[Seroprevalence of anti-SARS-CoV-2 IgG antibodies in resident physicians]. / Seroprevalencia de anticuerpos IgG anti-SARS-CoV-2 en médicos residentes.

Background: COVID-19 pandemic spread around the world swiftly; there are several diagnostic strategies available. Health workers, especially medical residents (MR), are a high-risk population for acquiring this infection. Objective: To estimate the seroprevalence of antibodies against SARS-CoV-2 and the associated factors in MR of a third level hospital. Material and methods: 330 MR from different specialties were evaluated with a questionnaire and collection of blood samples for analysis by microparticle chemiluminescent immunoassay. The prevalence of previous infection was defined by seropositivity of these antibodies. Descriptive statistics and concordance between the RT-PCR tests and the presence of anti-SARS-CoV-2 IgG were used. Results: Of 330 MR, 84.5% actively participated in COVID patient care. One out of 3 reported symptoms of COVID-19; in 67.6% the possible site of infection was a hospital setting not associated with the COVID area. Out of 71 symptomatic subjects, 61.9% underwent RT-PCR against SARS-CoV-2; 20 were positive. In 15.8% of the total, the presence of anti-SARS-CoV-2 IgG antibodies was determined. Only 1 out of 3 subjects with a positive PCR had antibodies, and 11.3% of the cases, even with a positive RT-PCR test, did not develop humoral immunity. Conclusions: The seroprevalence was lower than that reported at the national level, potentially due to protection measures. The main risk factor was contact with the virus in areas of the hospital not related to COVID, making it imperative to reinforce security protocols in those spaces.

Introducción: la pandemia por COVID-19 se extendió rápidamente a nivel mundial; hay disponibles varias estrategias de diagnóstico. Los trabajadores de la salud, en especial los médicos residentes (MR), son una población de alto riesgo para adquirir dicha infección. Objetivo: estimar la seroprevalencia de anticuerpos contra el SARS-CoV-2 y los factores asociados en los MR de un hospital de tercer nivel. Material y métodos: se evaluaron 330 MR de diferentes especialidades con un cuestionario y recolección de muestras de sangre para análisis mediante un inmunoensayo quimioluminiscente de micropartículas. La prevalencia de infección previa se definió por seropositividad de estos anticuerpos. Se utilizó estadística descriptiva y concordancia entre las pruebas RT-PCR y presencia de IgG anti-SARS-CoV-2. Resultados: de los 330 MR, 84.5% participó activamente en atención de pacientes COVID. Uno de cada tres refirió síntomas de COVID-19; 67.6% tuvo posible sitio de contagio en ámbito hospitalario no asociado a Área COVID. De los 71 sujetos sintomáticos, 61.9% se realizaron RT-PCR; 20 fueron positivas. En 15.8% del total se determinó la presencia de anticuerpos IgG anti-SARS-CoV-2. Solo uno de cada tres sujetos con PCR positiva presentó anticuerpos y 11.3% de los casos, aun con RT-PCR positiva, no desarrolló inmunidad humoral. Conclusiones: la seroprevalencia fue menor que la reportada a nivel nacional, potencialmente por medidas de protección. El principal factor de riesgo fue el contacto con el virus en áreas del hospital no relacionadas a COVID, por lo que es imperativo reforzar los protocolos de seguridad en esos espacios.

SARS-CoV-2 Antibody Prevalence in the Portuguese Municipality of Vila Nova de Gaia after the First Wave of the Pandemic.

