Wickramasinghe Dakshitha, Wickramasinghe Nilanka, Kamburugamuwa Sohan Anjana, Arambepola Carukshi, Samarasekera Dharmabandhu N
Department of Surgery, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka.
Department of Physiology, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka.
Trop Dis Travel Med Vaccines. 2020 Aug 28;6:17. doi: 10.1186/s40794-020-00117-z. eCollection 2020.
To investigate the association between parameters indicating immunity from BCG at country level (presence of BCG vaccination policy, BCG coverage, age-specific incidence of tuberculosis (TB)) and the morbidity and mortality of COVID-19.
Country-specific data for COVID-19 cases and deaths, demographic details, BCG coverage and policy, age-specific TB incidence and income level were obtained. The crude COVID-19 cases and deaths per 100,000 population were calculated and assessed against the parameters indicating immunity from BCG using linear regression analysis.
Univariate analysis identified higher income level of a country to be significantly associated with COVID-19 cases ( < 0.0001) and deaths ( < 0.0001) but not with its case fatality rate. The association between COVID-19 and TB was strongest for TB incidence in patients > 65-years (Cases (r = - 0.785, = 0.0001)) and deaths (r = - 0.647, = 0.0001).Multivariate analysis identified the higher income level of a country and not having a universal BCG vaccination policy to affect the COVID-19 cases. The deaths were inversely affected by the presence of BCG vaccination policy and coverage; and positively by the TB incidence in patients > 65-years.
Significant inverse correlations observed between cases and deaths of COVID-19 and BCG related parameters highlights immunity from BCG as a likely explanation for the variation in COVID-19 across countries.
调查国家层面卡介苗免疫相关参数（卡介苗接种政策的存在情况、卡介苗接种覆盖率、特定年龄结核病发病率）与新冠病毒病（COVID-19）的发病率和死亡率之间的关联。
获取各国COVID-19病例和死亡的特定数据、人口统计学详细信息、卡介苗接种覆盖率和政策、特定年龄结核病发病率以及收入水平。计算每10万人口中COVID-19的粗病例数和死亡数，并使用线性回归分析根据卡介苗免疫相关参数进行评估。
单因素分析确定，国家较高的收入水平与COVID-19病例（<0.0001）和死亡（<0.0001）显著相关，但与病死率无关。COVID-19与结核病之间的关联在65岁以上患者的结核病发病率方面最为显著（病例：r = -0.785，P = 0.0001）以及死亡方面（r = -0.647，P = 0.0001）。多因素分析确定，国家较高的收入水平以及没有普遍的卡介苗接种政策会影响COVID-19病例。死亡受到卡介苗接种政策和覆盖率的反向影响；并受到65岁以上患者结核病发病率的正向影响。
COVID-19病例和死亡与卡介苗相关参数之间观察到显著的负相关，这突出表明卡介苗免疫可能是各国COVID-19差异的一个解释。
