Coronavirus (COVID-19) Collection
Reduction in the infection fatality rate of Omicron variant compared with previous variants in South Africa
The COVID-19 pandemic has been in effect for nearly two years since 2019. According to the World Health Organization (WHO), there have been over 260 million cases including more than 5 million deaths reported (https://www.who.int/emergencies/diseases/novel-coronavirus-2019 2021). The SARS-CoV-2 virus, first identified in late 2019, has mutated multiple times, and its variants have been classified by the WHO into three categories: variants of concern (VOC), variants of interest, and variants under monitoring.Exported cases were infected on the way: A conjecture derived from analysis on Hong Kong monthly exported COVID-19 cases
During this COVID-19 pandemic, imported cases have played the role of triggering outbreaks in their arrival city and exported cases are used to infer the infection risk in their departure city (Imai et al., 2020; Menkir et al., 2021). Hong Kong, as a hub of international travel, faced this situation in particular. However, we argue that in the current phase of the pandemic, the role of exported cases in inferring the infection risk in their departure city loses its power; we use Hong Kong, an international travel hub, as an example.COVID-19 and Lassa fever in Nigeria: A deadly alliance?
COVID-19 has become one of the most dangerous pandemics to cause severe problems for humanity in the past decades. SARS-CoV-2, a virus that causes COVID-19, emanated from China in December 2019, when public health officials alerted the World Health Organization (WHO) about pneumonia of an unknown etiology (WHO, 2021; Li et al., 2020). Subsequently, the disease rapidly spread worldwide. Nigeria faces a potential public health crisis owing to the synergistic epidemic of COVID-19 and other infectious diseases (Sherrard-Smith et al., 2020; Bouba et al., 2021).Infection fatality ratio and case fatality ratio of COVID-19
The infection fatality ratio (IFR) and case fatality ratio (CFR) define the risk of death per infection and per case, respectively. The difference between IFR and CFR depends on the definition of the case. If infection is defined as case, then CFR equals IFR. It is very important to determine the IFR because it influences the control policy and individual risk perception. It would be straightforward to determine the IFR in a closed, small population, such as the Diamond Princess Cruise, where the CFR was 1.3% without age standardization (Russell et al. 2020) and 0.5% after age standardization (Faust and Del Rio 2020).
