were attributed to diarrhea (1). Between March and October 1991, 35% of deaths among Somali refugees in the Liboi camp in Kenya were caused by diarrhea. Among Central American refugees in Honduras, diarrheal diseases were responsible for 22.3% of mortality among children less than 5 years of age during a 3-year period (43). In April 1991, in camps for Iraqi refugees on the Turkish border, approximately 70% of all patients arriving at clinics had diarrhea (10). Of these, approximately 25% complained of bloody diarrhea during the first 2 weeks of April. (Figure 10 ) shows the gradual decline in diarrheal disease among clinic outpatients at a Kurdish refugee camp in Turkey.

Improvements in camp sanitation and water supply were probably responsible for this trend. Although the etiologies of diarrheal illness during refugee emergencies have not been well documented, the responsible pathogens are most likely to be the same agents that cause diarrhea in non-refugee populations in developing countries. In one study in a camp for famine victims in Ethiopia, of 200 patients with diarrhea, 15.6% had positive cultures for Escherichia coli (pathogenicity not specified by authors), 3.5% for Shigella spp., and 2% for Salmonella spp. (44).

Cholera

Outbreaks of cholera have occurred in several refugee populations, although overall, other diarrheal diseases have probably caused many more deaths than cholera. In addition to the morbidity and mortality directly caused by cholera, epidemics of this severe disease cause serious disruption to camp health services. Outbreaks of cholera have been reported in refugee camps in Thailand (16,45), Sudan (46), Ethiopia (11-12), Malawi (47), Somalia (48), and Turkey (10). The Somali Refugee Health Unit reported 6,560 cases of cholera and 1,069 cholera deaths in 1985. During the course of the epidemic, one camp (Gannet) experienced a CFR of 25%. The CFR in the remaining camps was 2.9%, with some areas reporting a CFR of less than 1% (Figure 11) (48). During the same year, two adjacent refugee camps in the Sudan reported a total of 1,175 cases of cholera with 51 deaths (CFR = 4%) over the course of a 2-week epidemic (46). Mozambican refugees in Malawi have been especially vulnerable to cholera; 20 separate outbreaks have been reported in Malawian camps since 1988 (49). Outbreak investigations have identified polluted water sources, shared water containers and cooking pots, lack of soap, failure to reheat leftover food, and possibly contaminated food (dried fish) as important risk factors for infection. Nearly 2,000 cases were reported among 80,000 refugees in one camp (Nyamithutu) during a 4-month period in 1990 ( Figure 12). Among 26,165 new arrivals during this period, 1,651 cases were reported for an attack rate of 6.3% in this group. The variation in CFRs between camps reflects the different levels of organizational preparedness, health worker training and experience, and available resources. One group of relief workers speculated that high CFRs in some Malawian camps may be associated with concurrent niacin deficiency, although their hypothesis has not yet been proven (Moren A, personal communication).

Acute respiratory infections

ARIs are among the leading causes of death among refugee populations. In Thailand (1979), Somalia (1980), Sudan (1985), and Honduras (1984-1987), ARIs were cited among the three main causes of mortality in refugee camps, particularly among children (16,43). Among children less than 5 years of age in refugee camps in Honduras, respiratory infections were responsible for slightly greater than 1 of every 5 deaths during a 3-year period (43).

Tuberculosis (TB)

TB is well recognized as a health problem among refugee populations. The crowded living conditions and underlying poor nutritional status of refugee populations may foster the spread of the disease. Although not a leading cause of mortality during the emergency phase, TB often emerges as a critical problem once measles and diarrheal diseases have been adequately controlled. For example, 26% of adult deaths among refugees in Somalia in 1985 were attributed to TB (16). During this time, TB was the third leading cause of death, and the leading cause among adults (48). In eastern Sudan, between 38% and 50% of all deaths in two camps were caused by TB during the 9 to 10 months period after the camps opened (16). TB has been cited as a major health problem among Afghan refugees in Pakistan (CDC. Serdula M, trip report). Although it may be theoretically easier to ensure patient compliance with protracted chemotherapy in the confined space of a refugee camp, the personnel needed to supervise treatment may not be available. In addition, the uncertain duration of stay, frequent changes of camp locations, and poor camp organization may hinder TB treatment programs.

Malaria

Malaria is a major health problem in many areas that host large refugee populations, including Somalia, Sudan, Ethiopia, Thailand, Guinea, Cote d'Ivoire, Malawi, Pakistan, and Kenya. Malnutrition and anemia, conditions that are common among refugees, may be directly related to recurrent or persistent malaria infection or may compound the effects of malaria and lead to high mortality. Malaria is the leading cause of morbidity among adult refugees in Malawi and in 1990 caused 18% of all deaths and 25% of deaths among children less than 5 years of age (CDC, unpublished data). Malaria is of particular concern w