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.

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.

Influenza A(H1N1)pdm09 infection and viral load analysis in patients with different clinical presentations

BACKGROUND Influenza viral load (VL) can be a decisive factor in determining the antiviral efficacy in viral clearance. OBJECTIVE This study aimed to evaluate the rate of infection and the role of influenza VL on the clinical spectrum of illnesses among different patient groups attended at a tertiary hospital in Brazil. METHODS Samples were collected from patients presenting acute respiratory infection from 2009 to 2013. Overall, 2262 samples were analysed and distributed into three groups: (i) asymptomatic (AS); (ii) symptomatic outpatients (OP); and (iii) hospitalised patients (HP). VL (expressed in Log10 RNA copies/mL) was calculated through a quantitative real-time one-step reverse transcription-polymerase chain reaction (RT-PCR) assay aimed at the M gene, with human RNAseP target as internal control and normalising gene of threshold cycle values. FINDINGS A total of 162 (7.16%) H1N1pdm09 positive samples were analysed. Patients aged from 0.08 to 77 years old [median ± standard deviation (SD): 12.5 ± 20.54]. Children with 5 to 11 years old presented the highest detection (p < 0.0001). AS patients had the lowest VL, with a significant difference when compared with symptomatic patients (p = 0.0003). A higher VL was observed within two days of disease onset. Ten patients (HP group) received antiviral treatment and were followed up and presented a mean initial VL of 6.64 ± 1.82. A complete viral clearance for 50% of these patients was reached after 12 days of treatment. MAIN CONCLUSIONS It is important to evaluate AS patients as potential spreaders, as viral shedding was still present, even at lower VL. Our results suggest that patients with underlying diseases and severe clinical symptoms may be considered for prolonged viral treatment.

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.

Organizaçäo do espaço urbano e expansäo do calazar / The organization of urban areas and expansion of kala-azar

Objetivos: verificar determinados processos que estäo relacionados com a ocupaçäo do espaço urbano e que contribuem para a ocorrência e expansäo do calazar em um município de médio porte com acentuado fluxo migratório e em expansäo econômica. Métodos: trata-se de um estudo epidemiológico, de corte transversal, no qual se realizou a investigaçäo domiciliar dos casos registrados em 8 bairros e respectivos setores censitários, no município de Petrolina, Pernambuco, no período de 1992 a 1997. Está subsidiado por elementos da pesquisa laboratorial, considerando o transmissor e o reservatório. Utiliza o modelo explicativo da determinaçäo social do processo saúde-doença a esta situaçäo endêmica-epidêmica. Resultados: observa-se uma concentraçäo de casos de calazar na periferia da zona urbana do município de Petrolina, em áreas de invasäo e expansäo, onde o saneamento básico é precário, há a presença de animais e do vetor no peridomicílio e a populaçäo apresenta um baixo grau de instruçäo. O sexo masculino e a faixa etária de 0-4 anos säo os mais acometidos. Conclusöes: os achados sugerem o estabelecimento de um novo padräo epidemiológico para o calazar em Petrolina, onde a ocorrência dessa endemia se dá em um espaço altamente modificado pela populaçäo. Tal situaçäo caracteriza um processo de ruralizaçäo das áreas periurbanas endêmicas nas grandes cidades.

First report of Lutzomyia (Nyssomyia) umbratilis Ward & Frahia, 1977 outside of Amazonian Region, in Recife, State of Pernambuco, Brazil (Diptera: Psychodidae: Phlebotominae)

Lutzomyia umbratilis, a known vector of Leishmania guyanensis in the north of Amazon basin, has been exclusively found in the Amazonian region. Here we report for the first time the occurrence of this species in northeastern Brazil. The epidemiological importance of the occurrence of this species in the Atlantic Forest is commented