Incidence of Hajj-related Acute Respiratory Infection among Hajjis from Riyadh, 1423 H (2003 G)

Hazards during Hajj have local and international ramifications as pilgrimaging Muslims return home.[1] A large number of domestic hajjis complain of Acute Respiratory Infections (ARIs) immediately after returning from Hajj. However, in the absence of the vital information regarding the magnitude of this problem and associated risk factors it is usually not possible to plan appropriate preventive measures. Keeping this in view, a prospective cohort study was conducted to assess the incidence of post-Hajj ARI and its associated risk factors among domestic hajjis from Riyadh in Hajj 1423H. Participating hajjis were recruited as study cohort from 10 Dhul Qaida to 1st Dhul Hajja 1423, while visiting ten randomly selected Primary Health Care Centers (PHCC) in Riyadh to get mandatory meningococcal meningitis vaccination. Each participating facility was allocated a number of hajjis to be recruited based on the number of hajjis vaccinated there the previous year. On return from hajj, hajjis were contacted by telephone to collect information about occurrence of ARI related symptoms along with other associated activities in Hajj.

For the purpose of this study, ARI was defined as any person suffering from at least one of the constitutional symptoms (fever, headache, myalgia) along with one of the local symptoms (runny nose, sneezing, throat pain, cough with/without sputum, difficulty in breathing) developed after reaching Makkah for the Hajj.

Out of the 1439 persons recruited as the study cohort, 1130 were traceable after the hajj. Among these only 1027 had performed the hajj. The mean age of these 1027 hajjis was 33.5 years (SD ± 11.7), and 73% of them were male. Saudi nationals formed 79.1%, while non-Saudi nationals constituted 20.9%. Regarding level of education, 11.1% were illiterate, 5.1% had primary school education, 11.1% had intermediate school education, 32.7% had high school education, and 40% had university education. Among the total, 13.5% hajjis were current smokers. Only 10.5% were vaccinated against influenza. Regarding chronic illness, 8.1% suffered from some chronic disease; 4.6% were diabetic, 1.8% had history of chronic sinusitis, 1.6% had chronic tonsillitis and 1.6% had bronchial asthma.

During the Hajj, 46.4% hajjis reported never using the facemask while 53.6% used the facemask; 33.1% used it for most of the time and 20.4% only sometimes. Among the 750 males 63.7% used facemask at least for sometimes. While among the 277 females 26.0% used facemask and 71.1% used face cover (Hijab/Niqab) most of the time, 13.4% used it for some time and 15.5% never used it. When combined with the facemask used by females it turned out that 89.5% women used either facemask or face cover for at least sometime during Hajj.

During their stay in Hajj area 27.4% of hajjis visited health care centers (HCCs) for a medical problem.

Out of the 1027 hajjis, 409 suffered from ARI, according to our case definition, during and within 2 weeks of end of Hajj. So the cumulative incidence of ARI among the hajjis was 39.8% (95% CI 36.8%-42.9%). The date of onset of illness ranged from the 8th to 27th of Dhul Hijjah. By the 12th of Dhul Hijjah (last day of Hajj) 41.3% had already developed symptoms of ARI. Among the cases 68.7% had visited HCCs during Hajj and 72.9% had used some antibiotic before they were contacted after the hajj.

While studying the relationship between occurrence of ARI and age it was observed that the small group of hajjis 70 years or older had an ARI incidence of 83.3%, as compared to the lowest incidence of 37.7% among those below 25 years old (RR-2.2, 95% CI=1.47-3.21). However, as compared to hajjis below 25 years old, the increase in other age groups was statistically not significant. There was no statistically significant relationship between ARI occurrence and gender or educational status.

As shown in table 1, among the hajjis who used a facemask most of the time during hajj, 15.0% had ARI as compared to hajjis who used it sometimes (31.4%) or never (61.2%). The risk was 2.1 times among sometime users (95% CI 1.52-2.89) and 4 times among never users (95% CI 3.14-5.31) as compared to hajjis who used facemask most of the time. When the data was stratified for gender, it was observed that the protective effect of facemask was visible only among males, and had no association with development of ARI among females. There was an increased risk of ARI among the females who used face cover sometimes (43.2%) or never (44.2%) as compared to those who used face cover for most of time, but the difference was statistically not significant. The pattern remained the same, even when the effect was observed for either facemask or face cover (RR 1.20, 95% CI 0.77-1.85).

