Respiratory Tract Infections and its Preventive Measures among Hajj Pilgrims, 2010: A Nested Case Control Study

BACKGROUND: Respiratory tract infections are very common among the Hajj pilgrims. Some preventive measures including Influenza vaccination, using face mask and salt water gargling have been considered to control these infections and the reports show conflicting results about the effects of each one of these measures. This study is trying to assess the effects of these recommendations on respiratory tract infections. METHODS: According to nested case-control design, in a cohort consisting of 338 Iranian pilgrims, the outcome examined, was all types of respiratory tract infections other than common colds. With occurrence of any patient in convoy, data collection form was completed for that person. On the same day, two people were randomly selected as control group from among pilgrims who have not affected so far. RESULTS: During Hajj, 32 pilgrims (9.5%) were affected by respiratory tract infections other than common colds. In univariable logistic regression analysis, salt water gargling (OR = 2.4, P = 0.08), existence of other patient in the room (OR = 2.14, P = 0.19), age over 60 years (OR = 1.84, P = 0.15) and the education more than or equal to 3 years (OR = 1.93, P = 0.16) were effective in the respiratory tract infections (P < 0.2). However, multivariable logistic regression analysis showed that none of the above mentioned factors are significantly associated with these infections. CONCLUSIONS: This study showed that measures such as seasonal influenza vaccination, use of face masks and personal prayer carpet have no effect on the incidence of respiratory tract infections. However, washing throat and mouth with salt water can be considered the most effective preventive measures.