ABSTRACT
ABSTRACT Background: São Paulo city has been one of the regions most affected by the COVID-19 pandemic in Brazil. Frequent asymptomatic and oligosymptomatic infections and poor access to diagnostic tests make serosurveys crucial to monitor the magnitude of the epidemic and to inform public health policies, such as vaccination plans. Objectives: To estimate, early in the epidemic, the seroprevalence of antibodies to SARS-CoV-2 in adults living in the six most affected districts in São Paulo city, and to assess potential associated risk factors. Methods: This was a cross-sectional population-based survey of 1,152 households randomly selected from 72 census tracts. During the period May 4-12, 2020, 463 participants completed a questionnaire on sociodemographic characteristics and history of symptoms in the past two weeks, and provided a blood sample. Prevalence of SARS-CoV-2 antibodies was the outcome of interest and was estimated based on results of two immunoassays, Maglumi SARS-CoV-2 chemiluminescence assay Immunoglobulin (Ig) M (IgM) and IgG, and Roche electrochemiluminescence assay total Ig. Serum samples reactive to either assay were considered positive. Results: Weighted overall seroprevalence was 6% (95%CI 3.9-8.3%). No association was observed between seropositivity and sex, age group or education level. Participants who reported black and brown skin color showed a 2.7 fold higher prevalence than people with white skin (p = 0.007). Among the 30 seropositive individuals, 14 (46.6%) reported no COVID-19 compatible symptoms in the past two weeks. Conclusion: This study represents the first assessment of SARS-CoV-2 seroprevalence in the city of São Paulo and 6% is the baseline estimate of a series of population-based seroprevalence surveys. Serological screening using sound serological assays is the key tool to monitoring temporal and geographic changes in the spread of the virus through an important epicenter of the COVID-19 pandemic in Brazil. Ultimately, it may inform prevention and control efforts.
Subject(s)
Humans , Adult , SARS-CoV-2 , COVID-19 , Brazil/epidemiology , Immunoglobulin G , Seroepidemiologic Studies , Cross-Sectional Studies , Pandemics , Antibodies, ViralABSTRACT
Antecedente: El dengue es una infección con diferentes formas clínicas de presentación, de gran importancia mundial. Objetivo: Caracterizar la prevalencia de infección reciente por dengue en la localidad de San Mateo. Métodos: El universo estuvo constituido por 15 000 habitantes representados a través de una muestra de 535, quienes fueron seleccionados por un método aleatorio simple. Se les realizó una encuesta clínica y seroepidemiológica. Para el cálculo de la prevalencia se utilizó la tasa por cada 100 habitantes. Resultados: La prevalencia encontrada fue de 14,95 porciento (IC: 95 porciento: 12,1-18,3), que afectó a todos los grupos de edades y géneros. Algunos casos con cuadro clínico típico presentaron IgM negativa. Conclusión: La localidad de San Mateo constituye un área con transmisión de dengue
Background: Dengue is an infection with different clinical ways of presentation and of a great significance at world scale. Objective: To characterize the prevalence of the recent infection due to dengue in San Mateo town. Methods: Universe included 15 000 inhabitants represented by a sample of 535 who were selected by a simple randomized method. A clinical and seroepidemiologic survey was applied. For prevalence estimation authors used the rate by 100 inhabitants. Results: The prevalence found was of 14.95 percent (95 percent CI: 12.1-18.3) involving all age groups and genders. Some cases with a typical clinical picture had an IgM negative. Conclusion: San Mateo town is an area of dengue transmission
Subject(s)
Aedes , Dengue Virus , Dengue/epidemiology , Health Surveys/methods , VenezuelaABSTRACT
Introducción. La toxoplasmosis es una zoonosis de distribución mundial, cuya población vulnerable está constituida por mujeres embarazadas e individuos inmunosuprimidos. Por tal motivo, la mayoría de los estudios de seroprevalencia se llevan a cabo en estos grupos de población y no en la población general. Objetivo. Determinar la seroprevalencia de anticuerpos IgG contra Toxoplasma gondii en donantes del banco de sangre de la Clínica Cardiovascular Santa María, Medellín, Colombia. Métodos. Se seleccionó por conveniencia una muestra constituida por 201 donantes sanos del banco de sangre de la Clínica Cardiovascular Santa María. A estos donantes se les aplicó un cuestionario, en el que se les indagó por datos sociodemográficos y la posible exposición a factores de riesgo relacionados con la toxoplasmosis, y se les tomó una muestra de sangre venosa para determinar los niveles séricos de IgG contra T. gondii, mediante una técnica de inmunoensayo por electroquimioluminiscencia, Resultados. El 29,9% de los donantes presentó una serología reactiva para anticuerpos IgG contra el parásito. Un análisis bivariado reveló que el resultado positivo de la prueba serológica se relacionaba con la edad y el nivel de escolaridad (p=0,007 y p=0,025, respectivamente).
