Kutty Jesheera M, RajanBabu Bijayraj, Thiruvoth Sohanlal
Department of Family Medicine and Microbiology, ASTER MIMS, Calicut, Kerala, India.
J Family Med Prim Care. 2019 Oct 31;8(10):3253-3257. doi: 10.4103/jfmpc.jfmpc_589_19. eCollection 2019 Oct.
Outbreaks of diphtheria continue to occur in Kerala with an age shift to older population. Antibody seroprevalence studies are essential to understand the immune status of the community and to develop an effective immunization strategy.
To assess the necessity of diphtheria vaccination among adults.
Cross-sectional study, among 152 healthy adults (>18 years).
Diphtheria IgG antibody detection was performed by using ELISA technique.
Out of 152 study population, 14 (9.2%) individuals had very low antibody levels, requiring basic immunization, 123 (80.9%) needed booster vaccination, 12 (7.9%) would need a booster dose in 5 years and 3 (2%) would need a booster dose in 7 years to maintain adequate antibody levels. Out of the total, 131 (86.2%) individuals had completed childhood immunization and 21 (13.8%) had incomplete or no immunization during childhood. In the population who had completed childhood immunization, 4 (3%) had very low antibody levels requiring basic immunization and 113 (86%) had antibody levels needing booster vaccine soon, with the remaining 14 (10.6%) individuals requiring a booster vaccine after 5 years and 7 years. In the partially immunized/unimmunized population, 10 (47.6%) had antibody levels requiring basic immunization and another 10 (47.6%) had antibody levels low enough to warrant a booster vaccine.
Majority of the subjects who had completed childhood immunization showed an inadequate immunity against diphtheria during adulthood. This indicates waning immunity against diphtheria. Hence, modifying the present diphtheria vaccination strategy to include booster doses during adulthood is essential.
Even in developed countries where nearly 100% universal immunization is achieved, diphtheria outbreaks are known to occur. Several seroprevalence studies have been conducted in those regions to determine whether those populations have adequate levels of antibodies against diphtheria. In India, sporadic outbreaks occur, and an increasing number of diphtheria cases are being reported over the last few years. Large outbreaks in Kerala 2016 were about 533 cases. Recent outbreaks in 2019, in Trivandrum, about 175 cases were suspected and 19 cases were confirmed in laboratory. However, Indian studies to determine whether the adult population has adequate protective antibody levels are lacking. Knowing the immune status of the population and devising an appropriate strategies to prevent outbreaks of diphtheria are the integral parts of primary care. These concerns are the basis and evaluation of the seroprevalence of IgG antibody levels against diphtheria antitoxin among healthy adults in our region in this study.
喀拉拉邦持续爆发白喉疫情，发病年龄有向老年人群转移的趋势。抗体血清流行率研究对于了解社区免疫状况和制定有效的免疫策略至关重要。
评估成人接种白喉疫苗的必要性。
对152名健康成年人（>18岁）进行横断面研究。
采用ELISA技术检测白喉IgG抗体。
在152名研究对象中，14人（9.2%）抗体水平极低，需要进行基础免疫；123人（80.9%）需要加强免疫；12人（7.9%）在5年后需要加强一剂；3人（2%）在7年后需要加强一剂以维持足够的抗体水平。总共有131人（86.2%）完成了儿童期免疫，21人（13.8%）儿童期免疫不完全或未免疫。在完成儿童期免疫的人群中，4人（3%）抗体水平极低需要基础免疫，113人（86%）抗体水平需要尽快加强免疫，其余14人（10.6%）在5年和7年后需要加强免疫。在部分免疫/未免疫人群中，10人（47.6%）抗体水平需要基础免疫，另外10人（47.6%）抗体水平低到足以需要加强免疫。
大多数完成儿童期免疫的受试者在成年期对白喉的免疫力不足。这表明对白喉的免疫力正在减弱。因此，修改目前的白喉疫苗接种策略以包括成年期加强剂量至关重要。
即使在几乎实现100%普遍免疫的发达国家，白喉疫情仍有发生。在这些地区进行了多项血清流行率研究，以确定这些人群对白喉的抗体水平是否足够。在印度，时有散发病例爆发，且在过去几年中报告的白喉病例数量不断增加。2016年喀拉拉邦的大规模疫情约有533例病例。2019年在特里凡得琅最近的疫情中，约有175例疑似病例，19例经实验室确诊。然而，印度缺乏关于成年人群是否具有足够保护性抗体水平的研究。了解人群的免疫状况并制定适当的策略来预防白喉疫情是初级保健的重要组成部分。这些问题是本研究中我们地区健康成年人抗白喉抗毒素IgG抗体水平血清流行率的基础和评估依据。