Regarding other risk factors studied, it was observed that Hajjis who prayed in Namera mosque in Arafat (3% of our study population) had 3.17 times higher risk of ARI as compared to those who did not pray there (95% CI 1.54-6.52). Smoking did not show any significant increase in the risk of ARI (RR 1.07; 95% CI 0.89-1.35). Suffering from some chronic disease showed 1.46 times increased risk of ARI and the difference was statistically significant (95% CI 1.13-1.89). Among the individual dis-eases studied, only diabetes mellitus showed a statistically significant increased risk of ARI (RR 2.54; 95% CI 1.54-4.93). Chronic sinusitis, chronic tonsillitis and bronchial asthma all showed an increased risk but statistically not significant.

Acute Respiratory Infections (ARIs) are the most common infections among humans,[2] As ARI, especially upper respiratory tract infection, has low risk of mortality and complications, except in physically debilitated and immunocompromised people, it is considered a low priority health problem.[3] However this attitude undermines its importance due to high infectiousness, capacity to lower the general immunity and high short term disability.

ARIs are a group of diseases that occur worldwide throughout the year and are not limited to any specific age, gender, or nationality. Several factors contribute to the wide spread of ARIs including direct contact with affected persons, change in climate, and crowded places; all of which are ominously present in the Hajj environment. [3] As observed in other studies, the risk of viral origin ARI increases during the winter months with a peak in January and February, especially Respiratory syncitial and influenza viruses, which currently coincide with the Hajj season, so a high ARI incidence was expected in Hajjis.[4]

Under the circumstances, it was not strange to find that almost 40% of the ARI free hajjis from Riyadh had an attack of ARI during and immediately after the Hajj. This high incidence of an illness, even if with low severity as indicated by low hospital admission rate, reveals a high burden of disease. The problem is further compounded by the fact that ARI, being communicable diseases with high secondary attack rates, has a great potential of spread among susceptible population of hometown on return of hajjis.

The disease is uniformly distributed among both genders and different nationalities, with a higher risk for older hajjis or diabetics, which are known to reduce the immunity and increase the risk for ARIs and other viral infections, indicating the importance of special attention to these high risk groups.

Regarding prevention of occurrence of ARI, given the circumstances of Hajj it is almost impossible to control the issue of crowding and exposure to contacts in Jamarat, Tawaf and Sa'ee; or advocate vaccination or chemoprophylaxis in the absence of clear etiology.

In this study, the facemask has turned out to be the most important practical protective factor, at least among males. Although studies have shown controversial information about the benefits of using facemask; there is a clear clinical and experiential evidence of its benefits. Use of facemasks has been advocated to protect from inhalation of aerosols containing organic and inorganic particulates. The CDC's recommendations for the prevention of influenza include wearing a facemask.5'6 Although wearing mask may not provide complete protection from infection; it will reduce the incidence of infection via preventing droplet inhalation, which is considered one of the main modes of transmission of most URTIs.

Use of face cover (Hijab/Niqab) by the women can also be treated as use of facemask. Since most of the female hajjis were Saudis, who use face cover more often during Hajj as compared to other nationalities, the usage of facemask alone was quite infrequent. However, there was no evidence of significant decrease in the incidence of ARI among women related to using facemask or face cover. This difference from males can be explained on the basis of either a small sample size of females in the study or other customary practices i.e. women when alone in their tents with other females do not cover their faces (as the use is meant mainly for Hijab and not for preventing ARI) thus having the same high risk of disease transmission in a closed environment with exposure to droplet infection. Use of face cover as proxy of facemask among females may therefore lead to misclassification of exposure status.

It is recommended that use of face-mask during Hajj should be encouraged specially among males. Old people and diabetics should be informed about special high risk of ARI and adopting protective measures.