RESUMEN
Background: Bilateral nipple-sparing mastectomy (NSM) is a technically feasible operation and is associated with excellent cosmetic outcomes. The aim of this study was to evaluate trends in patient characteristics, indications for surgery and long-term outcomes of bilateral NSM for breast cancer risk reduction over time. Methods: A review of a single-centre experience with bilateral NSM performed between 2001 and 2017 for breast cancer risk reduction in patients without breast cancer was performed. Trends in patient characteristics and indications for surgery were evaluated over four time intervals: 2001-2005, 2006-2009, 2010-2013 and 2014-2017. Statistical analysis was performed using χ2 tests. Results: Over the study period, 272 NSMs were performed in 136 patients; their median age was 41 years. The number of bilateral NSMs performed increased over time. The most common indication was a mutation in breast cancer-associated genes (104 patients, 76·5 per cent), which included BRCA1 (62 patients), BRCA2 (35), PTEN (2), TP53 (3) and ATM (2). Other indications were family history of breast cancer (19 patients, 14·0 per cent), lobular carcinoma in situ (10, 7·4 per cent) and a history of mantle irradiation (3, 2·2 per cent). The proportion of patients having a bilateral NSM for mutation in a breast cancer-associated gene increased over time (2001-2005: 2 of 12; 2006-2009: 9 of 17; 2010-2013: 34 of 41; 2014-2017: 61 of 66; P < 0·001). Mean follow-up was 53 months; no breast cancers were found during follow-up. Conclusion: The use of bilateral NSM for breast cancer risk reduction is increasing and the indications have evolved over the past 16 years. These excellent long-term oncological results suggest that bilateral NSM is a good option for surgical breast cancer risk reduction.
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Biomarcadores de Tumor/genética , Neoplasias de la Mama Masculina/cirugía , Neoplasias de la Mama/cirugía , Mastectomía Subcutánea/métodos , Tratamientos Conservadores del Órgano/métodos , Mastectomía Profiláctica/métodos , Adulto , Anciano , Neoplasias de la Mama/genética , Neoplasias de la Mama Masculina/genética , Femenino , Estudios de Seguimiento , Mutación de Línea Germinal , Humanos , Masculino , Mastectomía Subcutánea/efectos adversos , Anamnesis , Persona de Mediana Edad , Pezones/cirugía , Tratamientos Conservadores del Órgano/efectos adversos , Selección de Paciente , Mastectomía Profiláctica/efectos adversos , Estudios Retrospectivos , Resultado del Tratamiento , Adulto JovenRESUMEN
Parasites of wild primates are important for conservation biology and human health due to their high potential to infect humans. In the Amazon region, non-human primates are commonly infected by Trypanosoma cruzi and T. rangeli, which are also infective to man and several mammals. This is the first survey of trypanosomiasis in a critically endangered species of tamarin, Saguinus bicolor (Callitrichidae), from the Brazilian Amazon Rainforest. Of the 96 free-ranging specimens of S. bicolor examined 45 (46.8%) yielded blood smears positive for trypanosomes. T. rangeli was detected in blood smears of 38 monkeys (39.6%) whereas T. cruzi was never detected. Seven animals (7.3%) presented trypanosomes of the subgenus Megatrypanum. Hemocultures detected 84 positive tamarins (87.5%). Seventy-two of 84 (85.7%) were morphologically diagnosed as T. rangeli and 3 (3.1%) as T. cruzi. Nine tamarins (9.4%) yielded mixed cultures of these two species, which after successive passages generated six cultures exclusively of T. cruzi and two of T. rangeli, with only one culture remaining mixed. Of the 72 cultures positive for T. rangeli, 62 remained as established cultures and were genotyped: 8 were assigned to phylogenetic lineage A (12.9%) and 54 to lineage B (87.1%). Ten established cultures of T. cruzi were genotyped as TCI lineage (100%). Transmission of both trypanosome species, their potential risk to this endangered species and the role of wild primates as reservoirs for trypanosomes infective to humans are discussed.
