Recurrence of COVID-19 associated with reduced T-cell responses in a monozygotic twin pair.

Recurrence of COVID-19 in recovered patients has been increasingly reported. However, the immune mechanisms behind the recurrence have not been thoroughly investigated. The presence of neutralizing antibodies (nAbs) in recurrence/reinfection cases suggests that other types of immune response are involved in protection against recurrence. Here, we investigated the innate type I/III interferon (IFN) response, binding and nAb assays and T-cell responses to severe acute respiratory distress syndrome coronavirus 2 (SARS-CoV-2) with IFN gamma (IFNγ) enzyme-linked spot assay (ELISPOT) in three pairs of young adult monozygotic (MZ) twins with previous confirmed COVID-19, one of them presenting a severe recurrence four months after the initial infection. Twin studies have been of paramount importance to comprehend the immunogenetics of infectious diseases. Each MZ twin pair was previously exposed to SARS-CoV-2, as seen by clinical reports. The six individuals presented similar overall recovered immune responses except for the recurrence case, who presented a drastically reduced number of recognized SARS-CoV-2 T-cell epitopes on ELISPOT as compared to her twin sister and the other twin pairs. Our results suggest that the lack of a broad T-cell response to initial infection may have led to recurrence, emphasizing that an effective SARS-CoV-2-specific T-cell immune response is key for complete viral control and avoidance of clinical recurrence of COVID-19.

The raptor Chimango Caracara (Milvago chimango) (Aves: Falconiformes) - A new host for Trichomonas gallinae (protozoa: Trichomonadidae).

This work describes a specimen of Chimango Caracara (Milvago chimango - Vieillot, 1816), from southern Brazil, as a new natural host for Trichomonas gallinae (Rivolta, 1878). Caseous oral lesions were observed in a young bird, and the parasite was isolated in modified Diamond's media. Morphology of the parasite was evaluated through microscopy and subsequently, sequencing of the internal transcribed spacer 1 (ITS1) of ribosomal DNA was performed to confirm T. gallinae identification. As far as authors are concerned, this is the first report of Milvago chimango as a natural host for T. gallinae.

Oral trichomoniasis in raptors in Southern Brazil / Tricomoníase oral em rapinantes no sul do Brasil

A retrospective study of oral trichomoniasis cases in raptors was carried out at "Laboratório Regional de Diagnóstico" of "Faculdade de Veterinária" of "Universidade Federal de Pelotas" (LRD-UFPel) from December 2014 to August 2017. Seven necropsy reports were reviewed. All raptors including Falconiformes and Strigiformes orders were from periurban zones. Four birds were adults, and there was no apparent sex predisposition. Clinical signs included dysphagia, regurgitation, and anorexia. Gross lesions were characterized by multifocal yellow to coalescent caseous nodules adhered to the oral cavity, which extended to the entrance of the esophagus. Microscopically, the lesions were characterized by severe focally extensive heterophilic granulomatous stomatitis. Trichomonas gallinae was isolated in modified Diamond medium of all samples collected from birds. It is believed the transmission occurred by the predation of domestic pigeons (Columbia livia domestica) contaminated with T. gallinae that agglomerate in patios of grain processing complexes.(AU)

Foi realizado um estudo retrospectivo de casos de tricomoníase oral em rapinantes recebidos no Laboratório Regional de Diagnóstico da Faculdade de Veterinária da Universidade Federal de Pelotas (LRD-UFPel) no período de dezembro de 2014 a agosto de 2017. Foram revisados os protocolos de necropsia encontrando-se sete casos. Os animais eram todos de zonas periurbanas e foram afetadas a ordem Falconiformes e a ordem Strigiformes. Das aves afetadas 4/7 eram adultas e não houve aparente predisposição por sexo. Os sinais clínicos incluíram disfagia, regurgitação e anorexia. As lesões se caracterizaram por nódulos amarelados multifocais a coalescentes aderidos a cavidade oral, que se estendiam até a entrada do esôfago. Histologicamente as lesões caracterizaram-se por estomatite heterofílica granulomatosa focalmente extensiva acentuada. Foi isolado em meio Diamond modificado Trichomonas gallinae de todas as amostras coletadas das aves. Acredita-se que a fonte de transmissão tenha ocorrido a partir da predação por estes rapinantes de pombas domésticas (Columbia livia domestica) portadoras com T. gallinae que se aglomeram em pátios de complexos de beneficiamento de grãos.(AU)

Trichomonas vaginalis and HIV infection: relation and prevalence among women in southern Brazil

Trichomoniasis is a curable sexually transmitted infection (STI) that has been reported to be linked to exposure to human immunodeficiency virus (HIV), although few studies have described this association. The purpose of this study was to focus on the incidence of trichomoniasis in low-income women, its relation to HIV status, viral load levels and TCD4+cell counts, among other risk factors, using an in vitro culture as a diagnostic test. A cross-sectional study among 267 women (103 HIV-positive and 164 HIV-negative) was conducted in 2015. The overall prevalence of Trichomonas vaginalis (TV) infection was 6.4%. Among HIV-positive and HIV-negative women, the prevalence was 3.9% and 7.9%, respectively, yet these results were not statistically different (p=0.1878). The factors associated with TV infection were cigarette smoking (OR= 3.52), vaginal itching (OR=4.43) and bacterial vaginosis (BV) (OR= 5.29). HIV status, TCD4+ cell count and viral load were not associated with TV infection in this group. The prevalence rates found, lower than those observed in other studies, may be due to the fact that the women evaluated in the present study are part of a low-risk population as well as the limited sample size of HIV positive women

Aptima Trichomonas vaginalis assay elucidates significant underdiagnosis of trichomoniasis among women in Brazil according to an observational study.

