Climate factors and incidence of Middle East respiratory syndrome coronavirus

Journal of Infection and Public Health
ARTICLE IN PRESS

Asmaa Altamimi, Anwar E. Ahmed

Abstract

Background

Our understanding of climate factors and their links to the Middle East Respiratory Syndrome Coronavirus (MERS-CoV) outbreaks is incomplete. This study aimed to estimate the monthly incidence of MERS-CoV cases and to investigate their correlation to climate factors.

Methods

The study used aggregated monthly MERS-CoV cases that reported to the Saudi Center for Disease Prevention and Control from the Riyadh Region between November 1, 2012 and December 31, 2018. Data on the meteorological situation throughout the study period was calculated based on Google reports on the Riyadh Region (24.7136 °N, 46.6753 °E). The Poisson regression was used to estimate the incidence rate ratio (IRR) and its 95% confidence intervals (CI) for each climate factor.

Results

A total of 712 MERS-CoV cases were included in the analysis (mean age 54.2 ± 9.9 years), and more than half (404) (56.1%) MERS-CoV cases were diagnosed during a five-month period from April to August. The highest peak timing positioned in August 2015, followed by April 2014, June 2017, March 2015, and June 2016. High temperatures (IRR = 1.054, 95% CI: 1.043–1.065) and a high ultraviolet index (IRR = 1.401, 95% CI: 1.331–1.475) were correlated with a higher incidence of MERS-CoV cases. However, low relative humidity (IRR = 0.956, 95% CI: 0.948–0.964) and low wind speed (IRR = 0.945, 95% CI: 0.912–0.979) were correlated with a lower incidence of MERS-CoV cases.

Conclusion

The novel coronavirus, MERS-CoV, is influenced by climate conditions with increasing incidence between April and August. High temperature, high ultraviolet index, low wind speed, and low relative humidity are contributors to increased MERS-CoV cases. The climate factors must be evaluated in hospitals and community settings and integrated into guidelines to serve as source of control measures to prevent and eliminate the risk of infection.

Keywords

Weather conditions, Meteorological factors, MERS-CoV

Nucleocapsid Proteins From Other Swine Enteric Coronaviruses Differentially Modulate PEDV Replication

Virology
Volume 540, 15 January 2020, Pages 45-56

Sungsuwan, S.; Jongkaewwattana, A.; Jaru-Ampornpan, P.

Abstract

Porcine epidemic diarrhea virus (PEDV), transmissible gastroenteritis virus (TGEV) and porcine deltacoronavirus (PDCoV) share tropism for swine intestinal epithelial cells. Whether mixing of viral components during co-infection alters pathogenic outcomes or viral replication is not known. In this study, we investigated how different coronavirus nucleocapsid (CoV N) proteins interact and affect PEDV replication. We found that PDCoV N and TGEV N can competitively interact with PEDV N. However, the presence of PDCoV or TGEV N led to very different outcomes on PEDV replication. While PDCoV N significantly suppresses PEDV replication, overexpression of TGEV N, like that of PEDV N, increases production of PEDV RNA and virions. Despite partial interchangeability in nucleocapsid oligomerization and viral RNA synthesis, endogenous PEDV N cannot be replaced in the production of infectious PEDV particles. Results from this study give insights into functional compatibilities and evolutionary relationship between CoV viral proteins during viral co-infection and co-evolution.

Keywords

Porcine epidemic diarrhea virus, Swine coronavirus, Nucleocapsid protein

Chapter Four - Structural insights into coronavirus entry

Advances in Virus Research
Volume 105, 2019, Pages 93-116

M. Alejandra Tortorici, and David Veesler

Abstract

Coronaviruses (CoVs) have caused outbreaks of deadly pneumonia in humans since the beginning of the 21st century. The severe acute respiratory syndrome coronavirus (SARS-CoV) emerged in 2002 and was responsible for an epidemic that spread to five continents with a fatality rate of 10% before being contained in 2003 (with additional cases reported in 2004). The Middle-East respiratory syndrome coronavirus (MERS-CoV) emerged in the Arabian Peninsula in 2012 and has caused recurrent outbreaks in humans with a fatality rate of 35%. SARS-CoV and MERS-CoV are zoonotic viruses that crossed the species barrier using bats/palm civets and dromedary camels, respectively. No specific treatments or vaccines have been approved against any of the six human coronaviruses, highlighting the need to investigate the principles governing viral entry and cross-species transmission as well as to prepare for zoonotic outbreaks which are likely to occur due to the large reservoir of CoVs found in mammals and birds. Here, we review our understanding of the infection mechanism used by coronaviruses derived from recent structural and biochemical studies.

