Comparative analysis of Respiratory Syncytial Virus frequency rates and viral load in different patient cohorts in a University Hospital in São Paulo, Brazil, over an eight-year period (2005-2013)

Abstract Respiratory Syncytial Virus (RSV) poses a global health concern, particularly affecting young children, the elderly, and immunosuppressed individuals. RSV viral load is essential for understanding transmission, disease severity, prevention, and treatment. This retrospective study aimed to analyze the frequency rates and viral loads of RSV infections in different patient cohorts and age groups over an eight-year period in a university hospital in São Paulo, Brazil. This study analyzed 1380 Immunocompetent (IC) and Immunosuppressed (IS) patients with acute respiratory tract infections. IC included patients with chronic Heart Disease (HD), Primary Care service recipients (PC), and a subgroup suspected of having Severe Acute Respiratory Syndrome caused by Influenza A (H1N1)pdm09 virus (SARS H1N1). IS comprised transplant patients and those with HIV infection. Respiratory samples were collected between February 2005 and October 2013, with RSV detection and viral load quantification (Log10 copies of RNA/mL) using RT-qPCR. Overall RSV infection rate was 17.3 %, with higher rates in children (23.9 %) than in adults (12.9 %), particularly in children under two years of age (28.2 %). Children in the SARS H1N1 and PC subgroups had higher infection rates (16.4 % and 34.9 %, respectively), with the highest rate in PC children aged 1 to < 2 years (45.45 %). Adults with HD had a significantly higher frequency rate (27.83 %) than those in the SARS H1N1 (2.65 %) and IS (15.16 %) subgroups and higher hospitalization rate among adults under 65 years. RSV viral load ranged from 2.43 to 10.15 Log10 RNA copies/mL (mean ± SD 5.82 ± 2.19), with hospitalized patients exhibiting significantly higher viral loads (7.34 ± 1.9) than outpatients (4.38 ± 1.89). Elderly bone marrow transplant patients also had significantly higher viral loads (7.57 ± 2.41) than younger adults (5.12 ± 1.87). This study provides insights into the RSV infection patterns in different patient cohorts in Brazil. Further investigations are needed to understand susceptibility and risk factors associated with RSV infection. In conclusion, high RSV viral load among hospitalized patients could serve as a surrogate marker of disease severity. Additionally, patients with chronic heart disease deserve greater attention regarding complications associated with RSV infection.

Hepatitis E virus infection among patients with altered levels of alanine aminotransferase.

Hepatitis E virus (HEV) affects 20 million people worldwide, with 3.3 million cases and 56,000 deaths. The transmission is mainly by the fecal-oral route. Several studies have reported increased alanine aminotransferase (ALT) levels in association with viral hepatitis. This study evaluated the diagnosis of HEV infection among patients attending the emergency room (ER) of Hospital Beneficência Portuguesa (HBP) and Hospital São Paulo (HSP) in São Paulo, Brazil increased ALT levels (≥ 200 IU/L). From October 2018 to July 2019, 400 sera samples were collected from patients treated at the ER of HBP (n=200) and HSP (n=200). All samples were screened for HEV by RT-qPCR. 200 samples from HSP were tested for IgM of anti-Hepatitis A (HAV) and B (HBV) viruses, and total antibodies of Hepatitis C virus (HCV). Ninety samples (45 from each hospital), were tested for anti-HEV IgM antibodies. Patients aged under 1 to 91 years (mean = 46.29 ± 24.17, median = 48). ALT levels varied from 200 to 8,974 IU/l. 16 patients (4%) turned out positive for HEV by RT-qPCR (ALT levels = 299 to 698 IU/L). Of the 200 HSP patients, 18 (9%) were anti-HAV IgM reactive, 9 (4.5%) for anti-HBV IgM, and 7 (3.5%) for anti-HCV antibodies (ALT levels = 833 to 1918 IU/L). Two of 90 BPH patients (2.22%) were anti-HEV IgM reactive (ALT levels = 1502 to 3831 IU/L). This is the first Brazilian study evaluating patients with suspected HEV infection with increased ALT levels, which were higher than 12 and 60 times the normal upper limit, in the acute phase or for patients reactive for antibody detection, respectively. Liver damage could be minimized by implementing molecular diagnostic tests in the hospital routine.

