Cholera: How to Recognise It, Treat Dehydration at Home, and Know When to Go to Hospital

What is cholera and why does it spread so fast?

Cholera is an acute diarrhoeal disease caused by the bacterium Vibrio cholerae. The bacterium produces a toxin that causes the lining of the small intestine to secrete enormous amounts of fluid and salts into the bowel, resulting in profuse watery diarrhoea that resembles water left after rinsing rice. In severe cases this fluid loss can reach 20 litres in a day. It is this rapid loss of fluid and electrolytes, not the bacterium itself, that kills.

Cholera spreads primarily through drinking water contaminated with the bacterium or eating food prepared with contaminated water. It spreads explosively in environments where sewage mixes with drinking water supplies, which is exactly what happens in refugee camps, overcrowded urban neighbourhoods with broken sanitation infrastructure, and areas where conflict has destroyed water treatment systems. It does not typically spread through casual contact with a sick person, but uncontained faeces from infected individuals contaminate the surrounding environment rapidly.

Yemen has experienced one of the largest cholera outbreaks in recorded history since 2016, driven by the collapse of water infrastructure and health system disruption documented in research published in the Journal of Preventive Medicine and Public Health. A 2024 study published in the Journal of Infection in Developing Countries analysed the specific outbreak in Al-Mahweet, Yemen and found that areas with water supply interruptions and poor sanitation had significantly higher case rates. Syria and Sudan have seen multiple cholera waves in recent years, and the WHO and regional health journals track these as ongoing emergencies.

How do you recognise cholera?

Classic cholera is dramatic in onset: sudden, profuse, watery diarrhoea that typically has no blood and no abdominal cramps in the early stage, accompanied by vomiting. The characteristic description is diarrhoea that looks like rice-water because it is pale and watery rather than brown. A person who was entirely healthy can be in danger of death within hours if fluids are not replaced. This speed is what makes cholera fundamentally different from ordinary gastroenteritis.

However, not all cholera infections are classic. A comprehensive review published in Clinical Microbiology Reviews in 2022 found that more than 80 percent of cholera infections cause either no symptoms at all or only mild diarrhoea indistinguishable from other causes. These mild and asymptomatic cases silently amplify the bacteria in the environment through unseen faecal contamination of water and surfaces.

During an active outbreak, any sudden profuse watery diarrhoea should be treated as probable cholera and oral rehydration started immediately, regardless of whether laboratory confirmation is available. Waiting for test results before starting rehydration in a severe case can be fatal.

How to make and use oral rehydration solution at home

Oral rehydration solution (ORS) is one of the most important medical discoveries of the twentieth century. A landmark review published in Clinical Infectious Diseases showed that ORS reduces cholera mortality from more than 50 percent in untreated cases to less than 1 percent in those treated correctly. The principle is straightforward: the body loses both water and minerals together, and ORS replaces both simultaneously in proportions that allow the gut to absorb them far more efficiently than water alone.

Pre-packaged ORS sachets are available from health centres, pharmacies and relief organisation supply points in outbreak areas and should be the first choice whenever available. If sachets are not accessible, a home preparation can be made that provides meaningful protection against fatal dehydration until professional care can be reached.

The home solution is not identical to a medical-grade ORS, and it is not sufficient for severe dehydration. If the patient is losing fluid faster than they can drink, vomiting everything they swallow, or showing signs of severe dehydration, intravenous fluids in a health facility are the only safe option.

How much ORS does a patient need and how do you know it is working?

The general guideline is to replace what is lost: for an adult with moderate diarrhoea, aim for two to three litres of ORS in the first six to eight hours and continue replacing each loose stool with approximately 200 millilitres of solution. For a child under five years, the WHO recommends 75 millilitres per kilogram of body weight given over three to four hours for mild to moderate dehydration.

If the patient is vomiting, give very small amounts continuously, such as a teaspoon every one to two minutes for a small child. Even a vomiting gut absorbs small quantities. Breastfeeding infants should continue to breastfeed throughout their illness in addition to receiving ORS. Do not stop feeding in older children and adults because food helps the gut lining repair itself and prolonged fasting makes diarrhoea worse.

Signs that rehydration is working include the patient becoming more alert, urination resuming within three to four hours, eyes becoming less sunken, and the skin regaining its normal elasticity. If the patient is not improving after two to three hours of home treatment, or is deteriorating, seek a health facility without delay.

When must you go to hospital immediately?

Severe cholera requires intravenous fluids because the rate of fluid loss outpaces what can be replaced by drinking. The WHO standard treatment for severe dehydration is rapid intravenous rehydration with 100 millilitres per kilogram of Ringer's lactate solution given over three hours in adults, followed by ORS once the patient can drink. This can only be provided in a health facility.

