RESUMEN
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.
Asunto(s)
Infecciones por VIH , Cardiopatías , Subtipo H1N1 del Virus de la Influenza A , Infecciones por Virus Sincitial Respiratorio , Virus Sincitial Respiratorio Humano , Infecciones del Sistema Respiratorio , Síndrome Respiratorio Agudo Grave , Niño , Adulto , Anciano , Humanos , Lactante , Preescolar , Infecciones por Virus Sincitial Respiratorio/epidemiología , Carga Viral , Brasil/epidemiología , Estudios Retrospectivos , Enfermedad Crónica , Hospitales Universitarios , ARNRESUMEN
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.
RESUMEN
Acute viral bronchiolitis is the major cause of hospital admissions in children under 2 years of age, and respiratory syncytial virus (RSV) can be responsible for up to 80% of these infections. We aimed to describe RSV dynamics among hospitalized children with bronchiolitis. Upper respiratory samples of 101 hospitalized patients were collected and submitted to RSV detection by a quantitative real-time RT-PCR to assess viral load (Log10 RNA copies/mL). Seventy-two patients were positive for RSV infection, of which 38 (52.7%) could be followed up until RSV was no longer detected. The first RSV RT-qPCR was carried out on average on the 5th day of symptom onset. Thirty-six patients (94.7%) were still shedding RSV after 7 days, and 9 (23.6%) after 14 days of symptoms onset. Only 2 patients (5.2%) were still shedding RSV after 21 days. Only 7 of the followed patients (18.9%) were submitted to intubation. There was no difference between the viral load of the first collected sample and the viral persistence of patients with comorbidities, who needed intensive care unit and who needed intubation. These data could help understand RSV dynamics and future studies and treatments to come.
Asunto(s)
Bronquiolitis , Infecciones por Virus Sincitial Respiratorio , Virus Sincitial Respiratorio Humano , Niño , Progresión de la Enfermedad , Humanos , Lactante , Virus Sincitial Respiratorio Humano/genética , Carga ViralRESUMEN
The first SARS-CoV-2 intrafamilial transmission was investigated in China. We evaluated the dynamics of SARS-CoV-2 transmission in 242 individuals from 60 family clusters, including 30 healthcare workers (HCW) and 30 patients, in São Paulo city. Sixty index cases with COVID-19 were selected, being 30 HCW index cases from Hospital São Paulo (HSP) and its 93 household contacts and 30 index case patients from Hospital Infantil Sabará (HIS) and its 89 household contacts. Asymptomatic and symptomatic individuals participating were tested for COVID-19. The secondary attack rates in the family clusters of HCW and HIS patients were 37.63% and 68.54%, respectively. Considering all households, the transmission from adults to children was 55.4%, while the transmission from children to children was 37.5%. Children were more infected if the index case was an adult, suggesting that children were less competent to transmit. The average time for a household to be COVID-19 positive was 4 and 3 days for HCW and HIS patients. Although HCW have a higher risk of infection and social vulnerability, the secondary attack rate was lower than that observed for HIS patients, possibly because HCW are more aware of transmission risks than the general community.
Asunto(s)
COVID-19 , Adulto , Brasil/epidemiología , COVID-19/epidemiología , Niño , Personal de Salud , Humanos , Padres , SARS-CoV-2Asunto(s)
Vacunas contra la COVID-19 , COVID-19 , COVID-19/prevención & control , Personal de Salud , Humanos , SARS-CoV-2 , Vacunación , Carga ViralRESUMEN
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.