INTRODUCTION: Assessment of SARS-CoV-2 seroprevalence may detect the real spread of the virus because antibody data can provide a long-lasting measure of infection. Existing serological studies in Portugal have tested new serology methods, albeit with small sample sizes and a lack the focus on geographical regions with a high rate of infection cases. The aim of this study was to estimate the serological prevalence of SARS-CoV-2 in Vila Nova de Gaia, the most populous municipality in the north of Portugal and one of those most affected during the first pandemic wave. MATERIAL AND METHODS: A cross-sectional observational study was conducted between June 23rd and July 17th, 2020. Included in the cohort were 18- to 74-year-old men and women living in the municipality of Vila Nova de Gaia, who were sampled through a nonprobabilistic quota-based approach. Cases with a previous RT-PCR diagnosis of COVID-19 were excluded. Sociodemographic and clinical information was collected using a self-administered, written questionnaire. Blood samples were collected for serological laboratory analysis to detect and quantify SARS-CoV-2 anti-IgG antibodies. RESULTS: We tested 2754 participants. Our results show a SARS-CoV-2 seroprevalence of 3.03% (95% confidence interval: 2.37% - 3.87%). Being a smoker (odds ratio: 0.382, 95% confidence interval: 0.147 - 0.99) and having symptoms of COVID-19 (odds ratio: 2.480, 95% confidence interval: 1.360 - 4.522) were consistently associated with lower and higher odds of SARS-CoV-2 antibody presence, respectively, regardless of the analytic design. Moreover, without adjusting for any variables, having had contact with an infected person within the household was associated with increased odds of a positive test (odds ratio: 9.684, 95% confidence interval: 4.06 - 23.101); after adjusting, having self-reported chronic diseases (odds ratio: 0.448, 95% confidence interval: 0.213 - 0.941) was associated with decreased odds. CONCLUSION: This was the first study to estimate the serological prevalence of SARS-CoV-2 in one of the most populous municipalities in Portugal, representing the first step in the development of an epidemiological surveillance system in Portugal, which can help to improve the diagnosis of COVID-19.

Seroepidemiologicalmonitoring of SARS-CoV-2 IgG in main railway stations in the city of Buenos Aires, Argentina / Monitoreo seroepidemiológico de igg contra el sars-cov-2 en estaciones ferroviarias cabeceras de la ciudad autónoma de buenos aires, argentina

RESUMEN INTRODUCCIÓN : Los estudios de seroprevalencia permiten monitorear la circulación del SARS-CoV-2 y dan información para evaluar medidas sanitarias. El objetivo fue conocer la proporción y evolución de la seropositividad en puntos de gran circulación de la Ciudad Autónoma de Buenos Aires (CABA) y las características clínico-epidemiológicas de los seropositivos, de abril a octubre de 2020. MÉTODOS : Se realizó un estudio descriptivo transversal de seis rondas de testeos rápidos serológicos y una encuesta de datos epidemiológicos. Se realizó un muestreo por conveniencia en tres estaciones ferroviarias cabeceras de CABA consideradas puntos de alto tránsito bidireccional del Área Metropolitana de Buenos Aires. RESULTADOS : Participaron 7339 personas. La proporción de seropositivos fue 0,6% (IC95%: 0,2-0,9) en la primera ronda y aumentó a 5,6% en la última (IC95%: 4,3-7). Al inicio aumentó la seropositividad en residentes de CABA y de la zona sur de la Región Metropolitana de Buenos Aires. El antecedente de haber presentado síntomas y el de contacto con personas con COVID-19 fueron las únicas variables relacionadas con el resultado de inmunoglobulina G positivo (p <0,05). El 56,1% (n = 97) de los seropositivos no tuvo síntomas. El 78,4% (n = 134) no fue diagnosticado en la etapa aguda. DISCUSIÓN : La seropositividad fue en ascenso en cada ronda, en coincidencia con la situación epidemiológica de la zona de residencia. Las características epidemiológicas como la proporción de seropositivos sin antecedentes de síntomas, reafirman la importancia de las medidas sanitarias poblacionales.

