Public health response to two incidents of confirmed MERS-CoV cases travelling on flights through London Heathrow Airport in 2014 – lessons learnt

Global transmission of monkeypox virus-a potential threat under the COVID-19 pandemic

Monkeypox virus (MPXV) cases have increased dramatically worldwide since May 2022. The Atlanta Center for Disease Control and Prevention (Atlanta CDC) had reported a total of 85,922 cases as of February 20^th, 2023. During the COVID-19 pandemic, MPXV has emerged as a potential public threat. MPXV transmission and prevalence must be closely monitored. In this comprehensive review, we explained the basic characteristics and transmission routes of MPXV, individuals susceptible to it, as well as highlight the impact of the behavior of men who have sex with men (MSM) and airline traveling on recent outbreaks of MPXV. We also describe the clinical implications, the prevention of MPXV, and clinical measures of viral detection.

Does 2x2 airplane passenger contact tracing for infectious respiratory pathogens work? A systematic review of the evidence

We critically appraised the literature regarding in-flight transmission of a range of respiratory infections to provide an evidence base for public health policies for contact tracing passengers, given the limited pathogen-specific data for SARS-CoV-2 currently available. Using PubMed, Web of Science, and other databases including preprints, we systematically reviewed evidence of in-flight transmission of infectious respiratory illnesses. A meta-analysis was conducted where total numbers of persons on board a specific flight was known, to calculate a pooled Attack Rate (AR) for a range of pathogens. The quality of the evidence provided was assessed using a bias assessment tool developed for in-flight transmission investigations of influenza which was modelled on the PRISMA statement and the Newcastle-Ottawa scale. We identified 103 publications detailing 165 flight investigations. Overall, 43.7% (72/165) of investigations provided evidence for in-flight transmission. H1N1 influenza A virus had the highest reported pooled attack rate per 100 persons (AR = 1.17), followed by SARS-CoV-2 (AR = 0.54) and SARS-CoV (AR = 0.32), Mycobacterium tuberculosis (TB, AR = 0.25), and measles virus (AR = 0.09). There was high heterogeneity in estimates between studies, except for TB. Of the 72 investigations that provided evidence for in-flight transmission, 27 investigations were assessed as having a high level of evidence, 23 as medium, and 22 as low. One third of the investigations that reported on proximity of cases showed transmission occurring beyond the 2x2 seating area. We suggest that for emerging pathogens, in the absence of pathogen-specific evidence, the 2x2 system should not be used for contact tracing. Instead, alternate contact tracing protocols and close contact definitions for enclosed areas, such as the same cabin on an aircraft or other forms of transport, should be considered as part of a whole of journey approach.

Risk Assessment for the Transmission of Middle East Respiratory Syndrome Coronavirus (MERS-Cov) on Aircraft: A Systematic Review

Middle East respiratory syndrome coronavirus (MERS-CoV) causes a potentially fatal respiratory disease. Although it is most common in the Arabian Peninsula, it has been exported to 17 countries outside the Middle East, mostly through air travel. The Risk Assessment Guidelines for Infectious Diseases transmitted on Aircraft (RAGIDA) advise authorities on measures to take when an infected individual travelled by air. The aim of this systematic review was to gather all available information on documented MERS-CoV cases that had travelled by air, to update RAGIDA. The databases used were PubMed, Embase, Scopus and Global Index Medicus; Google was searched for grey literature and hand searching was performed on the EU Early Warning and Response System and the WHO Disease Outbreak News. Forty-seven records were identified, describing 21 cases of MERS that had travelled on 31 flights. Contact tracing was performed for 17 cases. Most countries traced passengers sitting in the same row and the two rows in front and behind the case. Only one country decided to trace all passengers and crew. No cases of in-flight transmission were observed; thus, considering the resources it requires, a conservative approach may be appropriate when contact tracing passengers and crew where a case of MERS has travelled by air.

SARS-CoV-2 and work-related transmission: results of a prospective cohort of airport workers, 2020

Introduction:

The coronavirus disease 2019 (COVID-19) pandemic has spread rapidly around the globe. Even though multiple strategies are available for controlling infectious respiratory diseases, the current approach for managing this pandemic is the prevention of person-to-person transmission. Despite the quarantine strategy, some work positions must remain active, such as airport personnel.

