July 22, 2024 Author: Saraiva da Cunha Cholera is caused by a bacteria called Vibrio cholerae . The disease spread throughout the world during the 19th century, from its original region, the Ganges River delta, in India, causing several epidemics that killed millions of people over the years. In developed countries, better living conditions, treatment of water, water supply and drainage networks, and widespread good hygiene practices have made it possible to eliminate the disease. However, cholera is still endemic and a public health problem in around 50 countries around the world , mainly in Africa and Asia, mainly due to the lack of access to drinking water and precarious basic sanitation conditions. For these reasons, the occurrence of cholera outbreaks is also a concern in areas of conflict or natural disasters, especially when associated with large population movements and resettlement in precarious conditions. Disease transmission Infection with the bacteria Vibrio cholerae occurs when contaminated water or food (mainly seafood) is ingested. Contamination of water and food originates from feces from infected people, who eliminate the bacteria even if they do not have symptoms. Vibrio cholerae is sensitive to acids . Since the stomach has acidic content and the initial action of the bacteria is in the intestine, for a healthy adult to have cholera, it is necessary to inoculate a large amount of bacteria. People exposed to Vibrio cholerae develop immunity to the serotype to which they were exposed. In addition to large concentrations of population in places with precarious sanitation conditions, there are other factors that increase the risk and severity of the disease, for example: Cohabitation with infected people; The main risk groups are pregnant women, children (especially malnourished children) and the elderly (especially those suffering from chronic diseases, such as diabetes, heart disease and kidney disease); Helicobacter pylori infection (due to chronic gastritis which decreases acid production); Decreased stomach acidity, for example, as a result of proton pump inhibitor medications. Cholera symptoms Infection with cholera bacteria may not cause any symptoms or these may be mild. However, the disease can also progress quickly, with severe symptoms occurring 12 hours to 5 days after infection (incubation period): Abundant watery diarrhea, with a milky appearance; Nausea and vomiting; Dehydration; Other symptoms may occur related to dehydration, like fatigue, sunken eyes, thirst, dry wrinkled mouth and skin, little urination, low blood pressure and changes in heart rate; Cramps and hypovolemic shock are serious complications of dehydration that can be fatal in a short time. Whether they have symptoms or not, infected people eliminate Vibrio cholerae in their feces for a period usually less than 5 days after infection (although there are cases in which elimination lasts for several weeks), mainly contaminating the water and perpetuating the infection cycle. Cholera prevention In countries where the disease is endemic, prevention measures are mainly: Teaching appropriate personal hygiene care , among which correct hand washing plays an essential role; Teaching actions that contribute to the safety of water , both for drinking water and that used for irrigating crops and preparing food. Food professionals are a particular target group for these actions. Implementation of measures to make drinking water available and correctly dispose of untreated water ; In case of outbreaks, widespread vaccination and containment of diagnosed cases to prevent spread. Anyone traveling to countries where the disease is endemic or to areas at greater risk must be aware of the disease and adopt prevention measures, for example: Reinforce frequent hand washing; Do not drink unbottled water and do not use ice in drinks; Use only bottled water to brush teeth; Try not to drink water when bathing or swimming in lakes, swimming pools, or other places; Do not eat raw foods, including fruits and vegetables, or seafood; Always eat freshly cooked food. The World Health Organization recommends vaccinating higher-risk travelers , such as people involved in humanitarian emergency and rescue operations. After traveling to regions with increased risk, it is still necessary to remain alert and quickly seek medical attention if some suspicion occurs. Severe and profuse diarrhea and a recent history of travel to a region where the disease is endemic are the main factors that should raise the suspicion of cholera. Immediate treatment, which is based on fluid therapy and antibiotics , significantly reduces the mortality rate. Meet the Infectious Diseases clinical team at the Hospital da Luz network. Sources European Center for Disease Prevention and Control. Surveillance Atlas of Infectious Diseases . European Center for Disease Prevention and Control. Cholera . Fanous M, King KC. Cholera. StatPearls. Treasure Island: StatPearls Publishing; 2023. World Health Organizations. Cholera . Kanungo S, Azman AS, Ramamurthy T, et al. Cholera. Lancet 2022; 399:1429-40. The content published in the Health Guide is intended for the general public and is provided for informational and educational purposes only. It does not replace individual medical assessment, diagnosis, or personalized clinical advice from a qualified healthcare professional. The content is produced or reviewed by physicians and other healthcare professionals at Hospital da Luz and is based on the knowledge available at the time of publication or the most recent update, as indicated at the beginning of each item.
