Meningococcal carriage among high school and university students in Gondar, Northwestern Ethiopia.

BACKGROUND

Meningococcal disease is caused by the bacterium Neisseria meningitidis, which is a commensal in the human upper airways. Teenagers and young adults are the main reservoir for the bacteria. The aim of this study was to assess the prevalence of meningococcal carriage and risk factors for carriage among high school and university students in Northwestern Ethiopia.

METHODS

Oropharyngeal swabs and buccal samples were collected and stored on Whatman FTA-cards pending PCR analysis. DNA was extracted and a Multiplex TaqMan® custom assay was performed to detect N. meningitidis bacteria using the genes sodC and porA as species-specific targets. Genogrouping was performed for the samples positive for N. meningitidis using multiplex real-time PCR for the groups A, B, C, W, Y and X using a Rotor-Gene Q real-time PCR system. RESULT: Out of the 1025 participants, 52% were female with a mean and median ages of 17 and 16 years, respectively. A total of 19 throat swab samples were positive for N. meningitidis giving an overall carriage rate of 1.9%. The carriage rate of N. meningitidis among high school students was 1.0% and 2.5% for the University students, respectively (p-value = 0.051). A significantly higher carriage rate was observed among participants with the age of 23 and above (p-value = 0.021). Among the N. meningitidis isolates, 16 out of 19 were non-groupable, while 3 were groupable. Of the groupable isolates, two belonged to group W and one to group B. Among the risk factors assessed, sharing a glass or bottle for drinking (86%), not having received a meningitis vaccine (66%), and having had a tonsillectomy (47%), were the most common risk factors. Among participants with positive meningococcal carriage, 89% of them have shared glass for drinking and 74% of them had not received previous meningococcal vaccine, while this figure is reduced to 66% and 65%, respectively among the non-carriers.

CONCLUSION

The overall meningococcal carriage rate was lower than those reported in previous Ethiopian studies, with age as the only identified risk factor.