A pandemic is an epidemic of an infectious disease that has spread across a large region, for instance multiple continents or worldwide, affecting a substantial number of individuals. Widespread endemic diseases with a stable number of infected individuals such as recurrences of seasonal influenza are generally excluded as they occur simultaneously in large regions of the globe rather than being spread worldwide.
An epidemic is the rapid spread of disease to a large number of hosts in a given population within a short period of time. For example, in meningococcal infections, an attack rate in excess of 15 cases per 100,000 people for two consecutive weeks is considered an epidemic.
In epidemiology, an infection is said to be endemic in a specific population or populated place when that infection is constantly present, or maintained at a baseline level, without extra infections being brought into the group as a result of travel or similar means. The term describes the distribution (spread) of an infectious disease among a group of people or within a populated area. An endemic disease always has a steady, predictable number of people getting sick, but that number can be high (hyperendemic) or low (hypoendemic), and the disease can be severe or mild. Also, a disease that is usually endemic can become epidemic.
Health may refer to "a state of complete physical, mental and social well-being and not merely the absence of disease and infirmity.", according to the World Health Organization (WHO). 78.7 was the average life expectancy for individuals at birth in 2017. The highest cause of death for United States citizens is heart disease. Infectious diseases such as sexually transmitted diseases impact the health of approximately 19 million yearly. The two most commonly reported infectious diseases include chlamydia and gonorrhea. The United States is currently challenged by the COVID-19 pandemic, and is 19th in the world in COVID-19 vaccination rates. All 50 states in the U.S. require immunizations for children in order to enroll in public school, but various exemptions are available by state. Immunizations are often compulsory for military enlistment in the United States.
In public health, social distancing, also called physical distancing, is a set of non-pharmaceutical interventions or measures intended to prevent the spread of a contagious disease by maintaining a physical distance between people and reducing the number of times people come into close contact with each other. It usually involves keeping a certain distance from others and avoiding gathering together in large groups.
The COVID-19 pandemic, also known as the coronavirus pandemic, is a global pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The novel virus was first identified in an outbreak in the Chinese city of Wuhan in December 2019. Attempts to contain it there failed, allowing the virus to spread to other areas of Asia and later worldwide in 2020. The World Health Organization (WHO) declared the outbreak a public health emergency of international concern (PHEIC) on 30 January 2020. The WHO ended its PHEIC declaration on 5 May 2023. As of 17 October 2023, the pandemic had caused 771,190,439 cases and 6,961,001 confirmed deaths, ranking it fifth in the deadliest epidemics and pandemics in history.
Coronavirus disease 2019 (COVID-19) is a contagious disease caused by the virus SARS-CoV-2. The first known case was identified in Wuhan, China, in December 2019. The disease quickly spread worldwide, resulting in the COVID-19 pandemic.
In the United States, the worldwide pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in 103,436,829 confirmed cases with 1,127,152 all-time deaths, the most of any country, and the 20th-highest per capita worldwide. The COVID-19 pandemic ranks first on the list of disasters in the United States by death toll; it was the third-leading cause of death in the U.S. in 2020, behind heart disease and cancer. From 2019 to 2020, U.S. life expectancy dropped by 3 years for Hispanic and Latino Americans, 2.9 years for African Americans, and 1.2 years for white Americans. These effects persisted as U.S. deaths due to COVID-19 in 2021 exceeded those in 2020, and life expectancy continued to fall from 2020 to 2021.
The COVID-19 pandemic was confirmed to have reached the U.S. state of Arizona in January 2020. As of June 3, 2021 Arizona public health authorities reported 322 new cases of COVID-19 and five deaths, bringing the cumulative totals since the start of the pandemic to 882,691 cases and 17,653 deaths. 12.3% of the state's population has been positively diagnosed with COVID-19 since the first case was reported on January 26, 2020.
Nils Anders Tegnell is a Swedish civil servant and physician specialising in infectious disease. From 2013 until his resignation in March 2022 he was Sweden's state epidemiologist.
Caitlin M. Rivers is an American epidemiologist who as Senior Scholar at the Johns Hopkins Center for Health Security and assistant professor at the Johns Hopkins Bloomberg School of Public Health, specializing on improving epidemic preparedness. Rivers is currently working on the American response to the COVID-19 pandemic with a focus on the incorporation of infectious disease modeling and forecasting into public health decision making.