Asunto(s)
Alanina Transaminasa/sangre , Anticuerpos Antihepatitis/sangre , Hepatitis E , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Brasil , Niño , Preescolar , Hepatitis E/diagnóstico , Hepatitis E/epidemiología , Virus de la Hepatitis E , Humanos , Inmunoglobulina M/sangre , Lactante , Persona de Mediana Edad , Adulto JovenRESUMEN
Cholesteatomas are frequent middle ear benign tumors of unknown etiology. Infectious agents have been considered as possible contributing factors in the pathogenesis of cholesteatomas. Aiming to investigate the presence of respiratory viruses in primary cholesteatoma tissues, 26 formalin-fixed paraffin-embedded primary cholesteatoma tissues obtained from patients seen at the of the Clinical Hospital of the University of São Paulo School of Medicine, in Ribeirão Preto, Brazil were tested by real-time polymerase chain reaction (PCR). Considering the PCR results, 35% of the tissues were positive for human rhinovirus (HRV), 15.3% for human enterovirus (EV), 3.8% for human metapneumovirus (HMPV), and 3.8% for human bocavirus (HBoV). Serial immunohistochemistry for virus antigens and cell surface markers evidenced that the viruses were associated with fibroblasts, dendritic cells, macrophages, B lymphocytes, CD4+ , and CD8+ T lymphocytes. These findings indicate for the first time the presence of active respiratory virus infection in primary cholesteatoma tissues, suggesting that persisting virus infection in the middle could play a role in the pathogenesis and evolution of cholesteatomas.
Asunto(s)
Colesteatoma/virología , Enterovirus/aislamiento & purificación , Bocavirus Humano/aislamiento & purificación , Metapneumovirus/aislamiento & purificación , Rhinovirus/aislamiento & purificación , Adolescente , Adulto , Anciano , Brasil , Colesteatoma/patología , Estudios Transversales , Enterovirus/genética , Femenino , Bocavirus Humano/genética , Humanos , Masculino , Metapneumovirus/genética , Persona de Mediana Edad , Reacción en Cadena en Tiempo Real de la Polimerasa , Rhinovirus/genética , Adulto JovenRESUMEN
Since the coronavirus disease 2019 (COVID-19) pandemic, Brazil has the third-highest number of confirmed cases and the second-highest number of recovered patients. SARS-CoV-2 detection by real-time RT-PCR is the gold standard but requires a certified laboratory infrastructure with high-cost equipment and trained personnel. However, for large-scale testing, diagnostics should be fast, cost-effective, widely available, and deployed for the community, such as serological tests based on lateral flow immunoassay (LFIA) for IgM/IgG detection. We evaluated three different commercial point-of-care (POC) LFIAs for anti-SARS-CoV-2 IgM and IgG detection in capillary whole blood of 100 healthcare workers (HCW) from São Paulo university hospital previously tested by RT-PCR: (1) COVID-19 IgG/IgM BIO (Bioclin, Brazil), (2) Diagnostic Kit for IgM/IgG Antibody to Coronavirus (SARS-CoV-2) (Livzon, China), and (3) SARS-CoV-2 Antibody Test (Wondfo, China). A total of 84 positives and 16 negatives HCW were tested. The data was also analyzed by the number of days post symptoms (DPS) in three groups: <30 (n=26), 30-59 (n=42), and >59 (n=16). The observed sensibility was 85.71%, 47.62%, and 44.05% for Bioclin, Wondfo, and Livzon, respectively, with a specificity of 100% for all LFIA. Bioclin was more sensitive (p<0.01), regardless of the DPS. Thus, the Bioclin may be used as a POC test to monitor SARS-CoV-2 seroconversion in HCW.