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Animales Salvajes/parasitología , Conservación de los Recursos Naturales , Enfermedades de los Monos , Saguinus/parasitología , Trypanosoma cruzi , Trypanosoma , Tripanosomiasis/veterinaria , Animales , Brasil/epidemiología , Enfermedad de Chagas/parasitología , Enfermedad de Chagas/veterinaria , Genotipo , Enfermedades de los Monos/epidemiología , Enfermedades de los Monos/parasitología , Reacción en Cadena de la Polimerasa/métodos , Prevalencia , Árboles , Trypanosoma/clasificación , Trypanosoma/genética , Trypanosoma/aislamiento & purificación , Trypanosoma/patogenicidad , Trypanosoma cruzi/clasificación , Trypanosoma cruzi/genética , Trypanosoma cruzi/aislamiento & purificación , Trypanosoma cruzi/patogenicidad , Tripanosomiasis/epidemiología , Tripanosomiasis/parasitologíaAsunto(s)
Adenoma/patología , Enfermedades del Ano/patología , Coristoma/patología , Enfermedad de Crohn/diagnóstico , Adenoma/diagnóstico , Adenoma/cirugía , Adulto , Enfermedades del Ano/diagnóstico , Enfermedades del Ano/cirugía , Biopsia con Aguja , Mama , Coristoma/diagnóstico , Coristoma/cirugía , Enfermedad de Crohn/terapia , Femenino , Estudios de Seguimiento , Humanos , Inmunohistoquímica , Dolor/diagnóstico , Dolor/etiología , Enfermedades Raras , Medición de Riesgo , Resultado del TratamientoRESUMEN
BACKGROUND: Single-session intraoperative radiation therapy (IORT) minimizes treatment demands associated with traditional whole breast radiation therapy (WBRT) but outcomes on local disease control and morbidity among the elderly is limited. METHODS: A multi-institutional retrospective registry was established from 19 centers utilizing IORT from 2007 to 2013. Patient, tumor, and treatment variables were analyzed for ages <70 and ≥70. RESULTS: We evaluated 686 patients (<70 = 424; ≥70 = 262) who were margin and lymph node negative. Patients <70 were more likely to have longer operative time, oncoplastic closure, higher rates of IORT used as planned boost, and receive chemotherapy and post-operative WBRT. Wound complication rates were low and not significantly different between age groups. Median follow-up was 1.06 (range 0.51-1.9) years for < 70 and 1.01 (range 0.5-1.68) years for ≥ 70. There were 5 (0.73%) breast recurrences (4 in <70 and 1 ≥ 70, p = 0.65) and no axillary recurrences during follow-up. CONCLUSIONS: IORT was associated with a low rate of wound complication and local recurrence on short-term follow-up in this cohort.
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Neoplasias de la Mama/radioterapia , Cuidados Intraoperatorios , Factores de Edad , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/patología , Neoplasias de la Mama/cirugía , Terapia Combinada , Femenino , Humanos , Mastectomía Segmentaria , Persona de Mediana Edad , América del Norte , Tempo Operativo , Complicaciones Posoperatorias/epidemiología , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
Thirty six stocks of Trypanosoma cruzi isolated from sylvatic mammals (32 Didelphis marsupialis and one Philander opossum) and triatomine bugs (Rhodnius robustus and one unidentified bug) in the Amazonian forest by Carajas, Brazil were characterized by isoenzyme and random amplified polymorphic DNA (RAPD) analysis as belonging to principal zymodeme '1 (Z1). Two different homozygous phenotypes and the corresponding heterozygous phenotype were found for phosphoglucomutase with an observed frequency almost identical with that predicted by the theoretical Hardy-Weinberg distribution. Parental and hybrid profiles were also suggested by RAPD analysis, which allowed exclusion of mixed parental strains from the hybrids: isoenzyme and RAPD profiles of biological clones were also indistinguishable from those of uncloned stocks. Trypanosoma cruzi stocks from widely separated geographic origins in Central and South America gave similar RAPD profiles that allowed them to be recognized as being Z1. These results indicate that genetic exchange could contribute to the generation of genetic diversity during the sylvatic cycle of T. cruzi, and this may have epidemiologic and taxonomic implications.