ABSTRACT INTRODUCTION : Seroprevalence studies allow monitoring the circulation of SARS-CoV-2, providing information to evalúate public health measures. The aim of this study was to determine the proportion and evolution of seropositivity in high circulation points in the Ciudad Autónoma de Buenos Aires (CABA) and clinical and epidemiological characteristics of seropositive individuals from April to October 2020. METHODS : A descriptive cross-sectional study was conducted during six rounds, using rapid serological testing together with an epidemiological data survey. A convenience sample was selected in three CABA railway stations considered as high bi-directional traffic points in the Buenos Aires Metropolitan Area (AMBA). RESULTS : 7,339 people participated. The seropositive proportion was 0.6% (95%CI: 0.2-0.9) in the first round, and rose to 5.6% in the last one (95%CI: 4.3-7). Initially, seropositivity increased in CABA residents and those living in the southern part of the Buenos Aires Metropolitan Region. Having presented symptoms and history of contact with COVID-19 cases were the only variables found to be related to positive IgG results (p<0.05). Among seropositive participantes, 56.1% (n=97) had no symptoms and 78.4% (n=134) didn't receive a COVID-19 diagnosis in the acute stage. DISCUSSION : Seropositivity increased between rounds, according to the epidemiological situation in the area of residence. Epidemiological characteristics, such as the proportion of seropositive individuals with no history of symptoms, reaffirm the importance of public health and social measures.

Seroprevalence of SARS-CoV-2 Infection in Portugal in May-July 2020: Results of the First National Serological Survey (ISNCOVID-19).

INTRODUCTION: The aim of this study was to estimate and describe the prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) specific antibodies (immunoglobulin M and/or immunoglobulin G) in Portugal in May-July 2020. MATERIAL AND METHODS: A cross-sectional seroepidemiological survey was developed after the peak of the first epidemic wave on a sample of 2301 Portuguese residents, aged 1 year or older. Survey sample was selected using a two-stage stratified non-probability sampling design (quota sampling). SARS-CoV-2 immunoglobulin M and immunoglobulin G antibodies were measured in serum samples by enzyme-linked immunosorbent assay. Seroprevalence estimates of immunoglobulin M and/or immunoglobulin G and 95% confidence intervals were stratified by sex, age group, health region and education. RESULTS: Overall, seroprevalence was 2.9% (95% confidence interval: 2.0% - 4.2%). Higher prevalence rates were observed in male (4.1%, 95% confidence interval: 2.6% - 6.6%) and those with secondary education (6.4%, 95% confidence interval: 3.2% - 12.5%). Differences in seroprevalence by age group and region were not statistically significant. DISCUSSION: The estimated seroprevalence of SARS-CoV-2 was higher than the cumulative incidence reported by the National Surveillance System but far from necessary to reach herd immunity. CONCLUSION: Our results support limited extent of infection by SARS-CoV-2 in the study population possibly due to early lockdown measures implemented in Portugal and support the need to continue monitoring of SARS-CoV-2 seroprevalence in order to increase our knowledge about the evolution of the epidemic and to estimate the proportion of the susceptible population over time.

Introdução: Este estudo tem como objetivo estimar e descrever a prevalência dos anticorpos específicos (imunoglobulina M e/ou imunoglobulina G) contra o vírus da síndrome respiratória aguda grave do coronavírus 2 (SARS-CoV-2) em Portugal em maio-julho de 2020. Material e Métodos: Após o pico da primeira onda epidémica foi realizado um estudo seroepidemiológico transversal numa amostra de 2301 pessoas residentes em Portugal, com idade igual ou superior a um ano. A amostra foi selecionada recorrendo um desenho amostral não probabilístico bietápico estratificado por quotas. Procedeu-se à deteção de anticorpos específicos contra SARS-CoV-2 (imunoglobulina M e imunoglobulina G) em amostras de soro por ensaio de imunoabsorção enzimática. As estimativas da seroprevalência (imunoglobulina M e/ou imunoglobulina G) e os respetivos intervalos de confiança a 95% foram estratificadas por sexo, grupo etário, região de saúde e escolaridade. Resultados: A seroprevalência de anticorpos específicos imunoglobulina M e/ou imunoglobulina G foi de 2,9 % (intervalo de confiança a 95%: 2,0% ­ 4,2%), tendo sido mais elevada em homens (4,1%, intervalo de confiança a 95%: 2,6% - 6,6%) e nos indivíduos com ensino secundário (6,4%, intervalo de confiança a 95%: 3,2% - 12,5%). Não foram identificadas diferenças estatisticamente significativas na entre os grupos etários estudados, nem entre regiões. Discussão: A seroprevalência estimada foi superior à incidência cumulativa de infeção reportada pelo Sistema Nacional de Vigilância, embora longe dos valores necessários para atingir a imunidade de grupo. Conclusão: Os resultados indicam uma extensão limitada da infeção por SARS-CoV-2, na população estudada compatível com uma implementação precoce das medidas de confinamento em Portugal e suporta a necessidade de monitorização a seroprevalência de SARS-CoV-2 para conhecer a evolução da epidemia e proporção da população suscetível ao longo do tempo.

