Indian Institute of Public Health Gandhinagar (IIPHG), Public Health Foundation of India (PHFI), Near Lekwada Bus Stop, Opp. New Air Force Station HQ, Palaj, Gandhinagar, 382042, Gujarat, India.
Indian Institute of Public Health Gandhinagar (IIPHG), Public Health Foundation of India (PHFI), Near Lekwada Bus Stop, Opp. New Air Force Station HQ, Palaj, Gandhinagar, 382042, Gujarat, India.
Environ Res. 2021 May;196:110417. doi: 10.1016/j.envres.2020.110417. Epub 2020 Nov 17.
Enteric Fever (EF) affects over 14.5 million people every year globally, with India accounting for the largest share of this burden. The water-borne nature of the disease makes it prone to be influenced as much by unsanitary living conditions as by climatic factors. The detection and quantification of the climatic effect can lead to improved public health measures which would in turn reduce this burden.
We obtained a list of monthly Widal positive EF cases from 1995 to 2017 from Ahmedabad and Surat Municipalities. We obtained population data, daily weather data, and Oceanic Niño Index values from appropriate sources. We quantified the association between extreme weather events, phases of El Niño Southern Oscillations (ENSO) and incidence of EF.
Both cities showed a seasonal pattern of EF, with cases peaking in early monsoon. Risk of EF was affected equally in both cities by the monsoon season -- Ahmedabad (35%) and Surat (34%). Extreme precipitation was associated with 5% increase in EF in Ahmedabad but not in Surat. Similarly, phases of ENSO had opposite effects on EF across the two cities. In Ahmedabad, strong El Niño months were associated with 64% increase in EF risk while strong La Niña months with a 41% reduction in risk. In Surat, strong El Niño was associated with 25% reduction in risk while moderate La Niña with 21% increase in risk.
Our results show that the risk of EF incidence in Gujarat is highly variable, even between the two cities only 260 kms apart. In addition to improvements in water supply and sewage systems, preventive public health measures should incorporate variability in risk across season and phases of ENSO. Further studies are needed to characterize nationwide heterogeneity in climate-mediated risk, and to identify most vulnerable populations that can benefit through early warning systems.
肠热病（EF）每年在全球影响超过 1450 万人，其中印度占这一负担的最大份额。这种疾病的水源性质使其容易受到不卫生的生活条件和气候因素的影响。检测和量化气候影响可以导致采取更好的公共卫生措施，从而减轻这一负担。
我们从艾哈迈达巴德和苏拉特市获得了 1995 年至 2017 年每月的伤寒阳性 EF 病例清单。我们从适当的来源获得了人口数据、每日天气数据和厄尔尼诺南方涛动（ENSO）阶段值。我们量化了极端天气事件、厄尔尼诺南方涛动（ENSO）阶段与 EF 发病率之间的关联。
两个城市都显示出 EF 的季节性模式，病例在早季风季达到高峰。季风季节对两个城市的 EF 风险的影响相同——艾哈迈达巴德（35%）和苏拉特（34%）。在艾哈迈达巴德，极端降水与 EF 增加 5%相关，但在苏拉特则没有。同样，ENSO 阶段对两个城市的 EF 有相反的影响。在艾哈迈达巴德，强厄尔尼诺月与 EF 风险增加 64%相关，而强拉尼娜月与风险降低 41%相关。在苏拉特，强厄尔尼诺与风险降低 25%相关，而中等拉尼娜与风险增加 21%相关。
我们的结果表明，古吉拉特邦 EF 发病率的风险变化很大，即使在相隔仅 260 公里的两个城市之间也是如此。除了改善供水和污水处理系统外，预防公共卫生措施还应将风险的季节性和 ENSO 阶段变化纳入其中。需要进一步研究以确定全国范围内气候介导风险的异质性，并确定受益于早期预警系统的最脆弱人群。