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Enfermedad de Chagas/parasitología , Variación Genética , Genoma de Protozoos , Trypanosoma cruzi/genética , Animales , Secuencia de Bases , Brasil/epidemiología , Enfermedad de Chagas/epidemiología , Cartilla de ADN/química , Insectos Vectores/parasitología , Isoenzimas/análisis , Datos de Secuencia Molecular , Zarigüeyas/parasitología , Fenotipo , Fosfoglucomutasa/análisis , Técnica del ADN Polimorfo Amplificado Aleatorio , Rhodnius/parasitología , Trypanosoma cruzi/enzimologíaRESUMEN
A total of 46 Trypanosoma rangeli stocks were isolated from naturally infected mammals and triatomine vectors. Twenty-two stocks were from the common opossum (Didelphis marsupialis), one from the brown "4-eyed" opossum (Metachirus nudicaudatus), one from the anteater (Tamandua tetradactyla), one from the coati (Nasua nasua), seven from Rhodnius pictipes and 14 from Rhodnius robustus. Two stocks were also isolated from recently fed sandflies (Lutzomyia sp., Shannoni group). The stocks were identified as T. rangeli on the basis of natural or experimental salivary gland infections in Rhodnius, inoculative (anterior station) transmission to mice, morphological parameters in parasitemic mice and comparisons of isozyme profiles with a known stock of T. rangeli isolated from man. Three other trypanosome stocks from D. marsupialis, T. tetradactyla and the three-toed sloth (Bradypus tridactylus) were morphologically similar to T. rangeli in culture but had quite different isozyme profiles and were not identified. It is concluded that T. rangeli is widely distributed in Amazonas, Pará and Rondonia States of Brazil, and probably extends into other regions where R. pictipes and R. robustus are known to occur. R. pictipes is light-attracted into houses and occasionally transmits Chagas' disease to man. It is likely that T. rangeli is also occasionally transmitted to man in the Amazon basin.
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Insectos Vectores/parasitología , Mamíferos/parasitología , Zarigüeyas/parasitología , Rhodnius/parasitología , Triatominae/parasitología , Trypanosoma/aislamiento & purificación , Animales , Brasil , Enfermedad de Chagas/parasitología , Enfermedad de Chagas/veterinaria , Isoenzimas/análisis , Ratones , Psychodidae/parasitología , Glándulas Salivales/parasitología , Trypanosoma/clasificación , Trypanosoma/fisiología , Xenarthra/parasitologíaRESUMEN
Just over 100 autochthonous cases of Chagas disease are reported from the Brazilian Amazon Basin. Panstrongylus geniculatus (Latreille) occurs throughout the region and is the known vector of Trypanosoma cruzi, principal zymodeme 3 (Z3) to the armadillo Dasypus novemcinctus. In the small riverine community of Furo do Rio Pau Grande, pigsties adjoining houses were heavily infested with P. geniculatus, which repeatedly attacked local inhabitants. Palm trees in the immediate vicinity were also infested. T. cruzi principal zymodeme 1 (Z1) was isolated from P. geniculatus, domestic pigs, and opossums, but no human infections were detected. The threat of endemic Chagas disease to the Amazon Basin from either domiciliation of local silvatic triatomine species, or from migration of domestic vectors, demands a program of vigilance and plans of action to eliminate household triatomine colonies.
