Impact of the introduction of the Haemophilus influenzae type b conjugate vaccine in an urban setting in southern India. Issue 12 (14th March 2019)

• Record Type: Journal Article
• Authors: Fitzwater, Sean Patrick; Ramachandran, Padmanabhan; Kahn, Geoffrey D; Nedunchelian, Krishnamoorthy; Suresh, Saradha; Santosham, Mathuram; Chandran, Aruna
• Is Part Of: Vaccine. Volume 37:Issue 12(2019)
• Page Start: 1608
• Page End: 1613
• Publication Date: 2019-03-14
• Subjects: CSF Cerebrospinal fluid -- DTP Diphtheria-tetanus-pertussis -- GBS Group B Streptococcus -- Hib Haemophilus influenzae type b -- Hib-CV Haemophilus influenzae type b conjugate vaccines -- ICH & HC Institute of Child Health and Hospital for Children -- LAT Latex agglutination test -- LP Lumbar puncture -- WBC White blood cell count -- WHO World Health Organization; Vaccines -- Periodicals; 615.372
• DOI: 10.1016/j.vaccine.2019.01.080
• Languages: English
• ISSNs: 0264-410X

Abstract

Highlights: Introduction led to in a rapid reduction of H. influenzae type b mengintis. Impact was larger than expected from vaccine coverage, suggesting herd immunity. Introduction resulted in reduction of probable meningitis with no etiology found. Abstract: Introduction: Haemophilus influenzae type b was the leading cause of bacterial meningitis in infants and children below the age of two years prior to the introduction of H. influenzae type b conjugate vaccines. In December 2011, the Indian government introduced H. influenzae b vaccine in the state of Tamilnadu. A prospective surveillance for bacterial meningitis was established at the Institute of Child Health in Chennai to evaluate the etiology of meningitis and impact of the vaccine. Material and Methods: Infants aged one to 23 months who were admitted to the hospital with symptoms of suspected bacterial meningitis were enrolled and lumbar puncture was performed. Cerebrospinal fluid samples were analyzed for white blood cells, protein, and glucose. Bacterial culture and a latex agglutination test for common bacterial pathogens were performed. Results: Between January 2009 and March 2014, 4, 770 children with suspected bacterial meningitis were enrolled. Prior to the introduction of the vaccine, an average of 11.7 cases of H. influenzae b meningitis and 31.1 cases of probable meningitis with no etiology were identified each year. After introduction, the number of cases were reduced by 79% and 44% respectively. The average H. influenzae b vaccine coverage after introduction was 69% among all children with clinically suspected meningitis. In contrast, the mean number of aseptic meningitis and pneumococcal meningitis cases remained stable throughout the pre and post vaccination period; 28.2 and 4.8 per year, respectively. Conclusions: H. influenzae b conjugate vaccine reduced the number of cases of H. influenzae b meningitis and probable meningitis within the first two years of its introduction. The impact against meningitis was higher than the vaccination rate, indicating indirect effects of the vaccine. India has recently scaled up the use of Hib conjugate vaccine throughout the country which should substantially reduce childhood meningitis rates further in the country.