Scabies is a parasitic skin infestation caused by the microscopic mite Sarcoptes scabiei — which burrows into the superficial skin to lay eggs, causing intense, relentless itching (particularly at night) and a characteristic rash. Transmitted through prolonged skin-to-skin contact (not casual touch). Approximately 200 million people are infected globally at any time — concentrated in LMICs with poverty, overcrowding and poor access to healthcare. Children under 15 account for approximately 50% of cases in endemic settings.

What does scabies feel like?

The hallmark symptom is severe pruritus (itching) — worst at night when the mite is most active. The rash consists of: scabies burrows (thin wavy lines in the skin — pathognomonic, most visible between fingers and on wrists); small papules and vesicles on the trunk and limbs; and excoriations (scratch marks) which become secondarily infected with bacteria. The first infestation causes pruritus only after 2-6 weeks (sensitisation period); reinfestation causes symptoms within 24-48 hours.

How is scabies spread?

Scabies requires prolonged skin-to-skin contact — typically >15-20 minutes of close contact (sleeping in the same bed, sexual contact, prolonged hand-holding). Indirect transmission via clothing or bedding is possible for up to 72 hours (mites survive off the body). Crusted scabies is highly contagious — mite-laden skin flakes contaminate the environment. Scabies spreads rapidly in: households; schools; care homes (nursing homes); refugee camps; prisons; and hospitals (particularly from undiagnosed crusted scabies patients).

Why does scabies cause kidney disease and heart disease?

Scabies is an indirect driver of serious long-term disease through secondary bacterial infection. Scratching from scabies itching breaks the skin barrier → bacterial colonisation with Streptococcus pyogenes and Staphylococcus aureus → impetigo (bacterial skin infection). Streptococcus pyogenes skin infections trigger: post-streptococcal glomerulonephritis (acute immune-mediated kidney injury → contributes to chronic kidney disease with repeated episodes); and rheumatic fever → rheumatic heart disease (permanent heart valve damage from autoimmune reaction to streptococcal antigens). In LMICs, scabies is therefore a significant indirect driver of kidney failure and rheumatic heart disease.

How is scabies treated?

Individual treatment: permethrin 5% cream (applied to all body surfaces, including scalp in infants, for 8-12 hours; repeated in 1-2 weeks) — safe in pregnancy and infants >2 months; or oral ivermectin (0.2mg/kg single dose; repeated in 1-2 weeks — contraindicated in pregnancy, not recommended for infants <15kg). All household contacts should be treated simultaneously — even if asymptomatic. Clothing and bedding should be washed at 60°C or hot-tumble dried.

What is community MDA for scabies?

Mass drug administration (MDA) with oral ivermectin — treating the entire community simultaneously, regardless of symptoms — dramatically reduces scabies prevalence at the community level, including through herd effect. The SHIFT trial (Fiji, 2019, Lancet) showed 78% reduction in scabies prevalence with MDA compared to usual care. The Salomon Islands trial confirmed these findings. MDA is recommended by WHO for communities with high scabies prevalence (>10%) and is logistically straightforward. It simultaneously reduces impetigo (secondary bacterial infection).

What is crusted scabies?

Crusted (Norwegian) scabies occurs in immunocompromised individuals — people with HIV, on corticosteroids, organ transplant recipients, or the elderly with poor immune responses. Instead of the usual 10-15 mites, crusted scabies involves thousands to millions of mites — in hyperkeratotic (thickened) plaques on the skin. It is highly contagious and causes major nosocomial outbreaks in hospitals and care homes. Management: strict contact isolation; multiple courses of oral ivermectin + topical scabicides; keratolytic treatment (to remove hyperkeratotic scale containing mites).

How does GMJ News cover scabies?

GMJ News covers WHO scabies NTD programme, MDA trial evidence (SHIFT, Salomon Islands), the scabies-impetigo-kidney disease nexus and rheumatic heart disease link. Scabies is part of the GMJ's skin disease and NTD coverage — and the secondary disease burden is directly relevant to PHIG's kidney and cardiovascular health priorities.

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Scabies

Q: What is community MDA for scabies?

Mass drug administration (MDA) with oral ivermectin — treating the entire community simultaneously, regardless of symptoms — dramatically reduces scabies prevalence at the community level, including through herd effect. The SHIFT trial (Fiji, 2019, Lancet) showed 78% reduction in scabies prevalence with MDA compared to usual care. The Salomon Islands trial confirmed these findings. MDA is recommended by WHO for communities with high scabies prevalence (>10%) and is logistically straightforward. It simultaneously reduces impetigo (secondary bacterial infection).

