LUNGLUNGPARASITESPARASITES

CESTOIDEACESTOIDEA Order:Order: CyclophyllideaCyclophyllidea

ECHINOCOCCUSECHINOCOCCUSGRANULOSUSGRANULOSUS

Echinococcus granulosus infection has a world-Echinococcus granulosus infection has a world-wide distribution with a higher prevalence in wide distribution with a higher prevalence in South-America (Argentina, Uruguay), Europe South-America (Argentina, Uruguay), Europe (mediterranean bassin), Northern Africa, Middle (mediterranean bassin), Northern Africa, Middle East, South-Central and East Asia.East, South-Central and East Asia.

Echinococcus granulosus: Echinococcus granulosus: hydatidosis is caused by hydatidosis is caused by the larval stage of the larval stage of E.granulosus.E.granulosus. After ingestion of eggs the onchospheres After ingestion of eggs the onchospheres penetrate the intestinal mucosapenetrate the intestinal mucosa and reach host and reach host organs (mainly liver and lung) where they encyst organs (mainly liver and lung) where they encyst within a week reaching 1 cm in diameter in about 5 within a week reaching 1 cm in diameter in about 5 months.months.

Echinococcus granulosus: Echinococcus granulosus: the cysts (2 to 30 cm) the cysts (2 to 30 cm) are constituted by an externalare constituted by an external acellular cuticule acellular cuticule and an inner cellular "germinal" layer (10-25 µ) and an inner cellular "germinal" layer (10-25 µ) that producesthat produces the brood capsules containing 6-12 the brood capsules containing 6-12 protoscolices or single protoscolices. (Germinal protoscolices or single protoscolices. (Germinal layer with a protoscolex).layer with a protoscolex).

Echinococcus granulosus: the larvae (scolices) Echinococcus granulosus: the larvae (scolices) develop from the germinal layer. develop from the germinal layer. The protoscolices are at first evaginated and The protoscolices are at first evaginated and measure 120-220 by 70-120 µ.measure 120-220 by 70-120 µ.

Echinococcus granulosus: the mature rotoscolices Echinococcus granulosus: the mature rotoscolices have 4 suckers and a rostellumhave 4 suckers and a rostellum with hooklets and with hooklets and can be observed in the hydatid fluid.can be observed in the hydatid fluid.

Echinococcus granulosus: detail of the rostellum.Echinococcus granulosus: detail of the rostellum.

Echinococcus granulosus: Echinococcus granulosus: the protoscolices then the protoscolices then become invaginated andbecome invaginated and measure 90-140 by 70-120 measure 90-140 by 70-120 µm.They can transform into daughter cysts. µm.They can transform into daughter cysts. These cysts can proliferate both internally and These cysts can proliferate both internally and externally giving exogenous cysts.Spontaneous or externally giving exogenous cysts.Spontaneous or surgical rupture of the cyst can originate a surgical rupture of the cyst can originate a secondary hydatidosis.secondary hydatidosis.

Echinococcus granulosus: Echinococcus granulosus: the liver is the most the liver is the most common site of development of cysts (50-75%). common site of development of cysts (50-75%). Lesions can be detected by CT scan or Lesions can be detected by CT scan or echography;a septate structure is a characteristic echography;a septate structure is a characteristic of active cysts. of active cysts. Treatment is based on surgical and/or medical Treatment is based on surgical and/or medical therapy (albendazole)therapy (albendazole)

Echinococcus granulosus: Echinococcus granulosus: definitive diagnosis is definitive diagnosis is obtained by meansobtained by means of serologic tests (EIA, IHA, of serologic tests (EIA, IHA, CIEP/Western Blot);the last two are confirmatory CIEP/Western Blot);the last two are confirmatory teststests and are useful for the follow-up of treated and are useful for the follow-up of treated patients.patients.--Detail of liver lesion, CT-scan with septa. Detail of liver lesion, CT-scan with septa. --Western blot analysis: both Ag5 (55 and 65 Kd) Western blot analysis: both Ag5 (55 and 65 Kd) and AgB (8, 16, 24 Kd) bands are present.and AgB (8, 16, 24 Kd) bands are present.

