Pasteurization of human milk to prevent transmission of Chagas disease

Although admittedly transmission of Trypanosoma cruzi infection through breastfeeding is a rare event, it involves serious risks. To test the effectiveness of pasteurization in preventing this mode of infection, three sets of samples of human milk were tested: a - contaminated with T. cruzi and pasteurized; b - contaminated with T. cruzi and non-pasteurized; c - non-contaminated and pasteurized. Samples from all sets were orally and intraperitoneally administered to 90 BALB/c mice. The animals inoculated with contaminated, non-pasteurized samples, got the infection. Controls and the animals inoculated with contaminated and pasteurized milk were not infected. The hypothesis was accepted that pasteurization inactivates T. cruzi trypomastigotes.

Oral transmission of Chagas disease: importance of Trypanosoma cruzi biodeme in the intragastric experimental infection

Oral transmission of Trypanosoma cruzi has been suspected when epidemic episodes of acute infection were observed in areas devoid of domiciled insect vectors. Considering that the distribution of T. cruzi biodemes differs in sylvatic and domestic cycles, results of studies on biodemes can be of interest regarding oral transmission. The infectivity of T. cruzi strains of different biodemes was tested in mice subjected to infection by the digestive route (gavage). Swiss mice were infected either with the Peruvian strain (Biodeme Type I, Z2b) or the Colombian strain (Biodeme Type III, Z1, or T. cruzi I); for control, intraperitoneal inoculation was performed in a group of mice. The Colombian strain revealed a similar high infectivity and pathogenicity when either route of infection was used. However, the Peruvian strain showed contrasting levels of infectivity and pathogenicity, being high by intraperitoneal inoculation and low when the gastric route was used. The higher infectivity of the Colombian strain (Biodeme Type III) by gastric inoculation is in keeping with its role in the epidemic episodes of acute Chagas disease registered in the literature, since strains belonging to Biodeme III are most often found in sylvatic hosts.

Microwave treatment of human milk to prevent transmission of Chagas disease

It is recognized that breast feeding is an alternative means of transmission of Chagas disease. However, thermal treatment of milk can prevent this occurrence. As domestic microwave ovens are becoming commonplace, the efficacy of microwave thermal treatment in inactivating Trypanosoma cruzi trypomastigotes in human milk was tested. Human milk samples infected with T. cruzi trypomastigotes (Y strain) from laboratory-infected mice, were heated to 63 °C in a domestic microwave oven (2 450 MHz, 700 W). Microscopical and serological examinations demonstrated that none of the animals inoculated orally or intraperitoneally with infected milk which had been treated, got the infection, while those inoculated with untreated, infected milk, became infected. It was concluded that the simple treatment prescribed, which can easily be done at home, was effective in inactivating T. cruzi trypomastigotes contained in human milk.

Epidemiological investigation of an acute case of Chagas disease in an area of active transmission in Peruvian Amazon region

The study objective was to investigate an acute case of Chagas disease in the San Pedro de Shishita community, Pebas District, in the Peruvian Amazon basin, a non-endemic area. Both parents of the index case (acute case) were thoroughly interviewed, a seroepidemiological survey was carried out in the community, parasitological exams were carried out only in relatives of the index case, and triatomine bugs were searched for inside houses, peridomiciliary, and in wild environments. Seroprevalence for IgG anti-T. cruzi antibodies was 1/104 (0.96%), using an ELISA test and an indirect immunofluorescence assay. Panstrongylus geniculatus and Rhodnius pictipes adults were found. The index case is autochthonous from San Pedro de Shishita, but the source of transmission is unknown.

FIRST REPORT OF ACUTE CHAGAS DISEASE BY VECTOR TRANSMISSION IN RIO DE JANEIRO STATE, BRAZIL

SUMMARY Chagas disease (CD) is an endemic anthropozoonosis from Latin America of which the main means of transmission is the contact of skin lesions or mucosa with the feces of triatomine bugs infected by Trypanosoma cruzi. In this article, we describe the first acute CD case acquired by vector transmission in the Rio de Janeiro State and confirmed by parasitological, serological and PCR tests. The patient presented acute cardiomyopathy and pericardial effusion without cardiac tamponade. Together with fever and malaise, a 3 cm wide erythematous, non-pruritic, papule compatible with a "chagoma" was found on his left wrist. This case report draws attention to the possible transmission of CD by non-domiciled native vectors in non-endemic areas. Therefore, acute CD should be included in the diagnostic workout of febrile diseases and acute myopericarditis in Rio de Janeiro.

