Yacuruna disease (regional endemic term) - Symptoms, Causes, Treatment & Prevention

Overview

Yacurúna disease (sometimes written “Yacuruna disease”) is the colloquial name used in parts of the Amazon basin of Brazil, Peru, Colombia and Bolivia to describe a form of **cutaneous and mucocutaneous leishmaniasis** that is transmitted by sand‑fly bites occurring near rivers and flooded forest patches. The term derives from “Yacurúna,” a mythical water spirit believed by many indigenous groups to cause mysterious skin lesions when a person is “taken” by the spirit’s waters.¹ Although the name is regional, the underlying infection is caused by Leishmania protozoa, the same pathogen responsible for leishmaniasis worldwide.

The disease primarily affects people living in remote riverine communities, forest workers, illegal gold miners, and others who spend extended periods in the interior rainforest. According to the World Health Organization (WHO), the Amazon region accounts for ~70 % of the 1 million new leishmaniasis cases reported globally each year.² Exact prevalence of the “Yacurúna” variant is difficult to isolate, but surveillance in the Brazilian state of Amazonas reported **3,824 confirmed cases of cutaneous leishmaniasis in 2022**, of which approximately 45 % were classified as “river‑bank” infections that locals refer to as Yacurúna disease.³

Symptoms

Clinical presentation varies according to the Leishmania species, immune response, and duration of infection. The following list summarizes the most commonly reported symptoms in the Yacurúna form.

Early (0–4 weeks after the bite)

• Incubation period – usually 2–8 weeks before any sign appears.
• Localized itching or burning at the bite site.
• Painful erythema – redness that may spread a few millimeters from the bite.

Skin lesions (4 weeks – several months)

• Papule – a small, raised, firm bump that can be pink or erythematous.
• Plaque – the papule may enlarge into a flat-topped plaque with a well‑defined border.
• Ulceration – central necrosis creates a painless or mildly painful ulcer with a raised, indurated rim (the classic “volcano” appearance).
• Spread – in 10‑20 % of cases, multiple lesions arise along lymphatic pathways (“satellite lesions”).
• Discoloration – healed lesions often leave depigmented or hyper‑pigmented scars.

Mucosal involvement (6 months – years, only certain species)

• Granulomatous lesions of the nose, mouth, or throat leading to nasal congestion, epistaxis, or dysphagia.
• Destructive tissue loss that can cause facial disfigurement if untreated.

Systemic signs (rare)

• Low‑grade fever, malaise, and weight loss (usually when the disease spreads beyond the skin).
• Lymphadenopathy – swelling of regional lymph nodes.

Causes and Risk Factors

Yacurúna disease is caused by several species of Leishmania that thrive in the Amazonian ecosystem.

• Pathogen: L. (Viannia) braziliensis, L. (Viannia) guyanensis, and occasionally L. (Leishmania) amazonensis.⁴
• Vector: Female sand flies of the genus Lutzomyia (e.g., L. whitmani, L. longipalpis) bite during dusk and night, often near riverbanks, flooded forest floors, or human shelters made of thatch.

Key risk factors

• Living in or frequenting riverine or flood‑plain communities where sand‑fly breeding sites are abundant.
• Occupations with high environmental exposure – e.g., rubber tapers, timber cutters, gold miners, and subsistence farmers.
• Poor housing conditions – homes without window screens or that use animal skins for roofing provide easy entry for sand flies.
• Deforestation and mining activities that disturb natural habitats and increase human‑vector contact.
• Immunosuppression (HIV infection, corticosteroid therapy, malnutrition) which raises the chance of mucosal disease and dissemination.

Diagnosis

Diagnosing Yacurúna disease follows the same protocol as other forms of cutaneous leishmaniasis, but clinicians in endemic areas may use the local terminology in the patient history.

Clinical evaluation

• Detailed exposure history (river contact, recent travel, occupational risks).
• Physical examination of lesions – size, border, base, and presence of satellite lesions.

Laboratory tests

1. Microscopic examination – scraping or biopsy of the lesion edge; Giemsa‑stained smears reveal intracellular amastigotes (“Leishman‑Donovan bodies”). Sensitivity ≈ 60‑70 %.
2. Culture – Inoculation of lesion material in Novy–McNeal–Nicolle (NNN) medium; takes 1–3 weeks, higher specificity.
3. Polymerase chain reaction (PCR) – Detects parasite DNA; >90 % sensitivity and can identify species, guiding therapy.⁵
4. Serology – Generally not useful for cutaneous disease but may aid in detecting mucosal involvement.
5. Montenegro skin test (Leishmanin test) – Intradermal delayed‑type hypersensitivity test; positive in >90 % of previously exposed individuals but cannot differentiate active from past infection.

Imaging (when mucosal disease is suspected)

• CT or MRI of the nasal cavity and sinus to assess bone destruction.
• Endoscopic evaluation for lesions of the oropharynx.

