Transmissibility of MERS-CoV Infection in Closed Setting, Riyadh, Saudi Arabia, 2015

Abstract

To investigate a cluster of Middle East respiratory syndrome (MERS) cases in a women-only dormitory in Riyadh, Saudi Arabia, in October 2015, we collected epidemiologic information, nasopharyngeal/oropharyngeal swab samples, and blood samples from 828 residents during November 2015 and December 2015–January 2016. We found confirmed infection for 19 (8 by reverse transcription PCR and 11 by serologic testing). Infection attack rates varied (2.7%–32.3%) by dormitory building. No deaths occurred. Independent risk factors for infection were direct contact with a confirmed case-patient and sharing a room with a confirmed case-patient; a protective factor was having an air conditioner in the bedroom. For 9 women from whom a second serum sample was collected, antibodies remained detectable at titers >1:20 by pseudoparticle neutralization tests (n = 8) and 90% plaque-reduction neutralization tests (n = 2). In closed high-contact settings, MERS coronavirus was highly infectious and pathogenicity was relatively low.

The first clusters of Middle East respiratory syndrome coronavirus in Oman: Time to act

“…Firstly, the cases reported from the North Al Batinah cluster were household contacts, indicating that for the first time in the country human-to-human transmission occurred at the household level. Similar family clusters were reported in Saudi Arabia [14,15,17,[34][35][36][37][38][39], Tunisia [40] and the UK [39]. Secondly, the epidemiological characteristics of these 13 cases are different from what has been observed in cases reported from other countries [5,10,11,39,40].…”

“…A similar situation was observed in Saudi Arabia, where up to 50% of MERS-CoV cases were classified as secondary, due to possible human-to-human transmission through contact with asymptomatic or symptomatic individuals infected with MERS-CoV [42]. Furthermore, limited human-to-human transmission of MERS-CoV was observed in several other clusters in other countries, including family members [14][15][16][17][18][19] and patients in health care facilities [39,40,[42][43][44].…”

“…Limited human-to-human transmission of MERS-CoV has been described mostly in health care setting [2,[6][7][8][9][10][11][12][13] and small household clusters of community-acquired cases, including a family cluster of mild disease [14][15][16][17][18][19]. Larger outbreaks have been reported in healthcare settings, which have led to multiple chains of limited transmission, as a result of contact with index cases or inadequate infection prevention and control measures causing excessive morbidity and mortality in several countries [2,[5][6][7][8][9][10][11].…”

A systematic review of antibody mediated immunity to coronaviruses: antibody kinetics, correlates of protection, and association of antibody responses with severity of disease

“…A comparison of a cohort of [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40] year-olds and a cohort of ≥65 year-olds found no clear difference in incidence between the two age groups, as measured by seroconversion or PCRconfirmed, HCoV-associated respiratory illness 120 . Finally, observational studies have shown evidence of coronavirus-associated respiratory illnesses in elderly populations [121][122][123] and across all ages 124 .…”

“…For example, at week 26, there were 12 patients with mild symptoms from studies that reported a cutoff, and 8 of those patients had IgG levels above that cutoff. MERS-CoV data were digitised from six studies 35,40,46,47,142,143…”