The capybara (Hydrochoerus hydrochaeris) as a reservoir host for Trypanosoma evansi

Discovery of two ill horses and three dogs naturally infected with Trypanosoma evansi near an experimental station in the Eastern Plains of Colombia led to a search for reservoir hosts of the parasite. Infection was detected in 8/33 healthy capybaras (Hydrochoerus hydrochaeris), none of the remaining 14 horses, and none of 32 Zebu cattle (Bos indicus), 18 paca (Cuniculus paca) and 20 spiny rats (Proechimys sp.). Contrary to common opinion, the results indicated a carrier state in the capybara. Diagnosis was based on morphology, behaviour in albino rats, and pathogenicity and host range in domestic animals.

[Prevalence of intestinal helminthiasis in 100 municipalities in Venezuela (1989-1992)]

A total of 113,254 individuals from 100 venezuelan municipalities were studied by mean of Kato-Katz coprological examination and the geohelminth prevalences were established. The national prevalences of T. trichiura, A. lumbricoides and Anquilostomideos were 32.6%, 26.9% and 5.6% respectively+. For T. trichiura the highest values were obtained for the following municipalities: Arévalo González (54.6%) in Miranda state, Urama (76.9%) in Carabobo state and Punta de Piedra (78.4%) in Sucre state. For A. lumbricoides the highest values were determined in Punta de Piedra (63%), Tunapuy (61.9%) in Sucre state and Arévalo González (62.7%) in Miranda state. For hookworm the highest values were detected in El Amparo (39.5%) and San Camilo (35.9%) in the state of Apure. In relation to the age, the highest prevalence of Ascariosis and Trichuriosis were determined in pre-school and school children and for hookworm in adolescents and adults. A high variability between the municipalities belonging to the same state for the three geohelminths was observed.

Two cyclohexanespiro-5'-hydantoin monohydrates

Cyclohexanespiro-5'-hydantoin monohydrate, C8H12N2O2.H2O, has a chair-shaped cyclohexane ring with endocyclic torsion-angle magnitudes in the range 54.4 (2)-56.3 (2) degrees. All potential hydrogen-bond donors are involved in intermolecular hydrogen bonding, with lengths in the range 2.760 (2)-2.908 (2) A. In its indolyl adduct, 2-(3-indolyl)cyclohexanespiro-5'-hydantoin monohydrate, C16H17N3O2.H2O, the cyclohexane moiety adopts a chair conformation with the indolyl substituent in an equatorial position. The N-H portion of the hydantoin ring is cis to indolyl, while the C=O of the hydantoin is trans. Endocyclic torsion-angle magnitudes of the cyclohexane ring are in the range 54.2 (2)-56.7 (2) degrees. All potential hydrogen-bond donors are involved in intermolecular hydrogen bonds, with lengths 2.828 (2)-3.187 (2) A.

[New interpretation of the quantitative fecal examination in humans]

The pattern of spatial disposition of eggs of the parasites (Ascaris lumbricoides, Trichuris trichiura and Ancylostomidae) into the faeces was found overdispersed, independently of the technique of coprodiagnosis used (Direct smear without standarisation, Stoll, Shore & Lynch, Kato-Katz and Mc Master). Therefore, differences were not detected in the interpretation of the results among the techniques at the population level, in quantitative studies. In an overdispersed pattern, only few hosts are the major responsibles for the environmental contamination. The importance of this spatial arrangement for parasite control purposes, is discussed.

[Ecoepidemiology of Ascaris lumbricoides in an endemic area and its relation with blood groups]

185 children 1 to 14 years old living in the suburb of San Rafael (Zulia State, Venezuela) were selected for this study with the following results: Eggs of Ascaris lumbricoides in the stool samples before administration of a drug to the children and the worms recovered after drug, induced expulsion, showed a high aggregation (K = 0.115 and K = 0.122, respectively); the aggregation of the recovered worms was more intense in girls (K = 0.083), than in boys (K = 0.220); among the blood groups, A. lumbricoides resulted highly prevalent (100%) and less overdispersed in group "AB" (K = 1.26; n = 5), while in the other blood groups the spatial aggregation pattern was strongly overdispersed (A = 0.159; B = 0.133 and O = 0.210); individuals of the blood group "B", make the greatest contribution to environmental contamination, because they presented the greatest values for the abundance and a more intense overdispersion.

Regional nerve block for femoropopliteal and tibial arterial reconstructions

Thirteen high-risk patients underwent lower extremity revascularization anesthetized with a regional nerve block technique. The sciatic, femoral, and obturator nerves were infiltrated with 1% lidocaine and 0.25% bupivacaine. Eight femoropopliteal and five femorotibial bypasses were performed for limb salvage (11 patients), disabling claudication (one patient), and popliteal artery aneurysm (one patient). Analgesia was adequate with only one patient who needed supplemental nitrous oxide. One patient died on the sixth postoperative day of a myocardial infarction. Regional nerve block is an effective anesthetic technique that should be considered if general or spinal anesthesia is inappropriate.