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Enfermedad de Chagas/veterinaria , Insectos Vectores , Panstrongylus/parasitología , Enfermedades de los Porcinos , Porcinos/parasitología , Animales , Animales Domésticos , Brasil , Enfermedad de Chagas/transmisión , Humanos , Trypanosoma cruzi/fisiologíaRESUMEN
Eleven of 27 decameric primers were found to be suitable for random amplification of polymorphic DNA (RAPD) from triatomine bugs on the basis that they produced discrete profiles and distinguished among Panstrongylus megistus (Burmeister), Rhodnius prolixus Stål, and Triatoma infestans (Klug). The legs, or single leg segments, of individual bugs were used as the source of DNA so that the taxonomic value of the bug was conserved. Within the scope of the specimens studied, RAPD profiles allowed assignment to species even when bugs were kept dry for up to 12 mo. Profiles for individuals within a species were not identical. RAPD profiles, with the specimens tested, distinguished among species of 3 pairs considered to be morphologically similar and closely related, namely, Rhodnius ecuadorensis Lent & León and Rhodnius pictipes Stål; Rhodnius nasutus Stål, and Rhodnius neglectus Lent; Rhodnius prolixus Stål and Rhodnius robustus Larrousse. RAPD data conformed with the perceived affinities among these species. RAPD polymorphisms were seen with T. infestans from 3 different localities, but none of the polymorphisms was confined to 1 source. RAPD provided a molecular basis to reassess taxonomic relationships within the Triatomine subfamily. The accurate distinction of triatomine species and of intraspecific bug populations may contribute to elimination of vector-borne Chagas disease from the Americas.
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Técnica del ADN Polimorfo Amplificado Aleatorio , Triatominae/genética , Animales , Triatominae/clasificaciónRESUMEN
The authors describe the main clinical findings relative to cardiac involvement, in patients with acute Chagas' disease (CD) in yet another familial micro-epidemic episode of CD in Amazon region. Thirteen patients were studied with acute Chagas' disease, resident in the city of Abaetetuba in Pará state; they were submitted to clinical and heart evaluation, with electrocardiograph and echocardiograph exams. Ventricular extrasystole occurred in 38.5% of the cases. Right bundle branch block and 1st and 2nd degree atrioventricular block were found in 30.8% of the patients. Attention is called to two findings in the Doppler echocardiography: pericardiac involvement and an image suggestive of aneurismatic formation in two patients. The findings reveal acute heart disease, with evidence of cardiomyopathy and alterations in the conduction system of the heart, bearing similarity with the description of the disease in endemic areas.
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Cardiomiopatía Chagásica/complicaciones , Cardiopatías/etiología , Adolescente , Adulto , Anciano , Brasil , Cardiomiopatía Chagásica/epidemiología , Niño , Salud de la Familia , Femenino , Cardiopatías/parasitología , Humanos , Masculino , Persona de Mediana Edad , Población RuralRESUMEN
A prospective study of acute diarrhoeal diseases was carried out from April 1990 to September 1992 with the purpose of assessing the immunogenicity, safety and efficacy of a Rhesus-human reassortant rotavirus ("RRV-TV") vaccine, involving 540 children living in Belém, Pará, Brazil. As half of the children received placebo, this trial provided the opportunity of broadening the knowledge on both clinical and epidemiological aspects of rotavirus infection in the Amazon region. There were 2,789 diarrhoeal episodes during the above mentioned period, of which 86 (3.1%) associated with rotavirus; serotype 1 was the more prevalent, accounting for 67.9% of serotyped strains. Rates of 5.9 and 0.2 episodes of diarrhoea per child/year were noted for all cases and the rotavirus-related ones, respectively. This agent was the only pathogen found in 70.9% of the 86 rotavirus-related episodes of acute diarrhoea, whereas the most frequent associations involved Giardia intestinalis and enteropathogenic Escherichia coli, accounting for 7.0% and 11.6% of mixed infections,respectively. The monthly rates of rotavirus-related episodes of diarrhoea ranged from 0.8% to 9.6%, reaching the highest peaks during the dry months of the year. Means of clinical severity scores of 9.4 and 5.3 were recorded for the rotavirus-related episodes of diarrhoea and those of other aetiology, respectively.
