Blood Parasites Different stages of Haemoflagellates African sleeping

Blood Parasites

Different stages of Haemoflagellates

African sleeping sickness Trypanosoma brucei rhodesiense: East Africa, wild and domestic animal reservoirs Trypanosoma brucei gambiense: West and Central Africa, mainly human infection

African Trypanosomiasis Life cycle of Trypanosoma brucei gambiense & T. b. rhodesiense

Animal reservoir hosts for African sleeping sickness

Tsetse fly

Pathology and clinical picture 1. Skin stage: chancre. 2. Haematolymphatic stage: generalized lymphadenopathy, anaemia, generalized organ involvement. 3. Central nervous system stage (CNS): Meningoencephalitis. (Development of the disease more rapid in Trypanosoma brucei rhodesiense)

chancre

Winterbottom’s stage

rd 3 stage CNS

Lymph node aspirate

trypanosoma

CSF

AMERICAN TRYPANOSOMIASIS LIFE CYCLE OF Trypanosoma cruzi

Reduviid (Triatomine) bug

T. cruzi causes cutaneous stage (chagoma)

Ocular lesion (Romana’ sign)

C-shape

Heart damage due to American trypanosomiasis

Diagnosis • Blood film • Serology: IFAT • Xenodiagnosis: feeding bugs on a suspected cases.

TREATMENT African trypanosomiasis For early infection • pentamidine • suramin For late infection • eflornithine (Diflouromethylornithine- DFMO) American trypanosomiasis (Chaga’s disease) • benznidazole • nifurtimox

FILARIALIASIS )

LYMPHATIC FILARIASIS

MAJOR FILARIAL INFECTIONS OF HUMANS species Disease Geographic distribution Location of adult in humans Location of microfilaria vector Lab. diagnosis Wuchereria elephantiasis bancrofti Tropical and subtropical areas Lymphatic vessels Blood (nocturnal periodicity) mosquitoes Blood film Brugia malayi elephantiasis Asia Lymphatic vessels Blood (nocturnal periodicity) mosquitoes Blood film Onchocerc a volvulus Onchocerciasis (river blindness) Africa, Subcutaneous Central and nodules South America, Yemen Skin, eyes, no periodicity Simulium spp. (black fly) Skin snip Loa loiasis Central Africa Chrysops spp. (deer fly) Blood film Moving in Blood subcutaneous (diurnal tissues periodicity)

Onchocerciasis (river blindness) Pathology: Adults worms live in subcutaneous nodules. Main pathology caused by microfilariae in: • Skin: dermatitis • Lymph nodes: lymphadenopathy • Eyes: blindness Diagnosis: skin snip to identify microfilariae. Treatment: Ivermectin

Lymphatic Filariasis

LYMPHATIC FILARIASIS Mainly caused by Wuchereria bancrofti and Brugia malayi Pathology: Due to adult worm obstructing lymphatics. • Acute: lymphadenitis lymphatic varices • Chronic: lymphedema, hydrocele, chyluria.

LYMPHATIC FILARIASIS Diagnosis: detection of microfilariae in blood in early stages of the disease: Blood film, Knott’s method ( concentration of 1 ml of blood), best 10 pm to 2 am (nocturnal periodicity). Immunological tests: Treatment: diethylcarbamazine (DEC) or ivermectin

Loa loa

Loiasis

Loiasis • Pathology: Adult worm continously migration in subcutaneous and subconjuntival tissues, causing Calabar swellings (allergic reactions) and conjunctivitis.

Loiasis • Diagnosis: detection of microfilariae in blood film. • Treatment: diethylcarbamazine (DEC) or ivermectin, surgical remonval.