Cholera in Emergency Care: Rehydration, Shock and Outbreak Management

1. Learning objectives

• Explain the organism, transmission cycle, incubation and pathophysiology of cholera.
• Recognise suspected cholera and distinguish no, some and severe dehydration.
• Perform safe triage and ABCDE assessment while beginning rehydration without delay.
• Describe oral rehydration, intravenous fluid resuscitation, ongoing replacement, nutrition and monitoring.
• Explain when antibiotics, zinc and other supportive treatments are appropriate—and what to avoid.
• Apply isolation, PPE, environmental cleaning, safe specimen collection and waste management in a cholera treatment area.
• Plan discharge teaching, notification, outbreak control, WASH interventions and oral cholera vaccination.

2. Definition and cause

Cholera is an acute secretory diarrhoeal illness caused by toxigenic strains of Vibrio cholerae, most importantly serogroups O1 and O139. The organism colonises the small intestine and produces cholera toxin. The toxin drives chloride and water secretion into the intestinal lumen without causing the invasive bloody inflammation typical of dysentery. Many infections are asymptomatic or mild, but severe dehydration can cause hypovolaemic shock, acute kidney injury, arrhythmia and death.

3. Transmission and risk factors

• Faecal–oral transmission occurs when contaminated water, food, hands, utensils or surfaces reach the mouth.
• Risk increases where water treatment, latrines, handwashing, food safety and waste disposal are disrupted by flooding, displacement, conflict or overcrowding.
• Eating raw seafood or food handled by an infected person can transmit disease; cooked food can become contaminated after cooking.
• Household contacts, healthcare workers and caregivers are exposed during cleaning, toileting, handling vomit/stool and laundering.
• Vibrio can survive in aquatic environments; epidemics require both clinical care and community WASH control.
• Incubation is commonly short—hours to several days—so ask about recent water, food, travel, community cases and household illness.

4. Pathophysiology and why shock develops

Cholera toxin activates adenylate cyclase in intestinal epithelial cells, increasing cyclic AMP and opening chloride channels. Sodium, bicarbonate, potassium and large volumes of water follow into the bowel. The patient loses extracellular fluid rapidly, causing intravascular depletion, metabolic acidosis, hypokalaemia and prerenal kidney injury. Vomiting adds further losses. The abdomen may remain soft and non-tender despite severe illness, so the stool volume and perfusion signs matter more than abdominal pain.

• Early compensation: thirst, tachycardia, dry mouth and reduced urine while blood pressure may remain normal.
• Progressive dehydration: sunken eyes, poor skin turgor, weak pulse, postural dizziness, lethargy and delayed capillary refill.
• Shock: hypotension, cold/mottled skin, altered consciousness, very weak or absent peripheral pulse, anuria and collapse.
• Electrolyte complications: cramps, weakness, ileus, arrhythmia, seizures and worsening acidosis.
• Rehydration risk: over-rapid or unmonitored fluid can cause pulmonary oedema, especially in infants, older adults, pregnancy or heart/renal disease.

5. Clinical features

6. Triage and infection-control precautions at first contact

1. Ask about watery diarrhoea and vomiting before the patient enters a crowded waiting area; provide a nearby toilet or stool container.
2. Perform hand hygiene and wear gloves. Add apron/gown, mask and eye protection when splash from vomit or stool is possible.
3. Place suspected cases in the designated cholera/acute-diarrhoea area with a clear one-way flow for patients, staff, specimens and waste.
4. Immediately identify shock, altered consciousness, severe dehydration, inability to drink, pregnancy, infancy, older age, malnutrition and serious comorbidity.
5. Begin ORS while waiting for assessment in any alert patient who can drink; do not make a dehydrated patient wait for a stool result.
6. Notify the responsible clinician, infection-control lead and public-health surveillance team according to local policy.

7. Focused history and examination

History

• Time of onset, number/volume of stools, vomiting frequency, thirst, dizziness, cramps and last urine.
• Ability to drink, breastfeed or retain ORS; recent oral medicines and fluid already taken.
• Household, school, workplace or camp cases; water source; food eaten; sanitation and recent travel/movement.
• Age, weight, pregnancy, breastfeeding, diabetes, renal/heart disease, HIV/immunosuppression, malnutrition and recent antibiotics.
• Blood in stool, severe abdominal pain, high fever, rash, altered consciousness or focal symptoms suggesting another diagnosis.

Examination

• General appearance, mental state, ability to sit/stand and severity of thirst.
• Pulse rate/quality, blood pressure, capillary refill, skin temperature/colour and respiratory pattern.
• Eyes, mucous membranes, tears in children, skin pinch, extremity temperature and urine output.
• Weight when possible—use the pre-illness weight if known to estimate the fluid deficit.
• Abdomen for distension, tenderness, ileus or an alternative surgical diagnosis; inspect stool only with appropriate PPE.