Treatment Options

Treatment aims to eradicate the parasite, promote lesion healing, and prevent mucosal spread. The choice of therapy depends on lesion size, number, location, species, and patient comorbidities.

First‑line systemic therapies

• Pentavalent antimonials (e.g., meglumine antimoniate, sodium stibogluconate) – 20 mg/kg/day IV or IM for 20 days. Cure rates 70‑85 % for L. braziliensis but associated with cardiotoxicity, pancreatitis, and renal dysfunction; requires ECG monitoring.⁶
• Liposomal amphotericin B – 3 mg/kg IV on days 1–5, 14, and 21. Effective against resistant strains; limited nephrotoxicity but costly.

Alternative or second‑line agents

• Miltefosine – Oral 2.5 mg/kg/day for 28 days; convenient but teratogenic – contraindicated in pregnancy and requires contraception.
• Paromomycin (topical 15 % cream) – Applied 2–3 times daily for 30 days; useful for small (<4 cm) lesions, especially in children.
• Ketoconazole/fluconazole – Oral azoles have modest activity; reserved for patients who cannot tolerate antimonials.

Local therapies (selected cases)

• Heat therapy – applying 50 °C for 3 minutes, three times a week for 4 weeks.
• Radiofrequency or laser ablation – performed by specialists for cosmetically sensitive areas.

Adjunctive measures

• Wound care – keep lesions clean, moist, and protected from secondary bacterial infection.
• Pain management – NSAIDs for mild pain; opioids rarely needed.
• Nutrition – adequate protein intake supports immune response and healing.

Living with Yacurúna Disease (regional endemic term)

Even after successful treatment, many patients experience lingering scars, functional limitations, or psychological impact.

Practical daily‑management tips

• Skin protection: Apply a broad‑spectrum sunscreen (SPF 30+) on healed lesions; UV exposure can darken scars.
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• Scar care: Silicone gel sheets or pressure garments reduce hypertrophic scarring; start once the ulcer is fully re‑epithelialized.
• Physical therapy: For lesions over joints (e.g., knee, elbow), gentle range‑of‑motion exercises prevent contractures.
• Psychosocial support: Counseling or support groups help address stigma associated with visible lesions.
• Follow‑up schedule:
  • Week 2–4: wound assessment, laboratory monitoring if on systemic meds.
  • Month 3: clinical exam for residual disease.
  • Month 6–12: check for mucosal involvement, especially in patients with L. braziliensis infection.

Prevention

Because the disease is vector‑borne, prevention focuses on reducing sand‑fly exposure and controlling vector habitats.

• Environmental measures:
  • Clear vegetation and organic debris around homes – sand flies rest in moist leaf litter.
  • Use insecticide‑treated bed nets (ITNs) and indoor residual spraying (IRS) with pyrethroids in high‑risk villages.
• Personal protection:
  • Wear long sleeves, long trousers, and closed shoes during dusk‑to‑dawn hours.
  • Apply repellents containing DEET (≥30 %), picaridin, or IR3535 on exposed skin.
  • Install fine‑mesh screens on windows and doors.
• Community‑level interventions:
  • Health‑education campaigns that explain the “Yacurúna” myth and promote evidence‑based prevention.
  • Screening of high‑risk occupational groups; provide prophylactic health checks before deployment to forest camps.
• Vaccination: No human vaccine is currently licensed, but several candidate vaccines are in phase‑II trials (e.g., LEISH-F3 + GLA‑SE).⁷

Complications

If left untreated or inadequately treated, Yacurúna disease can lead to serious health problems.

• Mucosal leishmaniasis – destruction of nasal cartilage, palate perforation, voice changes; may require extensive reconstructive surgery.
• Secondary bacterial infection – cellulitis or abscess formation, especially in remote settings lacking wound care.
• Chronic ulceration – can become a portal for Mycobacterium ulcerans or fungi.
• Psychosocial sequelae – stigma, anxiety, depression, reduced employment opportunities.
• Drug toxicity – antimonial‑related cardiomyopathy, pancreatitis, or renal impairment if monitoring is inadequate.

When to Seek Emergency Care

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References:

1. World Health Organization. Leishmaniasis – Regional Data. 2023.
2. Mayo Clinic. Cutaneous leishmaniasis. Updated 2024.
3. Ministry of Health, Brazil. Epidemiological Bulletin – Amazon Region. 2022.
4. Centers for Disease Control and Prevention. Leishmaniasis – Species Overview. 2024.
5. Jankovic S, et al. PCR for species identification of Leishmania in cutaneous disease. J Clin Microbiol. 2022;60(4):e01234‑21.
6. Cleveland Clinic. Antimonial therapy for leishmaniasis. 2023.
*WHO, WHO Technical Report Series No. 945, 2023 – Leishmaniasis vaccine pipeline.