Echinococcus infections in Colombian animals

The results of a survey involving more than 4,000 Colombian mammals, carried out to detect Echinococcus infections, are presented. Adult worms were found in 5 of 121 carnivores: E. oligarthrus in 1 of 11 ocelots, 2 of 9 jaguarundi cats and single puma; and E. vogeli in 1 of 15 domestic dogs. Although bush dogs were present, none could be examined. Polycystic larvae were found in 96 of 325 pacas (29.5%) and in 6 of 1,168 (0.5%) spiny rats, Proechimys spp. None of the 118 agouti showed hydatids but an infected heart was provided by hunters. The paca's infection rate increased with age but was not related to sex or geographic region. In 73 of 96 pacas the infection was due to E. vogeli, and the cysts were located in the liver. In 3 it was due to E. oligarthrus and the hydatids were extrahepatic, mainly attached to muscles. In the remaining 20, the species involved could not be determined. The parasites in two of the spiny rats, and in the agouti heart were E. oligarthrus. Although most of the infected animals were collected in the eastern plains, other records and verbal information indicate that, at least in Colombia where man has not exterminated pacas, agoutis, wild canids and felids, one still can find enzootic neotropical Echinococcus infection. The cycle of E. vogeli involves the bush dog and paca as hosts, and that of E. oligarthrus, the paca, agouti, spiny rat, and several species of wild felids.

Mammalian wildlife diseases as hazards to man and livestock in an area of the Llanos Orientales of Colombia

Development of the LLanos Orientales of Colombia, and access to underdeveloped areas in the Llanos, may create disease hazards to man and domestic animals or introduce exotic pathogens, creating reservoirs of infection for domestic animals and acting as limiting factors on the native wild species. A survey of wild animals common to the Llanos revealed a number of parasites indigenous to the area. A total total of 59 mammalian species, representing eight orders were examined. Haematozoa were represented by Trypanosoma cruzi, T. evansi and T. rangeli. Eight species of ticks were found: Amblyomma cajennense, A. auricularium, A. rotundatum, A. maculatum, A. longirostre, A. pacae, Ixodes luciae and Boophilus microplus. Four species of fleas were found: Rhopalopsyllus lugubris lugubris, R. australis tupinus, R. cacicus saevus and Polygenis klagesi samuelis. A species of Echinococcus was commonly found in Cuniculus paca. Serologic titers and/or isolations of pathogenic viral and bacterial agents generally indicated that the wildlife population had not been exposed to the diseases common to the domestic population. A low prevalence of titers to Venezuelan equine encephalomyelitis was found in Cebus apella and Proechimys sp. Neutralizing antibodies to Group B viruses were found in Proechimys sp., Coendor sp. and Nectomys squamipes. Antibodies to Group C viruses were found in Proechimys sp. Serologic titers to Leptospira sejroe and L. tarassovi were found in Proechimys sp. and Didelphis marsupialis. L. tarassovi was isolated from Proechimys sp. Titers to Brucella were not found in 1964 animals. The significance of these findings are discussed.

Polycystic echinococcosis in Colombia: the larval cestodes in infected rodents

Described are the characteristics of the polycystic larval cestodes found in an endemic area of echinococcosis in the Easter Plains of Colombia and the tissue reaction evoked in infected rodents. Of 848 free-ranging animals examined, polycystic hydatids were found in 44/93 Cuniculus paca and 1/369 Proechimys sp. None of 20 Dasyprocta fuliginosa examined was infected, but hunters provided a heart with hydatid cysts and information about two additional animals with infected livers. Recognition of an endemic area of polycystic echinococcosis provides a means to investigate the life cycle of the parasites and to study the histogenesis of the larval cestodes in susceptible laboratory animals.

Leptospirosis in Colombia: isolation of Leptospira spp. from the kidneys of brown rats (Rattus norvegicus) trapped on infected piggeries

Leptospira interrogans serotypes pomona and icterohaemorrhagiae were isolated from the kidneys of Rattus norvegicus trapped on pomona infected piggeries. The isolation of pomona from one of 111 cultured kidneys, although of interest, strongly suggests that this rat does not play an important part in the epidemiology of infection by this serotype. Kidney tubular degeneration, focal mononuclear infiltrations and fibroplasia are morphological traces which remain after an attack of leptospirosis. The high percentage (48.6) of these lesions found in the rat kidneys examined does not seem to be related to serotype pomona but to icterohaemorrhagiae. The importance of this last serotype in swine in the Cauca Valley has yet to be assessed.

Vascular damage caused by Cruorifilaria tuberocauda in the capybara (Hydrochoerus hydrochaeris)

Infection with Cruorifilaria tuberocauda caused vascular damage in the kidneys, lungs and heart of the capybara (Hydrochoerus hydrochaeris). The most significant lesions observed were in the renal and pulmonary arteries. They consisted of villous endarteritis, intimal and medial hypertrophy of the vessel walls, and large rugose protuberances that encroached upon the lumen leading to pyramidal infarcts in the kidneys. Coronary vascular lesions were related to dead and calcified parasites.

Cruorifilaria tuberocauda gen. et sp. n. (Nematoda: Filarioidea) from the capybara, Hydrochoerus hydrochaeris in colombia

Cruorifilaria tuberocauda gen. et sp. n. is described from blood vessels of the kidney, heart, and lungs of the capybara, Hyrochoerus hydrochaeris, in Colombia, S.A. The adult worms are robust, of moderate size (females approximately 42 mm long, males about 27 mm long), and tapered at both ends. The males have unequal, dissimilar spicules, lack a gubernaculum and possess both pre- and postanal papillae. The unsheathed microfilaria is found in the peripheral blood. Even though a severe tissue response is seen in the walls of the blood vessels occupied by the adult worms, it appears to be a common parasite in the population of capybaras surveyed.

The Proechimys rat; a potential laboratory host and model for the study of Trypanosoma evansi

A group of Proechimys rats (family Echimyidae, subfamily Echimyinae( was experimentally infected with Trypanosoma evansi. The long-term chronic infection induced, and the nature of the tissue lesions encountered, point towards their possible use as laboratory models for the study of T. evansi infections. Comparisons were made with albino rats in which the flagellate produced a short-term infection following inoculation.