The prevalence of moderate to severe acute undernutrition in a random sample of children less than 5 years of age is generally a reliable indicator of this condition in a population. Since weight is more sensitive to sudden changes in food availability than height, nutritional assessments during emergencies focus on measuring WFH. Also, WFH is a more appropriate measurement for ongoing monitoring of the effectiveness of feeding programs. As a screening measurement, the mid-upper arm circumference (MUAC) may also be used to assess acute undernutrition, although there is not complete agreement on which cutoff values should be used as indicators. Nutritional assessment methods are fully described in the Rapid Nutrition Assessment Manual. *
* Available from the International Health Program Office (IHPO), CDC, 1600 Clifton Road, MS F-03, Atlanta, GA 30333, 404-639-0308.
Anthropometric indices such as WFH and height-for-age are interpreted by comparison with a "reference population". Index values are assigned a "Z-score" based on the number of standard deviations above or below the median value in the reference population. Currently, the World Health Organization (WHO) recommends the use of the CDC/NCHS reference population for nutritional assessments in all countries (22). Before the mid-1980's, anthropometric data was reported as a percentage of the median of the reference population value. Current international guidelines, however, recommend the use of Z-scores to report nutritional assessment data. Tables in this report define acute undernutrition on the basis of percentage median in order to allow comparisons of recent data with data from surveys performed before the mid-1980s.
In a well-nourished population in which WFH values are distributed normally (i.e., the reference population), approximately 3% of children less than 5 years of age will have WFH Z-scores of less than -2. For less developed countries with lower "normal" nutritional intake levels, 5% of the children may have a Z-score less than -2 when compared with the reference population median, particularly at certain times of the year. Relief organizations agree that a nutritional emergency exists if greater than 8% of the children sampled have a Z-score less than -2. An excess of even 1% of children with Z-scores less than -3 indicates a need for immediate action. Acute PEM prevalence rates have been high in recent famine-affected populations, especially in Africa (Table 6).
In addition, acute undernutrition prevalence rates have been elevated in many displaced and refugee populations during the past 12 years, ranging as high as 50% in eastern Sudan in 1985 (Table 5) and (Table 7). PEM rates have decreased rapidly in situations where effective emergency relief operations have been mounted promptly, i.e., Thailand (1979) and Pakistan (1980). However, in other emergencies, such as in Somalia (1980) and Sudan (1985), PEM rates have remained high (greater than 20%) for 6-8 months. Of even greater concern is the observation that acute undernutrition rates among Somali refugees in Ethiopia (1988-1989) actually increased 6 months after a relief program was launched. Although most high acute undernutrition prevalence has been associated with inadequate food rations, it appears that malnutrition developed among Kurdish children 1-2 years of age in Turkey within a period of 1-2 months, primarily because of the high incidence of diarrheal diseases in the camps (10). Among internally displaced civilian populations, high PEM prevalence has been associated with the intentional use of food as a weapon by competing military forces (30).
The use of serial anthropometry surveys as monitoring tools has certain limitations when mortality rates are high. For example, an analysis of anthropometric data from two cross-sectional surveys in a refugee camp in Sudan in 1985 initially implied a relatively stable nutritional situation. In January, the prevalence of acute malnutrition in children less than 5 years of age was 26.3%; in March, the rate was 28.4%. During these two months, almost 13% of the children in the camp died, mainly from measles and diarrheal diseases. In this instance, the elevated child mortality rate masked diminished nutritional status in the population. Many malnourished children in the first survey, who had died, were "replaced" in the second survey sample by surviving children whose nutritional status had meanwhile deteriorated (31). Thus, anthropometry data need to be interpreted in the context of concurrent mortality rates.
Famine-affected and displaced populations often have low levels of dietary vitamin A intake before experiencing famine or displacement, and therefore, may have very low vitamin A reserves. Furthermore, the typical rations provided in large-scale relief operations lack vitamin A, putting these populations at high risk. In addition, some communicable diseases that are highly incident in refugee camps -- measles and diarrheal diseases -- rapidly deplete vitamin A stores. Depleted vitamin A stores need to be adequately replenished during recovery from these diseases to prevent the deficiency from becoming clinically important.
Active surveillance for scurvy among Ethiopian refugees in Somalia and Sudan in 1987 revealed cumulative incidence rates of up to 19.8% in some camps, with initial onset reported between 3-10 months after the arrival of the refugees (32). Cross-sectional surveys performed in 1986-1987 reported point prevalence rates as high as 45% among females and 36% among males; prevalence increased with age. The prevalence of scurvy was associated with the period of residence in camps, and the time exposed to rations lacking in vitamin C. In 1989, a population survey of children less than 5 years of age in Hartisheik camp in eastern Ethiopia in 1989 found the prevalence of clinical scurvy to be 2% (19). The international community has not developed an adequate strategy to prevent scurvy in refugee camps at the Horn of Africa, as demonstrated by an outbreak that took place among adult males (former Ethiopian soldiers) in a camp in eastern Sudan during 1991 (Bhatia R, personal communication, October 1991).
A 1987 study among refugees in Somalia demonstrated an anemia prevalence rate of 44%-71% among pregnant women, with that proportion being even greater if only women in the third trimester of pregnancy were considered. The cutoff point for hemoglobin concentration in this study was 10 g/dL; with the WHO cutoff of 11 g/dL, the prevalence would have been greater. Among children 9-36 months of age, 59%-90% were below the 10 g/dL cutoff. The inadequacy of the general ration was identified as the major factor causing iron deficiency anemia in this population. In a 1990 study, the prevalence rate of anemia was 13% among children less than 5 years of age in an Ethiopian camp for Somali refugees (Save the Children Fund UK, unpublished data). In addition to dietary iron deficiency, the high incidence of malaria in many refugee populations probably contributes to the high prevalence of anemia in children. This high prevalence of anemia found in some refugee populations may not be significantly greater than that found in local, non-refugee populations, since the latter group has been poorly documented. Nevertheless, anemia may be an additional important preventable risk factor for high mortality in refugee populations. The high prevalence of anemia is often correlated with a subset of the population with severe anemia (hemoglobin (Hb) less than 5 g). Severe anemia in itself can be a major cause of mortality for young children and pregnant women during the peripartum period.