Neglected Tropical Diseases - SP Flashcards
(20 cards)
Buruli ulcer
- Chronic debilitating skin and soft tissue infection
- Can lead to permanent disfigurement and disability
- Caused by Mycobacterium ulcerans bacterium (same family as leprosy and tuberculosis)
- Can be found in animals: Koalas, Possums, Horses, Dogs, Alpacas, Cats
- No vaccine
Buruli ulcer: Epidemiology
- Tropical and sub-tropical climates
- Found in at least 33 countries
- 5000-6000 cases annually
- Most cases in rural communities in sub-Saharan Africa
- Usually found in communities near rivers, swamps and wetlands
- Nearly half of people affected in Africa are children under 15
- Mode of transmission unknown
Buruli ulcer: Signs and Symptoms
- Usually starts as painless nodule
- Painless plaque
- Diffuse painless edema of legs, arms, or face
- Local immunosuppressive properties of mycolactone toxin enable painless progression
- Without treatment (or during treatment) ulceration occurs
- Occasionally bone is affected causing gross deformity
Buruli ulcer: Diagnosis
- No field test available
- IS2404 polylmerase chain reaction (PRC) is main method of confirmation
- Highest sensitivity
- Results can be available within 48 hours
-Usually clinical diagnosis if lab not available
Buruli ulcer: Treatment
-Rifampicin 10 mg/kg once daily and streptomycin 15mg/kg once daily (standard treatment)
Complementary treatment
- Wound care
- Surgery – debridement and skin grafting
- Interventions to minimize or prevent disability
Human African Trypanosomiasis, (sleeping sickness)
- Vector-born parasitic disease
- Protozoa belonging to the Trypanosoma genus
- Transmitted to humans by tsetse fly bites infected from humans or from animals harboring the human pathogenic parasites
Human AfricanTrypanosomiasis, (sleeping sickness): Modes of transmission
- Bite of infected tsetse fly
- Mother-to-child infection: trypanosomes can cross placenta and infect the fetus
- Accidental infections in laboratories due to pricks from contaminated needles
Human AfricanTrypanosomiasis, (sleeping sickness): Stages of disease
- Stage 1 – trypanosomes multiple in subcutaneous tissues, blood and lymph (haemolymphatic phase)
- Stage 2 – parasites cross blood-brain barrier to infect nervous system (neurological phase)
- Fatal without treatment
Human AfricanTrypanosomiasis, (sleeping sickness): Symptoms
Stage 1
- Bouts of fever
- Headaches
- Joint pains
- itching
Stage 2
- Changes in behavior
- Confusion
- Sensory disturbances and poor concentration
- Disturbance of sleep cycle
Human AfricanTrypanosomiasis, (sleeping sickness): Diagnosis
- Serologic testing
- Clinical signs (generally swollen cervical glands)
- Diagnosing whether the parasite is present
- Staging to determine the stage of disease progression through examination of cerebro-spinal fluid
Human AfricanTrypanosomiasis, (sleeping sickness): treatment
- Diagnosis must be made as early as possible and before the neurological stage
- Type of treatment depends on stage of disease
- Drugs used in the first stage are of lower toxicity and easier administer.
- The earlier the disease is identified, the better the prospect of a cure
- Treatment success in the second stage depends on a drug that can cross the blood-brain barrier to reach the parasite.
Leprosy
- Caused by slow-growing bacillus, -Mycobacterium leprae
- Transmitted via droplets from the nose and mouth of untreated patients with severe disease
- Not highly infectious
- If left untreated can cause nerve damage leading to muscle weakness and atrophy, and permanent disability
Leprosy: tx
- treated with 6-12 month course of multidrug therapy
- Treatment is highly effective
- Few side-effects and low relapse rates
- No known drug resistance
- Most effective way of preventing disability and further transmission is early diagnosis and treatment
Leprosy: Epidemiology
- 2012 – 107 countries or territories on leprosy
- 224,385 new cases reported during 2011
Lymphatic filariasis
- Infection with the filarial worms, Wuchereria bancrofti, Brugia malayi or B. timori
- Transmitted to humans through bite of infected mosquito and develop into adult worms in the lymphatic vessels
- Cause severe damage and swelling (lymphedema)
- Elephantiasis – painful disfiguring swelling of the legs and genital organs in late-stage disease
- Usually acquired in childhood, with visible manifestations later in life
Lymphatic filariasis: Clinical manifestations
Lymphedema of limbs
- Genital disease (hydrocele, chylocele, swelling of scrotum and penis)
- Recurrent attacks with fever are extremely painful
- Vast majority are asymptomatic
- Virtually all have subclinical lymphatic damage
- As many as 40% have kidney damage with proteinuria and hematuria
Lymphatic filariasis: Treatment
- Treatable condition, but chronic disease not curable by anti-filarial drugs
- Annual treatment of all at risk individuals with anti-filarial drug combinations recommended to prevent new infection and disease
Trachoma
- Result of eye infection with Chlamydia trachomatis
- Infection spread from person to person through contact with eye discharge
- Infection often begins during infancy or childhood and can become chronic
- If left untreated the infection causes the eyelid to turn inward which causes the eyelashes to rub the eyeball resulting I intense pain and scarring
- Ultimately leads to irreversible blindness, typically between 30 and 40 years of age
Trachoma: Epidemiology
Affects ~ 21.4 million people
~ 2.2 million visually impaired
-1.2 million blind
-Responsible for 3% of the world’s blindness
-Continues to be hyperendemic in many of the poorest and most remote poor rural areas of Africa, Asia, Central and South America, Australia and the Middle East
-In endemic areas active disease most common in pre-school children with prevalence rates as high as 60-90%
-Women more at risk of developing blinding complications than men
Trachoma: Risk factors & interventions
RF’s: Water shortage, Flies, Poor hygiene conditions, Crowded households
- Improved sanitation
- Reduction of fly breeding sites and increased facial cleanliness with clean water among children at risk of disease
- Simple surgical procedure to reverse the inturned eyelashes
- Antibiotic treatment: tetracycline eye ointment or azithromycin
