Fungal and Parasitic Infections of the Liver.

Hepatosplenic candidiasis and other fungal infections of the liver are uncommon in healthy individuals; however, high index of suspicion is essential in immunocompromised patients with prolonged fever. Parasitic infections are protozoan or helminthic; their distribution and epidemiology are variable among different world regions. Clonorchiasis, opisthorchiasis, fascioliasis, and ascariasis are helminthic infections that commonly involve the biliary systems. Signs and symptoms of cholangitis require prompt management to relieve biliary obstruction; addition of antihelminthic agents is essential. Parasitic infections are mostly transmitted to humans by fecally contaminated food and water. Proper hand and food sanitation measures are essential in preventing disease transmission.

An overview of the host spectrum and distribution of Calodium hepaticum (syn. Capillaria hepatica): part 2-Mammalia (excluding Muroidea).

Calodium hepaticum (syn. Capillaria hepatica) is a globally distributed zoonotic nematode with low host specificity and a high affinity to the liver. Although murid rodents are the main definite hosts, various other mammals can be affected with hepatic capillariasis: non-murid rodents, Insectivora, Chiroptera, Lagomorpha, Artiodactyla, Perissodactyla, Hyracoidea, Marsupialia, Carnivora, and Primates. Overall, more than 180 mammalian species (including humans) are known as suitable hosts of this pathogen. This review gives an overview of the distribution and host spectrum of C. hepaticum in non-Muroidean mammals in wildlife and zoos as well as in domesticated and laboratory animals. Furthermore, the role of spurious infections in animals and the dissemination of C. hepaticum by mammalian and non-mammalian animals are summarized.

Trematode infections: liver and lung flukes.

Food-borne trematodiases are an emerging public health problem in Southeast Asia and Latin America and of growing importance for travel clinics in Europe and North America. The disease is caused by chronic infections with liver, lung, and intestinal flukes. This article focuses on the most important liver and lung flukes that parasitize man, namely Clonorchis sinensis, Fasciola gigantica, Fasciola hepatica, Opisthorchis felineus, Opisthorchis viverrini, and Paragonimus spp. The article describes the epidemiology of major liver and lung fluke infections, including current distribution, burden, life cycle, clinical signs and symptoms, diagnostic approaches, and current tools for prevention, treatment, and control.

Effect of aestivation of Biomphalaria pfeifferi on the survival and infectivity of Schistosoma mansoni cercariae.

Schistosoma mansoni cercariae from post-aestivated Biomphalaria pfeifferi remain motile for 20 hours after release. Thereafter, their activity decreases with age. The difference in mortality rate of cercariae from aestivated and non-aestivated B. pfeifferi studied here proved to be statistically significant (P < 0.05) within the first 10 hours of the experimental period. Results of the percentage recovery of worms from different mouse organs infected with cercariae from aestivated and non-aestivated snails varied. The two main organs infected were the liver and intestine. In conclusion, the penetration, migration and maturation of cercariae into adult worms were not affected by the aestivation of B. pfeifferi.

[Porocephalosis, a little known parasitosis, literature review and a Congolese case report]. / La porocéphalose, parasitose méconnue, revue de la littérature à propos d'un cas congolais.

The authors describe another case of symptomatic porocephalosis in a 59-year-old man from the Congo and review recent epidemiologic, clinical, and laboratory data from the literature concerning pentastomiasis in man. There are a variety of modes of transmission to man, parasitic dead end, and sites of infection. A perusal of symptomatic cases reported since 1970 confirms that complications are mainly associated with uncalcified nymphal forms. This poses a diagnostic problem since clinical and laboratory findings associated with young forms in non-specific. When feasible, surgical resection of infested tissue allows diagnosis and treatment. Many questions remain unanswered concerning the incidence of pentastomiasis in endemic areas, its physiopathology, and its relationship with cirrhosis and liver cancer in the tropics. New diagnostic techniques (serologic tests, ultrasonography, CT-scan) may help to resolve these issues.