Introduction: Toxoplasmosis is a zoonosis of world-wide distribution. Pregnant women and immunosuppressed individuals constitute the susceptible population, reason why most of seroprevalence studies of T. gondii usually are made in these populations over those in healthy population. Objective: We sought to determine the prevalence of T. gondii infection in a sample of healthy blood donors from Medellín (Colombia). Materials and methods: Two hundred and one healthy blood donors from Clínica Cardiovascular Santa María (not selected randomly) were examined for toxoplasmosis infection between December 2000 and January 2010. Socio-demographic and behavioral characteristics acting from each participant were also obtained. Samples of venous blood were tested for anti- T. gondii IgG antibodies by using an electroquimioluminiscence assay. Results: Sixty (29.9%) of 201 donors had a reactive serology to IgG parasite antibodies. Bivariate analysis showed that the infection was related with age and schooling level (p=0,007 and p=0.025, respectively).
Subject(s)
Humans , Male , Female , Adult , Blood Donors , Toxoplasmosis , Parasites , Serology , Toxoplasma , Zoonoses , Risk Factors , Colombia , InfectionsABSTRACT
BACKGROUND/AIMS: Vaccination against hepatitis A virus (HAV) is recommended for patients with chronic hepatitis B (CHB), since they are potentially at an increased risk of HAV-related morbidity and mortality. However, little is known about the adherence to these recommendations in the community. This study evaluated the current vaccination status and immunity against HAV among Korean military soldiers with CHB. METHODS: We performed a prospective study of Korean military soldiers from August 2008 to January 2009. We enrolled 96 soldiers with CHB on a consecutive basis. We assessed their vaccination history and the presence of anti-HAV immunoglobulin G (IgG). RESULTS: The HAV vaccination rate of the soldiers enrolled in our study was 2% (2 of the 96 soldiers). The seroprevalence rates of anti-HAV IgG among military soldiers without a vaccination history were 0%, 50%, and 100% for those aged 19-29 years (n=71), 30-39 years (n=8), and 40 years or older (n=15), respectively (p<0.001). CONCLUSIONS: The HAV vaccination rate is very low among military soldiers. Public health efforts aimed at raising awareness about HAV vaccination in patients with CHB should be strongly encouraged.
Subject(s)
Aged , Humans , Hepatitis , Hepatitis A , Hepatitis A Antibodies , Hepatitis A virus , Hepatitis B, Chronic , Immunoglobulin G , Military Personnel , Prospective Studies , Public Health , Seroepidemiologic Studies , VaccinationABSTRACT
BACKGROUNDS/AIMS: The epidemiology of hepatitis A is associated with socioeconomic and hygiene status. Recently, the prevalence of hepatitis A in young adults has been steadily increasing in Korea. This study is to investigate the age-specific seroprevalence of hepatitis A virus in Korea. METHODS: Stored sera from 250 healthy adult subjects who visited the health promotion center in Samsung Medical Center between July and August 2006 were tested for IgG hepatitis A virus antibody (anti-HAV). RESULTS: The prevalence of anti-HAV was 2%, 72%, 92%, 94%, 100% in 20's, 30's, 40's, 50's, and 60's, respectively. The prevalence of anti-HAV was significantly lower in subjects below age 40 compared to those above 40 (37.0% vs. 95.3%, p<0.001). The seroprevalence was higher in area outside of Seoul compared to those living in Seoul in age group below 40 (25.6% vs. 55.6%, p=0.01). In Seoul area, the prevalence was significantly lower in Kangnam-Gu, Seocho-Gu, and Songpa-Gu district compared to the other areas of Seoul in the age group below 40 (20.0% vs. 42.1%, p<0.05). CONCLUSION: The seroprevalence of hepatitis A virus antibody in Korean population below 40 is quite low and immunity to hepatitis A virus in those subjects can be a public health issue. In view of changing seroepidemiology, a policy for hepatitis A vaccination in population below 40 might be warranted.
Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Age Factors , Demography , Hepatitis A/prevention & control , Hepatitis A Antibodies/blood , Hepatitis A Virus, Human/immunology , Korea , Seroepidemiologic StudiesABSTRACT
PURPOSE: The prevalence of hepatitis A virus (HAV) in a certain community reflects that community's living standards and hygienic conditions. And the pattern of HAV infection differs over time and geography. Recently, a shift in prevalence has been observed in cases from chilhood to adulthood. We studied the HAV antibody prevalence in the general population in Busan. METHODS: From October 2004 to March 2005, total 472 subjects were tested for HAV antibodies. All samples were collected from patients in Maryknol Hospital. RESULTS: The overall seropositive rate was 22.8% (108/472). The seropositive rates were 1.7% in subjects aged 2-5 years, 1.7% in 6-10 years, 0% in 11-20 years, 40.5% in 21-30 years, 82.1% in 31- 40 years, 94.7% in 41-50 years, and 100% in subjects aged over 50 years. There was no significant gap between gender groups. CONCLUSION: As the socioeconomic conditions in Korea have improved, the HAV seropositive rate in school-aged children has dramatically decreased in the last 20 years. But, the seropositive rate of HAV didn't differ according to gender. The seropositive rate of HAV in the pediatric group was very low, which suggests the increasing possibility of clinical HAV infection in adults in the near future. Therefore, we should actively prevent the spread of hepatits A virus. In order to do that, we need to reorganize our lifestyle and personel hygiene and carry out active and passive immunization to high risk groups.