Pneumonia in the context of Flu

Maximilian Carl Emil Weber (/ˈveɪbər/; German: [ˈveːbɐ] ; 21 April 1864 – 14 June 1920) was a German sociologist, historian, jurist, and political economist who was one of the central figures in the development of sociology and the social sciences more generally. His ideas continue to influence social theory and research.

Born in Erfurt in 1864, Weber studied law and history in Berlin, Göttingen, and Heidelberg. After earning his doctorate in law in 1889 and habilitation in 1891, he taught in Berlin, Freiburg, and Heidelberg. He married his cousin Marianne Schnitger two years later. In 1897, he had a breakdown after his father died following an argument. Weber ceased teaching and travelled until the early 1900s. He recovered and wrote The Protestant Ethic and the Spirit of Capitalism. During the First World War, he initially supported Germany's war effort but became critical of it and supported democratisation. He also gave the lectures "Science as a Vocation" and "Politics as a Vocation". After the war, Weber co-founded the German Democratic Party, unsuccessfully ran for office, and advised the drafting of the Weimar Constitution. Becoming frustrated with politics, he resumed teaching in Vienna and Munich. He died of pneumonia in 1920 at the age of 56, possibly as a result of the post-war Spanish flu pandemic. A book, Economy and Society, was left unfinished.

A coma is a deep state of prolonged unconsciousness in which a person cannot be awakened, fails to respond normally to painful stimuli, light, or sound, lacks a normal sleep-wake cycle and does not initiate voluntary actions. The person may experience respiratory and circulatory problems due to the body's inability to maintain normal bodily functions. People in a coma often require extensive medical care to maintain their health and prevent complications such as pneumonia or blood clots. Coma patients exhibit a complete absence of wakefulness and are unable to consciously feel, speak or move. Comas can be the result of natural causes, or can be medically induced, for example, during general anesthesia.

Clinically, a coma can be defined as the consistent inability to follow a one-step command. For a patient to maintain consciousness, the components of wakefulness and awareness must be maintained. Wakefulness is a quantitative assessment of the degree of consciousness, whereas awareness is a qualitative assessment of the functions mediated by the cerebral cortex, including cognitive abilities such as attention, sensory perception, explicit memory, language, the execution of tasks, temporal and spatial orientation and reality judgment. Neurologically, consciousness is maintained by the activation of the cerebral cortex—the gray matter that forms the brain's outermost layer—and by the reticular activating system (RAS), a structure in the brainstem.

Stroke is a medical condition in which poor blood flow to a part of the brain causes cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. Both cause parts of the brain to stop functioning properly.

Signs and symptoms of stroke may include an facial drooping, inability to walk, move or feel on one side of the body, problems understanding or speaking, dizziness, or loss of vision to one side. Signs and symptoms often appear soon after the stroke has occurred. If symptoms last less than 24 hours, the stroke is a transient ischemic attack (TIA), also called a mini-stroke. Hemorrhagic stroke may also be associated with a severe headache. The symptoms of stroke can be permanent. Long-term complications may include pneumonia and loss of bladder control.

Chickenpox, also known as varicella (/ˌværɪˈsɛlə/ VARR-iss-EL-ə), is a highly contagious disease caused by varicella zoster virus (VZV), a member of the herpesvirus family. The disease results in a characteristic skin rash that forms small, itchy blisters, which eventually scab over. It usually starts on the chest, back, and face. It then spreads to the rest of the body. The rash and other symptoms, such as fever, tiredness, and headaches, usually last five to seven days. Complications may occasionally include pneumonia, inflammation of the brain, and bacterial skin infections. The disease is usually more severe in adults than in children.

Chickenpox is an airborne disease which easily spreads via human-to-human transmission, typically through the coughs and sneezes of an infected person. The incubation period is 10–21 days, after which the characteristic rash appears. It may be spread from one to two days before the rash appears until all lesions have crusted over. It may also spread through contact with the blisters. Those with shingles may spread chickenpox to those who are not immune through contact with the blisters. The disease can usually be diagnosed based on the presenting symptom; however, in unusual cases it may be confirmed by polymerase chain reaction (PCR) testing of the blister fluid or scabs. Testing for antibodies may be done to determine if a person is immune. People usually only get chickenpox once. Although reinfections by the virus occur, these reinfections usually do not cause any symptoms.

Respiratory tract infections (RTIs) are infectious diseases involving the lower or upper respiratory tract. An infection of this type usually is further classified as an upper respiratory tract infection (URI or URTI) or a lower respiratory tract infection (LRI or LRTI). Lower respiratory infections, such as pneumonia, tend to be far more severe than upper respiratory infections, such as the common cold.