Echinococcus granulosus: Echinococcus granulosus: pulmonary infection is pulmonary infection is observed in about 20-30% of patients. observed in about 20-30% of patients. RoentRoentggenografic examination shows round mass enografic examination shows round mass lesionslesions and CT scan demonstrates the fluid and CT scan demonstrates the fluid content of the lesion. content of the lesion. Serology has a lower sensitivity in extrahepatic Serology has a lower sensitivity in extrahepatic hydatidosis.hydatidosis.

Echinococcus granulosus: Echinococcus granulosus: any other organ can be any other organ can be affected:nervous system, heart, bones, spleen affected:nervous system, heart, bones, spleen eyes, muscles are the most common sites. eyes, muscles are the most common sites. Multiple involvement is frequent.Symptoms and Multiple involvement is frequent.Symptoms and signs depend on the size,the site and the signs depend on the size,the site and the pressure of the cyst on host structures.pressure of the cyst on host structures.--CT scan of a spleen cyst.CT scan of a spleen cyst.--MRI scans of a muscular cyst.MRI scans of a muscular cyst.

Echinococcus granulosus: Echinococcus granulosus: medullary hydatidosis medullary hydatidosis is a severe form of the infection.In this case the is a severe form of the infection.In this case the mechanical pressure of host tissues caused mechanical pressure of host tissues caused paraplegia.The surgical treatment allowed paraplegia.The surgical treatment allowed resolution of symptoms.The infection relapsed resolution of symptoms.The infection relapsed and responded partially to medical treatment.and responded partially to medical treatment.

TREMATODA TREMATODA Order:Order: PlagiorchiataPlagiorchiata

PARAGONIMUS WESTERMANI PARAGONIMUS WESTERMANI

Paragonimus westermaniParagonimus westermani infection occurs in Asia infection occurs in Asia (especially in China, Corea,India, Japan, Laos, (especially in China, Corea,India, Japan, Laos, Philippines, Sri Lanka, Taiwan, Thailand, Viet-Nam), Philippines, Sri Lanka, Taiwan, Thailand, Viet-Nam), Central-West Africa, South America (Ecuador, Perù, Central-West Africa, South America (Ecuador, Perù, Venezuela).Venezuela).

Paragonimus westermani:Paragonimus westermani: eggs measure 80-100 eggs measure 80-100 by 40-60 µm,are golden-brown with a thick shell by 40-60 µm,are golden-brown with a thick shell and a prominent operculum. and a prominent operculum. Eggs are recovered from sputum and faeces. Eggs are recovered from sputum and faeces. (Fresh examination of stool sediment). (Fresh examination of stool sediment). 

Cross section of lung containing adult Cross section of lung containing adult Paragonimus westermani. Paragonimus westermani.

INCERTAE SEDIS INCERTAE SEDIS

PNEUMOCYSTISPNEUMOCYSTIS JIROVECI JIROVECI

(P.CARINII) (P.CARINII)

P.jiroveci:P.jiroveci: the infection has a world-wide the infection has a world-wide distributiondistribution and the transmission seems to occur and the transmission seems to occur by airborne route.The organims that causes by airborne route.The organims that causes human pneumocystosis ishuman pneumocystosis is now named now named Pneumocystis jiroveciPneumocystis jiroveci * Frenkel 1999,in honor of * Frenkel 1999,in honor of the Czech parasitologist Otto Jirovec. the Czech parasitologist Otto Jirovec. The organism is now considered a fungus,based The organism is now considered a fungus,based on nucelic acid and biochemical analysis; on nucelic acid and biochemical analysis; nevertheless,on the basis of morpholocic and nevertheless,on the basis of morpholocic and biologic characterisitcsbiologic characterisitcs it is included in the atlas it is included in the atlas of medical parasitology.of medical parasitology.

