Haidari Leila A, Brown Shawn T, Constenla Dagna, Zenkov Eli, Ferguson Marie, de Broucker Gatien, Ozawa Sachiko, Clark Samantha, Lee Bruce Y
Pittsburgh Supercomputing Center (PSC), Carnegie Mellon University, Pittsburgh, PA, United States.
Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States.
Vaccine. 2016 Jul 29;34(35):4161-4165. doi: 10.1016/j.vaccine.2016.06.065. Epub 2016 Jun 29.
With tetanus being a leading cause of maternal and neonatal morbidity and mortality in low and middle income countries, ensuring that pregnant women have geographic access to tetanus toxoid (TT) immunization can be important. However, immunization locations in many systems may not be placed to optimize access across the population. Issues of access must be addressed for vaccines such as TT to reach their full potential.
To assess how TT immunization locations meet population demand in Mozambique, our team developed and utilized SIGMA (Strategic Integrated Geo-temporal Mapping Application) to quantify how many pregnant women are reachable by existing TT immunization locations, how many cannot access these locations, and the potential costs and disease burden of not covering geographically harder-to-reach populations. Sensitivity analyses covered a range of catchment area sizes to include realistic travel distances and to determine the area some locations would need to cover in order for the existing system to reach at least 99% of the target population.
For 99% of the population to reach health centers, people would be required to travel up to 35km. Limiting this distance to 15km would result in 5450 (3033-7108) annual cases of neonatal tetanus that could be prevented by TT, 144,240 (79,878-192,866) DALYs, and $110,691,979 ($56,180,326-$159,516,629) in treatment costs and productivity losses. A catchment area radius of 5km would lead to 17,841 (9929-23,271) annual cases of neonatal tetanus that could be prevented by TT, resulting in 472,234 (261,517-631,432) DALYs and $362,399,320 ($183,931,229-$522,248,480) in treatment costs and productivity losses.
TT immunization locations are not geographically accessible by a significant proportion of pregnant women, resulting in substantial healthcare and productivity costs that could potentially be averted by adding or reconfiguring TT immunization locations. The resulting cost savings of covering these harder to reach populations could help pay for establishing additional immunization locations.
在低收入和中等收入国家，破伤风是孕产妇和新生儿发病及死亡的主要原因之一，因此确保孕妇能够在当地获得破伤风类毒素（TT）免疫接种至关重要。然而，许多系统中的免疫接种地点设置可能无法实现对全体人群的最佳覆盖。必须解决接种机会问题，以便诸如TT等疫苗能够充分发挥其潜力。
为评估莫桑比克的TT免疫接种地点如何满足人群需求，我们的团队开发并使用了SIGMA（战略综合地理时间映射应用程序），以量化现有TT免疫接种地点能够覆盖多少孕妇、有多少孕妇无法到达这些地点，以及未覆盖地理上难以到达人群的潜在成本和疾病负担。敏感性分析涵盖了一系列集水区面积大小，以纳入实际出行距离，并确定一些地点需要覆盖的面积，以便现有系统能够覆盖至少99%的目标人群。
为使99%的人口能够到达卫生中心，人们需要出行达35公里。将此距离限制在15公里会导致每年有5450例（3033 - 7108例）新生儿破伤风病例可通过TT预防，144240伤残调整生命年（79878 - 192866伤残调整生命年），以及治疗费用和生产力损失达110691979美元（56180326 - 159516629美元）。集水区半径为5公里会导致每年有17841例（9929 - 23271例）新生儿破伤风病例可通过TT预防，从而产生472234伤残调整生命年（261517 - 631432伤残调整生命年）以及治疗费用和生产力损失达362399320美元（183931229 - 522248480美元）。
很大一部分孕妇无法在当地获得TT免疫接种，这导致了大量的医疗保健和生产力成本，而通过增加或重新配置TT免疫接种地点有可能避免这些成本。覆盖这些难以到达人群所节省的成本可有助于支付建立额外免疫接种地点的费用。