RESUMEN
Trypanosoma cruzi and Trypanosoma rangeli are human-infective blood parasites, largely restricted to Central and South America. They also infect a wide range of wild and domestic mammals and are transmitted by a numerous species of triatomine bugs. There are significant overlaps in the host and geographical ranges of both species. The two species consist of a number of distinct phylogenetic lineages. A range of PCR-based techniques have been developed to differentiate between these species and to assign their isolates into lineages. However, the existence of at least six and five lineages within T. cruzi and T. rangeli, respectively, makes identification of the full range of isolates difficult and time consuming. Here we have applied fluorescent fragment length barcoding (FFLB) to the problem of identifying and genotyping T. cruzi, T. rangeli and other South American trypanosomes. This technique discriminates species on the basis of length polymorphism of regions of the rDNA locus. FFLB was able to differentiate many trypanosome species known from South American mammals: T. cruzi cruzi, T. cruzi marinkellei, T. dionisii-like, T. evansi, T. lewisi, T. rangeli, T. theileri and T. vivax. Furthermore, all five T. rangeli lineages and many T. cruzi lineages could be identified, except the hybrid lineages TcV and TcVI that could not be distinguished from lineages III and II respectively. This method also allowed identification of mixed infections of T. cruzi and T. rangeli lineages in naturally infected triatomine bugs. The ability of FFLB to genotype multiple lineages of T. cruzi and T. rangeli together with other trypanosome species, using the same primer sets is an advantage over other currently available techniques. Overall, these results demonstrate that FFLB is a useful method for species diagnosis, genotyping and understanding the epidemiology of American trypanosomes.
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Trypanosoma/genética , Animales , Genotipo , Reacción en Cadena de la Polimerasa , América del Sur , Especificidad de la EspecieRESUMEN
Faecal samples were obtained from 190 children, aged 0 to 5 years, admitted to a public hospital in Belém, Pará, Brazil. These patients were placed in a pediatric ward with 40 beds distributed in six rooms. Cases were classified into three groups: (a) nosocomial: children who developed gastroenteritis 72 hr or later after admission; (b) community-acquired: patients admitted either with diarrhoea or who had diarrhoea within 72 hr following admission; (c) non-diarrhoeic: those children who had no diarrhoea three days before and three days after collection of formed faecal sample. Specimens were routinely processed for the presence of rotaviruses, bacteria and parasites. Rotaviruses were detected through enzyme-linked immunosorbent assay (ELISA) and subsequently serotyped/electrophoretyped. Rotaviruses were the most prevalent enteropathogens among nosocomial cases, accounting for 39% (9/23) of diarrhoeal episodes; on the other hand, rotaviruses occurred in 8.3% (11/133) and 9% (3/34) of community-acquired and non-diarrhoeic categories, respectively. Mixed infections involving rotavirus and Giardia intestinalis and rotavirus plus G. intestinalis and Entamoeba histolytica were detected in frequencies of 8.6 and 4.3%, respectively, in the nosocomial group. The absence of bacterial pathogens in this category, and the unusual low prevalence of these agents in the other two groups may reflect the early and routine administration of antibiotics following admission to this hospital. Rotavirus serotype 2 prevailed over the other types, accounting for 77.8% of isolates from nosocomial diarrhoeal episodes. In addition, at least five different genomic profiles could be observed, of which one displayed an unusual five-segment first RNA cluster. Dehydration was recorded in all cases of hospital-acquired, rotavirus-associated diarrhoea, whereas in only 57% of nosocomial cases of other aetiology. It was also noted that nosocomial, rotavirus-associated diarrhoeal episodes occur earlier (7 days), following admission, if compared with those hospital-acquired cases of other aetiology (14 days).
