Detection of Leishmania infantum in naturally infected Lutzomyia longipalpis (Diptera: Psychodidae: Phlebotominae) and Canis familiaris in Misiones, Argentina: the first report of a PCR-RFLP and sequencing-based confirmation assay

In this study, a genotypification of Leishmaniawas performed using polimerase chain reaction-restriction fragment length polymorfism (PCR-RFLP) and sequencing techniques to identify species of Leishmaniaparasites in phlebotomine sand flies and dogs naturally infected. Between January-February of 2009, CDC light traps were used to collect insect samples from 13 capture sites in the municipality of Posadas, which is located in the province of Misiones of Argentina. Sand flies identified as Lutzomyia longipalpiswere grouped into 28 separate pools for molecular biological analysis. Canine samples were taken from lymph node aspirates of two symptomatic stray animals that had been positively diagnosed with canine visceral leishmaniasis. One vector pool of 10 sand flies (1 out of the 28 pools tested) and both of the canine samples tested positively for Leishmania infantumby PCR and RFLP analysis. PCR products were confirmed by sequencing and showed a maximum identity with L. infantum. Given that infection was detected in one out of the 28 pools and that at least one infected insect was infected, it was possible to infer an infection rate at least of 0.47% for Lu. longipalpisamong the analyzed samples. These results contribute to incriminate Lu. longipalpis as the vector of L. infantumin the municipality of Posadas, where cases of the disease in humans and dogs have been reported since 2005.

Leishmania infection in humans, dogs and sandflies in a visceral leishmaniasis endemic area in Maranhão, Brazil

Leishmania infection in humans, dogs and sandflies was examined in the endemic visceral leishmaniasis (VL) municipality of Raposa, state of Maranhão, Brazil. In this study, we examined Leishmania chagasi infection in the blood serum of both humans and Canis familiaris and the natural Leishmania sp. infection rate in the sandfly vector, Lutzomyia longipalpis. Enzyme-linked immunosorbent assay, indirect immunofluorescence reaction and polymerase chain reaction were performed to detect Leishmania infections in humans, dogs and sandflies, respectively. Overall, 186 out of 986 studied human beings were infected with L. chagasi parasites, representing an infection prevalence of 18.9%. An even higher infection rate was detected in dogs, where 66 (47.8%) out of 138 were infected. Among all Lu. longipalpis captured (n = 1,881), only 26.7% were females. The Leishmania infection frequency for the vector Lu. longipalpis was 1.56%. Remarkably, all infected sandflies were found in the peridomiciliary area. Furthermore, a high incidence of asymptomatic forms of VL in the human and canine populations was observed. The results of this study suggest autochthonous transmission of L. chagasi in this endemic area for visceral leishmaniasis because infection by Leishmania sp. was identified in all important elements of the transmission chain.

Prevalência de parasitismo por Toxocara canis em cães e presença de ovos de Toxocara sp. no solo de localidades públicas da zona urbana do município de Londrina, Estado do Paraná, Brasil

De um total de 158 cães examinados, através de exame parasitológico de fezes ou necropsia, 70 (44,30%) mostraram-se infectados por Toxocara canis, predominando a infecção nos animais com até 6 meses de idade. Através do exame de amostras de terra de localidades públicas utilizadas por crianças para diversão, demonstrou-se a presença de ovos de Toxocara sp. em 60% das amostras, evidenciando a possibilidade de ocorrer infecção humana, ingestão de ovos larvados do helminto.

Evidências epidemiológicas da ocorrência de escabiose, em humanos, causada pelo Sarcoptes scabiei (DeGeer, 1778) var. canis (Bourguignon, 1853)

A partir de 27 cães com sarna sarcóptica, envolvendo 143 pessoas expostas à infestação, observaram-se 58 (40,56%) com lesões cutâneas sugestivas de escabiose. Tais lesões mostraram-se mais incidentes nas mulheres do que nos homens e indivíduos de todas as faixas etárias foram acometidos, indistintamente. Foi demonstrada a presença do agente em 3 dos 12 casos humanos observados que mantiveram contato com animais escabiosos.

Pesquisa de aglutininas anti Brucella canis em soros humanos na cidade de São Paulo, Brasil

De 330 soros humanos examinados pela prova de soroaglutinação lenta em tubos, 4(1,21%) apresentaram aglutininas anti Brucella canis em diluição 1:100 (1 reagente com título 100, 2 reagentes com título 200 e 1 reagente com título 400).

Brucella canis: inquéritos sorológico e bacteriológico em população felina

De 134 soros de felinos domésticos examinados pela prova de soroaglutinação lenta em tubos, 4 (3%) foram positivos para Brucella canis, todos com título igual a 100. Não se obteve êxito na tentativa de isolamento de Brucella canis através de hemocultura desses animais.