Pneumocystosis Pneumocystosis is one of the most common is one of the most common infections ininfections in immunosuppressed patients with immunosuppressed patients with AIDS.Other impairements of cellular immunity AIDS.Other impairements of cellular immunity such as primary immunodeficiencies,steroid such as primary immunodeficiencies,steroid treatment, organ transplantation and cancers treatment, organ transplantation and cancers predispose to P.c. infection. predispose to P.c. infection. This typical chest roentgenogram shows diffuse This typical chest roentgenogram shows diffuse bilaterbilater interstitial infiltrates from the hilar interstitial infiltrates from the hilar regionregion. .

P.jiroveci:P.jiroveci: infiltrates are usually diffuse but atypical infiltrates are usually diffuse but atypical presentations can occur:nodules, cavitation, presentations can occur:nodules, cavitation, consolidation, pneumatocele and pneumotorax.consolidation, pneumatocele and pneumotorax.

P.jiroveci:P.jiroveci: after inhalation the microorganism after inhalation the microorganism reaches the alveolireaches the alveoli and adheres to the type I and adheres to the type I pneumocytes.The trophozoites then multiply slowly pneumocytes.The trophozoites then multiply slowly but extensively in the lungs andbut extensively in the lungs and progressively fill progressively fill the alveoli that are finally stuffed by the foamy the alveoli that are finally stuffed by the foamy exudate. exudate. The classical exudate consists of clusters of The classical exudate consists of clusters of P.jiroveciP.jiroveci, degenerated cells,host proteins and few , degenerated cells,host proteins and few alveolar macrophages.H&E stain.alveolar macrophages.H&E stain.

P.jiroveci:P.jiroveci: in tissue sections obtained with open in tissue sections obtained with open lung biopsy or at autopsylung biopsy or at autopsy the alveolar space the alveolar space appears filled by honeycombed material appears filled by honeycombed material consisting in clustersconsisting in clusters of of P.jiroveciP.jiroveci, host proteins , host proteins and degenerated cells. A scanty inflammation is and degenerated cells. A scanty inflammation is present.As the disease progresses interstitial present.As the disease progresses interstitial hyperplasia with edema and infiltration occur. hyperplasia with edema and infiltration occur. H&E stain. H&E stain.

P.jiroveci:P.jiroveci: clusters of cysts are demonstrated in the clusters of cysts are demonstrated in the alveolar space with stains which are selective for alveolar space with stains which are selective for the "parasite" wall: methenamine silverthe "parasite" wall: methenamine silver and and toluidine blue O. Open lung biopsy, silver toluidine blue O. Open lung biopsy, silver methenamine stain.methenamine stain.

P.jiroveci:P.jiroveci: clusters of cysts are demonstrated in clusters of cysts are demonstrated in the alveolar space. the alveolar space. Open lung biopsy, silver methenamine stain.Open lung biopsy, silver methenamine stain.

P.jiroveci:P.jiroveci: with higher magnification single with higher magnification single cysts are visible within the cluster. cysts are visible within the cluster. Open lung biopsy, silver methenamine stain.Open lung biopsy, silver methenamine stain.

P.jiroveci P.jiroveci diagnosis: fiberoptic bronchoscopy diagnosis: fiberoptic bronchoscopy with BAL is actuallywith BAL is actually the most commonly used the most commonly used diagnostic procedure. diagnostic procedure. The diagnosis is based on the observation of The diagnosis is based on the observation of cysts and trophozoites. cysts and trophozoites. Clusters of Clusters of P.jiroveciP.jiroveci can be observed in wet can be observed in wet mount preparations.mount preparations.

P.jiroveci:P.jiroveci: at higher magnification cysts with at higher magnification cysts with intracystic bodiesintracystic bodies can be detected within the can be detected within the clusters. (Wet-mount preparations).clusters. (Wet-mount preparations).

P.jiroveci:P.jiroveci: empty, collapsed and filled cysts empty, collapsed and filled cysts cohexist inside the cluster and can be observed cohexist inside the cluster and can be observed with oil immersion.(Wet-mount preparations)with oil immersion.(Wet-mount preparations)

P.jiroveci:P.jiroveci: the bronchoalveolar lavage can be the bronchoalveolar lavage can be stained with specific stainsstained with specific stains for trophozoites like for trophozoites like Giemsa. Clusters of typical pleomorphic trophozoites Giemsa. Clusters of typical pleomorphic trophozoites

(1-3 micron) and cysts can be observed: (1-3 micron) and cysts can be observed: trophic forms appear with reddish nuclei and blue trophic forms appear with reddish nuclei and blue cytoplasm.cytoplasm.