Application of combined detection of enterovirus nucleic acid and antibody in early etiological diagnosis for hand-foot-and-mouth disease / 中华检验医学杂志

Objective To assess the value of combined detection of enterovirus nucleic acid and antibody in early etiological diagnosis for hand-foot-and-mouth disease ( HFMD).Methods A case-control study was conducted.A total of 1 066 cases of children clinically diagnosed with HFMD from Hangzhou Children′s Hospital were involved into the research group from January to June 2014, consisting of 401 common cases and 665 severe cases; Throat swabs and serum samples from these children underwent combined detection for EV71/CA16/EV of enterovirus nucleic acid by fluorescence quantitative RT-PCR and for EV71/CA16-IgM by ELISA.All data were analyzed with SPSS 16.0.Results The total positive rate of enterovirus nucleic acid EV71/CA16/EV by fluorescence quantitative RT-PCR in the 1 066 cases of children clinically diagnosed with HFMD was 75.52%( 805/1 066 ) ( 95%CI: 72.80%-78.05%).But the total positive rate of combined detection was 91.46%( 975/1 066 ) ( 95%CI:89%.58-93.04%).The total positive rate of combined detection is higher than that of RT-PCR test(χ2 =98.338,P=0.000).The positive rate of EV71 type of combined detection was 64.63%(689/1 066)(95%CI:61.67%-67.49%),which is 15.38%higher than that of RT-PCR test 49.25%(525/1 066)(95%CI:46.21%-52.29%)(χ2 =51.453, P=0.000).In 665 severe cases of HFMD, the total positive rate of combined detection was 96.69%(643/665)(95%CI:94.95%-97.87%), which is higher than that of RT-PCR test 79.25%(527/665)(95%CI:75.92%-82.22%)(χ2 =95.607, P =0.000).In the severe cases, the positive rate of EV71 type of combined detection was 87.52%( 582/665 ) ( 95%CI:84.71%-89.89%) , which is 18.95% higher than that of RT-PCR test 68.57%(456/665) (95%CI:64.87%-72.06%) (χ2 =69.665, P=0.000).In the fatal cases, the positive rate of EV71 type of combined detection was 95.92%(94/98) (95%CI:89.28%-98.68%).Conclusions The combined detection of enterovirus nucleic acid and specific IgM antibody can significantly increase the positive rate of HFMD, especially for severe cases.The combine detection increases both the total positive rate and EV71 positive rate.Thus it has a high potential for becoming a new guidelines for laboratory diagnosis of HFMD.

