Coxiella burnetii is a global, highly infectious intracellular bacterium, able to infect a wide range of hosts and to persist for months in the environment. It is the etiological agent of Q fever—a zoonosis of global priority. Currently, there are no national surveillance data on C. burnetii’s seroprevalence for any South American country, reinforcing the necessity of developing novel and inexpensive serological tools to monitor the prevalence of infections among humans and animals—especially cattle, goats, and sheep. In this study, we used immunoinformatics and computational biology tools to predict specific linear B-cell epitopes in three C. burnetii outer membrane proteins: OMP-H (CBU_0612), Com-1 (CBU_1910), and OMP-P1 (CBU_0311). Furthermore, predicted epitopes were tested by ELISA, as synthetic peptides, against samples of patients reactive to C. burnetii in indirect immunofluorescence assay, in order to evaluate their natural immunogenicity. In this way, two linear B-cell epitopes were identified in each studied protein (OMP-H(51–59), OMP-H(91–106), Com-1(57–76), Com-1(191–206), OMP-P1(197–209), and OMP-P1(215–227)); all of them were confirmed as naturally immunogenic by the presence of specific antibodies in 77% of studied patients against at least one of the identified epitopes. Remarkably, a higher frequency of endocarditis cases was observed among patients who presented an intense humoral response to OMP-H and Com-1 epitopes. These data confirm that immunoinformatics applied to the identification of specific B-cell epitopes can be an effective strategy to improve and accelerate the development of surveillance tools against neglected diseases.

Gemycircularvirus (GemyCV) is a group of viruses which has been recently proposed as a new viral genus detected in fecal and environmental samples around the world. GemyCVs have been detected in human blood, brain tissue, cerebrospinal fluid, and stool sample. In the present study, we demonstrate for the first time, through molecular detection and characterization, the presence of GemyCVs in environmental samples from Brazil. Our results show a percentage of positivity ranging from 69 (25/36) to 97 % (35/36) in river water samples collected in Manaus, Amazon region, and wastewater from a wastewater treatment plant located in Rio de Janeiro, respectively, revealing GemyCVs as an important environmental contaminant.

Background Blood culture-negative infective endocarditis is a potentially severe disease that can be associated with infectious agents such as Bartonella spp., Coxiella burnetti, Tropheryma whipplei, and some fungi. Case presentation Reported here are two cases of blood culture-negative infective endocarditis in patients with severe aortic and mitral regurgitation in Brazil; the first case is a 47-year-old white man and the second is a 62-year-old white woman. Bartonella henselae deoxyribonucleic acid was detectable in the blood samples and cardiac valve with vegetation paraffin-fixed tissue samples. Additionally, an investigation was carried out on patients’ pets, within the context of One Health, and serum samples collected from cats and dogs were reactive by indirect immunofluorescence assay. Conclusions Even though the frequency of bartonellosis in Brazil is unknown, physicians should be aware of the possibility of blood culture-negative infective endocarditis caused by Bartonella, particularly in patients with weight loss, kidney changes, and epidemiological history for domestic animals.

Brazilian spotted fever, a zoonotic disease transmitted by ticks, is caused by Rickettsia rickettsii. We report a fulminant case of this zoonosis in a healthy 46-year-old military man in the urban region of Rio de Janeiro city, in October, 2021. Ticks and capybaras (Amblyomma sculptum, Hydrochoerus hydrochaeris, respectively) were identified in the military fields, pointing to the participation of this large synanthropic rodent, recognized as an efficient amplifier host of Rickettsia rickettsii in Brazil. As the military population is considered a risk group for spotted fever, it is necessary to alert health professionals to the importance of the early detection of the disease and its adequate management, mainly in populations that are particularly at risk of exposure to ticks, in order to avoid fatal outcomes.

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In view of the process of relaxating measures and the gradual return of activities, according to the essentiality of the service and health indicators, the Municipal Theater of Rio de Janeiro (TMRJ) is in the process of returning of work activities. In addition, the identification of symptomatic individuals and the use of rapid serological tests can assist in the surveillance of professionals who will return to activities in person.Objective: Assist the process of returning work activities at the TMRJ with the identification of seroreactive individuals with anti-SARS-Cov-2 antibodies and symptomatic professionals. Methodology:The study was carried out in December at TMRJ with professionals working in person and on a remote basis. Demographic data, work sector and the presence of symptoms were recorded. The presence of symptoms were screened in professionals by infectious disease doctor and subsequently subjected them to the collection of blood sample by digital puncture. Blood samples were analyzed by the commercial kit TR-DPP-COVID-19(TR) IgM/IgG (BIOMANGUINHOS/FIOCRUZ/RJ) according by manufacturer's protocol, considering reactivity for IgM and IgG antibodies a reading on the microreader> 0.30. Professionals seroreactive for SARS-CoV-2, with IgM antibodies and symptomatic professionals, were submitted to the collection of nasopharyngeal swab sample for the molecular diagnosis by RT-qPCR. Positive RT-qPCR professionals were followed up and tested weekly until no viral detection. Results:Of the 411 TMRJ professionals, 257 were men and 154 women, with an average age of 45.8 years (SD-13.7). There was a predominance of professionals from the administration sector (68) and orchestra (47). The 153 were seroreactives (153/411;37.2%) and 65% (99/153) were men. Anti-SARS-CoV-2 IgM antibodies were detected in 94 professionals: 25 (IgM) and 69 (IgM+IgG). A previous historic of respiratory symptoms was reported by 146 of the 153 seroreactives. In the analysis of RT-qPCR, viral detection was observed in 18 professionals: 01/25(IgM) and 17/69(IgM+IgG). Of the nine symptomatic but seronegative professionals, two were positive RT-qPCR. All IgM and IgM+IgG seroreactive professionals and symptomatic RT-qPCR positive patients were kept in isolation until the RT-qPCR result was released without viral detection. Only one professional required hospitalization due to the complications of the pulmonary condition, but she was discharged. Conclusion:The serological survey, combined with the identification of symptomatic individuals with a similar influenza-like infection, were fundamental to reduce the spread of SARS-CoV-2 among professionals in person work environment of TMRJ. Based on the serological evidence of anti-SARS-CoV-2 and the 18 positive RT-qPCR professionals, the application of TR contributed to the health vigilance, both in the implementation of preventive measures and as an auxiliary instrument in the process of returning activities in the pandemic context.