Studies in search of a suitable experimental insect model for xenodiagnosis of hosts with Chagas' disease: 3 - On the interaction of vector species and parasite strain in the reaction of bugs to infection by Trypanosoma cruzi

The reaction of nine vector species of Chagas' disease to infection by seven different Trypanosoma cruzi strains; Berenice, Y, FL, CL, S. Felipe, Colombiana and Gávea, are examined and compared. On the basis of the insects' ability to establish and maintain the infection, vector species could be divided into two distinct groups which differ in their reaction to an acute infection by T. cruzi. While the proportion of positive bugs was found to be low in Triatoma infestans and Triatoma dimidiata it was high, ranging from 96.9% to 100% in the group of wild (Rhodnius neglectus, Triatoma rubrovaria)and essentially sylvatic vectors in process of adaptation to human dwellings, maintained under control following successful insecticidal elimination of Triatoma infestans (Panstrongylus megistus, Triatoma sordida and Triatoma pseudomaculata). An intermediate position is held by Triatoma brasiliensis and Rhodnius prolixus. This latter has been found to interchange between domestic and sylvatic environments. The most important finding is the strikingly good reaction between each species of the sylvatic bugs and practically all T. cruzi strains herein studied, thus indicating that the factors responsible for the excellent reaction of P.megistus to infection by Y strain, as previously reported also come into operation in the reaction of the same vector species to acute infections by five of the remaining T.cruzi strains. Comparison or data reported by other investigators with those herein described form the basis of the discussion of Dipetalogaster maximus as regards its superiority as a xenodiagnostic agent.

Studies in search of a suitable experimental insect model for xenodiagnosis of hosts with Chagas' disease: 4 - The reflection of parasite stock in the responsiveness of different vector species to chronic infection with different Trypanosoma cruzi stocks

Previous studies (1982,1987) have emphasized the superiority of sylvatic vector species over domestic species as xenodiagnostic agents in testing hosts with acute or chronic infections by T. cruzi "Y" stock. The present study, which is unique in that it contains data on both infectivity rates produced by the same stock in 11 different vector species and also the reaction of the same vector species to seven different parasite stocks, establishes the general validity of linking efficiency of xenodiagnosis to the biotope of its agent. For example, infectivity rates produced by "São Felipe" stock varied from 82.5% to 98.3% in sylvatic vectors but decreased to 42.5% to 71.3% in domestic species. "Colombiana" stock produced in the same sylvatic vectors infectivity rates ranging from 12.5% to 45%. These shrank to 5%-22.5% in domestic bugs. The functional role of the biotope in the vector-parasite interaction has not been eluddated. But since this phenomenon has been observed to be stable and easy to reproduce, it leads us to believe that the results obtained are valid. Data presented also provide increasing evidence that the infectivity rates exhibited by bugs from xenodiagnosis in chronic hosts, are parasite stock specific. For example, infectivity rates produced by "Berenice", "Y", "FL" and "CL" varied in R. neglectus from 26.3% to 75%; in P. megistus from 56.3% to 83.8%; in T. sordida from 28.8% to 58.8% in T. pseudomaculata from 41.3% to 66.3% and in T. rubrovaria from 48.8% to 85%. Data from xenodiagnosis in the same hosts, carrying acute infections by the same parasite stocks, gave the five sylvatic vectors a positive rating of approximately 100%, thus suggesting that the heavy loads of parasites circulating in the acute hosts obscured the characteristic interspecific differences for the parasite stock. Nonetheless these latter were revealed in the same hosts with chronic infections stimulated by very low numbers of the same parasite stocks. Certain observations here described lead us to speculate as to the possibility of further results from other parasite stocks, allowing the association of the infectivity rates produced in bugs by different parasite stocks with the isoenzymic patterns revealed by these stocks.

A case-control study on the association of hepatitis B virus infection and hepatocellular carcinoma in Northeast Brazil

Hepatitis B virus (HBV) serological markers were investigated in 40 incident cases of hepatocellular carcinoma (HCC) and in two age and sex matched control groups, comprising 40 patients with other cancers and 80 healthy individuals, resident in Bahia, Brazil. Serologic tests were done by radioimmunoassay. The study observed high proportion of seropositivity to HBsAg (42.5%) and of those presenting HBsAg or antiHBc (65.0%) among HCC cases, higher in men than women and in those aged 17 to 30 years old. HBsAg seropositivity among HCC patients was greater than in the control group with other cancers (7.5%) and in healthy controls (2.5%), corresponding to odds ratio estimates of 15.0 (95% CI 3.29, 68.30) and 33.0 (95% CI 9.13, 119.28), both statistically significant. HBeAg was not observed and antiHBe was present in 41.2% of cases, suggesting the absence of viral replication, possibly with viral DNA intergration into the hepatocyte genome. The presence of cirrhosis was associated with HBsAg seropositivity among HCC cases. A history of chronic alcoholism is shown to be more frequently related to those cases with cirrhosis. This study highlights the relevant association between HCC and HBV in Northeast Brazil, particularly for young individuals, and the high risk of development of HCC for HBsAg carriers.

Surtos interespecíficos de dermatomicoses por Microsporum canis e Microsporum gypseum

As dermatomicoses dos animais domésticos constituem zoonoses importantes, urna vez que estes mantêm estreito contato com a espécie humana, dada a alta infectividade observada nesses processos. Relata-se a ocorrência de sete surtos de dermatomicoses, um por M. gypseum envolvendo um gato e um indivíduo do sexo feminino e os outros por M. canis envolvendo 20 indivíduos da espécie humana (adultos, jovens e crianças de ambos os sexos), 5 cães, 16 gatos e um macaco gibão (Hylobates lar).

