Norovirus in the context of "Travelers' diarrhea"

Hand sanitizer (also known as hand antiseptic, hand disinfectant, hand rub, or handrub) is a liquid, gel, or foam used to kill viruses, bacteria, and other microorganisms on the hands. It can also come in the form of a cream, spray, or wipe. While hand washing with soap and water is generally preferred, hand sanitizer is a convenient alternative in settings where soap and water are unavailable. However, it is less effective against certain pathogens like norovirus and Clostridioides difficile and cannot physically remove harmful chemicals. Improper use, such as wiping off sanitizer before it dries, can also reduce its effectiveness, and some sanitizers with low alcohol concentrations are less effective. Additionally, frequent use of hand sanitizer may disrupt the skin's microbiome and cause dermatitis.

Alcohol-based hand sanitizers, which contain at least 60% alcohol (ethanol or isopropyl alcohol), are recommended by the United States Centers for Disease Control and Prevention (CDC) when soap and water are not available. In healthcare settings, these sanitizers are often preferred over hand washing with soap and water because they are more effective at reducing bacteria and are better tolerated by the skin. However, hand washing should still be performed if contamination is visible or after using the toilet. Non-alcohol-based hand sanitizers, which may contain benzalkonium chloride or triclosan, are less effective and generally not recommended, though they are not flammable.

Gastroenteritis, also known as infectious diarrhea, is an inflammation of the gastrointestinal tract including the stomach and intestine. Symptoms may include diarrhea, vomiting, and abdominal pain. Fever, lack of energy, and dehydration may also occur. This typically lasts less than two weeks. Although it is not related to influenza, in Canada and the United States it is often referred to as "stomach flu".

Gastroenteritis is usually caused by viruses; however, gut bacteria, parasites, and fungi can also cause gastroenteritis. In children, rotavirus is the most common cause of severe disease. In adults, norovirus and Campylobacter are common causes. Eating improperly prepared food, drinking contaminated water or close contact with a person who is infected can spread the disease. Treatment is generally the same with or without a definitive diagnosis, so testing to confirm is usually not needed.

A toilet plume is the invisible to the naked eye, cloud-like dispersal of potentially infectious sewage particles as a result of flushing a toilet. Flush particles rapidly rise out of the bowl and several feet into the air after flushing. Aerosolized droplets can remain suspended in the air for tens of minutes between users. These invisible particles go on to coat and spread onto surfaces like floors and counters; or objects like hand towels, bathmats or even toothbrushes. Daily use of a toilet by healthy individuals is considered to pose a lower health risk in terms of infection. However, if an individual is immunocompromised and the previous user was sick and shed out quantities of an infectious virulent pathogen (virus or bacteria) in their urine, feces or vomitus that would be sufficient for infection, a significantly greater risk may arise to the immunocompromised individual.

Aerosolization of the toilet bowl contents allows infectious particles to free-float haphazardly, then potentially be inhaled and/or land on surfaces. There is evidence that specific pathogens such as norovirus or SARS coronavirus can be spread by toilet aerosols. It has been hypothesized that dispersal of pathogens may be reduced by closing the toilet lid before flushing, and by using toilets with lower flush energy. A 2024 study showed evidence that even closing the lid may still lead to small viral particles escaping through gaps under the lid, resulting in viral cross contamination of the air and surfaces in a washroom.

A medical classification is used to transform descriptions of medical diagnoses or procedures into standardized statistical code in a process known as clinical coding. Diagnosis classifications list diagnosis codes, which are used to track diseases and other health conditions, inclusive of chronic diseases such as diabetes mellitus and heart disease, and infectious diseases such as norovirus, the flu, and athlete's foot. Procedure classifications list procedure codes, which are used to capture interventional data. These diagnosis and procedure codes are used by health care providers, government health programs, private health insurance companies, workers' compensation carriers, software developers, and others for a variety of applications in medicine, public health and medical informatics, including:

• statistical analysis of diseases and therapeutic actions
• reimbursement (e.g., to process claims in medical billing based on diagnosis-related groups)
• knowledge-based and decision support systems
• direct surveillance of epidemic or pandemic outbreaks
• In forensic science and judiciary settings

There are country specific standards and international classification systems.

Viral load, also known as viral burden, is a numerical expression of the quantity of virus in a given volume of fluid, including biological and environmental specimens. It is not to be confused with viral titre or viral titer, which depends on the assay. When an assay for measuring the infective virus particle is done (Plaque assay, Focus assay), viral titre often refers to the concentration of infectious viral particles, which is different from the total viral particles. Viral load is measured using body fluids sputum and blood plasma. As an example of environmental specimens, the viral load of norovirus can be determined from run-off water on garden produce. Norovirus has not only prolonged viral shedding and has the ability to survive in the environment but a minuscule infectious dose is required to produce infection in humans: less than 100 viral particles.

Viral load is often expressed as viral particles, (virions) or infectious particles per mL depending on the type of assay. A higher viral burden, titre, or viral load often correlates with the severity of an active viral infection. The quantity of virus per mL can be calculated by estimating the live amount of virus in an involved fluid. For example, it can be given in RNA copies per millilitre of blood plasma.