搜尋結果
COVID-19 is the deadliest pandemic in US history; [358] it was the third-leading cause of death in the US in 2020, behind heart disease and cancer. [359] From 2019 to 2020, US life expectancy dropped by 3 years for Hispanic Americans, 2.9 years for African Americans, and 1.2 years for white Americans. [360]
- 6,956,160 (reported), 17.5–31.4 million (estimated)
- Worldwide
- Coronavirus disease 2019 (COVID-19)
- Severe acute respiratory syndromecoronavirus 2 (SARS‑CoV‑2)
18.2–33.5 million [6] (estimated) Coronavirus disease 2019 ( COVID-19) is a contagious disease caused by the coronavirus SARS-CoV-2. The first known case was identified in Wuhan, China, in December 2019. [7] Most scientists believe the SARS-CoV-2 virus entered into human populations through natural zoonosis, similar to the SARS-CoV-1 and MERS ...
- 6,960,770 (reported), 17.6–31.4 million (estimated)
- SARS-CoV-2
- 2–14 days (typically 5), after infection
- Symptomatic and supportive
Omicron (B.1.1.529) is a variant of SARS-CoV-2 first reported to the World Health Organization (WHO) by the Network for Genomics Surveillance in South Africa on 24 November 2021.[10][11] It was first detected in Botswana and has spread to become the predominant variant in circulation around the world.[12] Following the original B.1.1.529 ...
A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. [1] Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. [2] [3] Viruses are found in almost every ecosystem on Earth and are the most numerous type of biological entity.
Human papillomavirus infection ( HPV infection) is caused by a DNA virus from the Papillomaviridae family. [5] Many HPV infections cause no symptoms and 90% resolve spontaneously within two years. [1] In some cases, an HPV infection persists and results in either warts or precancerous lesions. [2] These lesions, depending on the site affected ...
- Human papillomavirus spread by direct contact
- None, warts
- Most people are infected at some point in time
Leucippus was a Greek philosopher of the 5th century BCE. He is credited with founding atomism, with his student Democritus. Leucippus divided the world into two entities: atoms, indivisible particles that make up all things, and the void, the nothingness between the atoms. Leucippus's ideas were influential in ancient and Renaissance philosophy.
Visna-maedi virus. The human immunodeficiency viruses ( HIV) are two species of Lentivirus (a subgroup of retrovirus) that infect humans. Over time, they cause acquired immunodeficiency syndrome (AIDS), [1] [2] a condition in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive. [3]
