Peela Sreeram Chandra Murthy, Sistla Sujatha, Nagaraj Geetha, Govindan Vandana, Kadahalli Ravi Kumar Lingegowda
Department of Microbiology, Jawaharlal Institute of Postgraduate Medical Education & Research, Puducherry, India.
Central Research Laboratory, Department of Microbiology, Kempegowda Institute of Medical Sciences, Bangalore, India.
Indian J Med Res. 2024;160(3&4):354-361. doi: 10.25259/ijmr_1811_23.
Background & objectives The Pneumococcal vaccines were introduced under the Universal Immunization Programme (UIP) in 2021 in India. Drawing from the collective experience of various nations, it is anticipated that there will be a substantial shift in serotype patterns following the introduction of this vaccine. The available data is limited to years until 2018 when the vaccine was introduced in only five States. The present study was carried out to estimate the changes in serotypes and antimicrobial resistance patterns pre- and post-vaccine introduction from a tertiary care centre. Methods All isolates from various clinical specimens in the pre-vaccine era (January 2015-July 2021, except for 2019) and post-vaccine era (August 2021- March 2023) were included. Antimicrobial susceptibility was tested using disc diffusion or VITEK2, and serotyping was performed using the Quellung test (post-vaccine introduction) or sequential multiplex PCR (pre-vaccine introduction). The Chi-square or Fisher exact test was used to identify associations between antimicrobial resistance and serotypes. The z-test for proportions was used to identify significant changes in serotype frequencies between the pre- and post-vaccine era; P<0.05 was considered as the level of significance. Results Overall, the resistance rates increased for most of the antibiotics in the post-vaccine era, and there was no significant increase in the non-vaccine serotypes. The proportion of serotypes 19F and 15B/C increased, and serotypes 23F and 14 reduced in the post-vaccine era. The majority of the 19F and 19A isolates (89.7% and 80%, respectively) were multidrug resistant in the post-vaccine era. Interpretation & conclusions Introducing pneumococcal vaccination reduced the burden of many vaccine serotypes, while the burden of non-vaccine serotypes slightly increased. Most of the vaccine serotypes (like 19F and 19A) that persisted in the post-vaccine era were drug resistant.
背景与目的 肺炎球菌疫苗于2021年在印度的扩大免疫规划（UIP）下引入。借鉴各国的集体经验，预计在引入该疫苗后血清型模式将发生重大转变。现有数据仅限于2018年之前，当时该疫苗仅在五个邦引入。本研究旨在评估一家三级医疗中心在疫苗引入前后血清型和抗菌药物耐药模式的变化。方法 纳入疫苗接种前时代（2015年1月至2021年7月，不包括2019年）和疫苗接种后时代（2021年8月至2023年3月）各种临床标本的所有分离株。采用纸片扩散法或VITEK2检测抗菌药物敏感性，采用荚膜肿胀试验（疫苗接种后）或序列多重PCR（疫苗接种前）进行血清分型。采用卡方检验或Fisher确切检验确定抗菌药物耐药性与血清型之间的关联。采用比例z检验确定疫苗接种前后血清型频率的显著变化；P<0.05被视为显著性水平。结果 总体而言，疫苗接种后时代大多数抗生素的耐药率有所上升，非疫苗血清型没有显著增加。疫苗接种后时代血清型19F和15B/C的比例增加，血清型23F和14减少。疫苗接种后时代，大多数19F和l9A分离株（分别为89.7%和80%）对多种药物耐药。解读与结论 引入肺炎球菌疫苗减轻了许多疫苗血清型的负担，而非疫苗血清型的负担略有增加。疫苗接种后时代持续存在的大多数疫苗血清型（如19F和19A）具有耐药性。