P.jiroveci:P.jiroveci: with Giemsa stain cysts (approx. 5-8 µm with Giemsa stain cysts (approx. 5-8 µm in diameter) are variably stained. in diameter) are variably stained. Intracystic bodies are present in different numbers Intracystic bodies are present in different numbers within the cysts. within the cysts. Mature cysts have 8 intracystic bodies. Some cysts Mature cysts have 8 intracystic bodies. Some cysts appear empty.appear empty.

P.jiroveci:P.jiroveci: cysts have a thick wall: sometimes the cysts have a thick wall: sometimes the wall appears as a transparentwall appears as a transparent outline with outline with intracystic bodies.intracystic bodies.

P.jiroveci:P.jiroveci: the sediment of the BAL can be stained the sediment of the BAL can be stained with stains forwith stains for the cysts wall such asthe cysts wall such as methenamine methenamine silver. silver. The cysts are well recognizable as round,oval or The cysts are well recognizable as round,oval or flat bodies of approx. 4-5 µm in diameter. flat bodies of approx. 4-5 µm in diameter. Gomori's methenamine silver stain (GMS).Gomori's methenamine silver stain (GMS).

P.jiroveci:P.jiroveci: fungi have the same affinity for silver fungi have the same affinity for silver methenamine andmethenamine and can be confused with can be confused with P.jiroveciP.jiroveci cysts. Cryptococcus neoformans in a cysts. Cryptococcus neoformans in a BAL specimen.(GMS stain).BAL specimen.(GMS stain).

P.jiroveci:P.jiroveci: toluidine blue O stains the cysts wall as toluidine blue O stains the cysts wall as silver methenamine. silver methenamine. Clusters of Clusters of P.jiroveci P.jiroveci are composed of cysts in are composed of cysts in different stage of developmentdifferent stage of development (empty, collapsed (empty, collapsed and mature cysts). Toluidine blue O stain.and mature cysts). Toluidine blue O stain.

P.jiroveci:P.jiroveci: sometimes with toluidine blue O some sometimes with toluidine blue O some clusters appear asclusters appear as honeycombed material honeycombed material containing few cysts. containing few cysts. Toluidine blue O stain.Toluidine blue O stain.

P.jiroveci:P.jiroveci: crowded and collapsed empty cysts 4 crowded and collapsed empty cysts 4 µm in diameter. µm in diameter. Cyst wall is blue. Bronchoalveolar lavage from a Cyst wall is blue. Bronchoalveolar lavage from a patient suffering from AIDS.patient suffering from AIDS. Gram-Weigert stain. Objective 100 X Gram-Weigert stain. Objective 100 X

P.jiroveci:P.jiroveci: indirect immunofluorescence  indirect immunofluorescence using monoclonal antibodies, FITC coupled, using monoclonal antibodies, FITC coupled, is a sensitive and specific technique of diagnosis.is a sensitive and specific technique of diagnosis.

P.jiroveci:P.jiroveci: with transmission electron microscopy with transmission electron microscopy (TEM) clusters of (TEM) clusters of P.jiroveciP.jiroveci appear composed of appear composed of cysts in different stages of development, ofcysts in different stages of development, of empty,empty, collapsed cysts and of trophozoites. collapsed cysts and of trophozoites. (TEM, 2.200 X). (TEM, 2.200 X).

P.jiroveci:P.jiroveci: with transmission electron microscopy with transmission electron microscopy cysts showcysts show a thick wall and the intracystic bodies a thick wall and the intracystic bodies a nucleus and mitochondria.(TEM, 11.500 X). a nucleus and mitochondria.(TEM, 11.500 X).

P.jiroveci:P.jiroveci: collapsed cyst within a cluster of collapsed cyst within a cluster of P.jiroveci.P.jiroveci. (TEM, 15.500 X). (TEM, 15.500 X).