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

Summary Statistics Glossary GMJ news FAQ Documents Organizations Research

Scabies — caused by the mite Sarcoptes scabiei var. hominis burrowing into the skin — infects approximately 200 million people globally at any time and was added to the WHO Neglected Tropical Diseases list in 2017 (WHO). Scabies causes intense pruritus (itching) — particularly at night — and spreads rapidly in overcrowded settings including schools, care homes, refugee camps and prisons. Secondary bacterial skin infection (by Streptococcus and Staphylococcus) from scratching leads to impetigo and — critically — post-streptococcal glomerulonephritis and rheumatic heart disease in LMICs, making scabies a significant indirect cause of chronic kidney and heart disease.

Key messages

200 million people infected

Scabies infects approximately 200 million people globally at any time — with the highest burden in LMICs, particularly in settings of poverty, overcrowding, conflict displacement and care institutions (WHO).

Added to WHO NTD list 2017

Scabies was added to the WHO Neglected Tropical Diseases list in 2017 — recognising the substantial disease burden and indirect consequences through secondary bacterial infection, impetigo, and post-streptococcal complications.

Secondary infection drives serious disease

Scratching from scabies itching leads to secondary bacterial skin infections (impetigo) — predominantly from Streptococcus pyogenes and Staphylococcus aureus. In LMICs, these secondary infections cause post-streptococcal glomerulonephritis, rheumatic heart disease and sepsis.

Crusted scabies — high-transmission emergency

Crusted (Norwegian) scabies — occurring in immunocompromised individuals — carries 1,000-2,000 mites vs 10-15 in ordinary scabies. A single patient can infect an entire ward. Requires strict isolation and multiple treatment courses.

Ivermectin MDA

Community-wide mass drug administration (MDA) with oral ivermectin — demonstrated in the SHIFT and Salomon Islands trials — dramatically reduces scabies prevalence community-wide, including the "herd effect" on untreated contacts.

Permethrin vs ivermectin

Topical permethrin 5% cream (applied to all body surfaces, repeated in 1-2 weeks) and oral ivermectin (0.2mg/kg, single or repeated dose) are both effective first-line treatments. Permethrin is safe in pregnancy and infants >2 months; ivermectin is contraindicated in pregnancy.

Key statistics

200M

people with scabies at any time

WHO

2017

year scabies added to WHO NTD list

WHO

1,000-2,000

mites in crusted (Norwegian) scabies vs 10-15 usual

WHO

30%

of Pacific Island populations affected in some settings

WHO

78%

reduction in scabies with MDA (SHIFT trial)

Lancet 2019

50%

of scabies cases in children under 15 (LMICs)

WHO

Scabies burden — population with active infection by region (millions estimated) — WHO

Source: WHO estimates. Pacific Island nations have highest community prevalence; Asia and Africa highest absolute numbers.

Glossary of key terms

Sarcoptes scabiei var. hominis
WHOA microscopic mite (0.3-0.4mm) that burrows into the superficial skin layers — preferentially in warm, thin-skinned areas (finger webs, wrists, genitals, axillae). The female lays 2-3 eggs per day. The intense pruritus results from a delayed-type hypersensitivity reaction to mite proteins.

Scabies burrow
WHO/DermatologyThe pathognomonic sign of scabies — a thin, wavy, slightly raised line (0.5-1cm) in the skin where the female mite has burrowed. Typically visible in the finger web spaces and on the wrists. Burrow ink test (applying ink to the skin, then wiping off) highlights burrows.

Crusted (Norwegian) scabies
WHOA severe, hyperkeratotic form of scabies occurring in immunocompromised individuals (HIV, corticosteroid users, organ transplant recipients, elderly) — characterised by thousands to millions of mites (vs 10-15 in classical scabies). Highly contagious; causes large outbreaks in care settings. Requires multiple courses of treatment.

Permethrin 5%
WHO EMLA pyrethroid insecticide cream applied topically to all body surfaces (from neck to toes) for 8-12 hours; repeated in 1-2 weeks. First-line topical treatment for scabies. Safe in infants >2 months and pregnant women. On WHO Essential Medicines List.

Post-streptococcal glomerulonephritis
WHOKidney disease following Streptococcus pyogenes skin infection (impetigo — from scabies scratching). Causes acute nephritic syndrome; in LMICs, repeated episodes contribute to the epidemic of chronic kidney disease. Scabies is therefore an indirect driver of kidney failure.

Rheumatic heart disease link
WHO/GBDStreptococcal skin infection from scabies scratching causes impetigo; repeated streptococcal infections (skin or throat) trigger autoimmune rheumatic fever → rheumatic heart disease (heart valve damage). Scabies control is therefore also rheumatic heart disease prevention in LMICs.