The 2009 swine flu pandemic, caused by the H1N1/swine flu/influenza virus and declared by the World Health Organization (WHO) from June 2009 to August 2010, was the third recent flu pandemic involving the H1N1 virus (the first being the 1918–1920 Spanish flu pandemic and the second being the 1977 Russian flu). The first identified human case was in La Gloria, Mexico, a rural town in Veracruz. The virus appeared to be a new strain of H1N1 that resulted from a previous triple reassortment of bird, swine, and human flu viruses which further combined with a Eurasian pig flu virus, leading to the term "swine flu".

Unlike most strains of influenza, the pandemic H1N1/09 virus did not disproportionately infect adults older than 60 years; this was an unusual and characteristic feature of the H1N1 pandemic. Even in the case of previously healthy people, a small percentage develop pneumonia or acute respiratory distress syndrome (ARDS). This manifests itself as increased breathing difficulty and typically occurs three to six days after initial onset of flu symptoms. The pneumonia caused by flu can be either direct viral pneumonia or a secondary bacterial pneumonia. A November 2009 New England Journal of Medicine article recommended that flu patients whose chest X-ray indicates pneumonia receive both antivirals and antibiotics. In particular, it is a warning sign if a child seems to be getting better and then relapses with high fever, as this relapse may be bacterial pneumonia.

Infant mortality is the death of an infant before the infant's first birthday. The occurrence of infant mortality in a population can be described by the infant mortality rate (IMR), which is the number of deaths of infants under one year of age per 1,000 live births. Similarly, the child mortality rate, also known as the under-five mortality rate, compares the death rate of children up to the age of five.

In 2013, the leading cause of infant mortality in the United States was birth defects. Other leading causes of infant mortality include birth asphyxia, pneumonia, neonatal infection, diarrhea, malaria, measles, malnutrition, term birth complications such as abnormal presentation of the fetus, umbilical cord prolapse, or prolonged labor. One of the most common preventable causes of infant mortality is smoking during pregnancy. Lack of prenatal care, alcohol consumption during pregnancy, and drug use also cause complications that may result in infant mortality. Many situational factors contribute to the infant mortality rate, such as the pregnant woman's level of education, environmental conditions, political infrastructure, and level of medical support. Improving sanitation, access to clean drinking water, immunization against infectious diseases, and other public health measures can help reduce rates of infant mortality.

Influenza, commonly known as the flu, is an infectious disease caused by influenza viruses. Symptoms range from mild to severe and often include fever, runny nose, sore throat, muscle pain, headache, coughing, and fatigue. These symptoms begin one to four (typically two) days after exposure to the virus and last for about two to eight days. Diarrhea and vomiting can occur, particularly in children. Influenza may progress to pneumonia from the virus or a subsequent bacterial infection. Other complications include acute respiratory distress syndrome, meningitis, encephalitis, and worsening of pre-existing health problems such as asthma and cardiovascular disease.

There are four types of influenza virus: types A, B, C, and D. Aquatic birds are the primary source of influenza A virus (IAV), which is also widespread in various mammals, including humans and pigs. Influenza B virus (IBV) and influenza C virus (ICV) primarily infect humans, and influenza D virus (IDV) is found in cattle and pigs. Influenza A virus and influenza B virus circulate in humans and cause seasonal epidemics, and influenza C virus causes a mild infection, primarily in children. Influenza D virus can infect humans but is not known to cause illness. In humans, influenza viruses are primarily transmitted through respiratory droplets from coughing and sneezing. Transmission through aerosols and surfaces contaminated by the virus also occur.

Shortness of breath (SOB), known as dyspnea (in AmE) or dyspnoea (in BrE), is an uncomfortable feeling of not being able to breathe well enough. The American Thoracic Society defines it as "a subjective experience of breathing discomfort that consists of qualitatively distinct sensations that vary in intensity", and recommends evaluating dyspnea by assessing the intensity of its distinct sensations, the degree of distress and discomfort involved, and its burden or impact on the patient's activities of daily living. Distinct sensations include effort/work to breathe, chest tightness or pain, and "air hunger" (the feeling of not enough oxygen). The tripod position is often assumed to be a sign.

Dyspnea is a normal symptom of heavy physical exertion but becomes pathological if it occurs in unexpected situations, when resting or during light exertion. In 85% of cases it is due to asthma, pneumonia, reflux/LPR, cardiac ischemia, COVID-19, interstitial lung disease, congestive heart failure, chronic obstructive pulmonary disease, or psychogenic causes, such as panic disorder and anxiety (see Psychogenic disease and Psychogenic pain). The best treatment to relieve or even remove shortness of breath typically depends on the underlying cause.