Infecçäo natural de roedores silvestres pelo Schistosoma mansoni / Natural infection of sylvatic rodents by Schistosoma mansoni

No município baiano de Planalto, 47% dos roedores silvestres capturados (Nectomys) estavam infectados pelo Schistosoma mansoni, enquanto a prevalência desta infecçäo na populaçäo humana da área era de 3,26%. Os roedores habitam zonas peridomiciliares, têm hábitos aquáticos e eliminam ovos viáveis do S. mansoni. Albergam número variável de vermes e formam granulomas periovulares pequenos, principalmente no fígado e intestinos, sem fibrose hepática importante ou sinais de hipertensäo porta. A deposiçäo maior de ovos se faz a nível do intestino, sobretudo do jejuno, com passagem de grande número de ovos para as fezes. Miracídios isolados a partir dos ovos retirados dos roedores infectaram normalmente a Biomphalaria glabrata, com eliminaçäo de cercárias, com as quais se provocou infecçäo no camundongo branco, em tudo semelhante aquelas causadas por outras cepas de origem humana. Também camundongos que foram deixados em contacto com as águas infestadas pelos roedores silvestres se infectaram facilmente, atestando o alto grau de transmissibilidade da área. Conclui-se que os roedores silvestres de planalto toleram bem a infecçäo esquistossomótica natural, säo bons eliminadores de ovos viáveis do S. mansoni, estäo infectados por uma cepa semelhante a que infecta o homem e podem ter um papel na manutençäo do ciclo vital do S. mansoni na área estudada

[Natural infection of wild rodents by Schistosoma mansoni]. / Infecção natural de roedores silvestres pelo Schistosoma mansoni.

UNLABELLED: In Planalto, a small locality in the interior of the Bahia state, Brazil, 47% of sylvatic rodents were found to be naturally infected with Schistosoma mansoni, whereas the prevalence of the infection in the inhabitants of the area was 3.26%. The rodents (Nectomys) live near the houses, in contact with water, passing viable schistosome eggs in the stools. Worm burden is variable amongst such rodents. Periovular granulomas are small, especially in liver and intestines, and hepatic fibrosis is mild or absent, with no morphological evidence of portal hypertension being noted. Miracidia isolated from the eggs recovered from Nectomys readly infected laboratory-raised Bahia strain of Biomphalaria glabrata. Cercariae then obtained infected Swiss mice in a similar way as the human strains of S. mansoni kept in laboratory. Also, Swiss mice left in contact with water collections in Planalto were easily infected, which proved the transmissibility potential of the area. IN CONCLUSION: sylvatic rodents found in the area of Planalto tolerate well S. mansoni infection, eliminate viable eggs in the stools, are usually infected with a strain probably of human origin and therefore may play a role in maintaining parasite cycle in the area.

Coeficiente de endocruzamento em portadores de esquistossomose mansônica / Imbreeding coefficient in carries of Schistosoma mansoni

O coeficiente de endocruzamento (f ou de Wright) foi calculado em 1123 indivíduos de Catolândia, Bahia, área hiperendêmica da esquistossomose mansônica: 148 (13,2%) tinham o coeficiente f > 0. A forma hepatosplênica foi significantemente maior nos indivíduos com f > 0 (26,8%). Nos brancos com f > 0 o risco relativo foi de 14,1; enquanto, nos brancos com f = 0, a freqüência da hepatosplenomegalia näo diferiu dos näo-brancos com f = ou f > 0. Com este coeficiente estimou-se a probabilidade de genes aléticos iguais, com origem em ancestral comum; os resultados reforçam a hipótese da regulaçäo genética na susceptibilidade à forma hepatosplênica da esquistossomose mansônica

[Inbreeding coefficient in carriers of Schistosoma mansoni]. / Coeficiente de endocruzamento em portadores de esquistossomose mansônica.

