scholarly journals Empirical Bayes estimation of farm prevalence adjusting for multistage sampling and uncertainty in test performance: a Brucella cross-sectional serostudy in southern Kazakhstan

2016 ◽  
Vol 144 (16) ◽  
pp. 3531-3539 ◽  
Author(s):  
W. BEAUVAIS ◽  
M. ORYNBAYEV ◽  
J. GUITIAN

SUMMARYEstimation of farm prevalence is common in veterinary research. Typically, not all animals within the farm are sampled, and imperfect tests are used. Often, assumptions about herd sizes and sampling proportions are made, which may be invalid in smallholder settings. We propose an alternative method for estimating farm prevalence in the context of Brucella seroprevalence estimation in an endemic region of Kazakhstan. We collected 210 milk samples from Otar district, with a population of about 1000 cattle and 16 000 small ruminants, and tested them using an indirect ELISA. Individual-level prevalence and 95% confidence intervals were estimated using Taylor series linearization. A model was developed to estimate the smallholding prevalence, taking into account variable sampling proportions and uncertainty in the test accuracy. We estimate that 73% of households that we sampled had at least one Brucella-seropositive animal (95% credible interval 68–82). We estimate that 58% (95% confidence interval 40–76) of lactating small ruminants and 14% (95% confidence interval 1–28) of lactating cows were seropositive. Our results suggest that brucellosis is highly endemic in the area and conflict with those of the official brucellosis-testing programme, which found that in 2013 0% of cows and 1·7% of small ruminants were seropositive.

2019 ◽  
Vol 220 (Supplement_3) ◽  
pp. S99-S107 ◽  
Author(s):  
Samuel G Schumacher ◽  
William A Wells ◽  
Mark P Nicol ◽  
Karen R Steingart ◽  
Grant Theron ◽  
...  

Abstract Tests that can replace sputum smear microscopy have been identified as a top priority diagnostic need for tuberculosis by the World Health Organization. High-quality evidence on diagnostic accuracy for tests that may meet this need is an essential requirement to inform decisions about policy and scale-up. However, test accuracy studies are often of low and inconsistent quality and poorly reported, leading to uncertainty about true test performance. Here we provide guidance for the design of diagnostic test accuracy studies of sputum smear-replacement tests. Such studies should have a cross-sectional or cohort design, enrolling either a consecutive series or a random sample of patients who require evaluation for tuberculosis. Adults with respiratory symptoms are the target population. The reference standard should at a minimum be a single, automated, liquid culture, but additional cultures, follow-up, clinical case definition, and specific measures to understand discordant results should also be included. Inclusion of smear microscopy and Xpert MTB/RIF (or MTB/RIF Ultra) as comparators is critical to allow broader comparability and generalizability of results, because disease spectrum can vary between studies and affects relative test performance. Given the complex nature of sputum (the primary specimen type used for pulmonary TB), careful design and reporting of the specimen flow is essential. Test characteristics other than accuracy (such as feasibility, implementation considerations, and data on impact on patient, population and health systems outcomes) are also important aspects.


2021 ◽  
Vol 8 (7) ◽  
pp. 137
Author(s):  
Ahmed Said Mohamud ◽  
John Pilate Kothowa ◽  
Ruth Lindizyani Mfune ◽  
Melai Mubanga ◽  
Jacques Godfroid ◽  
...  

Brucellosis is an important zoonotic disease caused by members of the genus Brucella. Camel brucellosis has been reported in almost all camel-rearing countries in Africa and Asia. A cross-sectional study was conducted between February 2020 and February 2021 in Galkayo, Garowe, and Bosaso districts in the Puntland State of Somalia to investigate the seroprevalence and risk factors of brucellosis in camels. A competitive enzyme-linked immunosorbent assay (c-ELISA) was used to detect anti-Brucella antibodies, while a structured questionnaire was used to collect epidemiological data. A total of 441 camel sera were screened against Brucella antibodies. Thirty-one (7%; 95% CI: 4.8–9.8%) samples were positive, and thirteen (54.2%; 95% CI: 32.8–74.4%) out of the twenty-four farms sampled had at least one seropositive animal. Galkayo district had the highest number of Brucella-seropositive camels (10.3%), followed by Bosaso district (8.6%), while Garowe district had the lowest number of seropositive camels (1.4%). The binary logistic regression model revealed that camels in Galkayo district (p = 0.015; OR: 9.428; 95% CI: 1.539–57.755), camels from large herd sizes of >50 animals (p = 0.019; OR: 5.822; 95% CI: 1.336–25.371), and those in contact with small ruminants (p = 0.011; OR: 10.941; 95% CI: 1.728–69.285) were significantly associated with seropositive cases of camel brucellosis in the Puntland State of Somalia. The present study shows that Brucella infections in camels are prevalent in the three districts covered by the study. This poses a public health risk, because milk from these camels is used for human consumption. Studies focusing on the isolation of Brucella strains in camels and investigating brucellosis in ruminants and humans are recommended in the study area. Validation of serological tests—including c-ELISA—for Brucella antibody detection in camels is also needed.


2020 ◽  
Author(s):  
Aude Richard ◽  
Ania Wisniak ◽  
Javier Perez-Saez ◽  
Henri Garrison-Desany ◽  
Dusan Petrovic ◽  
...  