Human case of gastric infection by a fourth larval stage of Pseudoterranova decipiens (Nematoda, Anisakidae)

Only three cases of human infection by anisakid nematodes have been reported in Chile since 1976. In the present case, an anisakid worm, identified as a fourth-stage Pseudoterranova decipiens larva, was removed with a gastroendoscopic biopsy clipper from the stomach of a 45 year-old man from southern Chile. The patient, who presented acute epigastric pain and a continuous sensation of having an empty stomach, reported having eaten smoked fish. The worm was fixed in 70% ethanol and cleaned in lactophenol for morphological study. The morphometric characteristics of the worm are described and drawn. Anisakid larvae in fish flesh can be killed by freezing or cooking.

HIV/tuberculosis co-infection: a request for a better surveillance

The increasing endemicity of tuberculosis resulting from causes such as immigration, poverty, a declining public health infrastructure and co-infection by HIV/Mycobacterium tuberculosis, is leading to a change in tuberculosis control programmes. One of the main reasons for the resurgence of tuberculosis is HIV infection - the risk of tuberculosis is greater in HIV patients than in the majority of the population as can be seen from numerous research projects. The need for systematic testing for HIV infection in all tuberculosis patients by undertaking confidential HIV tests on admission to a tuberculosis programme is brought out. This measure would increase the number of cases diagnosed and provide data for better surveillance of the co-infection.

Susceptibility of asthmatic children to respiratory infection

OBJECTIVE: A case-control study of patients with pneumonia was conducted to investigate whether wheezing diseases could be a risk factor. METHODS: A random sample was taken from a general university hospital in S. Paulo City between March and August 1994 comprising 51 cases of pneumonia paired by age and sex to 51 non-respiratory controls and 51 healthy controls. Data collection was carried out by two senior paediatricians. Diagnoses of pneumonia and presence of wheezing disease were independently established by each paediatrician for both cases and controls. Pneumonia was radiologically confirmed and repeatability of information on wheezing diseases was measured. Logistic regression analysis was used to identify risk factors. RESULTS: Wheezing diseases, interpreted as proxies of asthma, were found to be an important risk factor for pneumonia with an odds ratio of 7.07 (95%CI= 2.34-21.36), when the effects of bedroom crowding (odds ratio = 1.49 per person, 95%CI= 0.95-2.32) and of low family income (odds ratio = 5.59 against high family income, 95%CI= 1.38-22.63) were controlled. The risk of pneumonia attributable to wheezing diseases is tentatively calculated at 51.42%. CONCLUSION: It is concluded that at practice level asthmatics should deserve proper surveillance for infection and that at public health level pneumonia incidence could be reduced if current World Health Organisation's guidelines were reviewed as to include comprehensive care for this illness.

Prevalence of Helicobacter pylori infection in Fortaleza, Northeastern Brazil

The prevalence of Helicobacter pylori infection was assessed in a randomly selected sample of individuals from low-income community in Fortaleza, Northeastern Brazil. Overall, 384 out of 610 participants (62.9%) were H. pylori positive. A 47.5% infection rate was found in subjects aged six months to 10 years old, increased to 73.3% in subjects aged 11-20 years and then continued to increase with age reaching up to 87% in those over 60 years old. After this age group, the prevalence decreased slightly. The prevalence of infection increased significantly with age (p<0.0001).

HIV infection and AIDS in a small municipality in Southeast Brazil

OBJECTIVE: Studies on the aspects of HIV infection in small Brazilian municipalities are invaluable to appropriately design control strategies, better allocate resources, and improve health care services. The objective of the study was to assess the clinical and epidemiological aspects of HIV infection in a small municipality. METHODS: A descriptive study was carried out in Miracema, a small municipality in the northwestern area of the state of Rio de Janeiro, Brazil, between July 1999 and December 2003. All HIV-infected adult patients followed up at the local HIV/AIDS Program were included. Clinical and epidemiologic characteristics were prospectively assessed through standardized questionnaires. RESULTS: A total of 65 adult patients who attended the local HIV/AIDS Program were analyzed. Most (34) were women (male to female ratio: 0.9). An absolute predominance of patients who were born in Miracema or neighboring municipalities (94%), lived in Miracema (90.7%), were single (70.8%), attributed the acquisition of HIV infection to unprotected heterosexual intercourse (72.3%) and had a past history of snorting cocaine (27.7) was found Central nervous system disorders (including five cases of cryptococcal meningitis) and acute pulmonary pneumocystosis-like respiratory failure were major causes of morbidity. Most patients (56.9%) were at presented in advanced stages of HIV infection. CONCLUSIONS: The predominance of patients on advanced stages of HIV infection suggest the existence of a large pool of undiagnosed cases in the community. A major feature of the cohort was an inverted male to female ratio. Further investigations over a broader geographic area are urgently needed for better understanding the clinical and epidemiological characteristics of HIV infection in small Brazilian municipalities and rural areas.