Maimuna (Maia) Majumder is a computational epidemiologist and a faculty member at Harvard Medical School and Boston Children's Hospital's Computational Health Informatics Program (CHIP). She is currently working on modeling the spread of the COVID-19 pandemic.
COVID-19 surveillance involves monitoring the spread of the coronavirus disease in order to establish the patterns of disease progression. The World Health Organization (WHO) recommends active surveillance, with focus of case finding, testing and contact tracing in all transmission scenarios. COVID-19 surveillance is expected to monitor epidemiological trends, rapidly detect new cases, and based on this information, provide epidemiological information to conduct risk assessment and guide disease preparedness.
The Solidarity trial for treatments is a multinational Phase III-IV clinical trial organized by the World Health Organization (WHO) and partners to compare four untested treatments for hospitalized people with severe COVID-19 illness. The trial was announced 18 March 2020, and as of 6 August 2021, 12,000 patients in 30 countries had been recruited to participate in the trial.
The COVID-19 pandemic has had many impacts on global health beyond those caused by the COVID-19 disease itself. It has led to a reduction in hospital visits for other reasons. There have been 38 per cent fewer hospital visits for heart attack symptoms in the United States and 40 per cent fewer in Spain. The head of cardiology at the University of Arizona said, "My worry is some of these people are dying at home because they're too scared to go to the hospital." There is also concern that people with strokes and appendicitis are not seeking timely treatment. Shortages of medical supplies have impacted people with various conditions.
The COVID-19 pandemic in the United States has had far-reaching consequences in the country that go beyond the spread of the disease itself and efforts to quarantine it, including political, cultural, and social implications.
The COVID-19 pandemic has revealed race-based health care disparities in many countries, including the United States, United Kingdom, Norway, Sweden, Canada, and Singapore. These disparities are believed to originate from structural racism in these countries which pre-dates the pandemic; a commentary in The BMJ noted that "ethnoracialised differences in health outcomes have become the new normal across the world" as a result of ethnic and racial disparities in COVID-19 healthcare, determined by social factors. Data from the United States and elsewhere shows that minorities, especially black people, have been infected and killed at a disproportionate rate to white people.
Austin, Texas, reportedly confirmed its first cases on March 13, 2020, with the related onset of symptoms occurring as early as March 2, 2020. However, the disease may have reached the Austin area earlier. In an unconfirmed case, a 67 year old man in Bastrop, Tx, traveled to Clovis ,NM on December 21st. He was hospitalized in Clovis on December 23, 2019, then transported via ambulance to Lubbock where he was placed on a ventilator. He declined rapidly and died on January 2, 2020. Though there was no testing available at the time, he exhibited classic symptoms of COVID-19. The first fatality associated with the disease was reported on March 27, 2020. As of January 21, 2021, the City of Austin has reported over 50,000 cases of COVID-19, with 573 deaths associated with the disease.
The impact of the COVID-19 pandemic on Native American tribes and tribal communities has been severe and has emphasized underlying inequalities in Native American communities compared to the majority of the American population. The pandemic exacerbated existing healthcare and other economic and social disparities between Native Americans and other racial and ethnic groups in the United States. Along with black Americans, Latinos, and Pacific Islanders, the death rate in Native Americans due to COVID-19 was twice that of white and Asian Americans, with Native Americans having the highest mortality rate of all racial and ethnic groups nationwide. As of January 5, 2021, the mortality impact in Native American populations from COVID-19 was 1 in 595 or 168.4 deaths in 100,000, compared to 1 in 1,030 for white Americans and 1 in 1,670 for Asian Americans. Prior to the pandemic, Native Americans were already at a higher risk for infectious disease and mortality than any other group in the United States.
David Hayman is a New Zealand-based epizootic epidemiologist and disease ecologist whose general multi-disciplinary work focuses on the maintenance of infectious diseases within their hosts and the process of emergence and transmission to humans specifically related to bats. He has gathered data on the relationship between ecological degradation due to anthropogenic actions, and increased pathogen emergence in humans and animals. During COVID-19 he was involved as an expert in several international collaborations, some convened by the World Health Organization, and was a regular commentator in the New Zealand media about the country's response to the pandemic. He has had lead roles in research organisations at Massey University and Te Pūnaha Matatini and was the recipient of the 2017 Rutherford Discovery Fellowship Award. Since 2014 Hayman has been a professor at Massey University.