AbstractBackgroundPopulation-based serological surveys provide a means for assessing the immunologic landscape of a community, without the biases related to health-seeking behaviors and testing practices typically associated with rt-PCR testing. This study assesses SARS-CoV-2 seroprevalence over the first epidemic wave in Canton Geneva, Switzerland, as well as biological and socio-economic risk factors for infection and symptoms associated with IgG seropositivity.Methods and findingsBetween April 6 and June 30, 2020, former participants of a yearly representative cross-sectional survey of the 20-75-year-old population of the canton of Geneva were invited to participate in a seroprevalence study, along with household members five years and older. We collected blood and tested it for anti-SARS-CoV-2 immunoglobulins G (IgG). Questionnaires were self-administered. We estimated seroprevalence with a Bayesian model accounting for test performance and sampling design. We included 8344 participants (53.5% women, mean age 46.9 years). The population-level seroprevalence over the 12-week study period was 7.8 % (95% Credible Interval (CrI) 6.8-8.9), accounting for sex, age and household random effects. Seroprevalence was highest among 18-49 year olds (9.5%, 95%CrI 8.1-10.9), with young children (5-9 years) and those >65 years having significantly lower seroprevalence (4.3% and 4.7-5.4% respectively). Men were more likely to be seropositive than women (relative risk 1.2, 95%CrI 1.1-1.4). Odds of seropositivity were reduced for female retirees (0.46, 95%CI 0.23-0.93) and unemployed men (0.35, 95%CI 0.13-1.0) compared to employed individuals, and for current smokers (0.36, 95%CI 0.23-0.55) compared to never-smokers. We found no significant association between occupation, level of education, neighborhood income and the risk of being seropositive. Symptoms most strongly associated with seropositivity were anosmia/dysgeusia, loss of appetite, fever, fatigue and myalgia and/or arthralgia. Thirteen percent of seropositive participants reported no symptoms.ConclusionsOur results confirm a low population seroprevalence of anti-SARS-CoV-2 antibodies after the first wave in Geneva, a region hard hit by the COVID-19 pandemic. Socioeconomic factors were not associated with seropositivity in this sample. The elderly and young children were less frequently seropositive, though it is not clear how biology and behaviors shape these differences. These specificities should be considered when assessing the need for targeted public health measures.


2019 ◽  
Vol 6 (1) ◽  
pp. 19-28
Author(s):  
Rakhmie Rafie ◽  
Yusmaidi Yusmaidi ◽  
Mira Fitriyani

Berdasarkan Permenkes 585/1989 dikatakan bahwa informed consent adalah persetujuan yang diberikan oleh pasien atau keluarganya atas dasar penjelasan mengenai tindakan medis yang akan dilakukan terhadap pasien tersebut. Peran dan tanggung jawab dokter terhadap pelaksanaan tindakan medis berdasarkan imformed consent sangat penting untuk mencegah kemungkinan yang akan terjadi kepada pasien nantinya. Pemahaman terhadap informasi yang diberikan dipengaruhi oleh beberapa faktor, diantaranya karakteristik orang tersebut. Survey analitik dengan desain cross sectional dengan wawancara terpimpin menggunakan kuesioner terhadap 100 responden, dan diolah menggunakan analisa univariat dan bivariat dengan uji Chi-Square. Hasil penelitian menunjukkan bahwa: yang berusia dewasa 84 responden (84%) dan yang berusia muda sebanyak 16 responden (16%), laki- laki 63 responden (63%) dan perempuan 37 responden (37%), yang berpendidikan rendah 41 responden (41%) dan yang berpendidikan tinggi 59 responden, yang tidak bekerja 24 responden (24%) sedangkan yang bekerja 76 responden (76%), yang mempunyai pemahaman baik 58 responden (58%) dan yang tidak baik sebanyak 42 responden (42%). Variabel yang terdapat hubungan bermakna dengan pemahaman terhadap persetujuan tindakan medis pada tindakan bedah di RSPBA pada bulan Maret 2015 adalah umur (nilai p value = 0,037) OR = 3.761 dengan nilai Confidence Interval (1.195-11.835)dan pendidikan (nilai p value = 0,00) OR = 8.551 dengan Confidence Interval (3.436-21.285). Sedangkan variabel yang tidak terdapat hubungan bermakna dengan pemahaman persetujuan tindakan medispada tindakan bedah di RSPBA pada bulan Maret 2015 adalah jenis kelamin (nilai p value = 0,987) dan pekerjaan (p value = 0,251). Terdapat hubungan bermakna antara umur dan pendidikan dengan pemahaman terhadap persetujuan tindakan medis pada tindakan bedah di RS Pertamina Bintang Aamin (RSPBA) pada bulan Maret 2015.  


Author(s):  
Molly R Petersen ◽  
Eshan U Patel ◽  
Alison G Abraham ◽  
Thomas C Quinn ◽  
Aaron A R Tobian

Abstract Data from the cross-sectional National Health and Nutrition Examination Surveys (NHANES) indicate that the seroprevalence of cytomegalovirus immunoglobulin G (IgG) antibodies among US children aged 1–5 years was 20.7% (95% confidence interval [CI]: 14.0, 29.0) in 2011–2012 and 28.2% (95% CI: 23.1–34.0) in 2017–2018 (adjusted prevalence difference, +7.6% [95% CI: −.4, +15.6]).


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