COVID-19 in health care workers in a university hospital during the quarantine in São Paulo city

Abstract Health care workers (HCW) are at a higher risk of being infected in their workplace. Out of a total of 466 HCW of Hospital São Paulo with influenza-like illnesses or any clinical suspicion of COVID-19 were tested for COVID-19 by RT-PCR for SARS-CoV-2 169 (36%) turned out positive and were analyzed by type of exposure and hospital occupation. Data of HCW household locations were also obtained. Logistic workers had the highest positivity rate for SARS-CoV-2 (p = 0.002), while nurse technicians had the highest rate among those reporting routine contacts with patients (p = 0.001). Physicians presented the lowest rate of infection, although living in most affected districts (p < 0.001). Policies and adequate training for all hospital employees may improve prevention of COVID-19 among all health care service categories.

Epidemiological profile of Zika, Dengue and Chikungunya virus infections identified by medical and molecular evaluations in Rondonia, Brazil.

Several arboviruses have emerged and/or re-emerged in North, Central and South-American countries. Viruses from some regions of Africa and Asia, such as the Zika and Chikungunya virus have been introduced in new continents causing major public health problems. The aim of this study was to investigate the presence of RNA from Zika, Dengue and Chikungunya viruses in symptomatic patients from Rondonia, where the epidemiological profile is still little known, by one-step real-time RT-PCR. The main clinical signs and symtoms were fever (51.2%), headache (78%), chills (6.1%), pruritus (12.2%), exanthema (20.1%), arthralgia (35.3%), myalgia (26.8%) and retro-orbital pain (19.5%). Serum from 164 symptomatic patients were collected and tested for RNA of Zika, Dengue types 1 to 4 and Chikungunya viruses, in addition to antibodies against Dengue NS1 antigen. Direct microscopy for Malaria was also performed. Only ZIKV RNA was detected in 4.3% of the patients, and in the remaining 95.7% of the patients RNA for Zika, Dengue and Chikungunya viruses were not detected. This finding is intriguing as the region has been endemic for Dengue for a long time and more recently for Chikungunya virus as well. The results indicated that medical and molecular parameters obtained were suitable to describe the first report of symptomatic Zika infections in this region. Furthermore, the low rate of detection, compared to clinical signs and symptoms as the solely diagnosis criteria, suggests that molecular assays for detection of viruses or other pathogens that cause similar symptoms should be used and the corresponding diseases could be included in the compulsory notification list.

Natural infection of Neotropical bats with hantavirus in Brazil.

Bats (Order: Chiroptera) harbor a high diversity of emerging pathogens presumably because their ability to fly and social behavior favor the maintenance, evolution, and dissemination of these pathogens. Until 2012, there was only one report of the presence of Hantavirus in bats. Historically, it was thought that these viruses were harbored primarily by rodent and insectivore small mammals. Recently, new species of hantaviruses have been identified in bats from Africa and Asia continents expanding the potential reservoirs and range of these viruses. To assess the potential of Neotropical bats as hosts for hantaviruses and its transmission dynamics in nature, we tested 53 bats for active hantaviral infection from specimens collected in Southeastern Brazil. Part of the hantaviral S segment was amplified from the frugivorous Carollia perspicillata and the common vampire bat Desmodus rotundus. DNA sequencing showed high similarity with the genome of Araraquara orthohantavirus (ARQV), which belongs to one of the more lethal hantavirus clades (Andes orthohantavirus). ARQV-like infection was detected in the blood, urine, and organs of D. rotundus. Therefore, we describe a systemic infection in Neotropical bats by a human pathogenic Hantavirus. We also propose here a schematic transmission dynamics of hantavirus in the study region. Our results give insights to new, under-appreciated questions that need to be addressed in future studies to clarify hantavirus transmission in nature and avoid hantavirus outbreaks.

A real-time reverse transcriptase polymerase chain reaction for detection and quantification of Vesiculovirus.

Vesiculoviruses (VSV) are zoonotic viruses that cause vesicular stomatitis disease in cattle, horses and pigs, as well as sporadic human cases of acute febrile illness. Therefore, diagnosis of VSV infections by reliable laboratory techniques is important to allow a proper case management and implementation of strategies for the containment of virus spread. We show here a sensitive and reproducible real-time reverse transcriptase polymerase chain reaction (RT-PCR) for detection and quantification of VSV. The assay was evaluated with arthropods and serum samples obtained from horses, cattle and patients with acute febrile disease. The real-time RT-PCR amplified the Piry, Carajas, Alagoas and Indiana Vesiculovirus at a melting temperature 81.02 ± 0.8ºC, and the sensitivity of assay was estimated in 10 RNA copies/mL to the Piry Vesiculovirus. The viral genome has been detected in samples of horses and cattle, but not detected in human sera or arthropods. Thus, this assay allows a preliminary differential diagnosis of VSV infections.