OBJECTIVES: Trichomonas vaginalis (TV) infection is the most common non-viral STI globally and can result in adverse pregnancy outcomes and exacerbated HIV acquisition/transmission. Nucleic acid amplification tests (NAATs) are the most sensitive diagnostic tests, with high specificity, but TV NAATs are rarely used in Brazil. We investigated the TV prevalence and compared the performance of the US Food and Drug Association-cleared Aptima TV assay with microscopy (wet mount and Gram-stained) and culture for TV detection in women in Pelotas, Brazil in an observational study. METHODS: From August 2015 to December 2016, 499 consecutive asymptomatic and symptomatic sexually active women attending a Gynaecology and Obstetrics Outpatient Clinic were enrolled. Vaginal fluid and swab specimens were collected and wet mount microscopy, Gram-stained microscopy, culture and the Aptima TV assay performed. RESULTS: The median age of enrolled women was 36.5 years (range: 15-77). The majority were white, had a steady sexual partner and low levels of education. The TV detection rate was 4.2%, 2.4%, 1.2% and 0% using the Aptima TV assay, culture, wet mount microscopy and Gram-stained microscopy, respectively. The sensitivity of culture and wet mount microscopy was only 57.1% (95% CI 36.5 to 75.5) and 28.6% (95% CI 13.8 to 50.0), respectively. CONCLUSIONS: A 4.2% positivity rate of T. vaginalis was found among women in Pelotas, Brazil and the routine diagnostic test (wet mount microscopy) and culture had low sensitivities. More sensitive diagnostic tests (NAATs) and enhanced testing of symptomatic and asymptomatic at-risk women are crucial to mitigate the transmission of TV infection, TV-associated sequelae and enhanced HIV acquisition and transmission.

Trichomonas Vaginalis Infection Among Women Attending in the Public Service in Rio Grande do Sul,Brazil: Frequency, Risk Factors and Clinical Signs / Infecção por Trichomonas Vaginalis em Mulheres a Tendidas pelo Serviço Público no Rio Grande do Sul, Brasil: Frequência, Fatores de Risco e Sinais Clínicos

Trichomoniasis is a cosmopolitan disease that can affect the female fertility, and is commonly underdiagnosed, both in private practices and in public health services, because of the low sensitivity of the wet mount exam used routinely. Objective: To understand the occurrence of T. vaginalis infection by means of in vitro culture in women receiving care in a public health unit, in the city of Pelotas, Rio Grande do Sul, Brazil, as well as to identify the possible risk factors associated with this infection. Methods: Cross­sectional study was carried out, which included 201 women undergoing interview and gynecological exam, with the collection of vaginal discharge in the Gynecology Ambulatory at the School of Medicine of Universidade Federal de Pelotas. The material collected was examined in the form of fresh smears and cultivated in Diamond's medium. Epidemiological data were obtained by means of patient interviews and clinical trials, from the medical records. The results were statistically analyzed through χ 2 and Fisher's exact tests, using version 9.0 of the Statistix program. Results: The occurrence of T. vaginalis infection was 7% (14/201). In the wet mount exam, used routinely for the diagnosis of this agent, only 42.85% of the infected women (6/14) were positive. It was noted that 21.4% of the infected women were asymptomatic, and 89.05% were not aware of the existence of the Trichomonas vaginalis infection. Factors independently associated with the infection were the smoking habit (odds ratio [OR] = 11.8), not having a stable sexual partner (OR = 6.36), presence of vaginal discharge with odor (OR = 5.65), and altered vaginal microbiota (OR = 5.31). Conclusion : T. vaginalis infection was present among the women studied, being underestimated because of the diagnostic technique, and because many of them were asymptomatic. The smoking habit, not having a stable sexual partner, having fetid discharge, and altered vaginal microbiota are the risk factors for infection.

A tricomoníase é cosmopolita, pode afetar a fertilidade feminina, e geralmente é subdiagnosticada, tanto em consultórios particulares, quanto em serviços públicos, devido à baixa sensibilidade do exame a fresco, usado rotineiramente. Objetivo: Conhecer a ocorrência de infecção por Trichomonas vaginalis , através de cultivo in vitro , em mulheres atendidas em unidade pública, na cidade de Pelotas, Rio Grande do Sul, além de identificar os possíveis fatores de risco associados a essa infecção. Métodos: Estudo de corte transversal que incluiu 201 mulheres, submetidas a entrevista e exame ginecológico, com coleta de conteúdo vaginal, no Ambulatório de Ginecologia da Faculdade de Medicina da Universidade Federal de Pelotas. O material coletado foi examinado a fresco e cultivado em meio de Diamond. Foram obtidos dados epidemiológicos através de entrevista, e clínicos, nos prontuários. Os resultados foram analisados estatisticamente através dos testes do χ 2 e exato de Fisher, utilizando o programa Statistix versão 9.0. Resultados: A ocorrência da infecção por T. vaginalis foi de 7% (14/201). No exame a fresco, usado como rotina para o diagnóstico desse agente, apenas 42,85% das infectadas (6/14) foram positivas. Constat ou­se que 21,4% das mulheres infectadas são assintomáticas, e que 89,05% desconhecia a existência da tricomoníase. Os fatores independent emente associados com a infecção foram o hábito de fumar (OR=11,8), não ter companheiro fixo (OR=6,36), apresentar corrimento vaginal fétido (OR=5,65) e microbiota vaginal alterada (OR=5,31). Conclusão: A infecção por T. vaginalis está presente entre as mulheres estudadas, e sendo subestimada, devido à técnica de diagnóstico e por muitas serem assintomáticas. O hábito de fumar, não ter companheiro fixo, ter corrimento fétido e microbiota vaginal alterada são fatores de risco para a infecção.