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Infección Hospitalaria/virología , Diarrea Infantil/virología , Brasil , Preescolar , Heces/virología , Femenino , Genoma Viral , Humanos , Lactante , Recién Nacido , Pacientes Internos , Masculino , Rotavirus/genética , Infecciones por Rotavirus/complicacionesRESUMEN
A tetravalent rhesus-human reassortant rotavirus (RRV-TV) vaccine (4 x 10(4) plaque-forming units/dose) was evaluated for safety, immunogenicity and efficacy in a prospective, randomized, double-blind, placebo-controlled trial involving 540 Brazilian infants. Doses of vaccine or placebo were given at ages 1, 3 and 5 months. No significant differences were noted in the occurrence of diarrhoea or vomiting in vaccine and placebo recipients following each dose. Low-grade fever occurred on days 3-5 in 2-3% of vaccinees after the first dose, but not after the second or third doses of vaccine. An IgA antibody response to rhesus rotavirus (RRV) occurred in 58% of vaccinees and 33% of placebo recipients. Neutralizing antibody responses to individual serotypes did not exceed 20% when measured by fluorescent focus reduction, but exceeded 40% when assayed by plaque reduction neutralization. There were 91 cases of rotavirus diarrhoea among the 3-dose (vaccine or placebo) recipients during two years of follow-up, 36 of them among children given the vaccine. Overall vaccine efficacy was 8% (P = 0.005) against any diarrhoea and 35% (P = 0.03) against any rotavirus diarrhoea. Protection during the first year of follow-up, when G serotype 1 rotavirus predominated, was 57% (P = 0.008), but fell to 12% in the second year. Similar results were obtained when analysis was restricted to episodes in which rotavirus was the only identified pathogen. There was a tendency for enhanced protection by vaccine against illness associated with an average of 6 or more stools per day. These results are sufficiently encouraging to warrant further studies of this vaccine in developing countries using a higher dosage in an attempt to improve its immunogenicity and efficacy.
Asunto(s)
Infecciones por Rotavirus/prevención & control , Rotavirus/inmunología , Vacunas Virales/normas , Animales , Anticuerpos Antivirales/aislamiento & purificación , Método Doble Ciego , Ensayo de Inmunoadsorción Enzimática , Humanos , Recién Nacido , Macaca mulatta , Estudios Prospectivos , Rotavirus/clasificación , Infecciones por Rotavirus/inmunología , Serotipificación , Vacunas Virales/inmunologíaRESUMEN
From November 1992 to November 1994 stool samples were obtained from 237 children admitted to a public hospital in Belém. Rotaviruses were detected in 19.3 per cent (60/310) of faecal samples. Of these, 32.1 per cent (18/56), 20.9 per cent (38/181), and 5.4 per cent (4/73) were recorded in cases of nosocomial diarrhoea, community-acquired diarrhoea, and controls, respectively. Fifty-two (86.7 per cent) of the 60 rotavirus-positive specimens were subgrouped and the G serotypes of 55 (91.7 per cent) of them were determined. Subgroups I and II were detected in 50 per cent each of the 52 subgrouped strains. G type 2 was present in 46 (83.6 per cent) of the 55 serotyped samples; serotypes G1 and (mixed) G1 and G4 were found in 14.5 per cent and 1.8 per cent, respectively, of these specimens. Viral RNA electrophoresis showed 14 distinct patterns, including 56.7 per cent (34/60) and 43.3 per cent (26/60) of long and short profiles, respectively. In 40 (66.6 per cent) of the 60 rotavirus-positive faecal samples no enteropathogens other than rotavirus were detected. There was an increased incidence of rotavirus infection from July 1993 to February 1994. The rotavirus-related episodes of diarrhoea were more severe than those of other aetiology and greater clinical severity was not related to a specific G type, subgroup, or electrophoretype.
