CholeraCholera ('kɒlərə) is an infection of the small intestine by some strains of the bacterium Vibrio cholerae. Symptoms may range from none, to mild, to severe. The classic symptom is large amounts of watery diarrhea that lasts a few days. Vomiting and muscle cramps may also occur. Diarrhea can be so severe that it leads within hours to severe dehydration and electrolyte imbalance. This may result in sunken eyes, cold skin, decreased skin elasticity, and wrinkling of the hands and feet. Dehydration can cause the skin to turn bluish.
EpidemicAn epidemic (from Greek ἐπί epi "upon or above" and δῆμος demos "people") 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. Epidemics of infectious disease are generally caused by several factors including a change in the ecology of the host population (e.g.
History of choleraSeven cholera pandemics have occurred in the past 200 years, with the first pandemic originating in India in 1817. The seventh cholera pandemic is officially a current pandemic and has been ongoing since 1961, according to a World Health Organization factsheet in March 2022. Additionally, there have been many documented major local cholera outbreaks, such as a 1991–1994 outbreak in South America and, more recently, the 2016–2021 Yemen cholera outbreak.
EpidemiologyEpidemiology is the study and analysis of the distribution (who, when, and where), patterns and determinants of health and disease conditions in a defined population. It is a cornerstone of public health, and shapes policy decisions and evidence-based practice by identifying risk factors for disease and targets for preventive healthcare. Epidemiologists help with study design, collection, and statistical analysis of data, amend interpretation and dissemination of results (including peer review and occasional systematic review).
1846–1860 cholera pandemicThe third cholera pandemic (1846–1860) was the third major outbreak of cholera originating in India in the 19th century that reached far beyond its borders, which researchers at University of California, Los Angeles (UCLA) believe may have started as early as 1837 and lasted until 1863. In the Russian Empire, more than one million people died of cholera. In 1853–1854, the epidemic in London claimed over 10,000 lives, and there were 23,000 deaths for all of Great Britain.
SanitationSanitation refers to public health conditions related to clean drinking water and treatment and disposal of human excreta and sewage. Preventing human contact with feces is part of sanitation, as is hand washing with soap. Sanitation systems aim to protect human health by providing a clean environment that will stop the transmission of disease, especially through the fecal–oral route. For example, diarrhea, a main cause of malnutrition and stunted growth in children, can be reduced through adequate sanitation.
Sanitation workerA sanitation worker (or sanitary worker) is a person responsible for cleaning, maintaining, operating, or emptying the equipment or technology at any step of the sanitation chain. This is the definition used in the narrower sense within the WASH sector. More broadly speaking, sanitation workers may also be involved in cleaning streets, parks, public spaces, sewers, stormwater drains, and public toilets. Another definition is: "The moment an individual’s waste is outsourced to another, it becomes sanitation work.
Epidemiological transitionIn demography and medical geography, epidemiological transition is a theory which "describes changing population patterns in terms of fertility, life expectancy, mortality, and leading causes of death." For example, a phase of development marked by a sudden increase in population growth rates brought by improved food security and innovations in public health and medicine, can be followed by a re-leveling of population growth due to subsequent declines in fertility rates.
Network layerIn the seven-layer OSI model of computer networking, the network layer is layer 3. The network layer is responsible for packet forwarding including routing through intermediate routers. The network layer provides the means of transferring variable-length network packets from a source to a destination host via one or more networks. Within the service layering semantics of the OSI (Open Systems Interconnection) network architecture, the network layer responds to service requests from the transport layer and issues service requests to the data link layer.
PandemicA pandemic (paen'dEmIk ) 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. Throughout human history, there have been a number of pandemics of diseases such as smallpox.