Keywords

Coronavirus, Spike glycoprotein, Fusion protein, Membrane fusion, Proteolytic activation, Vaccine design

Human Coronaviruses: General Features

Reference Module in Biomedical Sciences
2019

ARTICLE IN PRESS

Xin Li, Hayes K. H. Luk, Susanna K. P. Lau, Patrick C. Y. Woo

Abstract

Human coronaviruses (HCoVs), including HCoV-229E, HCoV-OC43, HCoV-NL63, and HCoV-HKU1, are traditionally known to cause symptoms of common cold with only moderate clinical impact. Severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV), on the other hand, have strike humans in the past two decades as highly fatal human pathogens leading to considerable mortality and economic loss. This article summaries the updates on the structure, genome organization, replication and clinical features of human coronaviruses. Recent studies also shed light upon the zoonotic origin of emerging human pathogens including SARS-CoV and MERS-CoV, providing insight for future surveillance and intervention.

Keywords

Epidemiology, Genome, Human coronavirus, MERS, Replication, SARS, Structure

Some One Health based control strategies for the Middle East respiratory syndrome coronavirus

One Health
Volume 8, December 2019, 100102

Maged Gomaa Hemida, Abdelmohsen Alnaeem

Abstract

The Middle East respiratory syndrome coronavirus (MERS-CoV) presents an ideal example for developing One Health concepts. Dromedary camels are the principal reservoir for the virus. Infected camels shed the virus in body secretions, particularly nasal discharges. MERS-CoV has the potential to remain active in the environment for some time under optimum conditions of temperature and humidity. This shedding sustains the virus in endemic communities and thus contact with camels is considered a major risk factor for human infection. Reducing virus shedding from camels will have a great positive impact on reducing the human risk of infection. Our main objective is to highlight the potential aspects of reducing virus shedding from camels to the environment, thereby reducing the possibility of human infection. We will focus on the potential roles of camel markets, camel shows, importation, transportation and grazing in the amplification and shedding of the virus, providing some novel concepts for the control approaches for the MERS-CoV.

Keywords

MERS-CoV, One Health, Dromedary camel, Human, Transmission, Shedding

Changes in infection control policies and advancing infection control advanced practice nurse education in the Republic of Korea

AJIC - American Journal of Infection Control
Volume 48, Issue 2, Pages 204-206

Choi, J. S.; Kim, K. M..

Abstract

After the Middle East respiratory syndrome outbreak of 2015, the Korean government became the payer for infection control (IC) and prevention when hospitals developed IC offices and appointed IC doctors and IC advanced practice nurses. The goal was to enhance IC for all hospitalized patients to prevent the occurrence and spread of infection among them. Measures resulted in increased demand for IC personnel, especially IC advanced practice nurses. This study addressed changes in Korea's IC policies and their impact on the IC advanced practice nursing education program.

Keywords

Infection control, Nurse, Education

A high-throughput inhibition assay to study MERS-CoV antibody interactions using image cytometry

Journal of Virological Methods
Volume 265, March 2019, Pages 77-83

Osnat Rosen, Leo Li-Ying Chan, Olubukola M. Abiona, Portia Gough, Lingshu Wang, Wei Shi, Yi Zhang, Nianshuang Wang, Wing-Pui Kong, Jason S. McLellan, Barney S. Graham, Kizzmekia S. Corbett

Abstract

The emergence of new pathogens, such as Middle East respiratory syndrome coronavirus (MERS-CoV), poses serious challenges to global public health and highlights the urgent need for methods to rapidly identify and characterize potential therapeutic or prevention options, such as neutralizing antibodies. Spike (S) proteins are present on the surface of MERS-CoV virions and mediate viral entry. S is the primary target for MERS-CoV vaccine and antibody development, and it has become increasingly important to understand MERS-CoV antibody binding specificity and function. Commonly used serological methods like ELISA, biolayer interferometry, and flow cytometry are informative, but limited. Here, we demonstrate a high-throughput protein binding inhibition assay using image cytometry. The image cytometry-based high-throughput screening method was developed by selecting a cell type with high DPP4 expression and defining optimal seeding density and protein binding conditions. The ability of monoclonal antibodies to inhibit MERS-CoV S binding was then tested. Binding inhibition results were comparable with those described in previous literature for MERS-CoV spike monomer and showed similar patterns as neutralization results. The coefficient of variation (CV) of our cell-based assay was <10%. The proposed image cytometry method provides an efficient approach for characterizing potential therapeutic antibodies for combating MERS-CoV that compares favorably with current methods. The ability to rapidly determine direct antibody binding to host cells in a high-throughput manner can be applied to study other pathogen-antibody interactions and thus can impact future research on viral pathogens.

Keywords

MERS-CoV, Antibody binding, Inhibition assay, Antibody neutralization, Image cytometry, Celigo