Vitamin A deficiency is an important risk factor for measles, a highly contagious and sometimes deadly disease.
Measles is caused by a virus and is spread through the air by breathing, coughing or sneezing. Symptoms include fever, runny nose, red eyes and a cough.
According to the World Health Organization (WHO), about half of the world’s children are vitamin A deficient by age five. This deficiency is responsible for more than 500,000 deaths from measles each year, with children under five years old being particularly vulnerable to its effects.
In addition to having a high mortality rate among children under five years old, measles also can lead to complications such as blindness, encephalitis (inflammation of the brain) and pneumonia.
Vitamin A For Measles
Background: Measles is a leading cause of childhood morbidity and mortality. Vitamin A deficiency is a recognised risk factor for severe measles. The World Health Organization (WHO) recommends administration of an oral dose of 200,000 IU (or 100,000 IU in infants) of vitamin A per day for two days to children with measles in areas where vitamin A deficiency may be present.
Objectives: The purpose of this review is to determine whether vitamin A when commenced after measles has been diagnosed, is beneficial in preventing mortality, pneumonia and other complications in children.
Search strategy: MEDLINE and the Cochrane Library, Issue 4, 1999 were searched.
Selection criteria: Only randomized controlled trials in which children with measles were given vitamin A or placebo along with standard treatment were considered.
Data collection and analysis: Studies were assessed independently by two reviewers. The analysis of dichotomous outcomes was done using the StatXact software package. Sub-group analyses were done for dose, formulation, age, hospitalisation and pneumonia specific mortality. Weighted mean difference with 95% CI were calculated for continuous outcomes.
Main results: The relative risks (RR) and 95% Confidence Intervals (CI) are based on the estimates from the StatXact software package. There was no significant reduction in mortality in the vitamin A group when all the studies were pooled together (RR 0.60; 95% CI 0.32 to 1.12)(StatXact estimate). There was a 64% reduction in the risk of mortality in children who were given two doses of 200,000 IU of vitamin A (RR=0.36; 95% CI 0.14 to 0.82) as compared to placebo. Two doses of water based vitamin A were associated with a 81% reduction in risk of mortality (RR=0.19; 95% CI 0.02 to 0.85) as compared to 48% seen in two doses of oil based preparation (RR=0.52; 95% CI 0.16 to 1.40). Two doses of oil and water based vitamin A were associated with a 82% reduction in the risk of mortality in children under the age of 2 years (RR=0.18; 95% CI 0.03 to 0.61) and a 67% reduction in the risk of pneumonia specific mortality (RR=0.33; 95% CI 0.08 to 0.92). There was no evidence that vitamin A in a single dose of 200,000 IU was associated with a reduced risk of mortality among children with measles (RR=0.77; 95% CI 0.34 to 1.78). Sub-groups like age, dose, formulation, hospitalisation and case fatality in the study area were highly correlated and there were not enough studies to separate out the individual effects of these factors. There was a 47% reduction in the incidence of croup (RR=0.53; 95% CI 0.29 to 0.89), while there was no significant reduction in the incidence of pneumonia (RR=0.92; 95% CI 0.69 to 1.22) or of diarrhoea (RR=0.80; 95% CI 0.27 to 2.34). Duration of diarrhoea was measured in days and there was a reduction in its duration of almost two days WMD -1.92, 95% CI -3.40 to -0.44. Only one study evaluated otitis media and found a 74% reduction in its incidence (RR=0.26, 95% CI, 0.05 to 0.92). We did not find evidence that a single dose of 200,000 IU of vitamin A per day, given in oil-based formulation in areas with low case fatality, was associated with reduced mortality among children with measles. However, there was evidence that the same dose given for two days was associated with a reduced risk of overall mortality and pneumonia specific mortality.
Reviewer’s conclusions: Although we did not find evidence that a single dose of 200,000 IU of vitamin A per day was associated with reduced mortality among children with measles, there was evidence that the same dose given for two days was associated with a reduced risk of overall mortality and pneumonia specific mortality. The effect was greater in children under the age of two years. There were no trials that compared a single dose with two doses, although the precision of the estimates of trials that used a single dose were similar to the trials that used two doses.
complications of measles
Measles can be serious. Children younger than 5 years of age and adults older than 20 years of age are more likely to suffer from complications. Common complications are ear infections and diarrhea. Serious complications include pneumonia and encephalitis.
People and groups at risk of measles complications
Measles can be serious in all age groups. However, there are several groups that are more likely to suffer from measles complications:
- Children younger than 5 years of age
- Adults older than 20 years of age
- Pregnant women
- People with compromised immune systems, such as from leukemia or HIV infection
Prevent measles: talk to your health provider about the measles, mumps, and rubella (MMR) vaccine.
- Ear infections occur in about one out of every 10 children with measles.
- Diarrhea is reported in less than one out of 10 people with measles.
Severe complications in children and adults
Some people may suffer from severe complications, such as pneumonia (infection of the lungs) and encephalitis (swelling of the brain). They may need to be hospitalized and could die.
Hospitalization. About 1 in 5 unvaccinated people in the U.S. who get measles hospitalized.
Pneumonia. As many as 1 out of every 20 children with measles gets pneumonia, the most common cause of death from measles in young children.
Encephalitis. About 1 child out of every 1,000 who get measles will develop encephalitis (swelling of the brain) that can lead to convulsions and can leave the child deaf or with intellectual disability.
Death. Nearly 1 to 3 of eve
1,000 children who become infected with measles will die from respiratory and neurologic complications.
Complications during pregnancy. Measles may cause pregnant women who have not had the MMR vaccine to give birth prematurely, or have a low-birth-weight baby.
Related page: The Measles chapter of the Epidemiology and Prevention of Vaccine Preventable Diseases (Pink Book) describes measles complications in more depth.
Subacute sclerosing panencephalitis (SSPE) is a very rare, but fatal disease of the central nervous system that results from a measles virus infection acquired earlier in life.
- SSPE generally develops 7 to 10 years after a person has measles, even though the person seems to have fully recovered from the illness.
- Since measles was eliminated in 2000, SSPE is rarely reported in the United States.
- Among people who contracted measles during the resurgence in the United States in 1989 to 1991, 7 to 11 out of every 100,000 were estimated to be at risk for developing SSPE.
- The risk of developing SSPE may be higher for a person who gets measles before they are 2 years of age.
- To learn more, visit the Subacute sclerosing panencephalitis (SSPE) MedlinePlus Medical Encyclopediaexternal icon.