title: Investigation of the use of serology and ultrasonography to detect hepatic cystic echinococcosis in Heilongjiang, China, using a Bayesian framework.
abstract: BACKGROUND
  Cystic echinococcosis (CE) is a public health problem in China. However, the prevalence and incidence of CE in Heilongjiang province is still poorly understood. Because there is no perfect gold standard, evaluation of ultrasound (US) and serological methods have been limited. This study evaluated the use of these two diagnostic methods for the diagnosis of CE in suspected cases.
  
  
  METHODS
  A total of 522 suspected hepatic CE patients, as well as their demographic and clinical features were collected and detected by immunoglobulin (IgG)-ELISA and US. The marginal posterior densities of sensitivity and specificity for both tests, and the prevalence of hepatic CE amongst participants, were estimated from the product of the likelihood function of observed and latent data by a Bayesian framework.
  
  
  RESULTS
  Most of the patients were from rural areas. The most common symptom was upper abdominal pain. The antibody-positive proportion determined by IgG-ELISA was 24.33% (127/522), significantly higher than with US examination (17.24%, 90/522). Bayesian analysis indicated that the estimated prevalence of CE amongst suspected cases was 17.70% (95% credible interval: 14.23-21.54%). The sensitivity and specificity of the ELISA test were 92.63% and 90.37%, and that of US were 93.05% and 98.44%, respectively. Among US-confirmed hepatic CE cases, the male to female ratio was 0.46 and the peak age group was 40-49 years.
  
  
  CONCLUSIONS
  The results of the current study demonstrate that CE is present in Heilongjiang province. They also suggest that, whilst ultrasonography appears to be the detection modality of choice, serology may have a use for detection of infection in individuals suspected to be infected. This may have applications for surveillance within the province.
authors.affiliation: Department of Parasitology, Harbin Medical University, Harbin, PR China; National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Key Laboratory of Parasite and Vector Biology, MOH, PR China; WHO Collaborating Center for Malaria, Schistosomiasis and Filariasis, Shanghai, PR China.
authors.forename: Su
authors.initials: S
authors.lastname: Han
authors.affiliation: Department of Orthopedics, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, PR China.
authors.forename: Rui
authors.initials: R
authors.lastname: Chen
authors.affiliation: Department of Microbiology and Parasitology, Shanghai University of Medical & Health Sciences, Shanghai, PR China.
authors.forename: Wenjuan
authors.initials: W
authors.lastname: Fang
authors.affiliation: Department of Epidemiology and health statistics, Public Health College, Fujian Medical University, Fuzhou, PR China.
authors.forename: Rong
authors.initials: R
authors.lastname: Fu
authors.affiliation: Department of Parasitology, Harbin Medical University, Harbin, PR China.
authors.forename: Jingshan
authors.initials: J
authors.lastname: Wen
authors.affiliation: Department of Parasitology, Harbin Medical University, Harbin, PR China. Electronic address: zhangxiaoli1119@126.com.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Gastroenterology, The Second Affiliated Hospital of Harbin Medical University, Harbin, PR China. Electronic address: mx_1983@yeah.net.
authors.forename: Xiao
authors.initials: X
authors.lastname: Ma
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001499:Bayes Theorem; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D004444:Echinococcosis, Hepatic / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011634:Public Health; D012680:Sensitivity and Specificity; D055815:Young Adult
keywords: Bayesian modeling; Cystic echinococcosis; Diagnosis; ELISA; Ultrasound