Indian Journal of Medical Microbiology Medknow Publications on behalf of Indian Association of Medical Microbiology ISSN: 0255-0857 EISSN: 1998-3646 Vol. 29, Num. 1, 2011, pp. 74-76

Indian Journal of Medical Microbiology, Vol. 29, No. 1, January-March, 2011, pp. 74-76

Correspondence

Laboratory confirmed outbreak of meningococcal infections in Tripura

T Majumdar, S Bhattacharya, D Barman, R Begum

Department of Microbiology, Agartala Government Medical College, Agartala - 799 006, Tripura (W), India

Correspondence Address: T Majumdar, Department of Microbiology, Agartala Government Medical College, Agartala - 799 006, Tripura (W), India, drtapan1@ rediffmail.com

Date of Submission: 18-May-2010
Date of Acceptance: 18-Aug-2010

Code Number: mb11020

PMID: 21304204

DOI: 10.4103/0255-0857.76533

Dear Editor,

Outbreaks of meningococcal diseases are an important public health problem in sub-Saharan Africa and Southeast Asia. ^[1] Neisseria meningitides (meningococcus), the causative agent for acute purulent meningitis and fulminant meningococcemia, has13serogroups (A , B, C, E, H, I, K, L, M, X, Y, Z, W135) out of which serogroup A is responsible for sporadic cases and outbreaks in India, Africa and some other developing countries. ^[2] Isolation, identification and confirmation of serogrouping were done using standard microbiological procedures from the cerebrospinal fluid (CSF) and blood samples. ^[3],[4]

Tripura, a state in North Eastern region of India, experienced its first outbreak of meningococcal diseases in 2009. The cases started reporting from 22 January 2009, from the most affected area of Chawmanu Block of Dhalai District, and the first case was laboratory confirmed on 7 February 2009.

Out of 72 CSF samples processed, [Table - 1] 19 (26.4%) were positive for the presence of Gram negative diplococci, on direct microscopy [Figure - 1]. Culture was positive for meningococcus in 6 (32%) cases [Figure - 2]. Latex agglutination test (LAT) for meningococcus serogroup A was found to be positive in 19 (26.4%) samples [Figure - 3]. All the culture isolates were identified as N. meningitidis serogroup A, In 84 serum samples analysed by LAT,13(15.5%) were positive for Meningococcus serogroup A [Table - 2].

In order to assess the carrier status, 69 nasopharyngeal swabs were collected from apparently healthy population of Chowmanu block in the month of February 2009, ^[5] out of which 22 (32%) were culture positive for meningococcus [Table - 1].

The outbreak of meningococcal infection in the state of Tripura started from the third week of January 2009 and lasted till August 2009 with its peak in the month of May 2009. During this period, the number of suspected and confirmed cases was 285 with 62 deaths, with an Attack Rate of 8.4/lakh and a Case Fatality Rate (CFR) of 22% [Table - 6]. As per the geographical clustering of cases maximum cases were reported from Chowmanu block of Dhalai district where a total of 125 cases were reported with 31 deaths and the CFR was reported to be 25% with an Attack Rate of 351/lakh [Figure - 4].

Majority of the cases presented with moderate to high grade fever of sudden onset with severe headache,and a sizeable number of patients presenting with vomiting and skin rashes/echymotic patches. Along with these, few cases also reported with loose motion [Table - 3]. Cases were reported from all age groups (from 2 months to 60 years) with the maximum ranging in age from 20 to 30 years and sex distribution of confirmed case showed male preponderance [Table - 4]. E-test results shows all the isolates were sensitive to Penicillin, Ampicillin, Erythromycin, Ceftriaxone, and Rifampicin [Table - 5]. Both suspected and diagnosed cases were treated with intravenous administration of antibiotics like Ceftriaxone and Penicillin, either alone or in combination with Chloramphenicol, along with other supportive measures. CFR in treated cases was found to be 12%. Most of the deaths were seen in cases presenting with sudden onset of fever with bluish black skin rashes. Deaths usually occurred within 24-48 hours of the onset of symptoms even before reaching the hospital.

In Chowmanu block of Dhalai District where the maximum number of cases had been reported, [Table - 6]nasopharyngeal carriage rate was also found to be much higher (32%). The relationship between climatic condition and carriage rate could not be evaluated.

Acknowledgement

The authors are grateful to Microbiology Division, National Institute of Communicable Diseases (NICD), New Delhi; Director of Family Welfare and Preventive Medicine, Government of Tripura; Programme Officer, Integrated Disease Surveillance Project (IDSP), Tripura; andMedecins Sans Frontieres (MSF), New Delhi branch, for their help.

References

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