8. ABCDE emergency assessment

9. Assessing dehydration

10. Rehydration: the life-saving treatment

10.1 Oral rehydration solution (ORS)

• Give standard low-osmolarity ORS made with the correct amount of safe water. Use the packet instructions; an overly concentrated solution can worsen hypernatraemia.
• For an alert patient with no severe dehydration, give frequent small sips with a cup or spoon. After each stool, continue age/weight-appropriate replacement and replace vomited fluid.
• If vomiting occurs, pause briefly and restart more slowly. Persistent vomiting, inability to drink or worsening perfusion requires IV assessment.
• Continue breastfeeding and age-appropriate feeding. ORS replaces water and salts but does not replace nutrition.
• Never mix ORS with milk, juice, soda or unsafe water; discard prepared solution according to local guidance.

10.2 Supervised oral rehydration for some dehydration

Under the current national protocol, give a measured weight-based volume of ORS over the first few hours (commonly 75 mL/kg over 4 hours for children), reassessing pulse, mental status, thirst, tears, skin signs and urine. Continue replacing ongoing losses and refer for IV therapy if the patient deteriorates, cannot drink or fails to improve.

10.3 Intravenous rehydration for severe dehydration or shock

1. Move to a resuscitation area, call a senior clinician, monitor continuously and obtain weight if this will not delay treatment.
2. Use Ringer's lactate where recommended; normal saline may be an alternative if Ringer's lactate is unavailable. Avoid hypotonic fluids for shock.
3. Use the current weight-based Plan C schedule. A commonly taught WHO schedule is 100 mL/kg total: 30 mL/kg rapidly then 70 mL/kg over the next period, with the timing adjusted for infants versus older children/adults. Follow the Uganda protocol and reassess after each phase.
4. Begin ORS as soon as the patient can drink; give through a cup, nasogastric tube or other approved route under supervision if safe.
5. Reassess pulse, blood pressure, capillary refill, mental state, breathing, lung sounds and urine at frequent intervals. Stop or slow fluids and seek senior review for crackles, worsening hypoxaemia or pulmonary oedema.
6. In severe malnutrition, heart failure, renal failure, pregnancy or paediatric shock, use the specific protocol and senior supervision rather than copying an adult schedule.

11. Replace ongoing losses and correct complications

• Measure or estimate every stool and vomit; use a stool chart and weigh diapers/containers where feasible.
• Continue ORS after each watery stool and adjust IV replacement to clinical response and facility protocol.
• Check electrolytes, glucose, renal function and acid–base status in severe disease or prolonged losses; correct potassium and glucose carefully.
• Treat hypoglycaemia promptly. Severe cramps, weakness, arrhythmia, seizures or ileus may signal electrolyte disturbance.
• Do not routinely give antidiarrhoeal antimotility agents, opioids or unnecessary antiemetics; they can mask deterioration or cause adverse effects. Use prescribed medicines only when clinically indicated.
• Continue nutrition and breastfeeding. In children with acute diarrhoea, provide zinc according to the national paediatric protocol.

12. Antibiotics and other medicines

Rehydration is the cornerstone. Antibiotics are an adjunct, not a replacement for fluid and electrolyte treatment. They may be recommended for severely ill patients, very high-output disease or selected high-risk cases according to current Uganda guidance and local susceptibility patterns.

• Collect a stool specimen when indicated and do not delay resuscitation while waiting for culture.
• The prescriber should choose an effective local agent, route, dose and duration after considering age, pregnancy, allergy, renal/liver function and recent antibiotic exposure.
• Use susceptibility results and outbreak guidance to avoid ineffective therapy and prevent AMR.
• Document indication, time, medicine, route, response and adverse effects; review whether therapy can be stopped or narrowed.
• Avoid routine prophylactic antibiotics for every contact and avoid self-medication or leftover drugs.

13. Investigations and diagnosis

• Diagnosis during an outbreak is primarily clinical and epidemiological; laboratory confirmation supports surveillance and guides public-health action.
• Collect stool or rectal-swab specimens using the approved container, label at bedside, maintain the cold chain and notify the laboratory before transport.
• Do not delay ORS, IV fluids, referral or isolation while waiting for culture or molecular testing.
• In severe disease, monitor full blood count, electrolytes, urea/creatinine, glucose, lactate and blood gas when available.
• Consider malaria, dysentery, typhoid, acute gastroenteritis, food poisoning, rotavirus/norovirus, diabetic ketoacidosis, bowel obstruction, appendicitis and toxic ingestion when the presentation is atypical.
• Blood in stool, high persistent fever, severe focal pain, peritonism or no improvement should prompt evaluation for another or additional diagnosis.