The control of Chagas' disease transmission in Mambaí, Goiás-Brazil (1980-1981)

BHC application in Mambai in 1980 resulted in a significant decline but not elimination of domiciliated T. infestans. T. sordida peridomestic populations persist and could pose a threat to interupting human transmission of T. cruzi The results of one massive attack spray application alone was compared with this application plus one selective application as regards the presence of T. infestans in houses oneyear later. No significance difference could be detected. It is likely that for interruption of T. infestans transmission cheaper procedures can be devised than those currently in use. A further pilot study of a virgin community afflicted by T. infestans transmission is indicated since Mambai cannot be regarded as a representative areafor those still awaiting insecticide application.

Human mucocutaneous leishmaniasis in Três Braços, Bahia - Brazil: an area of Leishmania braziliensis braziliensis transmission. II. Cutaneous disease. Presentation and evolution

The clinical records of 182 patients with cutaneous leishmaniasis probably due to Leishmania braziliensis braziliensis are analysed. 68% had a single lesion which was usually an ulceron the lower anterior tibial third. Many had short histories of one to two months and all age groups were represented 13% had closed lesions of a verrucose or plaque like nature. Evolution of these skin lesions after treatment was related to the regularity of antimony therapy. Although healing usually occurred in three months, the time to scarring after commencing treatment was variable and related to the size ofthe lesion (p < 0.01). Usually if sufficient antimony treatment was given the lesion closed. Seven of the ten patients with initially negative leishmanin skin tests converted to positive after treatment. A significant decline of indirect fluorescent antibody titres occurred in patients followed, during and after therapy.

Usefulness of serology for the evaluation of Trypanosoma cruzi transmission in endemic areas of Chagas' disease

Thirteen communities from 7 Argentinian provinces were selected for the evaluation of serology as an indicator of transmission of Chagas disease. Of the communities appraised, 6 did not have a history of previous treatment with insecticides and 7 had received sporadic or continuous insecticide treatment. The inhabitants of 20% of the houses of each locality were studied by serology. The samples were obtained byfinger pricking and 50 fil of blood were mixed with 150μl of 50% glycerine solution in tissue culture media to be assayed by Indirect Hemagglutination and Indirect Immunofluorescence tests. In untreated areas, the prevalence of infection in infants 0-4 years old was 17.5%, reaching to over 22% for the 5-9 year old group, and to 33.3% in 10-14 year old individuals. The prevalence in treated and surveyed areas was 2.6% in 0-4 year old children, 5.4% in 5-9 year old and 6,2% in 10-14 year old youngsters. The differences between both areas were statistically significant (p < 0.005). This study favors serology as a valid indicator for the evaluation of transmission of Chagas disease in rural areas.

Chagas' disease: study of congenital transmission in cases of acute maternal infection

We studied three pregnant women with acute chagasic infection. Two patients, infected in the third trimester of pregnancy, had uninfected children. The third patient, infected earlier, had an infected newborn. These results encourage research on risk factors of transmission and on medical decisions concerning pregnant women with acute Chagas' disease.

Acute Chagas disease outbreak associated with oral transmission

Seven individuals living in a town in the Southwest of Bahia developed sudden signs of cardiac and systemic impairment, with lethality of 28.6%. Serological tests were positive at least in one test in the five patients examined. Forty percent of the Triatoma sordida mynphs found inside or around Trypanosoma cruzi were found by blood culturig in there out five cases the homes of these cases were positive for Trypanosoma cruzi. Transmission probably occurred through consumption of water contaminated with triatomine feces. These findings emphasize the necessity to evaluation the importance of vectors like Triatoma sordida in maintaining the endemicity of this disease.

New focus of active transmission of Chagas disease in indigenous populations in the Peruvian Amazon basin

Introduction Several cases of acute Chagas disease (ACD) have been reported in the Peruvian Amazon basin. Methods The objective was to describe and investigate 6 ACD cases in children from indigenous Amazon communities in the province of Datem del Marañón in Loreto department (2006-2010). Results The mean age was 3.6 years. All patients had fever, 4/6 hepatomegaly, 2/6 splenomegaly, and 5/6 had trypomastigotes of Trypanosoma cruzi on thick smears. The fatality rate was 33.3%. Rhodnius pictipes and Rhodnius robustus adults were found inside the homes and in the peri-domiciles. Conclusions All cases reported were isolated cases. We report a new focus of ACD in indigenous populations.

