Prospective multi-centre sentinel surveillance for Haemophilus influenzae type b & other bacterial meningitis in Indian children.

Background & objectives: Haemophilus influenzae type b (Hib) is one of the leading bacterial causes of invasive disease in populations without access to Hib conjugate vaccines (Hib-CV). India has recently decided to introduce Hib-CV into the routine immunization programme in selected States. Longitudinal data quantifying the burden of bacterial meningitis and the proportion of disease caused by various bacteria are needed to track the impact of Hib-CV once introduced. A hospital-based sentinel surveillance network was established at four places in the country and this study reports the results of this ongoing surveillance. Methods: Children aged 1 to 23 months with suspected bacterial meningitis were enrolled in Chennai, Lucknow, New Delhi, and Vellore between July 2008 and June 2010. All cerebrospinal fluid (CSF) samples were tested using cytological, biochemical, and culture methods. Samples with abnormal CSF (≥10 WBC per μl) were tested by latex agglutination test for common paediatric bacterial meningitis pathogens. Results: A total of 708 patients with abnormal CSF were identified, 89 of whom had a bacterial pathogen confirmed. Hib accounted for the majority of bacteriologically confirmed cases, 62 (70%), while Streptococcus pneumoniae and group B Streptococcus were identified in 12 (13%) and seven (8%) cases, respectively. The other eight cases were a mix of other bacteria. The proportion of abnormal CSF and probable bacterial meningitis that was caused by Hib was 74 and 58 per cent lower at Christian Medical College (CMC), Vellore, which had a 41 per cent coverage of Hib-CV among all suspected meningitis cases, compared to the combined average proportion at the other three centres where a coverage between 1 and 8 per cent was seen (P<0.001 and P= 0.05, respectively). Interpretation & conclusions: Hib was found to be the predominant cause of bacterial meningitis in young children in diverse geographic locations in India. Possible indications of herd immunity was seen at CMC compared to sites with low immunization coverage with Hib-CV. As Hib is the most common pathogen in bacterial meningitis, Hib-CV would have a large impact on bacterial meningitis in Indian children.

Antibiotic use and resistance: perceptions and ethical challenges among doctors, pharmacists and the public in Vellore, South India.

Inappropriate antibiotic use and resistance are major public health challenges. Interventional strategies require ascertaining the perceptions of major stakeholders and documenting the challenge to changing practice. Towards this aim, a qualitative study was conducted in Vellore, South India, using focus group discussions among doctors, pharmacists and public. There were eight groups with six to eight participants each. The themes explored were: understanding of infections, antibiotics and resistance; practices and pressure driving antibiotic use; and strategies for appropriate use. Data were transcribed, analysed, verified and a summary prepared with salient features and quotations.

Increasing invasive disease due to penicillin resistant S. pneumoniae in India.

S. pneumoniae continues to be a major cause of invasive disease worldwide with considerable mortality and morbidity. Here we report the emergence of penicillin intermediate resistance to S. pneumoniae in India, which may predispose for an increased incidence of invasive pneumococcal disease in both children and adults with multi-drug resistance profile resulting in clinical failure.

Comparison of disc diffusion & E test methods with agar dilution for antimicrobial susceptibility testing of Haemophilus influenzae.

BACKGROUND & OBJECTIVES: Reliable methods of detection of antimicrobial resistance are of paramount importance in the treatment and management of infections caused by Haemophilus influenzae. The objective of the present study was to compare and evaluate the performance of disc diffusion and E test (Epsilometer test) with agar dilution method for antimicrobial susceptibility testing of H. influenzae. METHODS: A total of 46 isolates of H. influenzae from various invasive sites were included as test strains. Antimicrobial susceptibility testing was performed by Kirby-Bauer disc diffusion method for ampicillin, chloramphenicol, trimethoprim-sulphamethoxazole (TMP-SMZ) and cefotaxime. Minimum Inhibitory Concentration (MIC) determination was performed by E test and agar dilution for the same set of antimicrobials. All tests were performed on Haemophilus test medium (HTM). RESULTS: Disc diffusion showed a very major (2%) and minor (4%) interpretative error with TMP-SMZ and minor interpretative errors to ampicillin (13%) and chloramphenicol (24%) when compared to agar dilution method. E test produced only minor interpretative errors to chloramphenicol (7%) and TMP-SMZ (2%) and no interpretative errors with ampicillin and cefotaxime as against agar dilution. E test showed good agreement with agar dilution for each of the antimicrobial tested. INTERPRETATION & CONCLUSION: Disc diffusion test may be used as a preliminary screen for susceptibility testing of H. influenzae. E test is simple, easy to perform and a reliable method for determination of resistance in H. influenzae. However its cost and limited availability in India may limit its use. The reference agar dilution method can be used reliably in routine susceptibility testing of H. influenzae.

Community prevalence of sexually transmitted diseases and human immunodeficiency virus infection in Tamil Nadu, India: a probability proportional to size cluster survey.

BACKGROUND: Human immunodeficiency virus (HIV) infection and AIDS is threatening the survival of many nations. To evaluate ongoing interventional strategies and burden of illness estimates, valid data on the prevalence of HIV are required. Often, in the absence of community prevalence data, estimates are based on surrogate markers such as prevalence of HIV in antenatal clinics. Even though the antenatal prevalence of HIV is easier to measure and can be repeated for evaluation, it is important to establish the association between antenatal and community prevalence of sexually transmitted diseases (STDs) and HIV, so that the validity of the estimates can be verified. METHODS: A 'probability proportional to size' cluster survey was conducted in three randomly selected districts of Tamil Nadu in India. The basic unit of the survey was households from rural and urban clusters. Adults 15-45 years of age from the selected households were eligible for recruitment. Demographic, behavioural and laboratory data were collected. Clinical examination was done to identify STD syndromes and blood, urine, vaginal/urethral and endocervical swabs were taken for laboratory diagnosis of STDs from the subjects. Direct smear examination for Trichomonas vaginalis; serological tests for syphilis, hepatitis B, HIV, herpes simplex virus 2, Chlamydia trachomatis; and culture of Neisseria gonorrhoeae and Haemophilus ducreyi were performed on the collected specimens. The data were analysed adjusting for cluster effect. RESULT: We selected and screened 1981 individuals (1157 women and 824 men) for STDs and HIV from 1114 households representing the 25 million projected adult population of Tamil Nadu. The overall community prevalence of STDs including HIV and hepatitis B in Tamil Nadu was 14.6% (CI: 14.1-15.1), and 8.3% (CI: 7.9-8.6) when HIV and hepatitis B were excluded. Community prevalence of HIV and hepatitis B infection was 1.8% (CI:1.7-1.9) and 5.3% (CI: 5.1-5.5), respectively. The distribution of HIV involved both rural and urban regions of Tamil Nadu. On clinical examination, at least one STD syndrome was noted in 486 (24.5%) of the women subjects; vaginal discharge was the most common and found in 421 women (38.4%). CONCLUSION: The prevalence of STD and HIV in Tamil Nadu is higher than expected and has extended into the non-high risk population (generalized epidemic).