Meningococcal Carriage among College Freshmen in Kashmir, North India- A Single Centre Study
Dr. Parvaiz A Koul,
Professor and Head, Department of Internal and Pulmonary Medicine, Sher-i-Kashmir Institute of Medical Sciences,
Soura, Srinagar-190011, Jammu and Kashmir, India.
Introduction: Data on the community carriage of meningococci in developing countries are sparse. Knowledge about the same would help identify demographic and socio-behavioural risk factors, the need for infection control strategies and the composition of the relevant serogroup for locally effective meningococcal vaccine.
Aim: To assess the meningococcal carriage and the major serotypes among fresh college hostellers.
Materials and Methods: Charcoal-impregnated nasopharyngeal swabs were collected from 274 consenting fresh college recruits (first year students residing in the college hostel) and plated on to Thayer-Martin medium. Oxidase-positive diplococci were taken as presumptive Neisseria species. DNA was extracted from the isolates and Sanger sequencing was performed on the amplified PCR product. Blast analysis of all sequenced samples was performed against the retrieved Neisseria meningitidis sequences from whole NCBI-nr/nt database and within the dataset. Phylogentic analysis was done by Mega-6 professional package comparing published sequences of serogroups against the detected Neisseria meningitidis.
Results: Ten (3.6%) samples grew oxidase-positive diplococci suggestive of Neisseria. On molecular testing and sequence analysis, 4 samples were found to be N.meningitidis, one (Neisseria spp) had close similarity to N.meningitidis and the others included N.perflava (n= 3), N.pharyngis (n=1) and N. flavescens (n=1). N.meningitidis isolates on blast and phylogenetic analysis bore molecular homology to serogroup B.
Conclusion: Nasal carriage of N. meningitis (serogroup B) was found in about 1.5% (n=4) of the fresh college recruits in the present study. Close proximity amongst the hostellers is likely to result in transmission and such preventive strategies for infection control are desirable. Further, studies of similar kind are mandated to determine the appropriate serogroups required for inclusion in the vaccine.