Cytomegalovirus (CMV) (from cyto- 'cell' via Greek κύτος kútos- 'container' + μέγας mégas 'big, megalo-' + -virus via Latin vīrus 'poison') is a genus of viruses in the order Herpesvirales, in the family Herpesviridae, in the subfamily Betaherpesvirinae. Humans and other primates serve as natural hosts. The 11 species in this genus include human betaherpesvirus 5 (HCMV, human cytomegalovirus, HHV-5), which is the species that infects humans. Diseases associated with HHV-5 include mononucleosis and pneumonia, and congenital CMV in infants can lead to variety of birth defects, including those involving the eyes, ears, liver, and spleen.

In the medical literature, most mentions of CMV without further specification refer implicitly to human CMV. Human CMV is the most studied of all cytomegaloviruses.

Measles (probably from Middle Dutch or Middle High German masel(e), meaning "blemish, blood blister") is a highly contagious, vaccine-preventable infectious disease caused by measles virus. Other names include morbilli, rubeola, 9-day measles, red measles, and English measles.

Symptoms usually develop 10–12 days after exposure to an infected person and last 7–10 days. Initial symptoms typically include fever, often greater than 40 °C (104 °F), cough, runny nose, and inflamed eyes. Small white spots known as Koplik spots may form inside the mouth two or three days after the start of symptoms. A red, flat rash which usually starts on the face and then spreads to the rest of the body typically begins three to five days after the start of symptoms. Common complications include diarrhea (in 8% of cases), middle ear infection (7%), and pneumonia (6%). These occur in part due to measles-induced immunosuppression. Less commonly, seizures, blindness, or inflammation of the brain may occur.

Hemoptysis or haemoptysis is the discharge of blood or blood-stained mucus through the mouth coming from the bronchi, larynx, trachea, or lungs. In other words, it is the airway bleeding, and does not necessarily involve coughing. This can occur with lung cancer, infections such as tuberculosis, bronchitis, or pneumonia, and certain cardiovascular conditions. Hemoptysis is considered massive at 300 mL (11 imp fl oz; 10 US fl oz). In such cases, there are always severe injuries. The primary danger comes from choking, rather than blood loss.

The COVID-19 pandemic in China is part of the worldwide pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). China was the first country to experience an outbreak of the disease, the first to impose drastic measures in response (including lockdowns and face mask mandates), and one of the first countries to bring the outbreak under control.

The first wave of the disease manifested as the 2019–2020 COVID-19 outbreak in mainland China, beginning with a cluster of mysterious pneumonia cases, mostly related to the Huanan Seafood Market, in Wuhan, the capital of Hubei province. It was first reported to the local government on 27 December 2019, and published on 31 December. On 8 January 2020, a new coronavirus (SARS-CoV-2) was identified as the cause of the pneumonia by Chinese scientists. By 29 January, the virus was found to have spread to all provinces of mainland China. The virus was first confirmed to have spread to Hong Kong on 23 January 2020, thus originating the COVID-19 pandemic in Hong Kong. Confirmed cases were generally transferred to Princess Margaret Hospital's Infectious Disease Centre for isolation and centralized treatment. On 5 February, after a five-day strike by front-line medical workers, the Hong Kong government closed all but three border control points – Hong Kong International Airport, Shenzhen Bay Control Point, and Hong Kong–Zhuhai–Macau Bridge Control Point remaining open. The first case of the disease in Macau was confirmed on 22 January 2020, originating the COVID-19 pandemic in Macau. The city saw nine more cases by 4 February, but no more cases until 15 March, when imported cases began to appear. Until 26 April 2021, the city had 49 cumulative confirmed cases of COVID-19, all of those having recovered, and no deaths from the disease. Stringent government measures have included the 15-day closure of all 81 casinos in the territory in February; in addition, effective 25 March, the territory disallowed connecting flights at its airport as well as entry by all non-residents (with the exception of residents of mainland China, Hong Kong, and Taiwan), and from 6 April, the Hong Kong–Zhuhai–Macau Bridge was closed to public transport and most other traffic.

On December 31, 2019, China announced the discovery of a cluster of pneumonia cases in Wuhan. The first American case of COVID-19 was reported on January 20, and Health and Human Services Secretary Alex Azar declared a public health emergency on January 31. Restrictions were placed on flights arriving from China, but the initial U.S. response to the COVID-19 pandemic was otherwise slow in terms of preparing the healthcare system, stopping other travel, and testing. The first known American deaths occurred in February and in late February President Donald Trump proposed allocating $2.5 billion to fight the outbreak. Instead, Congress approved $8.3 billion and Trump signed the Coronavirus Preparedness and Response Supplemental Appropriations Act, 2020 on March 6. Trump declared a national emergency on March 13. The government also purchased large quantities of medical equipment, invoking the Defense Production Act of 1950 to assist. By mid-April, disaster declarations were made by all states and territories as they all had increasing cases. A second wave of infections began in June, following relaxed restrictions in several states, leading to daily cases surpassing 60,000. By mid-October, a third surge of cases began; there were over 200,000 new daily cases during parts of December 2020 and January 2021.

