title: Transmission of MERS-coronavirus in household contacts.
abstract: BACKGROUND
  Strategies to contain the Middle East respiratory syndrome coronavirus (MERS-CoV) depend on knowledge of the rate of human-to-human transmission, including subclinical infections. A lack of serologic tools has hindered targeted studies of transmission.
  
  
  METHODS
  We studied 26 index patients with MERS-CoV infection and their 280 household contacts. The median time from the onset of symptoms in index patients to the latest blood sampling in contact patients was 17.5 days (range, 5 to 216; mean, 34.4). Probable cases of secondary transmission were identified on the basis of reactivity in two reverse-transcriptase-polymerase-chain-reaction (RT-PCR) assays with independent RNA extraction from throat swabs or reactivity on enzyme-linked immunosorbent assay against MERS-CoV S1 antigen, supported by reactivity on recombinant S-protein immunofluorescence and demonstration of neutralization of more than 50% of the infectious virus seed dose on plaque-reduction neutralization testing.
  
  
  RESULTS
  Among the 280 household contacts of the 26 index patients, there were 12 probable cases of secondary transmission (4%; 95% confidence interval, 2 to 7). Of these cases, 7 were identified by means of RT-PCR, all in samples obtained within 14 days after the onset of symptoms in index patients, and 5 were identified by means of serologic analysis, all in samples obtained 13 days or more after symptom onset in index patients. Probable cases of secondary transmission occurred in 6 of 26 clusters (23%). Serologic results in contacts who were sampled 13 days or more after exposure were similar to overall study results for combined RT-PCR and serologic testing.
  
  
  CONCLUSIONS
  The rate of secondary transmission among household contacts of patients with MERS-CoV infection has been approximately 5%. Our data provide insight into the rate of subclinical transmission of MERS-CoV in the home.
authors.affiliation: From the Institute of Virology, University of Bonn Medical Center, Bonn (C.D., B.M., M.A.M., V.M.C., A.S.), and Euroimmun, Lübeck (E.L.) - both in Germany; Global Center for Mass Gatherings Medicine, Ministry of Health (M.A.-M., R.F.A., A.M. Assiri, A.I.Z., Z.A.M.), Prince Sultan Military Medical City (A.M. Albarrak), and Alfaisal University (Z.A.M.), Riyadh, Johns Hopkins Aramco Healthcare, Dhahran (J.A.A.-T.), and Regional Laboratory, Ministry of Health, Jeddah (R.H., H.M.) and Riyadh (W.H.) - all in Saudi Arabia; Indiana University School of Medicine, Indianapolis (J.A.A.-T.); the Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands (B.J.B.); and the Division of Infection and Immunity, University College London (UCL), and National Institute for Health Research Biomedical Research Centre, UCL Hospitals, London (A.I.Z.).
authors.forename: Christian
authors.initials: C
authors.lastname: Drosten
authors.forename: Benjamin
authors.initials: B
authors.lastname: Meyer
authors.forename: Marcel A
authors.initials: MA
authors.lastname: Müller
authors.forename: Victor M
authors.initials: VM
authors.lastname: Corman
authors.forename: Malak
authors.initials: M
authors.lastname: Al-Masri
authors.forename: Raheela
authors.initials: R
authors.lastname: Hossain
authors.forename: Hosam
authors.initials: H
authors.lastname: Madani
authors.forename: Andrea
authors.initials: A
authors.lastname: Sieberg
authors.forename: Berend Jan
authors.initials: BJ
authors.lastname: Bosch
authors.forename: Erik
authors.initials: E
authors.lastname: Lattwein
authors.forename: Raafat F
authors.initials: RF
authors.lastname: Alhakeem
authors.forename: Abdullah M
authors.initials: AM
authors.lastname: Assiri
authors.forename: Waleed
authors.initials: W
authors.lastname: Hajomar
authors.forename: Ali M
authors.initials: AM
authors.lastname: Albarrak
authors.forename: Jaffar A
authors.initials: JA
authors.lastname: Al-Tawfiq
authors.forename: Alimuddin I
authors.initials: AI
authors.lastname: Zumla
authors.forename: Ziad A
authors.initials: ZA
authors.lastname: Memish
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D017934:Coronavirus / Q000235:genetics / Q000302:isolation & purification; D018352:Coronavirus Infections / Q000635:transmission*; D005191:Family Characteristics; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D008297:Male; D008877:Middle East; D010614:Pharynx / Q000821:virology; D012367:RNA, Viral / Q000032:analysis; D012141:Respiratory Tract Infections / Q000635:transmission*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D012367:RNA, Viral