Background: The common cold is the most prevalent sickness and an important cause of absence from job. Furthermore, it often disturbs travel, including the practice of hajj, causing the use of many inappropriate drugs by these travelers. The health belief model is a psychological model that attempts to explain and predict health behaviors. The purpose of this study was to determine the effects of zinc and health belief model based educational intervention on the behavior of hajj travelers with regard to viral upper respiratory tract infections (URTI).

Methods: This double-blinded randomized controlled trial was performed among hajj travelers in 2005. Preventive measures were randomly allocated to four groups: 1- education + zinc sulfate. 2- education + placebo. 3- zinc sulfate only 4- placebo only. Data regarding incidence and duration of URTIs, background disorders, vaccination and health behaviors for cold were gathered by questionnaire by physicians and finally analyzed by SPSS 11.5 software using chi-square, t-test and independent samples t-test.

Results: A total of 646 travelers were studied. The incidence of common cold in groups receiving zinc were significantly less than that for those receiving the placebo. (P=0.05). However, incidence was statistically the same for those who received education versus those who did not. Use of handkerchief was the most prevalent behavior and use of mask was the least prevalent behavior. Mean duration of symptoms was less in those receiving zinc and education (3.7 days) comparing to those who received placebo and education (5.6 days). 

Conclusions: This study showed that zinc consumption can decrease the incidence and duration of the common cold. Health belief model based education could promote some preventive behaviors although most people do not take advantage of them. We recommend the use of zinc by those attending hajj.