Antibiotics are sometimes used in severe cases to reduce the duration and volume of diarrhoea, but they are not a replacement for rehydration and are not necessary in mild cases. Azithromycin is the antibiotic most commonly recommended by the WHO for cholera when antibiotic treatment is indicated. The decision to use antibiotics belongs to the treating doctor or health worker, not the patient.

Oral cholera vaccines are available and are distributed by international health organisations in outbreak areas. They offer good protection for approximately two years but do not eliminate the need for safe water and food hygiene measures. If you are in an area with a declared outbreak, ask at the nearest health centre whether vaccine is available and how to access it.

How to protect your household during an outbreak

Safe water is the foundation of cholera prevention. During an outbreak, all drinking and cooking water must be treated. Boiling for a full minute is the most reliably effective method and requires no special equipment. Chemical treatment with household bleach or dedicated water purification tablets distributed by relief organisations is the practical alternative when fuel is scarce. A systematic review published in PloS One found that water treatment and hygiene interventions reduce cholera transmission significantly when implemented consistently.

Handwashing with soap and water before preparing or eating food and after using the toilet or handling a sick person's waste is the primary behavioural barrier against transmission. In situations where soap is unavailable, wood ash and water provides meaningful protection. Wet hands that are not dried properly can still transfer bacteria, so drying on a clean cloth or air matters.

Food must be cooked thoroughly and eaten while hot. Raw or partially cooked fish and shellfish are high risk during outbreaks. Raw fruits and vegetables that will be eaten unpeeled should be washed with treated water. Human waste must be buried away from water sources and food preparation areas, and children's faeces managed carefully because they are a major source of environmental contamination.

Feeding and nutrition after cholera

There is a widespread and harmful belief that patients should fast until the diarrhoea stops. This is wrong. Food helps the lining of the intestine heal, and withholding it prolongs diarrhoea and worsens weakness. As soon as the patient can eat, begin with easy-to-digest foods: boiled rice, boiled potato, banana, or plain porridge. Continue breastfeeding throughout illness without interruption for infants.

Avoid fatty foods, spicy foods and full-fat dairy products until recovery is complete, as these can irritate the recovering intestine. Gradually return to a normal diet over three to four days as the diarrhoea subsides. Maintaining adequate nutrition during and after acute illness is especially important for children, whose development can be set back by severe diarrhoeal episodes.

For children under five years, zinc supplementation is recommended during and for two weeks after any acute diarrhoeal episode, including cholera. The WHO recommends 20 milligrams of zinc daily for children over six months for ten to fourteen days. Zinc reduces the severity and duration of diarrhoea and decreases the likelihood of a recurrent episode in the following weeks, which is important in contexts where re-exposure is likely.

Why cholera keeps returning to the region and what changes it

Cholera persists where three conditions exist together: a bacterial reservoir in the environment, contaminated water reaching people, and a health system too weak to catch and contain cases early. In Yemen, Syria and Sudan, conflict has created all three simultaneously for years. The bacteria do not disappear between outbreaks, they persist in aquatic environments and re-emerge when water treatment systems fail or population displacement creates new sanitation gaps.

The solution is not a drug or a vaccine alone. It requires sustained investment in water and sanitation infrastructure, which is exactly what war destroys first. In the short term, the most effective interventions are mass distribution of water purification tablets and ORS sachets in at-risk communities, paired with community education on when to seek care. A 2024 review of cholera in Africa and the Middle East published in Health Science Reports highlighted that case fatality rates fall sharply when communities have access to ORS and basic information about severe dehydration signs.

The knowledge gap is often the difference between a death and a recovery. A family that knows how to make ORS, recognises when the situation has moved beyond home treatment, and knows where to go can save a life with materials costing almost nothing. Use Sihtak to record your family members' symptoms during an illness episode, track whether dehydration signs are improving or worsening with each hour, and keep a note of the nearest health facility in your area so you do not lose time searching when urgency matters most.

Sources

• Chowdhury F, Ross AG, Islam MT et al: Diagnosis, Management, and Future Control of Cholera, Clinical microbiology reviews, 2022
• Harris JB, LaRocque RC, Qadri F et al: Cholera, Lancet, 2012
• Nasr H, Al-Zumair M, Al-Mahbashi T et al: Factors associated with the cholera outbreak in Al-Mahweet-Yemen: Analytic Study, Journal of infection in developing countries, 2024
• Ng QX, De Deyn MLZQ, Loke W et al: Yemen's Cholera Epidemic Is a One Health Issue, Journal of preventive medicine and public health, 2020
• Ahmed AK, Sijercic VC, Akhtar MS et al: Cholera rages in Africa and the Middle East: A narrative review on challenges and solutions, Health science reports, 2024
• Guerrant RL, Carneiro-Filho BA, Dillingham RA et al: Cholera, diarrhea, and oral rehydration therapy: triumph and indictment, Clinical infectious diseases, 2003
• World Health Organization: Cholera fact sheet