COVID-19 vaccines became available in December 2020, under emergency use, beginning the national vaccination program, with the first vaccine officially approved by the Food and Drug Administration (FDA) on August 23, 2021. Studies have shown them to be highly protective against severe illness, hospitalization, and death. In comparison with fully vaccinated people, the CDC found that those who were unvaccinated were from 5 to nearly 30 times more likely to become either infected or hospitalized. There nonetheless was some vaccine hesitancy for various reasons, although side effects were rare. There were also numerous reports that unvaccinated COVID-19 patients strained the capacity of hospitals throughout the country, forcing many to turn away patients with life-threatening diseases.

Lower respiratory tract infection (LRTI) is a term often used as a synonym for pneumonia but can also be applied to other types of infection including lung abscess and acute bronchitis. Symptoms include shortness of breath, weakness, fever, coughing and fatigue. A routine chest X-ray is not always necessary for people who have symptoms of a lower respiratory tract infection.

Influenza affects both the upper and lower respiratory tracts.

Chest pain is pain or discomfort in the chest, typically the front of the chest. It may be described as sharp, dull, pressure, heaviness or squeezing. Associated symptoms may include pain in the shoulder, arm, upper abdomen, or jaw, along with nausea, sweating, or shortness of breath. It can be divided into heart-related and non-heart-related pain. Pain due to insufficient blood flow to the heart is also called angina pectoris. Those with diabetes or the elderly may have less clear symptoms.

Serious and relatively common causes include acute coronary syndrome such as a heart attack (31%), pulmonary embolism (2%), pneumothorax, pericarditis (4%), aortic dissection (1%) and esophageal rupture. Other common causes include gastroesophageal reflux disease (30%), muscle or skeletal pain (28%), pneumonia (2%), shingles (0.5%), pleuritis, traumatic and anxiety disorders. Determining the cause of chest pain is based on a person's medical history, a physical exam and other medical tests. About 3% of heart attacks, however, are initially missed.

Fungal infection, also known as mycosis, is a disease caused by fungi. Different types are traditionally divided according to the part of the body affected: superficial, subcutaneous, and systemic. Superficial fungal infections include common tinea of the skin, such as tinea of the body, groin, hands, feet and beard, and yeast infections such as pityriasis versicolor. Subcutaneous types include eumycetoma and chromoblastomycosis, which generally affect tissues in and beneath the skin. Systemic fungal infections are more serious and include cryptococcosis, histoplasmosis, pneumocystis pneumonia, aspergillosis and mucormycosis. Signs and symptoms range widely. There is usually a rash with superficial infection. Fungal infection within the skin or under the skin may present with a lump and skin changes. Pneumonia-like symptoms or meningitis may occur with a deeper or systemic infection.

Fungi are everywhere, but only some cause disease. Fungal infection occurs after spores are either breathed in, come into contact with skin or enter the body through the skin such as via a cut, wound or injection. It is more likely to occur in people with a weak immune system. This includes people with illnesses such as HIV/AIDS, and people taking medicines such as steroids or cancer treatments. Fungi that cause infections in people include yeasts, molds and fungi that are able to exist as both a mold and yeast. The yeast Candida albicans can live in people without producing symptoms, and is able to cause both superficial mild candidiasis in healthy people, such as oral thrush or vaginal yeast infection, and severe systemic candidiasis in those who cannot fight infection themselves.

The common cold, or the cold, is a viral infectious disease of the upper respiratory tract that primarily affects the respiratory mucosa of the nose, throat, sinuses, and larynx. Signs and symptoms may appear in as little as two days after exposure to the virus. These may include coughing, sore throat, runny nose, sneezing, headache, fatigue, and fever. People usually recover in seven to ten days, but some symptoms may last up to three weeks. Occasionally, those with other health problems may develop pneumonia.

Well over 200 virus strains are implicated in causing the common cold, with rhinoviruses, coronaviruses, adenoviruses and enteroviruses being the most common. They spread through the air or indirectly through contact with objects in the environment, followed by transfer to the mouth or nose. Risk factors include going to child care facilities, not sleeping well, and psychological stress. The symptoms are mostly due to the body's immune response to the infection rather than to tissue destruction by the viruses themselves. The symptoms of influenza are similar to those of a cold, although usually more severe and less likely to include a runny nose.