The Biosecurity Program, The Kirby Institute, UNSW Medicine, The University of New South Wales, Sydney, Australia.
School of Public Health and Community Medicine, The University of New South Wales, Sydney, Australia.
BMC Infect Dis. 2020 Oct 7;20(1):735. doi: 10.1186/s12879-020-05469-7.
The pandemic of COVID-19 has occurred close on the heels of a global resurgence of measles. In 2019, an unprecedented epidemic of measles affected Samoa, requiring a state of emergency to be declared. Measles causes an immune amnesia which can persist for over 2 years after acute infection and increases the risk of a range of other infections.
We modelled the potential impact of measles-induced immune amnesia on a COVID-19 epidemic in Samoa using data on measles incidence in 2018-2019, population data and a hypothetical COVID-19 epidemic.
The young population structure and contact matrix in Samoa results in the most transmission occurring in young people < 20 years old. The highest rate of death is the 60+ years old, but a smaller peak in death may occur in younger people, with more than 15% of total deaths in the age group under 20 years old. Measles induced immune amnesia could increase the total number of cases by 8% and deaths by more than 2%.
Samoa, which had large measles epidemics in 2019-2020 should focus on rapidly achieving high rates of measles vaccination and enhanced surveillance for COVID-19, as the impact may be more severe due to measles-induced immune paresis. This applies to other severely measles-affected countries in the Pacific, Europe and elsewhere.
COVID-19 大流行紧随麻疹在全球范围内的死灰复燃而发生。2019 年，萨摩亚发生了一场前所未有的麻疹疫情，需要宣布进入紧急状态。麻疹会导致免疫记忆丧失，在急性感染后可持续超过 2 年，并增加一系列其他感染的风险。
我们使用 2018-2019 年麻疹发病率、人口数据和假设的 COVID-19 疫情数据，对麻疹引起的免疫记忆丧失对萨摩亚 COVID-19 疫情的潜在影响进行了建模。
萨摩亚的年轻人口结构和接触矩阵导致 20 岁以下年轻人的传播率最高。死亡率最高的是 60 岁以上人群，但年轻人中可能会出现死亡率较小的高峰，20 岁以下人群的死亡人数超过总死亡人数的 15%。麻疹引起的免疫记忆丧失可能会使病例总数增加 8%，死亡人数增加 2%以上。
萨摩亚在 2019-2020 年发生了大规模麻疹疫情，应重点迅速实现高麻疹疫苗接种率，并加强对 COVID-19 的监测，因为由于麻疹引起的免疫无力，其影响可能更为严重。这适用于太平洋、欧洲和其他地区其他受麻疹严重影响的国家。