Outbreak of acute Chagas disease associated with oral transmission in the Rio Negro region, Brazilian Amazon

Introduction Chagas disease is considered as emerging in the Brazilian Amazon, usually occurring in acute outbreaks. Methods We describe 17 cases of acute Chagas disease in Rio Negro, Amazonas. Results There were 15 males (average age, 31.3 years), all positive for Trypanosoma cruzi in fresh blood smear examination, and 14 positive by xenodiagnosis and PCR. The top clinical manifestations were fever, asthenia, abdominal pain, and palpitations. Electrocardiograms featured low-voltage QRS, anterosuperior divisional block, and right bundle branch block associated with anterosuperior divisional block. Conclusions All patients had consumed açaí products from Monte Alegre in the rural area around Santa Izabel do Rio Negro, Brazil.

Spatial analysis of visceral leishmaniasis in the municipality of Rondonópolis, in the Brazilian State of Mato Grosso, from 2003 to 2012: human, canine and vector distribution in areas of disease transmission

INTRODUCTION: Visceral leishmaniasis (VL) is a zoonosis of great importance to public health and is considered a neglected disease by the World Health Organization. The disease has expanded and become more prevalent in urban areas in Brazil. METHODS: Geospatial analyses were performed and thematic maps of the triad of the disease were produced for the study period (2003-2012) in the urban area of the municipality of Rondonópolis in the midwestern State of Mato Grosso (MT), Brazil, TerraView 4.2.2 software was used for the analyses. RESULTS: A total of 87.9% of the 186 confirmed human cases of VL were cured. Children between the ages of 1 and 4 were the most affected. Registered deaths were predominant among adults aged 60 years or older. The urban area of the municipality consists of eight strata and 12 census districts include 237 neighborhoods. All sectors had confirmed cases of VL. During the study period, human cases of the disease were recorded in 90 neighborhoods. The 23 deaths from the disease were distributed in 21 neighborhoods. Sandflies carrying the parasite were captured in 192 out of 200 neighborhoods evaluated for the presence of the VL vector. The presence of dogs carrying the parasite was confirmed in, 140 out of 154 surveyed neighborhoods. CONCLUSIONS: The data demonstrated the endemic nature of VL, with a high percentage of infected children, a high distribution of canine infection, and a wide adaptation and dispersal of the vectors in the urban environment. These results, illustrate the process of urbanization of VL in the municipality of Rondonópolis, MT, Brazil.

Transmission and progression to disease of Mycobacterium tuberculosis phylogenetic lineages in The Netherlands

The aim of this study was to determine if mycobacterial lineages affect infection risk, clustering, and disease progression among Mycobacterium tuberculosis cases in The Netherlands. Multivariate negative binomial regression models adjusted for patient-related factors and stratified by patient ethnicity were used to determine the association between phylogenetic lineages and infectivity (mean number of positive contacts around each patient) and clustering (as defined by number of secondary cases within 2 years after diagnosis of an index case sharing the same fingerprint) indices. An estimate of progression to disease by each risk factor was calculated as a bootstrapped risk ratio of the clustering index by the infectivity index. Compared to the Euro-American reference, Mycobacterium africanum showed significantly lower infectivity and clustering indices in the foreign-born population, while Mycobacterium bovis showed significantly lower infectivity and clustering indices in the native population. Significantly lower infectivity was also observed for the East African Indian lineage in the foreign-born population. Smear positivity was a significant risk factor for increased infectivity and increased clustering. Estimates of progression to disease were significantly associated with age, sputum-smear status, and behavioral risk factors, such as alcohol and intravenous drug abuse, but not with phylogenetic lineages. In conclusion, we found evidence of a bacteriological factor influencing indicators of a strain's transmissibility, namely, a decreased ability to infect and a lower clustering index in ancient phylogenetic lineages compared to their modern counterparts. Confirmation of these findings via follow-up studies using tuberculin skin test conversion data should have important implications on M. tuberculosis control efforts.