Cholera

Cholera is an acute diarrheal illness caused by Vibrio cholerae. Most infections are mild, but some cause rapid loss of fluids after ingesting contaminated water or food, especially in areas with poor sanitation.

Symptoms include sudden onset of profuse watery diarrhea, vomiting, muscle cramps, and dehydration. Severe dehydration can progress to shock and death if not treated promptly.

The main epidemic strains are V. cholerae O1 and O139, and transmission is fecal-oral via contaminated water or foods. The infectious dose depends on stomach acidity.

Cholera toxin causes increased cAMP in intestinal cells, leading to massive fluid secretion and a characteristic rice-water stool.

Diagnosis and treatment: Diagnosis is clinical in outbreaks, with confirmation by stool culture on selective media or rapid tests. Treatment consists of rapid rehydration (ORS or IV) with electrolyte and zinc replacement. In severe cases, antibiotics can shorten illness, with choices depending on local resistance.

Prevention consists of safe water, proper sanitation, hygiene, and vaccination in certain settings with oral cholera vaccines.

Cholera occurs worldwide in endemic areas and during outbreaks, especially after disasters. With prompt treatment, the case fatality rate is about 1% or less; without treatment it can be high. The bacterium Vibrio cholerae was identified in the 19th century, and cholera has caused several pandemics since then.