Detección y cuantificación de SARS-CoV-2 en plantas de tratamiento de aguas residuales de diferentes ciudades de Chile: hacia la implementación de una vigilancia centinela permanente

Introducción: La cuantificación de SARS-CoV-2 en aguas residuales es una herramienta que permite determinar la tendencia de la circulación viral en un área geográfica determinada. Objetivo: Cuantificar el virus SARS-CoV-2 en 15 plantas de tratamiento de aguas residuales en diferentes ciudades de Chile para establecer una comparación con las variables de: i) casos activos por cada 100.000 habs.; ii) positividad diaria (casos nuevos); y iii) fases del plan de confinamiento. Metodología: SARS-CoV-2 se concentró a partir de muestras de aguas residuales. Para obtener el número de genomas del virus por litro se realizó una cuantificación absoluta utilizando qRT-PCR. Resultados: Entre enero y junio de 2021 se procesaron 253 muestras, siendo todas positivas para la presencia del virus. Asimismo, se logró determinar que la tasa de casos activos por cada 100.000 habs. es la variable que mejor se ajusta a las tendencias obtenidas con la cuantificación de la carga viral en las aguas residuales. Conclusiones: La cuantificación de SARS-CoV-2 en las aguas residuales de manera permanente es una herramienta eficiente para determinar la tendencia del virus en un área geográfica determinada y, en conjunto con una vigilancia genómica, puede constituirse en una vigilancia centinela ideal generando alertas sobre futuros brotes.

Background: The quantification of SARS-CoV-2 in wastewater is a tool that allows determining the trend of viral circulation in a particular geographical area. Aim: To quantify the SARS-CoV-2 virus in 15 wastewater treatment plants in different Chilean cities to establish a comparison with the variables of: i) Active cases per 100,000 inhabitants; ii) daily positivity (novel cases); and iii) phases of the lockdown strategy. Methods: SARS-CoV-2 was concentrated from wastewater samples. To obtain the number of virus genomes per liter, absolute quantification was performed using qRT-PCR. Results: Between January and June 2021, 253 samples were processed, all of which were positive for the presence of the virus. Likewise, it will be determined that the rate of active cases per 100,000 inhabitants is the variable that best fits the trends obtained with the quantification of the viral load in wastewater. Conclusions: The quantification of SARS-CoV-2 in wastewater as a continuous strategy is an efficient tool to determine the trend of the viral circulation in a delimited geographical area and, combined with genomic surveillance, it can constitute an ideal sentinel surveillance alert on future outbreaks.

Polyomavirus en hospederos inmunocomprometidos: situación en Sudamérica / Polyomavirus in immunocompromised patients: the South America's situation

Resumen A 46 años de la identificación de los primeros polyomavirus en humanos (PyV), la preocupación por encontrar nuevos tipos relacionados a patologías de distintos órganos en pacientes inmunosuprimidos persiste. Hasta el momento de esta revisión, 15 PyV han sido descritos, muchos de ellos sin estar claramente asociados a enfermedades. En nuestro país, al igual que en gran parte de Sudamérica, el conocimiento y la pesquisa de estos agentes infecciosos son insuficientes por lo que sistematizamos aquello que se sabe sobre estos virus y su relación con los diferentes sistemas del cuerpo humano, con énfasis en los inmunosuprimidos y señalamos aquellos datos publicados en nuestro continente. Esperamos así incentivar un mayor estudio de estas infecciones virales.

Forty-six years after the identification of the first polyomaviruses in humans (PyV) still there are strong concerns to find new types related to pathologies of different organs in immunocompromised patients. At the time of this review, 15 PyV have been described, many of them without being clearly associated with diseases. In our country, as in much of South America, the knowledge and research of these infectious agents are insufficient, so we systematized what is known about these viruses and their relationship with different human systems with emphasis on immunocompromised and we pointed out data published in our continent. Thus, we hope to encourage the study of these infections.

Detección de polyomavirus BK y JC en extractos leucocitarios de sangre periférica de pacientes con infección por VIH del área norte de Santiago / BK and JC polyomavirus detection in leukocyte extracts of peripheral blood samples of HIV+ patients from the north area of Santiago

Introducción: Polyomavirus BK (BKPyV) y JC (JCPyV) son patógenos persistentes con capacidad de reactivación en inmunocomprometidos, afectando principalmente el sistema urinario y el sistema nervioso central, respectivamente. No existen estudios chilenos en población infectada por VIH. Objetivo: Detectar la presencia de BKPyV y JCPyV en muestras de sangre de pacientes adultos, chilenos, con infección por VIH y correlacionar los resultados con variables clínicas. Materiales y Métodos: Analizamos 96 muestras de extractos leucocitarios de pacientes del área norte de Santiago. El genoma viral se detectó mediante RPC en tiempo real. Para el análisis estadístico se utilizó las pruebas chi-cuadrado de Pearson y Mann-Whitney, considerando significativo un valor de p < 0,05. Resultados: 33% de las muestras resultaron positivas para BKPyV y se encontró una correlación significativa entre la presencia de genoma de BKPyV y la ausencia de carga viral de VIH. Se evidenció la necesidad de considerar más de un blanco de amplificación del genoma de BKPyV. Todas las muestras fueron negativas para JCPyV. Discusión: La prevalencia de BKPyV en pacientes chilenos con infección por VIH es superior a la informada en la mayoría de los reportes internacionales. Se requiere estudios que evalúen la interacción entre ambos virus. Estos pacientes deberían ser sometidos a controles urológicos y nefrológicos periódicos.

