Common Clinical Presentations of Parasitic Infections Parasites causing this clinical presentation How did the parasite produce this presentation (Pathogenesis) Mode of infection Hepatosplenomegaly Enlarged lymph nodes Anaemia Dysentery

A child presenting with hepatosplenomegaly Helminths causing hepatosplenomegaly: Schistosoma Skin penetration by Furcocercous cercaria HOW? Schistosoma eggs that pass in the circulation as emboli to the liver cause hepatosplenomegaly

A child presenting with hepatosplenomegaly Protozoa causing hepatosplenomegaly: Leishmania infantum, Leishmania donovani, Leishmania chagasi Visceral leishmaniasis Promastigote Trypanosoma b.gambiense, Trypanosoma b.rhodesiense Sleeping sickness Stumpy metacyclic trypanosomes Trypanosoma cruzi Chagas’ disease

How can Leishmania cause hepatosplenomegaly? Amastigotes multiply in skin macrophage Via blood stream to Taken by Promastigotes Amastigotes Reticulo-endothelial cells present in human viscera Through the bite of female Phlebotomus injecting Promastigote stage with saliva When amastigotes enter reticulo-endothelial cells present in liver & spleen Hepatosplenomegaly occurs

How can African Trypanosomes cause Hepatosplenomegaly? How can American Trypanosomes cause Hepatosplenomegaly? Short stumpy metacyclic trypanosomes enter the site of bite with saliva of Glossina Short stumpy metacyclic trypanosomes contaminate skin abrasion by winged bug faeces To blood stream C-shaped Trypanosoma cruzi Polymorphic trypanosomes amastigote To liver & spleen Hepatosplenomegaly occurs

Parasites causing Enlarged lymph nodes Helminths affecting lymph nodes: W.bancrofti Usually affects lymph nodes draining genitalia & lower limbs Brugia malayi Usually affects lymph nodes draining legs below knees & arms below elbows O.volvulus Hanging groin containing enlarged lymph nodes

Enlarged lymph nodes Protozoa affecting lymph nodes: Leishmania infantum, Leishmania donovani, Leishmania chagasi Visceral leishmaniasis Trypanosoma b.gambiense, Trypanosoma b.rhodesiense Sleeping sickness Winterbottom sign Trypanosoma cruzi Chagas’ disease Toxoplasma gondii Toxoplasmosis

Decrease in number of RBCs below 4 millions / ml Anaemia Decrease in number of RBCs below 4 millions / ml Helminthic infections causing anaemia: a- Schistosomiasis b- Trichuriasis Iron deficiency: Due to blood loss c- Ancylostomiasis d- Diphyllobothriasis Megaloblastic: Due vit B12 deficiency Schistosomiasis Due to hypersplenism Trichuriasis Blood in urine Blood in stool Due to toxic products of the worm

Protozoal infections associated with anaemia Malaria: haemolytic anaemia due to rupture of infected red cells. merozoites Babesiosis: haemolytic anaemia due to rupture of infected red cells. Sleeping sickness: Polymorphic trypanosomes hypoplastic anaemia Leishmania amastigotes due to bone marrow affection. Visceral leishmaniasis:

Mode of Infection with Schistosoma Skin penetration by furcocercous cercaria from contaminated canal water. Aided by: - Surface tension of drying droplets of water. - Proteolytic enzymes secreted by penetration glands. Proteolytic enzymes - Strong lashing movement of the tail pressing the body of the cercaria into the skin.

Skin penetration by filariform larvae Mode of infection with D.latum T.trichiura A.duodenale ingestion of plerocercoid larva in improperly cooked infected salmon, Perch or Trout fish Skin penetration by filariform larvae Ingestion of embryonated eggs in contaminated raw vegetables and contaminated water. Negative geotropism Positive hygrotropism Thermotropism

Through the bite of Hard Tick injecting sporozoite stage with saliva Mode of infection with Malaria Babesiosis Through the bite of female Anopheles injecting sporozoite stage with saliva Through the bite of Hard Tick injecting sporozoite stage with saliva

Visceral leishmaniasis Mode of infection with Visceral leishmaniasis Sleeping sickness Through the bite of female Phlebotomus injecting Promastigote stage with saliva Through the bite of Glossina injecting short stumpy metacyclic trypanosomes

A patient presenting with Dysentery Painful frequent evacuation of small quantities of stool containing mucus tinged with blood. This indicates that the large intestine is affected Parasites causing dysentery: 1- Schistosoma mansoni. 2-Trichuris trichiura. 3- Strongyloides stercoralis (heavy infection). 4- Entamoeba histolytica. 5- Balantidium coli. 6- Leishmania (visceral) 7- P.falciparum

How can helminths cause Dysentery 1- Schistosoma mansoni 2- Trichuris trichiura 3- heavy infection with Strongyloides stercoralis Anterior part of worms embedded in intestinal mucosa cause oedematous, hyperaemic, fragile mucosa. Number of worms increase and fill the small and large intestine Egg pass in stool with mucus and blood stool with mucus & blood stool with mucus & blood

How Entamoeba and Balantidium cause Dysentery Balantidium trophozoite Entamoeba trophozoite Boring action of cilia Histolytic enzyme Flask-shaped ulcer Flask-shaped ulcer

How can Leishmania cause Dysentery? Amastigotes multiply in skin macrophage Via blood stream to Taken by Promastigotes Amastigotes Reticulo-endothelial cells present in human viscera When amastigotes enter payer’s patches of Intestinal mucosa: Diarrhoea & dysentery occur

How can P.falciparum cause Dysentery? Knobs develop on surface of infected RBCs Knobs are parasite antigens expressed on the surface of infected red cells containing trophozoites and schizont stages. Infected RBCs adhere to receptors found on endothelium of blood capillaries of intestine Diminished blood supply to intestine necrosis of intestinal wall cause dysentery. Normal RBC Infected RBC

Strongyloides stercoralis Mode of infection with Trichuris trichiura Strongyloides stercoralis Skin penetration by filariform larvae Ingestion of embryonated eggs in contaminated raw vegetables and contaminated water. Negative geotropism Positive hygrotropism Thermotropism

Entamoeba histolytica Balantidium coli Mode of infection with Entamoeba histolytica Balantidium coli Ingestion of quadrinucleate cyst Ingestion of cyst - In contaminated raw green vegetables and contaminated water. - Through flies and food handlers. - By faeco-oral route (hand to mouth). This is called autoinfection.

Mode of infection of Visceral Leishmania Falciparum malaria Through the bite of female Phlebotomus injecting Promastigote stage with saliva Through the bite of female Anopheles gambia injecting sporozoite stage with saliva