A real-time reverse transcriptase polymerase chain reaction for detection and quantification of Vesiculovirus

Vesiculoviruses (VSV) are zoonotic viruses that cause vesicular stomatitis disease in cattle, horses and pigs, as well as sporadic human cases of acute febrile illness. Therefore, diagnosis of VSV infections by reliable laboratory techniques is important to allow a proper case management and implementation of strategies for the containment of virus spread. We show here a sensitive and reproducible real-time reverse transcriptase polymerase chain reaction (RT-PCR) for detection and quantification of VSV. The assay was evaluated with arthropods and serum samples obtained from horses, cattle and patients with acute febrile disease. The real-time RT-PCR amplified the Piry, Carajas, Alagoas and Indiana Vesiculovirus at a melting temperature 81.02 ± 0.8ºC, and the sensitivity of assay was estimated in 10 RNA copies/mL to the Piry Vesiculovirus. The viral genome has been detected in samples of horses and cattle, but not detected in human sera or arthropods. Thus, this assay allows a preliminary differential diagnosis of VSV infections.

Genomic features and evolutionary constraints in Saffold-like cardioviruses.

This study identified the complete genomic sequence of four type 2 and type 3 human Saffold-like cardioviruses (SLCVs) isolated in Germany and Brazil. The secondary structures of the SLCV internal ribosome entry sites (IRESs) were deduced based on RNA base-pairing conservation and co-variation, using an established Theiler's murine encephalomyelitis virus (TMEV) IRES structure as a reference. The SLCV IRES was highly similar to that of TMEV, but motifs critical in TMEV for binding of the polypyrimidine tract-binding protein (PTB) were disrupted. In TMEV, corresponding alterations have been associated with reduced neurovirulence in mice. In the non-structural genome region, there was evidence of multiple intertypic recombination events between different SLCV types. Between viruses of the same type, recombination also occurred in the capsid-encoding genome region. There were apparently no recombination events between mouse TMEV and human SLCV. In another genus of the family Picornaviridae, Enterovirus, natural recombination occurs strictly within species and can serve as an additional criterion for delimiting species. Accordingly, the results of this study suggest that SLCV and TMEV may represent distinct species within the genus Cardiovirus.

Circulation of 3 lineages of a novel Saffold cardiovirus in humans.

Cardioviruses cause serious disease, mainly in rodents, including diabetes, myocarditis, encephalomyelitis, and multiple sclerosis-like disseminated encephalomyelitis. Recently, a human virus isolate obtained 25 years ago, termed Saffold virus, was sequenced and classified as a cardiovirus. We conducted systematic molecular screening for Saffold-like viruses in 844 fecal samples from patients with gastroenteritis from Germany and Brazil, across all age groups. Six cardioviruses were identified in patients <6 years of age. Viral loads were 283,305-5,044,412,175 copies/g of stool. Co-infections occurred in 4 of 6 children. No evidence for outbreak-like epidemic patterns was found. Phylogenetic analysis identified 3 distinct genetic lineages. Viral protein 1 amino acids were 67.9%-77.7% identical and had a distance of at least 39.4% from known cardioviruses. Because closely related strains were found on 2 continents, global distribution in humans is suspected. Saffold-like viruses may be the first human cardiovirus species to be identified.

Spectrum of viruses and atypical bacteria in intercontinental air travelers with symptoms of acute respiratory infection.

Respiratory infections after air travel are frequent, but epidemiological data are incomplete. Using sensitive polymerase chain reactions, we studied the spectrum of atypical bacteria and respiratory viruses in travelers fulfilling the case definition of severe acute respiratory syndrome. A pathogen was identified in 67 travelers (43.2%). Influenza and parainfluenza viruses were most prevalent, at 14.2% and 15.5%, respectively. Prevalences of adenoviruses, human metapneumovirus, coronaviruses, and rhinoviruses ranged between 2.6% and 4.8%. Human bocavirus, respiratory syncytial virus, and Legionella, Mycoplasma, and Chlamydophila species were absent or appeared at frequencies of <1%. To our knowledge, these are the first specific baseline data for the mentioned agents in the context of air travel.