What causes childhood diarrhoea?

Contaminated water, food or person-to-person faecal-oral spread. Main pathogens: rotavirus (leading cause of severe diarrhoea, vaccine-preventable); other viruses (norovirus, adenovirus); bacteria (E. coli, Salmonella, Shigella, V. cholerae); parasites (Cryptosporidium, Giardia). Malnutrition and lack of breastfeeding increase susceptibility.

ORT uses glucose-electrolyte solution to replace fluids and salts lost in diarrhoea — exploiting intestinal sodium-glucose cotransport that remains functional even in severe diarrhoea. The WHO/UNICEF ORS formula contains glucose, sodium chloride, potassium chloride and sodium citrate per litre of water. Can be prepared at home or given as pre-packaged sachets.

Why do 440,000 children still die from diarrhoea?

Despite ORT being available for 50+ years, children die because: ORT use rates remain below 50% in many LMICs; caregivers may not recognise dehydration; health workers may inappropriately prefer IV fluids; and the root cause — contaminated water and poor sanitation — generates the infections in the first place.

WASH prevents diarrhoea at source: safe drinking water reduces incidence by ~48%; improved sanitation by ~36%; handwashing with soap by ~47%. All three together reduce diarrhoea by 70-80%. Yet 2 billion people lack safe water and 3.6 billion lack safely managed sanitation. SDG 6 targets universal WASH by 2030 — progress is severely off-track.

Cholera — from V. cholerae — causes profuse watery diarrhoea with rapid dehydration that can kill within hours if untreated. Controlled in high-income countries through safe water, it persists in 40+ countries — especially conflict and post-disaster settings. Oral cholera vaccines are used alongside WASH and case management in outbreak control.

What is rotavirus vaccine?

Rotavirus oral vaccines (Rotarix, RotaTeq) are WHO-recommended for all national immunisation programmes. GAVI financing has enabled rollout across LMICs. High-coverage countries have seen 40-60% reductions in severe childhood diarrhoea hospitalisations.

When should a child see a doctor?

Warning signs requiring immediate care: signs of severe dehydration (sunken eyes, no tears, skin turgor loss, drowsiness, no urination for 8+ hours); blood in stool; high fever; diarrhoea for 14+ days; vomiting preventing oral rehydration. Without these, ORT at home with continued feeding is appropriate.

Why is breastfeeding protective?

Breastfed infants have 64% lower risk of gastrointestinal infections requiring hospitalisation — from antibodies (secretory IgA), lactoferrin, lysozyme and oligosaccharides in breast milk. Breastfeeding also ensures safe, uncontaminated milk in settings with contaminated water.

What is the role of zinc?

WHO/UNICEF recommend zinc (10 mg/day <6 months; 20 mg/day older) for 10-14 days alongside ORT in all children with diarrhoea — reducing duration by ~25%, severity and recurrence for up to 3 months by restoring intestinal barrier function and immune response.

The Global Action Plan for the Prevention and Control of Pneumonia and Diarrhoea (GAPPD) — WHO/UNICEF 2013 — provides an integrated protect-prevent-treat framework addressing the two leading infectious child killers simultaneously.

Does diarrhoea affect adults?

Yes — travellers' diarrhoea affects up to 40% of international travellers. C. difficile causes healthcare-associated diarrhoea in older antibiotic-treated patients. Cholera severely affects adults in endemic settings.

How does GMJ News cover diarrhoeal diseases?

GMJ News covers WHO diarrhoea burden data, rotavirus vaccine rollout, cholera outbreaks and WASH policy. Georgia achieved significant childhood diarrhoeal mortality reduction — directly relevant to PHIG's public health work.

Home › Topics › Diarrhoeal Diseases

Diarrhoeal Diseases

Q: What is GAPPD?

The Global Action Plan for the Prevention and Control of Pneumonia and Diarrhoea (GAPPD) — WHO/UNICEF 2013 — provides an integrated protect-prevent-treat framework addressing the two leading infectious child killers simultaneously.

GMJ News knowledge hub · last reviewed September 2026 · Georgian Medical Journal

Summary Statistics Glossary GMJ news FAQ Documents Organizations Research

Diarrhoeal diseases remain the second leading infectious killer of children under five, causing approximately 440,000 child deaths per year — despite the fact that oral rehydration therapy (ORT) can prevent the dehydration that kills them (WHO). Rotavirus — vaccine-preventable — drives about a third of severe cases; contaminated water and poor sanitation drive the rest. WASH improvement and rotavirus vaccination are the most impactful prevention interventions.

Key messages

Second child killer

Diarrhoeal diseases kill approximately 440,000 children under 5 per year — the second leading infectious cause of child mortality — despite cheap, effective prevention and treatment.

ORT — a century's greatest advance

Oral rehydration therapy (ORT) — described as "potentially the most important medical advance of this century" (Lancet 1978) — prevents death from dehydration at near-zero cost and can be prepared at home.

WASH prevents it

Safe water, sanitation and handwashing with soap would prevent the vast majority of diarrhoeal disease. Yet 2 billion people still lack safe drinking water.

Rotavirus vaccine

Rotavirus causes ~1/3 of severe childhood diarrhoea hospitalisations. The WHO-recommended rotavirus vaccine reduces severe hospitalisations by 40-60% in high-coverage countries.

Zinc + ORT

WHO/UNICEF recommend 10-14 days of zinc alongside ORT — reducing episode duration, severity and recurrence for up to 3 months.

Antibiotic overuse

Most diarrhoea is viral and does not require antibiotics — yet massive overprescription drives AMR. Correct management uses ORT and zinc first.

Key statistics

440K

child under-5 deaths/year

WHO

1.7B

cases/year worldwide

WHO

infectious child killer under 5

WHO

without safe drinking water

WHO/UNICEF

1/3

severe cases from rotavirus

WHO/GAVI

47%

reduction from handwashing with soap

Cochrane

Child under-5 diarrhoeal deaths (thousands) 2000-2019 — WHO/IGME

Source: UN IGME / WHO. Decline driven by ORT, rotavirus vaccine and WASH improvement.

Glossary of key terms

Oral rehydration therapy (ORT)
WHO/UNICEFGlucose-electrolyte solution replacing fluids and salts lost in diarrhoea. Exploits intestinal sodium-glucose cotransport. Prevents dehydration at near-zero cost.

Rotavirus
WHO/SAGELeading cause of severe diarrhoea in children under 5. Vaccine-preventable (Rotarix, RotaTeq). WHO recommends in all national immunisation programmes.

Cholera
WHORapidly fatal dehydrating diarrhoea from Vibrio cholerae. Endemic in 40+ countries. Prevented by WASH; treated with ORT plus antibiotics for severe cases.

Zinc
WHO/UNICEF10-14 days of zinc alongside ORT — reduces duration, severity and recurrence for up to 3 months.

WASH
WHO/UNICEFWater, Sanitation and Hygiene — prevents diarrhoea at source. Safe water reduces incidence by ~48%; sanitation by ~36%; handwashing by ~47%.

Persistent diarrhoea
WHODiarrhoea lasting 14+ days — particularly dangerous, associated with malnutrition and immune compromise.