14. Cholera treatment-centre nursing care

15. Infection prevention in the health facility

1. Use a dedicated cholera area with separate entry, triage, rehydration, observation, admission, discharge, toilet and waste routes.
2. Perform hand hygiene with soap and safe water; alcohol rub may not replace washing when hands are visibly soiled.
3. Wear gloves and apron/gown for patient or excreta contact; add eye/face protection for splash risk. Remove PPE safely and clean hands immediately.
4. Use dedicated thermometers, weighing scales and stethoscopes where possible; clean and disinfect shared equipment between patients.
5. Disinfect high-touch surfaces, beds, toilets, buckets and spills with the locally approved chlorine concentration and contact time.
6. Handle linen, stool containers, vomit and dead bodies as infectious material; follow facility waste and burial policy.
7. Protect food handlers and cleaners, provide staff training, monitor exposures and report occupational incidents promptly.

16. Discharge and follow-up teaching

• Explain how to mix ORS with safe water, how often to sip it and how to replace every continuing watery stool.
• Teach caregivers to continue breastfeeding and feeding, wash hands after toileting/cleaning and before preparing food, and use a safe latrine.
• Provide clear return precautions: increasing thirst, inability to drink, repeated vomiting, little/no urine, fainting, confusion, blood in stool, fever, severe abdominal pain or worsening weakness.
• Advise safe water treatment, covered storage, food cooking/reheating, safe disposal of child faeces and cleaning of contaminated surfaces.
• Notify the surveillance team and link households to community health workers for contact advice and WASH support.

17. Community outbreak response

• Report suspected cases through the established public-health channel; use a line list with onset, location, exposure, treatment and outcome.
• Open oral rehydration points and treatment centres close to affected communities while maintaining safe patient flow.
• Provide safe water, chlorine/household water-treatment advice, handwashing stations, latrines and hygiene education.
• Investigate water sources and food chains, communicate risk without blame, and engage local leaders, schools, markets and refugee/displaced-person services.
• Oral cholera vaccine can be used as an additional outbreak/endemic-control tool under national campaign guidance; vaccination does not replace WASH or early treatment.
• Use a One Health approach: coordinate clinicians, laboratories, environmental health officers, water authorities, surveillance teams and community leaders.

18. Special populations

• Infants and children: weigh if possible, assess tears/feeding/wet nappies, use paediatric weight-based fluids, continue breastfeeding and monitor glucose.
• Severe acute malnutrition: signs can be unreliable and standard rapid IV volumes may harm; use the specialised malnutrition protocol and senior review.
• Pregnancy: dehydration threatens both mother and fetus; monitor perfusion, fetal status where appropriate and involve obstetric services.
• Older adults/heart or renal disease: may decompensate with both dehydration and overhydration; use frequent lung, oxygenation and fluid-balance assessment.
• People with disability: adapt communication, provide accessible toilets and do not assume inability to report thirst or pain means low risk.

19. Clinical scenarios

20. Common errors to avoid

• Waiting for a laboratory result before starting ORS or IV fluid.
• Giving plain water, soda, juice or overly concentrated homemade salt solution instead of correctly prepared ORS.
• Giving antibiotics to every patient while neglecting rehydration and source-control/public-health measures.
• Using an unmonitored fluid schedule in a child, malnourished patient, pregnant person or patient with heart/renal disease.
• Failing to measure stool, vomit and urine output or to repeat perfusion observations.
• Allowing suspected cases to share toilets, buckets, linen, weighing scales or food areas without disinfection.
• Using antidiarrhoeal medicines that slow gut motility in a severely ill or febrile patient without senior advice.

21. Revision questions

1. Define cholera and describe its faecal–oral transmission cycle.
2. Explain how cholera toxin produces profuse watery diarrhoea and hypovolaemic shock.
3. List the clinical signs of some dehydration and severe dehydration.
4. What are the priorities during the first five minutes of a patient with cholera shock?
5. Why is ORS the cornerstone of treatment, and why can plain water be inadequate?
6. When may antibiotics be considered, and why must they never replace rehydration?
7. List six infection-prevention measures in a cholera treatment centre.
8. Give five household actions that interrupt cholera transmission.

22. Key take-home points

• Cholera can kill within hours through fluid and electrolyte loss, but correct rehydration is highly effective.
• Assess perfusion and mental state repeatedly; blood pressure may remain normal until late shock.
• Start ORS immediately when the patient can drink and IV crystalloid immediately for severe dehydration or shock.
• Continue breastfeeding and nutrition, measure ongoing losses and monitor urine, glucose and electrolytes.
• Antibiotics are selective adjuncts; local protocol and susceptibility data determine the choice.
• WASH, hand hygiene, safe stool disposal, surveillance and oral cholera vaccination protect the wider community.

References for further study

• WHO: Cholera fact sheet
• CDC: Treating cholera
• WHO: Preventing and controlling cholera in endemic countries
• WHO: Cholera vaccines and immunization
• WHO Africa: Cholera management guidelines
• Uganda Ministry of Health: current national cholera case-management, WASH and surveillance guidance.