Asunto(s)
Anticuerpos Antivirales/sangre , Prueba Serológica para COVID-19 , COVID-19/diagnóstico , Pruebas en el Punto de Atención , SARS-CoV-2/aislamiento & purificación , Adulto , Anciano , Brasil/epidemiología , COVID-19/epidemiología , Personal de Salud , Humanos , Inmunoensayo , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Persona de Mediana Edad , SARS-CoV-2/inmunología , Sensibilidad y Especificidad , Adulto JovenRESUMEN
Respiratory syncytial virus (RSV) is a relevant cause of acute respiratory infection among children. Viral replication and immune conditions may account for severity. RSV viral load (VL) was assessed in 486 children (290 hospitalized and 196 from primary care) attended at São Paulo Hospital from 2009 to 2013. VL was calculated by real-time reverse transcription-polymerase chain reaction and expressed in Log10 RNA copies/mL. Coinfection with rhinovirus (RV) and influenza A virus was also tested. Young children (<1 year of age) had a higher mean VL than older children at primary care (6.35 and 4.34 Log10 RNA copies/mL, respectively; P = .0006). Conversely, hospitalized children ≥2 years of age, presented higher mean VL compared with the same age children of primary care (6.10 and 4.26, respectively; P = .0024). RV was the most codetected virus in RSV positive patients (20% from primary care and 14% in hospitalized), and influenza A virus was found in 11% of primary care and 0.4% in hospitalized children with RSV, without RSV VL association (P = .2903). These findings may guide future therapies and immunization policies considering the role of viral load on clinical presentation among older hospitalized children and also the change of infection transmissions.
Asunto(s)
Hospitales Universitarios/estadística & datos numéricos , Atención Primaria de Salud/estadística & datos numéricos , Infecciones por Virus Sincitial Respiratorio/virología , Virus Sincitial Respiratorio Humano/genética , Carga Viral/estadística & datos numéricos , Factores de Edad , Brasil , Niño , Preescolar , Coinfección/virología , Hospitalización/estadística & datos numéricos , Humanos , ARN Viral/genéticaRESUMEN
BACKGROUND: Some studies have shown that hydroxychloroquine (HCQ) is an effective drug in reducing the in vitro replication of SARS-CoV-2. However, the in vivo effect of HCQ still unclear. OBJECTIVES: This study aims to evaluate viral load clearance in patients with COVID-19 who underwent HCQ treatment in comparison with a control group that did not receive the drug. STUDY DESIGN: This prospective study comprised consecutive viral load measurements in patients with COVID-19 hospitalized with a moderate illness. Patients received 400 mg of HCQ every 12 h for 10 days according to the medical decision. Nasal swab samples were collected from patients during early, intermediary, and final clinical stage of COVID-19. RESULTS: A total of 155 samples were collected from 66 patients with COVID-19 (60% female), with a median age of 58 years. The viral load between studied groups, assumed as a semiquantitative measure of cycle threshold (Ct) values, presented no significant difference within the three consecutive measures (ΔCt) (p > 0.05). We also analyzed the ΔCt viral load at different intervals of sample collection (Δt < 7; 7-12; and > 12 days) without significant differences at any ΔCt (p > 0.05). CONCLUSION: In this study, we did not observe any change in viral load reduction in vivo with the use of HCQ.
Asunto(s)
Tratamiento Farmacológico de COVID-19 , Hidroxicloroquina/farmacología , SARS-CoV-2/efectos de los fármacos , Carga Viral/efectos de los fármacos , Adulto , Antivirales/farmacología , Antivirales/uso terapéutico , Femenino , Humanos , Hidroxicloroquina/uso terapéutico , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Adulto JovenRESUMEN
SARS coronavirus-2 (SARS-CoV-2) detection in different clinical specimens has raised important insights about its pathogenesis, but some details remain to be understood. In that respect, disrupt viral control seen in solid organ transplant patients on chronic immunosuppression can help unveil pathogenic mechanisms and characterize new coronavirus disease-19 (COVID-19) immunological and clinical aspects, as well as secondary complications. We herein report a case of SARS-CoV-2 detection in ascitic fluid from a kidney transplant patient with decompensated cirrhosis and COVID-19 and then discuss about immune, cellular, and virological aspects of such clinical presentation of the disease, which also included a disseminated infection, demonstrated by viral detection in his blood sample. We subsequently discuss about the fatal outcome caused by a secondary bloodstream infection by Cryptococcus neoformans. This unprecedented case report presents ascitic fluid as a novel specimen in which SARS-CoV-2 can be detected. Immune dysregulation and cumulative risk factors may lead to secondary infections by opportunistic agents, including Cryptococcus neoformans.
