To determine the incidence and type of RTI-causing bacteria and viruses during a period of epidemic infections.METHOD
A total of 395 sputum specimens and 761 throat swabs were collected during the 1991 and 1992 pilgrimage seasons (Haj to Makkah Al-Mukarama, Saudi Arabia) from patients referred to one hospital and three dispensaries with symptoms of respiratory tract infections. All 761 throat swabs of both Haj seasons were also screened for the presence of viral pathogens with monoclonal antibodies specific for 7 viruses known to cause respiratory infections.RESULTS
Bacterial pathogens were detected in 118 (29.9%) specimens. During the 1991 Haj season Haemophilus influenzae was the most frequent bacterial pathogen detected (10%), followed by Klebsiella pneumoniae (5.2%),Streptococcus pneumoniae (4.8%), Staphylococcus aureus(3.8%) and Streptococcus pyogenes (2.4%). In the 1992 Haj seasonKlebsiella pneumoniae was predominant (15.1%), followed byHaemophilus influenzae and Streptococcus pneumoniae(12.3%). Screening of all sputum specimens for acid-fast bacteria showed that the overall incidence rate of tuberculosis was 1%. Cultures from the 761 throat swabs were largely negative for bacteria except forStreptococcus pyogenes isolated from 7 patients. Viruses were detected in 148 (19.5%) specimens with influenza A and adenovirus being the most common viruses.CONCLUSION
The pattern of virus prevalence in the 1991 and 1992 pilgrimage seasons was identical: influenza A and adenovirus predominated. Thus these two viruses should be targeted in future prophylactic measures.