The value of detection of three anti-Epstein-Barr viral antibodies for nasopharyngeal carcinoma diagnosis / 中华检验医学杂志

Objective To evaluate the value of Epstein-Barr virus (EBV) IgG antibody to EBV Rta protein(Rta-IgG),IgA antibody to EBV early antigen (EA-IgA) and IgA antibody to EBV viral capsid antigen(VCA-IgA) for nasopharyngeal carcinoma (NPC) diagnosis.Methods From May 2012 to July 2013,serum samples from 8 884 healthy donors,1 546 clinical screening patients and 155 NPC patients in Fujian Medical University Union Hospital were collected,and EBV Rta-IgG,EA-IgA and VCA-IgA were detected by ELISA.The ROC curve analysis and correlation analysis were performed to assess the value of Rta-IgG,EA-IgA and VCA-IgA for NPC diagnosis.The positive rate among three kinds of antibodies were compared with chi-square test.Results Positive rates of EBV Rta-IgG,VCA-IgA and EA-IgA in NPC patient group were 81.9％ (127/155),90.3％ (140/155) and 48.3％ (75/155),respectively,which were higher than those in clinical screening patient group and healthy donor group (x2 =1 538.6,479.3 and 643.3 respectively,P ＜ 0.01).The sensitivity of VCA-IgA (90.3％,140/155) and the specificity of EA-IgA (95.1％,9 915/10 430) were the highest in all groups.Further analysis showed that negative predictive value of EBV Rta-IgG,VCA-IgA and EA-IgA for NPC diagnosis were 99.7％ (9 826/9 854),99.8％ (8 168/8 183),99.2％ (9 915/9 995),respectively,suggesting that three anti-EBV antibodies showed very good negative predictive value for NPC diagnosis.Next,combined detection of three anti-EBV antibodies could improve the sensitivity (94.1％,146/155) and specificity (98.9％,10 469/10 585) for the NPC diagnosis.Conclusion The EBV Rta-IgG,VCA-IgA and EA-IgA all show the clinical value for NPC diagnosis,and combined detection for Rta-IgG,VCA-IgA and EA-IgA is more suitable to screen NPC and can improve the sensitivity and specificity of NPC diagnosis.

Serum levels of antibody against enterovirus 71 in healthy children at Shanghai in 2011 / 中华传染病杂志

Objective To test the levels of enterovirus 71 (EV71) antibody among children of different ages in Shanghai in 2011,and to investigate the relationship between antibody levels and virus infection.Methods EV71 antibody was detected by microneutralization assay from the serum specimens of healthy children of different ages collected during July to August,2011.The results were analyzed by t test for quantitative data with normal distribution,and by x2 test for count data.Results The positive rate of EV71 antibody among the 93 serum specimens was 58.1％ (54/93).The geometric mean titer (GMT) of EV71-specific neutralizing antibody was 1 ∶ 14.48.The positive rate of EV71 antibody in infants less than 6 months old was 87.5％ (21/24),and the GMT was 1∶29.56.In children aged 2 to 3 years,the positive rate of EV71 antibody decreased to 3.7％ (1/27),and GMT decreased to 1∶4.21,which were both statistically significantly lower than those less than 6 months old (x2 =36.37,t=7.58; both P＜0.01).The positive rate of EV71 antibody increased to 83.3％ (20/24) in children aged 5 to 6 years,with GMT reaching 1∶21.74.Whereas in children aged 7 to 8 years,the positive rate was 66.7％ (12/18) and GMT was 1∶20.76,without statistically significant difference compared with those aged 5 to 6 years (x2 =1.58,t=0.597; both P＞0.05).No statistically significant difference was found between boys and girls in positive rate of EV71 antibody [62.7 ％ (32/51) vs 52.4 ％ (22/42),x2 =1.02,P＞0.05] or GMT (1 ∶ 16.23 vs 1 ∶ 12.61,t=0.881,P＞0.05).Conclusions Children aged 2 to 3 years were at higher risk for EV71 infection,with EV71 antibody level significantly lower than other age groups.

