Muscle cramping and weakness, altered consciousness, seizures, or even coma due to electrolyte imbalances are common, especially in children. Cause
Transmission
Cholera bacteria have been found in shellfish and plankton.Transmission is usually through the fecal-oral route of contaminated food or water caused by poor sanitation. Most cholera cases in developed countries are a result of transmission by food, while in developing countries it is more often water. Food transmission can occur when people harvest seafood such as oysters in waters infected with sewage, as Vibrio cholerae accumulates in planktonic crustaceans and the oysters eat the zooplankton.People infected with cholera often have diarrhea, and disease transmission may occur if this highly liquid stool, colloquially referred to as "rice-water", contaminates water used by others. A single diarrheal event can cause a one-million fold increase in numbers of V. cholerae in the environment. The source of the contamination is typically other people with cholera when their untreated diarrheal discharge is allowed to get into waterways, groundwater or drinking water supplies. Drinking any contaminated water and eating any foods washed in the water, as well as shellfish living in the affected waterway, can cause a person to contract an infection. Cholera is rarely spread directly from person to person.V. cholerae also exists outside the human body in natural water sources, either by itself or through interacting with phytoplankton, zooplankton, or biotic and abiotic detritus. Drinking such water can also result in the disease, even without prior contamination through fecal matter.
For his work on cholera, John Snow is often regarded as the "Father of Epidemiology".The bacterium was isolated in 1854 by Italian anatomist Filippo Pacini, but its exact nature and his results were not widely known. In the same year, the Catalan Joaquim Balcells i Pascual discovered the bacterium. In 1856 António Augusto da Costa Simões and José Ferreira de Macedo Pinto, two Portuguese researchers, are believed to have done the same.Between the mid-1850s and the 1900s, cities in developed nations made massive investment in clean water supply and well-separated sewage treatment infrastructures. This eliminated the threat of cholera epidemics from the major developed cities in the world. In 1883, Robert Koch identified V. cholerae with a microscope as the bacillus causing the disease.Hemendra Nath Chatterjee, a Bengali scientist, was the first to formulate and demonstrate the effectiveness of oral rehydration salt (ORS) to treat diarrhea. In his 1953 paper, published in The Lancet, he states that promethazine can stop vomiting during cholera and then oral rehydration is possible. The formulation of the fluid replacement solution was 4 g of sodium chloride, 25 g of glucose and 1000 ml of water. Indian medical scientist Sambhu Nath De discovered the cholera toxin, the animal model of cholera, and successfully demonstrated the method of transmission of cholera pathogen Vibrio cholerae.Robert Allan Phillips, working at US Naval Medical Research Unit Two in Southeast Asia, evaluated the pathophysiology of the disease using modern laboratory chemistry techniques. He developed a protocol for rehydration.