Background: Acute diarrhea is the fifth leading cause of death due to infectious diseases and responsible for 16.2% of the infectious disease burden in Iran. This study assessed the incidence and some determinants of acute diarrheal diseases in Tehran, the capital of Iran.

Patients and methods: Using cluster sampling, a population based survey was conducted among 2095 children aged 6 to 60 months in the southern districts of Tehran during May 2005. The incidence of acute diarrhea during the past 2 weeks, the duration and frequency of diarrhea, acute diarrhea in siblings and socioeconomic determinants were gathered by a questionnaire.

Results: Totally, 10.3% of children experienced new onset of diarrhea during the past two weeks with the average number of episodes of 2.8 per child. Half of the cases were 6-18 months of age (p<0.001). The mean (±standard deviation) duration of disease was 4.5±2.1 days and the frequency of diarrhea was 5.1±5 episodes per day. In 9.1% of the families, other cases of concurrent acute diarrhea were reported in siblings (OR=1.29, 95%CI:0.67-2.47). The mean age of the mothers was 31±7.5 years. Less than 4% of the parents were illiterate.

Conclusion: Childhood acute diarrhea remains a public health concern in Tehran. Improving the environmental sanitation and personal hygiene and raising the socioeconomic status of the population will contribute to the elimination of the underlying causes of acute diarrhea.