and the availability of vitamin C-containing foods in these markets or the ability of food donors to purchase and provide such foods. Because of seasonal variation in the availability of these foods and dynamic changes in the market situation, periodic assessments are needed. It is extremely unlikely that biochemical assessment of vitamin C status will be feasible in most field situations, although this might be of interest for research purposes.
Ideally, systematic evaluation of the situation with regard to vitamin C should be included in the initial and subsequent periodic assessments of a population's general nutrition and health condition. It would be useful for international agencies and nongovernmental organizations to achieve some consensus on how this assessment might be accomplished and interpreted.
In any situation where more than 0.1 percent of individuals are found to have clinical scurvy, therapeutic interventions should be initiated as quickly as possible. Because the appearance of any cases of scurvy is likely to indicate that the entire population is deficient to some degree, therapeutic approaches might be considered for all members of the population until adequate preventive measures are in place. Moreover, since there is generally a lag of two to three months between the onset of low vitamin C intake and the first appearance of clinical signs of scurvy, it can be assumed that if any scurvy is present in a population at the initial assessment, the incidence of new disease is likely to increase progressively unless the population has access to local food sources of vitamin C or other preventive measures are introduced.
There is evidence of scurvy outbreaks among refugee populations entirely dependent on emergency relief rations that provide less than 2 mg of vitamin C per day per person. The greatest number of outbreaks occurred in the 1980s in Somalia. Only four outbreaks have been reported since January 1994, when the World Food Programme (WFP) and the United Nations High Commissioner for Refugees (UNHCR) adopted a policy of providing fortified blended foods to populations wholly dependent on food aid, in an effort to preempt any micronutrient deficiencies. One outbreak occurred among Rwandan refugees in eastern Zaire in the spring of 1994 prior to the time at which the newly adopted food aid plan could be implemented. Recurring mild outbreaks of scurvy were reported among Bhutanese refugees in Nepal in 1994, 1995, and 1996, and moderate outbreaks were reported among Somali refugees in the Dadaab camp in Kenya in 1994 and 1996. However, the scurvy outbreaks in the Dadaab camp did not appear to be related to the presence or abscence of fortified, blended foods in the diet. Thus, the need for higher vitamin C fortification of corn-soy blend (CSB) and wheat-soy blend (WSB) would be sporadic and apparently localized.