Microbio: Blood And Lymphatics - "hints"

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talk about the pathogenesis of malaria

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Splenomegaly is also seen from the congestion caused by the removal of damaged red blood cells. Hepatomegaly may also be seen. P. falciparum causes the most severe form with hemorrhage and necrosis (esp. the brain). Hemolysis and kidney damage results in hemoglobinuria: "blackwater fever." Other species of Plasmodia may cause self limiting disease with low mortality. Relapses can occur from latent organisms (hypnozoites) in the liver. Sickle cell anemia and thalasemias are partially protective against malaria because these red blood cells are not as permissive to the growth of the parasite.

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what is special about the bugs inside us during p. vivax and p. ovale

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In both P. vivax and P. ovale infections, some of the intrahepatic forms do not divide immediately and remain dormant for periods ranging from weeks to years before reproduction begins. These dormant forms, called hypnozoites, are the cause of the relapses that characterize infection with P. vivax and P. ovale.

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know all about the life cycle of babesiosis / babesia microti

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The Babesia microti life cycle involves two hosts, which includes a rodent, primarily the white-footed mouse. During a blood meal, a Babesia-infected tick introduces sporozoites into the mouse host. Sporozoites enter erythrocytes and undergo asexual reproduction (budding). In the blood, some parasites differentiate into male and female gametes. The definitive host is the deer tick, Ixodes dammini. Once ingested by an appropriate tick, gametes unite resulting in sporozoites. Humans enter the cycle when bitten by infected ticks. During a blood meal, a Babesia-infected tick introduces sporozoites into the human host. Sporozoites enter erythrocytes and replicate. Multiplication of the blood stage parasites is responsible for the clinical manifestations of the disease. Humans are, for all practical purposes, dead-end hosts and there is probably little, if any, subsequent transmission that occurs from ticks feeding on infected persons. However, human to human transmission is well recognized to occur through blood transfusions. Note: Deer are the hosts upon which the adult ticks feed and are indirectly part of the Babesia cycle as they influence the tick population. When deer populations increase, the tick population also increases, thus heightening the potential for transmission.

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how do you make the diagnosis of babesiosis

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Diagnosis can be made by microscopic examination of thick and thin blood smears stained with Giemsa. Repeated smears may be needed. Babesia microti infection, Giemsa-stained thin smear. B. microti most commonly appear as ring forms inside of erythrocytes. The organisms may resemble Plasmodium falciparum; however Babesia parasites present several distinguishing features: Babesia vary in shape and size, can be vacuolated and Babesia do not produce pigment. Babesia may form “tetrads.”

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talk about the life cycle of leishmania

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Life cycle and transmission: Humans are infected via the bite of sandflies - tiny sand-colored blood-feeding flies that breed in forest areas, caves, or the burrows of small rodents. Wild and domesticated animals, and humans themselves can act as a reservoir of infection. The promastigote stage in the saliva of sandflies is transmitted through a bite. Within the human host, the promastigote forms of the parasite are ingested by macrophages where they metamorphose into amastigote forms and reproduce by binary fission. In the human the amastigote stage replicates resulting in tissue destruction. The amastigotes replicate in number until cells eventually burst, infecting other phagocytic cells continuing the cycle. The infected host is bitten by another female sandfly. Parasites are picked up by the fly during the blood meal. The parasites are transformed inside the fly and delivered to a new host, and the life-cycle continues

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how do you make the diagnosis of leishmaniasis

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Examination of Giemsa-stained slides of biopsied tissues, bone marrow, lymph node aspirates and blood smears is the technique most commonly used to detect the amastigote stage of the parasite. In visceral leishmaniasis aspirates and biopsies of spleen, bone marrow, liver, or lymph nodes reveals the presence of amastigotes. In cutaneous and mucosal leishmaniasis aspirates and biopsy specimens of skin lesions and lymph nodes can also reveal the presence of amastigotes. - - - characteristic AMASTIGOTES!

