In order to evaluate the use of a Western blot methodology for the diagnosis of infectious bursal disease virus (IBDV) infection, chickens were experimentally infected with IBDV strains and tested for the presence of viral antigens and antibodies by a blocking Western blot test (bWB). The viral proteins obtained from the bursa of Fabricius (BF) were transferred to a nitrocellulose membrane after sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and the chicken sera obtained by heart puncture were used for the detection of these proteins. In order to eliminate nonspecific reactions, we used a rabbit anti-chicken serum (blocking tool). By the use of the bWB test, two distinct viral proteins of 43-kDa (VP2) and 32-kDa (VP3) were detected. We suggest the use of this methodology for the detection of IBDV infection in animals suspected of having IBDV reinfection and a chronic subclinical form of the disease. With the use of the rabbit anti-chicken sera for blocking, this method is practical, sensitive and less time consuming

The diagnosis of HSV infection in the CNS is based on the early detection of viral DNA with the polymerase chain reaction (PCR) in the cerebrospinal fluid (CSF). The sensitivity of this method is greater over the first week after symptoms onset or before treatment⁵. From seven to 10 days after that, the diagnosis can be determined by the presence of antibodies against the viral antigen^5,6. The presence of IgM indicates recent primary infection being rare in the CSF, whereas the specific IgG demonstration supports the retrospective diagnosis of the herpetic infection in the CNS and may persist for years⁷. The demonstration of the intrathecal synthesis of specific antibodies is an immunological method of choice for retrospective analysis. However, such analysis requires serum and paired CSF, which are rarely available.

Human Polyomaviruses such as MCPyV and HPyV6 are frequently found as part of healthy skin microbiota and have been associated with Merkel cell carcinoma (MCC), pruritic and dyskeratotic dermatoses, respectively. Their presence in other types of skin conditions varies greatly depending on lesion type and population. To analyse comparatively the presence of MCPyV and HPyV6 in nonmelanoma skin cancers and healthy skin. The authors utilized qPCR techniques to quantify these pathogens in NMSC, premalignant diseases, and healthy skin of 87 patients. MCPyV was detected in over 40% of samples, while HPyV6 was in 9.6%. MCPyV load was higher in squamous cell carcinomas (SCC) compared to basal cell carcinomas (BCC) (p=0.016) and HPyV6 showed a higher percentage of infected cells in areas of low solar exposure as well as normal skin (p=0.012). A fair agreement (kappa=0.301) was found between MCPyV detection in lesions and their respective perilesional skin, indicating a random process of local dissemination of the virus. The lack of a larger sampling of different lesion types and protein expression analyses limits the correlation findings. This is the first report of HPyV6 detection in the healthy skin of a Brazilian population, but the role of both polyomaviruses in NMSC has yet to be demonstrated.

Objective: In order to study the scenario of respiratory infections in pediatrics after the emergence of SARS-CoV-2 in Brazil, this study aimed to compare characteristics of children admitted for SARS or upper airway infection caused by either RSV or SARS-CoV-2. Methods: This was a cross-sectional study involving children up to 48 months of age admitted to a tertiary pediatric hospital with a diagnosis of SARS or upper airway infection between April of 2020 and April of 2021. Respiratory secretion samples were collected 2-5 days after hospitalization, and antigen/PCR tests for viral etiologies were performed. In this analysis, patients with laboratorial diagnosis of SARS-CoV-2 and/or RSV were selected, and their clinical and epidemiological characteristics were compared using logistic regression. Results: Our sample initially comprised 369 participants. SARS-CoV-2 and RSV infections were confirmed in 55 (15%) and 59 children (16%), respectively. Mean age was 12 months (0-48 months), and 47 were female. The following characteristics were significantly more frequent in patients with RSV when compared with those with COVID-19: younger age (OR = 0.94; 95% CI: 0.90-0.98); lower frequency of fever (OR = 0.18; 95% CI: 0.05-0.66); and more frequent upper airway symptoms: cough (OR = 7.36; 95% CI: 1.04-52.25); and tachypnea (OR = 6.06; 95% CI: 1.31-28.0). Conclusions: Children with RSV-related SARS were younger, had lower frequency of fever at admission, but had a higher frequency of signs of upper airway infection and lower systemic inflammation when compared with children hospitalized for COVID-19 during the first year of the pandemic.