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Infección Hospitalaria/virología , Diarrea Infantil/virología , Infecciones por Rotavirus/epidemiología , Rotavirus/clasificación , Brasil/epidemiología , Preescolar , Infección Hospitalaria/epidemiología , Infección Hospitalaria/prevención & control , Diarrea Infantil/epidemiología , Diarrea Infantil/prevención & control , Femenino , Humanos , Incidencia , Lactante , Recién Nacido , Masculino , Infecciones por Rotavirus/prevención & controlRESUMEN
Se evaluó la inocuidad, inmunogenicidad y eficacia de una vacuna tetravalente obtenida por recombinación genética de rotavirus aislados de monos rhesus y seres humanos (RRV-TV) (4 x 104 unidades formadoras de placas por dosis) en un ensayo prospectivo, aleatorio, a doble ciego y controlado con placebo que se efectuó con 540 lactantes brasileños. Se administraron dosis de vacuna o de placebo a la edad de 1, 3 y 5 meses. No se observaron diferencias significativas en la frecuencia de diarrea o vómito en los bebés de ninguno de los dos grupos después de administrar la dosis correspondiente. De 2 a 3% de los vacunados tuvieron fiebre baja los días tercero a quinto después de recibir la primera dosis, pero no después de las dosis segunda o tercera. Se observó una respuesta de anticuerpos del tipo IgA al rotavirus aislado de monos rhesus (RRV) en 58% de los vacunados y en 33% de quienes recibieron placebo. La respuesta de anticuerpos neutralizantes a cada serotipo no pasó de 20% cuando se determinó con la prueba de reducción de focos de fluorescencia, pero fue superior a 40% al medirse con la prueba de neutralización a base de reducción de placas. Se presentaron 91 casos de diarrea causada por rotavirus entre los niños que recibieron las tres dosis (de vacuna o de placebo) durante un seguimiento de 2 años, 36 de ellos en los niños vacunados. La eficacia general de la vacuna fue de 8% (P = 0,005) contra toda clase de diarrea y de 35% (P = 0,03) contra la diarrea causada por rotavirus. La protección durante el primer año de seguimiento, cuando predominó el rotavirus G del serotipo 1, fue de 57% (P = 0,008), pero se redujo a 12% en el segundo año. Se obtuvieron resultados similares al restringir el análisis a episodios en que el rotavirus fue el único agente patógeno identificado. Se observó en la vacuna una mayor tendencia a proteger contra casos de enfermedad con un promedio de seis o más deposiciones diarias. Estos resultados son lo suficientemente...
A tetravalent rhesus-human reassortant rotavirus (RRV-TV) vaccine (4 x 104 plaque-forming units/dose) was evaluated for safety, immunogenicity and efficacy in a prospective, randomized, double-blind, placebo-controlled trial involving 540 Brazilian infants. Doses of vaccine or placebo were given at ages, 1, 3 and 5 months. No significant differences were noted in the occurrence of diarrhoea or vomiting in vaccine and placebo recipients following each dose. Low-grade fever occurred on days 35 in 23% of vaccinees after the first dose, but not after the second or third doses of vaccine. An IgA antibody response to rhesus rotavirus (RRV) occurred in 58% of vaccinees and 33% of placebo recipients. Neutralizing antibody responses to individual serotypes did not exceed 20% when measured by fluorescent focus reduction, but exceeded 40% when assayed by plaque reduction neutralization. There were 91 cases of rotavirus diarrhoea among the 3-dose (vaccine or placebo) recipients during two years of follow-up, 36 of them among children given the vaccine. Overall vaccine efficacy was 8% (P = 0.005) against any diarrhoea and 35% (P = 0.03) against any rotavirus diarrhoea. Protection during the first year of follow-up, when G serotype 1 rotavirus predominated, was 57% (P = 0.008), but fell to 12% in the second year. Similar results were obtained when analysis was restricted to episodes in which rotavirus was the only identified pathogen. There was a tendency for enhanced protection by vaccine against illness associated with an average of 6 or more stools per day. These results are sufficiently encouraging to warrant further studies of this vaccine in developing countries using a higher dosage in an attempt to improve its immunogenicity and efficacy.