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how do you make a diagnosis of african sleeping sickness (TTrryyppaannoossoommaa bbrruucceeii ((ggaammbbiieennssee//rrhhooddeessiieennssee)))

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Laboratory Diagnosis: A definitive diagnosis requires microscopic identification of flagellated trypanosomes in fluid from a chancre (bite site); a needle aspiration biopsy of a lymph node; and wet preparations and Giemsa-stained thin and thick films of serial blood samples. Trypanosomes may be seen in the sediment of centrifuged cerebrospinal fluid. Fresh wet mounts reveal motile trypomastigotes while Giemsa stained smears revel fixed trypomastigotes. ; KNOW THE GEOGRAPHIC AREA (east and west africa)!! - LYMPH NODE BIOPSY OR CSF ; WET MOUND - MOTILE ; FIXED - YOU CAN SEE THE FIXED TRYPOMASTIGOTES

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talk about the life cycle of t. cruzi

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T. cruzi is transmitted among its mammalian hosts by blood sucking triatomine insects, also called reduviid bugs or “kissing” bugs. The insects become infected by sucking blood from animals or humans who have circulating parasites. Ingested organisms multiply in the gut of the triatomines, and infective trypomastigotes are discharged with the feces at the time of subsequent blood meals. Inside the human or animal host, the trypomastigotes invade cells, where they differentiate into intracellular amastigotes. The amastigotes differentiate into trypomastigotes and are released into the bloodstream as trypomastigotes. (must know geographic area - and know trypomastigotes!!)

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what are clinical features of t. cruzi

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A local lesion can appear at the site of inoculation. The acute phase is usually asymptomatic, but can present with manifestations that include fever, anorexia, lymphadenopathy, mild hepato-splenomegaly, and myocarditis. Most acute cases resolve over a period of 2 to 3 months into an asymptomatic chronic stage. The symptomatic chronic stage may not occur for years or even decades after initial infection. Its manifestations include cardiomyopathy (the most serious manifestation); most deaths in acute Chagas' disease are due to heart failure. Chronic Chagas disease and its complications can be fatal. Chronic Chagas disease includes hepato-splenomegaly, myocarditis, and enlargement of the esophagus and colon. (most deaths are due to heart failure - intracellular amastigotes in the heart tissue)

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how do you get schistosoma

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in the water - the circariae enter thru the skin and leave their flagellae behind

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what is life cycle of the schistosoma species

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The stages in the snail include the production of cercariae. Upon release from the snail, the infective cercariae swim, penetrate the skin of the human host, and shed their forked tail

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how to make lab diagnosis of schistosoma

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Microscopic identification of eggs in stool or urine is the most practical method for diagnosis. Stool examination should be performed when infection with S. mansoni or S. japonicum is suspected, and urine examination should be performed if S. haematobium is suspected. Eggs can be present in the stool in infections with all Schistosoma species. Schistosoma mansoni eggs are large and have a characteristic prominent lateral spine near the posterior end. The eggs of Schistosoma japonicum are large and more rounded than other species and the spine is smaller and less conspicuous than with other species. The eggs of Schistosoma haematobium are large and bear a conspicuous terminal spine. CONSPICUOUS TERMINAL SPINE - KNOW THE DIFFERENT GEOGRAPHIC LOCATIONS TOO! SHED IN FECES, NO URINE ; MANSONI - PROMINENT LATERAL SPINE ; JAPONICUM - TRUNCATED (NO NOTICEABLE) SPINE WHATSOEVER - LOOKS ROUND.

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clinical features of filiarisis

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eosinophilia is often prominent

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lab diagnosis of wuchereria bancrofti

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Identification of microfilariae by microscopic examination of a Giemsa stained blood smear is the most practical diagnostic procedure. Examination of blood samples will allow identification of microfilariae of Wuchereria bancrofti and Brugia malayi. LOOK FOR MICROFILARIAE! THIS LOOKS LIKE NOTHING ELSE