Serological study of blood donors with occult hepatitis B virus infection / 中国医师杂志

Objective Some blood donors were negative for the surface antigen but positive for the core antibody,leading to acute hepatitis.This study was to determine the seroprevalence of the hepatitis B core antibody in voluntary blood donors.Methods A total of 9100 donor samples were screened for hepatitis B surface antigen and Hepatitis B core antibody with enzyme-linked immunosorbent assay(ELISA).The samples which were positive for the core antibody were subjected to real-time polymerase chain reaction (PCR) for the hepatitis B DNA detection.Results Among the 9100 donors,911 (10.01％) donors were positive for the core antibody.The hepatitis B surface antigen was positive in 199 (2.19％) donors.Among the 911 donors who were positive for the core antibody,820 (90.01％) donors were negative for the HB-sAg,and 35 donors were positive for hepatitis B DNA.Conclusions If a routine screening of the sera for the core antibody is not done,the HBV DNA viraemia may not be identified.The absence of the surface antigen in the blood of apparently healthy individuals may not be sufficient to ensure the lack of the circulating virus.It is necessary to attach importance to the blood donors screening HBsAg-negative population further serological testing,suspicious specimens should detect HBV DNA.

Soroprevalência de anticorpos contra vírus herpes simples 1-2 no Brasil / Seroprevalencia de anticuerpos contra virus herpes simples 1-2 en Brasil / Seroprevalence of herpes simplex 1-2 antibodies in Brazil

OBJETIVO: Estimar a soroprevalência de anticorpos por vírus herpes simples (HSV-1 e HSV-2) e analisar fatores associados no Brasil. MÉTODOS: Estudo transversal realizado entre 1996 e 1997 em 1.090 indivíduos com idade entre um e 40 anos da população geral, em quatro diferentes regiões geográficas no Brasil. Foram analisadas amostras sangüíneas para detecção de anticorpos para HSV-1 e HSV-2 com teste tipo-específico Elisa. Foram descritas freqüências e proporções, comparadas entre grupos utilizando o teste de Fisher bilateral exato. Foi realizada análise de regressão logística para avaliar influência das variáveis sociodemográficas e histórico de DST, sobre a soroprevalência de HSV-1 e/ou HSV-2. RESULTADOS: As soroprevalências de anticorpos para HSV-1 e HSV-2, ajustadas por idade, foram 67,2 por cento e 11,3 por cento respectivamente, sem diferença quanto ao sexo e maiores na Região Norte...

OBJECTIVE: To estimate the seroprevalence of HSV-1 and HSV-2 antibodies in Brazil and to analyze factors associated. METHODS: Cross-sectional study including subjects aged 1-40 years from the general population in four different geographical areas in Brazil between 1996 and 1997. All subjects were stratified by age and gender and 1,090 of them were included in the final analysis. Blood samples were tested for HSV-1 and HSV-2 antibodies by type-specific (gG1 and gG2) ELISA. Frequencies and proportions were described and compared among groups using two-sided Fisher's exact test. A logistic regression analysis was performed to assess the influence of the variables age, gender, geographical area, socioeconomic condition, past history of STD, seropositivity for anti-HSV-1 or anti-HSV-2 and interactions of any of these factors on the seroprevalence of HSV-1 and/or HSV-2. RESULTS: The age-adjusted seroprevalences of HSV-1 and HSV-2 antibodies were 67.2 percent and 11.3 percent, respectively, without sex differences and being higher in the North region...

OBJETIVO: Estimar la seroprevalencia de anticuerpos por virus herpes simples (HSV-1 y HSV-2) en diferentes áreas geográficas en Brasil y analizar factores asociados. MÉTODOS: Estudio transversal realizado entre 1996 y 1997 con individuos de la población en general en cuatro diferentes áreas geográficas en Brasil y estratificados por edad (de uno a 40 años) y sexo, de los cuales 1.090 fueron incluidos en el análisis final. Fueron analizadas muestras de sangre para detección de anticuerpos para HSV-1 y HSV-2 con prueba tipo-específica ELISA gG1-gG2. Fueron descritas frecuencias y proporciones y comparadas entre grupos utilizando la prueba de Fisher bilateral exacta. Fue realizado análisis de regresión logística para evaluar influencia de las variables edad, sexo, geografía, grupo económico, histórico de DST, seropositividad para anti-HSV-1 o anti-HSV-2 e interacciones de cualquiera de esos factores sobre la seroprevalencia de HSV-1 y/o HSV-2. RESULTADOS: La tasa de seroprevalencia de anticuerpos para HSV-1 ajustada por edad fue de 67,2 por ciento, sin diferencia con relación al sexo, siendo mayor en la Región Norte...