RESUMEN
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.
Asunto(s)
Humanos , Neumonía Viral , Infecciones por Coronavirus , Pandemias , Neumonía Viral/epidemiología , Cuarentena , Ciudades , Infecciones por Coronavirus/epidemiología , Betacoronavirus , SARS-CoV-2 , COVID-19RESUMEN
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.
Asunto(s)
Infecciones por Coronavirus , Pandemias , Neumonía Viral , Betacoronavirus , COVID-19 , Ciudades , Infecciones por Coronavirus/epidemiología , Humanos , Neumonía Viral/epidemiología , Cuarentena , SARS-CoV-2Asunto(s)
Infecciones por Coronavirus/epidemiología , Virus de la Influenza A/aislamiento & purificación , Virus de la Influenza B/aislamiento & purificación , Gripe Humana/diagnóstico , Neumonía Viral/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Betacoronavirus/aislamiento & purificación , Brasil/epidemiología , COVID-19 , Niño , Preescolar , Hospitales Universitarios/estadística & datos numéricos , Humanos , Lactante , Recién Nacido , Gripe Humana/epidemiología , Persona de Mediana Edad , Pandemias , SARS-CoV-2 , Adulto JovenRESUMEN
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.
Asunto(s)
Subtipo H1N1 del Virus de la Influenza A/genética , Gripe Humana/virología , Infecciones del Sistema Respiratorio/virología , Enfermedad Aguda , Adolescente , Adulto , Anciano , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Subtipo H1N1 del Virus de la Influenza A/clasificación , Subtipo H1N1 del Virus de la Influenza A/patogenicidad , Masculino , Persona de Mediana Edad , ARN Viral/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Carga Viral , Adulto JovenRESUMEN
Currently, 2 genotypes of Influenza B viruses (IFB) are cocirculating in humans: Victoria (VIC) and Yamagata (YAM). Infection and viral load (VL) were analyzed in 105 genotyped IFB (59 VIC and 46 YAM) out of 3452 respiratory samples from immunodepressed (ID), immunocompetent (IC) including outpatients (OP) and hospitalized patients (HP) attended during 2001-2013 at São Paulo Hospital. VL (Log10 RNA copies/mL) calculation was possible in 78 samples (47 VIC, 31 YAM). The age group of 12 to 18 years presented the highest detection (14.13%). Rates of infection among groups were of 3.67% (IC), 1.68% (ID), 3.50% (OP), 0.6% (HP), and VLs varied from 2.8 to 10.13 with no difference regarding age, immune status, and disease severity. From 10 OP vaccinated against influenza, 8 (7 children, 1 ID) received a matching strain shot (VIC), and 2 a monovalent influenza A H1N1pdm09. Those patients presented a VL of 6.31 ± 1.62 (mean ± SD). IFB infection rates follow an age pattern, but VL seems not to be related to frequency or clinical outcome. IFB patients with previous immunization could point to some protection for VIC infections since there was no HP. Other immunological aspects, such as lineage infection immune priming, previous infections, and vaccinations, should be further investigated.
Asunto(s)
Virus de la Influenza B/genética , Gripe Humana/virología , Infecciones del Sistema Respiratorio/virología , Carga Viral/estadística & datos numéricos , Adolescente , Adulto , Anciano , Anticuerpos Antivirales/sangre , Brasil , Niño , Preescolar , Femenino , Humanos , Inmunización/estadística & datos numéricos , Lactante , Virus de la Influenza B/inmunología , Vacunas contra la Influenza/administración & dosificación , Gripe Humana/inmunología , Persona de Mediana Edad , Infecciones del Sistema Respiratorio/inmunología , Índice de Severidad de la Enfermedad , Centros de Atención Terciaria , Adulto JovenRESUMEN
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.