Military recruits come from different areas and have had varied social exposure to the communicable diseases. Recruits who come from rural areas neither have had primary vaccinations, nor been exposed to infectious diseases. During the annual pilgrimage to Makkah in 1995 an outbreak of rubella occurred among police cadets on a field training exercise. We began an investigation to identify the extent of and reasons for the outbreak.
Methodology
We defined a rubella case as fever and rash with anti-rubella IgM detected in a cadet from SFTC from 25/10 to 15/12/15 Hejra. To find all possible rubella cases we questioned cadets and reviewed outpatient registries for rash illnesses among cadets in all Makkah hospitals and the SFTC dispensary in Riyadh. We determined the rubella vaccination history by questioning rubella patients and two control patients who were selected by a systematic random sample for each case.
Results
For 7 weeks following the appearance of two rubella cases, 43 additional rubella cases developed (AR 49 per 1000). The outbreak had two peaks: the first, during a routine class (21 cases) in Riyadh, the second, after cadets had traveled to Makkah for duty on the annual pilgrimage. All three training groups were affected and attack rates were similar (70 per 1000 and 60 per 1000) in the two groups where the first two cases appeared but lower in the other group (17 per 1000). Rubella cases clustered by classroom (Chi Square = 25.5 p <0.05) and by dormitory (Chi-square = 23.2, p <0.05). Cadets with rubella were sent home, but 23% had pregnant females in their family. None of the rubella cases or control cadets had a history of previous rubella vaccination. The outbreak ended after rubella vaccine was given to all cadets in Makkah.
Conclusion
Lack of rubella vaccination and delayed response to early reports of rubella led to an outbreak which interfered with cadet training. Medical military services must ensure that cadets have received MMR vaccine and all other routine childhood vaccines upon entering the program since those coming from rural areas may not have had the required vaccines.