Analysis of levels of antibodies against influenza A virus of population in Shanghai during 2009 / 中华传染病杂志

Objective To know the levels of antibodies against influenza A virus subtypes H1 and H3 of population in Shanghai during 2009, and the detection of antibodies against avian influenza virus subtypes H5 and H9 in population which contacts with avian. Methods The serological survey of the antibodies against influenza A viruses subtypes H1, H3, H5 and H9 in 356 close contacts with avian (professional population) and 332 general subjects (general population) at various age groups were carried out using hemagglutinin inhibit (HI) test. Results The positive rates of antibodies against influenza virus A/Brisbane/59/2007 (H1N1) in general population and professional population were 82.8% (275/332) and 73.9% (263/356), respectively; those of A/Brisbane/10/2007 (H3N2)were 50.6% (168/332) and 54.8% (195/356), respectively. The positive rate of antibodies against influenza virus A/Brisbane/59/2007 (H1N1 )was significantly higher than that of influenza A viruses subtype H3, which was consistent with etiological survey of influenza virus in Shanghai during 2008.The positive rates of antibodies against influenza A virus subtype H5 in professional population and general population were 4.2% (15/356) and 0.3% (1/332), respectively; those of influenza A virus subtype H9 were 34.6% (123/356) and 2.4% (8/332), respectively. The positive rates of antibodies against influenza virus A/Brisbane/59/2007 (H1N1 ) and A/Brisbane/10/2007 (H3N2) in age groups of 6 months-5 years and ≥60 years were lower than other age groups. Conclusions The immune protective response against seasonal influenza A subtype H1 and H3 of population in Shanghai is high,while those of children and the elders were low. The levels of antibodies against influenza A viruses subtype H5 and H9 in professinal population present obviously ascending trend, which indicates that the etiological and serological survey of influenza virus in this population should be enhanced.

[Evaluation of the response to vaccination against poliomyelitis and measles in malnourished children in Morocco]

We made a comparative survey of the poliovirus antibodies [anti-poliovirus type 1, anti-poliovirus type 2 and anti-poliovirus type 3] and the measles antibodies in malnourished but completely vaccinated children [37] and control children [34].The age range was 10 months to 5 years. Immunization in children with protein-energy malnutrition was low for both vaccines. Seroprevalence rates of the polio 1, polio 2, polio 3 antibodies and the measles antibodies in the control group were 94.1%, 97.1%, 91.2% and 82.4% respectively. In malnourished children the respective rates were in some cases significantly lower being: 40.5% [P = 0.001], 59.5% [P = 0.001], 40.5% and 35.1%. Malnutrition is a major determinant of the humoral response to oral polio and measles vaccines and must be given due consideration to prevent vaccination failure

Prevalence of measles antibody in children of different ages in Shiraz, Islamic Republic of Iran

An outbreak of measles due to secondary vaccine failure prompted this investigation into the prevalence of measles antibody in children. We studied 608 children in 7 different age groups: 6, 9, 14 and 18 months and 6, 10 and 15 years. Children in the 2 youngest groups received no vaccination; the rest were vaccinated at 9 months and 15 months. The 15-year-old age group received an additional vaccination. Transplacental measles antibody [Ab] decreased from 10.0% at 6 months to 0% at 9 months. Measles Ab was positive in 52.9% [14 months], 89.4% [18 months], 60.8% 96 years], 45.0% [10 years] and 96.8% [15 years].To increase Ab levels, a booster vaccination is recommended, administered either with the second DPT booster or at pre-high school age