The coefficient of inbreeding (for Wright) was studied in Catolândia, in the state of Bahia, Brazil, an area considered hyperendemic for manson schistosomiasis in a population of 1,130 inhabitants. The coefficient of inbreeding was estimated for 1,123 individuals it was classified as f greater than 0 in 13.2% (n = 148). In the hepatosplenic group the frequency of f greater than 0 was 26.8%, and in the hepatointestinal group the frequency was 12.5%. The frequency of the hepatosplenic diagnosis in whites who were f = 0 did not differ from that which was observed in the negroid group. These verifications were confirmed by the Woolf's test; the relative risk of the whites, f greater than 0 in acquiring hepatosplenic schistosomiasis was 14.1. These observations reinforce the influence of the genetic component in the development of the hepatosplenic form of the mansons schistosomiasis.

Dicroceliasis (lancet fluke disease) in an HIV seropositive man.

Dicroceliasis is an unusual zoonotic trematode infection caused by the lancet liver fluke, Dicrocoelium dendriticum. Grazing herbivores (usually sheep or cattle) are the definitive hosts. The life cycle proceeds through two intermediate hosts: the land snail and the field ant. Human infection is acquired by consuming the field ant. This case report describes a human immunodeficiency virus-seropositive patient who presumably acquired this parasite from bottled water contaminated with ants. A brief discussion of the parasitology, pathology, clinical findings and treatment is presented.

An inquiry into the causes of liver damage in lambs.

The lamb slaughter records of a large private abattoir showed that a small minority of farms had a lamb liver rejection rate exceeding 40 per cent. Small sheep farms were most likely to have high rejection rates and farms producing both lambs and pigs had relatively high lamb liver rejection rates. In a farm survey statistical analysis showed that the spreading of pig slurry, access to the grazing land by hunts and the infrequent use of dog cestocides were factors significantly linked to high lamb liver rejection rates. A survey of 4000 lambs' livers confirmed the importance of Cysticercus tenuicollis as a cause of rejection. Fifty-two per cent of the livers had lesions which could not be identified but showed histological similarities to ascarid lesions.

Opisthorchis viverrini: life cycle, intermediate hosts, transmission to man and geographical distribution in Thailand.

Opisthorchis viverrini has been found to be the only species of liver fluke in Thailand. The morphology is similar to that of O. felineus, but it has more deeply lobated testes, situated near the ovary. The appearance and distribution of the vitellaria with few granular clumps and the shorter and wider egg closely resemble that of C. sinensis. The adult worms live in the biliary system. Eggs pass out in faeces. On reaching water the eggs are eaten by snails, the first intermediate host. In the snail the miracidia hatch and develop further through the stages of sporocysts, rediae and cercariae in six to eight weeks. The cercariae then leave the snail, penetrate into susceptible fresh water fish, encyst in the muscle and develop into metacercariae, and infective stage, in six weeks. When ingested by man or animal the metacercariae excyst in the duodenum or jejunum and then migrate to the bile duct. They become mature within four weeks and begin to produce eggs. The life span of the fluke is over 10 years. The snail intermediate hosts are Bithynia goniomphalus, B. funiculata and B. siamensis. Many species of cyprinoid fish serve as second intermediate host; Cyclocheilichthys siaja is the most important. Cats, dogs and many fish eating mammals are definitive hosts. Man and animals acquire infection by eating raw fish containing metacercariae cysts. In Northeast Thailand "Koi-Pla" is the most popular raw fish dish. In 1980-1981 the prevalence in the north, northeast, centre and south of Thailand was 5.59, 34.60, 6.34, and 0.01%, respectively, with an overall prevalence of 14% or 7 million people.

Demonstration of hypnozoites in sporozoite-transmitted Plasmodium vivax infection.

Hypnozoites of two strains of the human relapsing malaria parasite, Plasmodium vivax, have been detected among maturing 7- and 10-day pre-erythrocytic schizonts in liver biopsies of chimpanzees infected by intravenous inoculation of sporozoites obtained from dissected salivary glands of heavily infected anopheline mosquitoes. As in the simian relapsing species, P. cynomolgi, the hypnozoites of P. vivax at 7 and 10 days are uninucleate forms of approximately 4-5 micrometers diameter, lying within the cytoplasm of individual hepatocytes. Their presence in this relapsing human species is added support for the hypnozoite theory of malarial relapse.