Raed Z. Ahmed, Medical Parasitology Lab.,2012 Blood Parasites Raed Z. Ahmed, Medical Parasitology Lab.,2012

Comparison Thick smear Thin smear Lysed RBCs, many layer Fixed RBCs, single layer ( large volume ) 0.25 μl blood/100 fields ( small volume ) 0.005 μl blood/100 fields Good screening test ( positive or negative ) Good species differentiation Save time in examination Requires more time to read Low density infection can be detected as blood elements more concentrate (more sensitive) Low density infections can be missed (less sensitive) Raed Z. Ahmed, Medical Parasitology Lab.,2012

Either thick or thin films may be used depending on the circumstances. The thick film is more sensitive in detecting parasite and also saves time in examination. The thin film technique cause very little distortion of the parasite, and permits species identification when it may not be possible in thick films, but many fields must be examined to detect parasite when they are few in number.

Plasmodium falciparum Blood Protozoa Blood Parasite Microfilariae Trypanosoma Leishmania Plasmodium Plasmodium falciparum Plasmodium vivax Plasmodium ovale Plasmodium malariae Raed Z. Ahmed, Medical Parasitology Lab.,2012

Raed Z. Ahmed, Medical Parasitology Lab.,2012 Blood Parasites Trypanosoma spp. Raed Z. Ahmed, Medical Parasitology Lab.,2012

Raed Z. Ahmed, Medical Parasitology Lab.,2012 Life cycle Raed Z. Ahmed, Medical Parasitology Lab.,2012

Raed Z. Ahmed, Medical Parasitology Lab.,2012 Trypanosoma spp. Trypanosoma cruzi (Americans) cause Chaga’s disease. Trypanosoma bruzi (Africans) cause sleeping sickness disease. Trypanosoma have many stages: Amastigote, Promastigote, Epimastigote and Trypomastigote. Reservoir host: mammalian animal. Intermediate host: Tsetse fly (Glossina spp.) for Trypanosoma bruzi Reduviidae bug(kissing bug) for Trypanosoma cruzi Definitive host: Human. Infective stage: Metacyclic trypomastigote. Diagnostic stage: Trypomastigote. Raed Z. Ahmed, Medical Parasitology Lab.,2012

Raed Z. Ahmed, Medical Parasitology Lab.,2012 Continue …… Diagnosis: Detection of Trypanosoma chancer after bite Blood smear within 21 days from the bite, it will show the parasites. Lymph node aspiration (most reliable). Lumber puncture if brain affected. Undulating membrane Flagellum Nucleus kinetoblast Raed Z. Ahmed, Medical Parasitology Lab.,2012

Trypanosoma Trypomastigotes Raed Z. Ahmed, Medical Parasitology Lab.,2012

Trypansoma brucei ssp. in thick blood smears stained with Giemsa

Trypansoma brucei ssp. in thin blood smears stained with Giemsa

Raed Z. Ahmed, Medical Parasitology Lab.,2012 Blood Parasites Leishmania spp. Raed Z. Ahmed, Medical Parasitology Lab.,2012

Raed Z. Ahmed, Medical Parasitology Lab.,2012 Life cycle Raed Z. Ahmed, Medical Parasitology Lab.,2012

Raed Z. Ahmed, Medical Parasitology Lab.,2012 Leishmania spp. There is many species affect man: Leishmania tropica : cause skin lesion ( cutaneous ) Leishmania braziliense : cause muco-cutaneous lesion. Leishmania donovani : cause visceral lesion.(kala azar) Leishmania have two stages: Amastigote (Leishmania stage), in man (reticuloendothelial cell). Promastigote (Leptomonas stage), the infective stage and present in the lumen gut of the sand fly. Reservoir host: dogs and rodents. Intermediate host: Sand fly (Phlebotomus). Definitive host: Human. Raed Z. Ahmed, Medical Parasitology Lab.,2012

Cutaneous leishmaniasis

Raed Z. Ahmed, Medical Parasitology Lab.,2012 Continue …… Diagnosis: Thick and thin blood film Skin scraping Blood culture on N.N.N media* (Novy-MacNeal-Nicolle) Serological tests Nucleus Flagellum * Culture media used to growth leishmania is Novy, MacNeal and Nicolle's “NNN” or Schneider's Drosophila medium, supplemented with 30% fetal bovine serum, Raed Z. Ahmed, Medical Parasitology Lab.,2012 19