Influenza surveillance in the Islamic Republic of Iran from 1991 to 2001

To better underst and the annual distribution of influenza virus in our country, we isolated and typed 45 viruses from 1043 patients with acute respiratory illnesses in a 10-year study conducted by the National Influenza Centre of the Islamic Republic of Iran. The seasonal distribution of influenza typically ran from November to April. Type A influenza was most common during the winters of 1991-92, 1997-98 and 2000-01 and type B influenza was most common during 1992-5 and 1996-97. Both type A and type B viruses circulated in 1995-96 and 1998-2000. A serological survey based on haemagglutination inhibition test confirmed our findings. The annual pattern of strains isolated was similar to the worldwide pattern during the same interval

Epstein-Barr virus in head and neck squamous cell carcinoma

We compared 50 patients with head and neck squamous cell carcinomas [cases] and 45 matched healthy controls. Biopsy specimens were taken from tumours and normal tissue of the cases and controls respectively and serial paraffin embedded sections were processed to detect Epstein-Barr [EB] viral antigen. We found EB viral proteins in 38% of cases and none in controls, which suggests a positive correlation. Serum samples were also tested for the presence of EB virus IgG by ELISA for comparison with immunohistochemical findings. Patients with positive immunohistochemical staining results had significantly higher mean antibody titres compared with those with negative results. ELISA may be useful in determining the etiology of head and neck cancers, but the results are not unequivocally reliable

Seroprevalence of three emerging arboviral infections in Kuwaiti nationals

Diseases caused by dengue, s and fly fever and hanta viruses pose a major health risk in many countries. We determined the threat of these arboviral infections through a serologic using enzyme linked immunosorbent assay [ELISA] based tests. Hantavirus-specific antibodies were also detected using immunofluorescence. Of 499 samples tested for dengue virus IgG antibodies l4% were as positive for dengue positive by all the ELISA tests. Among the 42 showing strong IgG reactivity, only 1 was positive for dengue virus IgM antibodies. All samples tested for IgG antibodies to s and fly fever virus were negative. Hantavirus antibodies were detected in 11% of the 46 samples from high-risk individuals. The low prevalences suggest that at present these infections are not a serious problem in Kuwait

Measles immunization in Saudi Arabia: the need for change

This paper describes the measles immunization programme in Saudi Arabia and the change from the single-dose schedule with the Schwartz vaccine to the double-dose schedule with the Edmonston-Zagreb vaccine. The recent measles-mumps-rubella school campaign is also described

The role of vitamin A in enhancing humoral immunity produced by antirabies vaccine

We tested the effects of vitamin A supplementation on the antibody titre of 40 healthy volunteers [age range: 10-35 years], who had received a complete course of antirabies vaccine [5 injections over 30 days]. After determining the baseline serum vitamin A status of 80 volunteers, 20 pairs were matched for serum vitamin A level, body mass index, age, sex and socioeconomic status. One person from each pair was randomly assigned to an experimental or control group. The experimental group received vitamin A and antirabies vaccine. Controls received only the vaccine. The experimental group had significantly greater [2.1 times] serum antirabies titre than controls. This finding is an important step towards improving the economy of dosage of antirabies vaccines

Preparation and characterization of polyclonal antibody against N protein of SARS-CoV / 解放军医学杂志

Objective To prepare and characterize the polyclonal antibody against N protein of SARS-CoV. Methods The polyclonal antibody against SARS-CoV N was obtained from immunized rabbit with purified GST-N. The titer of the antibody was determined by indirect ELISA, and the specificity by Western blot and immunochemical staining. Results The rabbit′s antibody against SARS-CoV N was prepared successfully. The titer of antiserum against SARS-CoV N was about 1.2?10~ -5 . Western blot and immunochemical staining analysis showed that the polyclonal antibody could bind to the expressed fusion protein specifically. Conclusion The rabbit′s antibody against SARS-CoV N has been prepared successfully, and it can be a useful reagent for clinical diagnosis and further research.