Severity of measles: a study at the Queen Sirikit National Institute of Child Health

Thousands of measles cases are reported annually in Thailand even though measles vaccine has been introduced in the expanded program of immunization for every 9-month-old infant for nearly 20 years. Severe cases are admitted to the hospital, usually with complications, some cases lead to death.

To study the clinical presentations of severe cases of measles and its complications and find the correlations of severity of pneumonia with age, nutritional status and history of vaccination.

The hospital charts of measles patients admitted to the Queen Sirikit National Institute of Child Health (QSNICH) during 1998-2002 were retrospectively reviewed. Demographic data, history including history of measles vaccination, physical examinations, laboratory investigations, treatment and hospital course which were relevant were recorded. Paired t-test and Pearson's correlation were used for data analysis.

There were 156 cases of measles admitted to the QSNICH. There were 95 boys and 61 girls and the male to female ratio was 1.56:1. The age range was 2 months to 14.8 years, median = 1.5 years, mode 8 months. Fifty-nine percent of the cases were under 2 years of age; 40% under one year and 23.9% were under 9 months. About 44% of the cases had one dose of previous measles vaccination, no history of measles vaccination in 91.4% of cases whose age was under 1 year in contrast to 80% of cases over 5 years that had a history of measles vaccination. Sixty-six percent of the cases had normal nutritional status while 12.4%, 4.8% and 2.1% had mild, moderate and severe protein calorie malnutrition. Fourteen cases (9%) had underlying diseases. At least 3 of the classical signs and symptoms of measles (rash, cough and coryza) were found in 92.3% of the cases. The mean duration of fever at the time of admission was 5.3 days. The common complications in admitted measles cases were pneumonia (62.2%) and diarrhea (38.1%). The likely causes of pneumonitis were measles viruses (52.6%) and bacteria (47.4%). There was one dead case with severe pneumonia, with ARDS and respiratory failure. Young infants had a higher incidence of diarrhea with dehydration (p = 0.000) but severity of pneumonia was not different from older children (p = 0.512). The severity of pneumonia was not correlated with the age (r = 0.087), nutritional status (r = 0122) or the history of receiving measles vaccine (r = 0.116).

Measles is one of the important diseases of in-patients admitted to the QSNICH, because of the severity of the diseases due to pneumonia and diarrhea. One severe case died because of severe pneumonia that lead to ARDS and respiratory failure. Young infants had a higher incidence of diarrhea and dehydration, while there was no correlation between severe pneumonia with age, nutritional status and history of vaccination.