1,720,976 research outputs found
Adverse pregnancy outcomes among pregnant women with acute Rubella infections in Mwanza city, Tanzania
Objective: This study investigated the adverse pregnancy outcomes among pregnant women with acute Rubella infections in the city of Mwanza, Tanzania. Methods: A longitudinal study was conducted between 2014 and 2016 among pregnant women attending antenatal clinics. Women were screened for Rubella IgG and IgM antibodies using enzyme immunoassay (EIA). IgM seropositive pregnant women were followed up until the end of the pregnancy to determine Congenital Rubella Syndrome, congenital infections and other pregnancy outcomes. Results: The median age of 685 enrolled pregnant women was 23 (IQR: 19–27) years. A total of 629(91.8%) were Rubella IgG seropositive while 61 (8.9%) were IgM seropositive. The IgM seropositivity was found to decrease significantly from first trimester to third trimester, p < 0.001. Forty six (83.6%) of 55 Rubella IgM seropositive women had adverse pregnancy outcomes and 6 (10.9%) delivered neonates with CRS, making the overall incidence of CRS to be 6/685 (0.87%). First trimester IgM seropositive women had significantly higher adverse pregnancy outcomes than those in second/third trimesters (70.4% vs. 35.7, p = 0.01). Conclusion: There is one case of CRS in every 100 pregnancies necessitating additional strategies to reach a goal of elimination of CRS in developing countries. Keywords: Pregnant women, CRS, Acute Rubella, Tanzani
Serological makers of rubella infection in Africa in the pre vaccination era: a systematic review
Background: Rubella infections in susceptible women during early pregnancy often results in congenital rubella
syndrome (CRS). World Health Organisation (WHO) recommends that countries without vaccination programmes to
assess the burden of rubella infection and CRS. However; in many African countries there is limited data on epidemiology
of rubella infection and CRS. This review was undertaken to assess the serological markers and genotypes of
rubella virus on the African continent in order to ascertain the gap for future research.
Findings: A systematic search of original literatures from different electronic databases using search terms such
as ‘rubella’ plus individual African countries such as ‘Tanzania’, ‘Kenya’, ‘Nigeria’ etc. and different populations such as
‘children’, ‘pregnant women’ etc. in different combinations was performed. Articles from countries with rubella vaccination
programmes, outbreak data and case reports were excluded. Data were entered in a Microsoft Excel sheet
and analyzed. A total of 44 articles from 17 African countries published between 2002 and 2014 were retrieved; of
which 36 were eligible and included in this review. Of all population tested, the natural immunity of rubella was
found to range from 52.9 to 97.9 %. In these countries, the prevalence of susceptible pregnant women ranged from
2.1 to 47.1 %. Rubella natural immunity was significantly higher among pregnant women than in general population
(P < 0.001). Acute rubella infection was observed to be as low as 0.3 % among pregnant women to 45.1 % among
children. All studies did not ascertain the age-specific prevalence, thus it was difficult to calculate the rate of infection
with increase in age. Only two articles were found to report on rubella genotypes. Of 15 strains genotyped; three
rubella virus genotypes were found to circulate in four African countries.
Conclusion: Despite variations in serological assays, the seroprevalence of IgG rubella antibodies in Africa is high
with a substantial number of women of childbearing age being susceptible to rubella infection. Standardized seroepidemiological
data in various age groups as well as CRS data are important to implement cost-effective vaccination
campaigns and control strategies
Serological Evidence of Acute Rubella Infection among Under-Fives in Mwanza: A Threat to Increasing Rates of Congenital Rubella Syndrome in Tanzania.
Control of rubella infection is essential for preventing congenital rubella syndrome (CRS) and one of the important steps is to define a target population for vaccination. Therefore this study was done to determine serological evidence of acute rubella infection among under-fives in order to anticipate the magnitude of rubella virus transmission in Tanzania. A cross-sectional study involving children aged between 1 and 59 months was conducted between September and October 2014 before national rubella vaccination campaigns commenced. Rubella IgM antibodies were detected using commercial indirect enzyme-linked immunosorbent assay (ELISA). Data were analyzed using STATA version 11. A total of230 under-fives were enrolled, their median age was 14 (Interquartile range (IQR) 7-26) months. The overall seroprevalence of rubella IgM antibodies was 10.9 % (25/230) with two confirmed cases of CRS. Two-sample Wilcoxon rank-sum test showed that the median age of rubella IgM seropositive children was significantly higher than that of IgM seronegative children (39 IQR: 18-51months vs. 14 IQR: 7-24 months, P < 0.001). On multivariate logistic regression analysis increase in age (OR: 1.07, 95 % CI; 1.03-1.1, P < 0.001) and residing in rural areas (OR: 8.07, 95 % CI; 1.43-45.6, P = 0.018) were independently found to predict acute rubella infection among under-fives. Our findings indicate that rubella virus is prevalent in our setting posing a risk of transmitting to childbearing aged women hence increasing the risk of CRS. Increasing prevalence of acute infection with age in under-fives indicates the protective role of maternal antibodies among infants. The sustained vaccination programme of under-fives as effective measure to control CRS should be emphasized in developing countries
Rubella natural immunity among adolescent girls in Tanzania: the need to vaccinate child bearing aged women
Abstract Background Rubella primary infection during early stages of pregnancy is associated with high risk of congenital Rubella syndrome (CRS). Prevention of CRS in the resource-limited countries requires multiple strategies. Here, we document the data on the magnitude of Rubella natural immunity among adolescent girls which is a crucial group in devising effective control strategies to prevent CRS. Methods A cross sectional study involving 397 adolescent girls was conducted in the city of Mwanza involving five secondary schools. Socio-demographic and other relevant information were collected using pre-tested data collection tool. Rubella IgG antibodies were determined using enzyme immunoassay. The presence of Rubella IgG titers of >10 IU/ml indicated natural immunity. Results The mean age of the study participants was 15.18 ± 1.48 years. Of 397 girls, 340 (85.6%) and 57 (14.4%) were from secondary schools representing peri-urban and rural areas, respectively. Out of 397 girls, 90.4% (95% CI: 87-93) were found to be naturally immune with median Rubella IgG antibodies titers of 56.7 IU/ml interquartile range (IQR): 40.8-137. The median Rubella IgG antibodies titers were significantly high in adolescent girls from families with high socio-economic status (63.96 vs. 47.13 IU/ml, P < 0.001) and in adolescent girls from peri-urban areas of the city (63.33 vs. 39.9 IU/ml, P < 0.001). Conclusion The majority of adolescent girls in the city of Mwanza are naturally immune to Rubella virus. There is a need to compare the effectiveness of screening and vaccinating susceptible adolescent girls with the effectiveness of vaccinating all women of childbearing in controlling CRS in low-income countries
Going Beyond Counting First Authors in Author Co-citation Analysis
The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
We conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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