Introduction: Polyomavirus BK (BKPyV) and JC (JCPyV) are persistent pathogens able to reactivate in im-munocompromised patients, involving mostly urinary and central nervous system. There are no Chilean studies in HIV positive patients. Objective: To detect BKPyV and JCPyV in blood of Chilean HIV positive adult patients and to correlate these results with clinical-related variables. Materials and Methods: 96 stored blood samples from HIV patients belonging to the north area of Santiago were analyzed. Viral genomes of both viruses were detected by real-time PCR. For statistical analysis, chi-square (Pearson) and Mann-Whitney tests were used and p-values < 0.05 were considered significant. Results: 33% of the samples were positive for BKPyV and a significant correlation was found between the presence of BKPyV genome and the absence of detectable HIV viral load. We demonstrated the need to consider more than one amplification target to detect the BKPyV genome. All the samples were negative for JCPyV genome. Discussion: BKPyV prevalence in Chilean HIV patients is higher than most of international studies. New studies regarding the interaction between both viruses are required. These patients should undergo periodic evaluations by urologist and nephrologist.

Aumento de interleuquinas proinflamatorias y de cortisol plasmático en bronquiolitis por virus respiratorio sincicial: relación con la gravedad de la infección / Levels of inflammatory cytokines and plasma cortisol in respiratory syncytial virus bronchiolitis

Background: An increased inflammatory innate response may play a role in pathogenesis of respiratory syncytial virus (RSV) infection. Aim: To quantify pro-inflammatory cytokines (IL-6-IL-8, ÍL-2-P and TNF-a) in nasopharyngeal aspirate (NPA) and plasma, and plasma cortisol in previously healthy infants with RSV bronchiolitis. Patients and Methods: We studied 49 infants aged less than one year of age with RSV bronchiolitis and 25 healthy controls. Severity was defined using a previously described modified score. We quantified interleukins in NPA and plasma by flow cytometry and plasma cortisol by radioimmunoanalysis. Results: Among patients with RSV bronchiolitis, 25 were classified as severe and 24 as moderate or mild. Significantly higher levels ofIL-6 and IL-8 in NPA and plasma and IL-lfi in NPA were found in children classified as severe, when compared to those with moderate or mild disease and controls. There was a positive correlation between IL-6 and cortisol in plasma (r = 0,55; p < 0,0001) and both were correlated with the severity of the disease. Conclusions: RSV bronchiolitis severity was associated with higher levéis of inflammatory interleukins and plasma cortisol.

Detección de ADN de parvovirus B19 en donantes de sangre de tres hospitales en Santiago, Chile / Parvovirus B19 among blood donors from three hospitals in Santiago, Chile

Background: Parvovirus B19 (B19) is associated with a wide range of diseases in humans, whose severity depends on the immunological and hematological status of the host. It is transmitted mainly through the airway but also by transfusions. Aim: To determine the B19 DNA carrier frequency in a population of volunteer blood donors from three hospitals blood banks in Santiago, Chile, and to determine the viral load in DNA positive cases. Material and Methods: A total of477 serum samples were analyzed. The screening of B19 DNA was carried out by nested polymerase chain reaction (PCR) directed to the non-structural region of the virus (NS1). The viral load in positives cases was quantified by NS1 Real Time PCR. Results: Parvovirus B19 was detected in four samples, rendering a frequency of 1:119. The viral loads ranged from less than 2000 to 5,626 x 10(5) genome equivalents/ml. Conclusions: Parvovirus B19 was present in four of 477 blood bank blood donors from three hospitals in Santiago.

Seroprevalencia de anticuerpos IgG contra parvovirus B19 en donantes de sangre de hospitales en Santiago, Chile / Seroprevalence of IgG antibodies against parvovirus B19 among blood donors from Santiago, Chile

Background: Parvovirus B19 (B19) is associated with a wide range of disease manifestations, whose severity depends on the immunological and hematological status of the host. Infection with B19 has been reported worldwide and the prevalence of immunoglobulin G antibodies against B19 increases with age and varies by location and time of the last B19 epidemic. Aim: To evaluate the prevalence of IgG antibodies against Parvavirus B19 virus in a population of volunteer blood donors at two hospital blood banks in Santiago, Chile. Material and Methods: A total of 400 serum samples from blood donors aged 18 to 65 years, were examined for the presence of IgG antibodies against Parvovirus B19. Results: The overall prevalence of IgG antibodies was 54.8 percent. No significant difference was found between men and women (57.6 percent and 49.3 percent, respectively). Conclusions: IgG antibody seroprevalence against Parvovirus B19, was 55 percent in this sample of Chilean blood donors. This figure is in agreement with previous reports from abroad.