Leishmania promastigotes Raed Z. Ahmed, Medical Parasitology Lab.,2012

Raed Z. Ahmed, Medical Parasitology Lab.,2012 Blood Parasites Plasmodium spp. Raed Z. Ahmed, Medical Parasitology Lab.,2012

Malaria Blood parasites of the genus Plasmodium. There are approximately 156 named species of Plasmodium which infect various species of vertebrates.  Four species are considered true parasites of humans, as they utilize humans almost exclusively as a natural intermediate host: P. falciparum, P. vivax, P. ovale  and P. malariae. 

Clinical features fever and chills, which can be accompanied by headache, myalgias, arthralgias, weakness, vomiting, and diarrhea.  Other clinical features include splenomegaly, anemia, thrombocytopenia, hypoglycemia, pulmonary or renal dysfunction, and neurologic changes. The clinical presentation can vary substantially depending on the infecting species, the level of parasitemia, and the immune status of the patient   Infections caused by P. falciparum can progress to severe, potentially fatal forms with central nervous system involvement (cerebral malaria), acute renal failure, severe anemia, or adult respiratory distress syndrome.   Complications of P. vivax malaria include splenomegaly (with, rarely, splenic rupture), and those of P. malariae include nephrotic syndrome.

Laboratory Diagnosis Microscopic identification is the method most frequently used to demonstrate an active infection. Morphological comparison and images of Plasmodium species Molecular diagnosis techniques can complement microscopy, especially in species identification. Antibody Detection can detect past (not necessarily active) infections. Immunologic/Biochemical detection of malaria parasite products are available and under evaluation. Bench aids for Malaria

Raed Z. Ahmed, Medical Parasitology Lab.,2012 Life cycle Raed Z. Ahmed, Medical Parasitology Lab.,2012

Raed Z. Ahmed, Medical Parasitology Lab.,2012 Plasmodium spp. Four species of Plasmodium are the causative agent of malaria, these are: P. vivax, P. malariae, P. falciparum, and P. ovale. Intermediate host: Human. Definitive host: Anopheles mosquitoes. Plasmodium spp. have 4 stages: Ring form (young trophozoite.) Late ( old ) trophozoite Schizonts Gametocyte. Infective stage: Sporozoites. Diagnosis: Thick and stained thin blood film to detect parasites. Raed Z. Ahmed, Medical Parasitology Lab.,2012

Raed Z. Ahmed, Medical Parasitology Lab.,2012

Raed Z. Ahmed, Medical Parasitology Lab.,2012

Raed Z. Ahmed, Medical Parasitology Lab.,2012

Raed Z. Ahmed, Medical Parasitology Lab.,2012

Raed Z. Ahmed, Medical Parasitology Lab.,2012 Ring form P. vivax P. ovale P. malariae P. falciparum Raed Z. Ahmed, Medical Parasitology Lab.,2012

Raed Z. Ahmed, Medical Parasitology Lab.,2012 Trophozoite form P. vivax P. ovale P. malariae P. falciparum Raed Z. Ahmed, Medical Parasitology Lab.,2012

Raed Z. Ahmed, Medical Parasitology Lab.,2012 Schizonts form P. vivax P. ovale P. malariae P. falciparum Raed Z. Ahmed, Medical Parasitology Lab.,2012

Raed Z. Ahmed, Medical Parasitology Lab.,2012 Gametocyte form P. vivax P. ovale P. malariae P. falciparum Raed Z. Ahmed, Medical Parasitology Lab.,2012

Species Differentiation On Thin Films   Species Differentiation On Thin Films Feature P. falciparum P. vivax P. ovale P. malariae Enlarged infected RBC - + Infected RBC shape round round, distorted oval, fimbriated Stippling infected RBC Maurer’s clefts Schuffner's spots Schuffner's dots none Trophozoite shape small ring, applique large ring, amoeboid large ring, compact small ring, compact Chromatin dot often double single large Mature schizont rare, 12-30 merozoites 12-24 merozoites 4-12 merozoites ( scattered ) 6-12 merozoites ( rosette ) Gametocyte crescent shape large, round compact, round Raed Z. Ahmed, Medical Parasitology Lab.,2012