Objectives:

To identify risk factors for COVID-19 transmission among workers at the El Dorado, Luis Carlos Galán Airport from March to July 2020.

Methods:

This is a prospective cohort study with workers of the El Dorado International Airport, in Bogotá, Colombia. A sociodemographic questionnaire was for searching for symptoms associated with COVID-19 and other risk factors. Nasopharyngeal swabs were collected for determining the presence of COVID-19. In order to identify seroconversion, we used an automated chemiluminescent immunoassay for anti-SARS-CoV-2 IgM and IgG antibodies. Patients with positive results were followed-up for 21 days.

Results:

We observed an incidence of infection of 7.9%; most cases were asymptomatic. The main risk factor associated with infection was the duration of daily commute (relative risk 1.02 [95% confidence interval, 1.002-1.041]).

Conclusions:

We observed asymptomatic infection by COVID-19 among airport workers. Future research should contribute with knowledge for developing strategies that guarantee the protection of airport workers.

Demographic, clinical, and outcomes of confirmed cases of Middle East Respiratory Syndrome coronavirus (MERS-CoV) in Najran, Kingdom of Saudi Arabia (KSA); A retrospective record based study

Introduction

MERS is caused by a viral infection, which was first identified in KSA, 2012. MERS-CoV infection consequences with either hospitalization or death.

Methods

All positive MERS-CoV cases that diagnosed in and reported to a referral hospital in Najran, KSA from March/2014 to December/2018 were revised retrospectively. We identified patients from infection control department and medical records. Demographic, clinical, and outcome data were collected.

Results

Of the 54 positive MERS-CoV cases, 3 cases were excluded because no available data. Therefore, the final number of the included cases in the study was 51 cases (94.4). Most of the patients were Saudi 36 (70.6%), and majority of cases were reported in the winter 18 (35.3) season. Fever 47 (92.2%), cough 44 (86.3%), and shortness of breath 37 (72.5%) were reported as most common symptoms. Most patients had diabetes mellitus and hypertension. Overall mortality rate was 37.3%, and interestingly the mortality rate dropped sharply over 5 years. In logistic regression analysis, Season and Chronic Kidney disease patients were the only two variables statistically significantly associated with death. The odds of death the patients infected by MERS-CoV during Autumn and Winter season were 4.09 times higher than those patients who infected during Spring and Summer season (OR = 4.09, CI 1.18-14.15, P < 0.026). Compared with MERS-CoV patients who had Non-Chronic kidney diseases, the odds of death the MERS-CoV patients who had chronic kidney diseases were 18.08 times higher (OR = 18.08, CI -2.01-162.99, P < 0.01).

Conclusion

The case fatality rate of MERS-CoV infection was high. Further studies with large sample sizes are needed to explore the reasons behind the decrease in the mortality rate over the time period.

Lack of Secondary Transmission of Ebola Virus from Healthcare Worker to 238 Contacts, United Kingdom, December 2014

In December 2014, Ebola virus disease (EVD) was diagnosed in a healthcare worker in the United Kingdom after the worker returned from an Ebola treatment center in Sierra Leone. The worker flew on 2 flights during the early stages of disease. Follow-up of 238 contacts showed no evidence of secondary transmission of Ebola virus.

Conveyance Contact Investigation for Imported Middle East Respiratory Syndrome Cases, United States, May 2014

In 2014, the Centers for Disease Control and Prevention conducted conveyance contact investigations for 2 Middle East respiratory syndrome cases imported into the United States, comprising all passengers and crew on 4 international and domestic flights and 1 bus. Of 655 contacts, 78% were interviewed; 33% had serologic testing. No secondary cases were identified.

Middle East respiratory syndrome coronavirus in Al-Madinah City, Saudi Arabia: Demographic, clinical and survival data

BACKGROUND

Middle East respiratory syndrome coronavirus (MERS-CoV), is an emerging virus respiratory infection. It has a high mortality rate and a wide spectrum of clinical features. This study describes the clinical characteristics and outcome of MERS infected patients.

METHODS

A retrospective study was conducted of all confirmed MERS-CoV infections from March 2014 to May 2014 at two tertiary care hospitals in Al-Madinah region (Saudi Arabia). We gathered data about demographic, clinical presentation, and factors associated with severity and mortality.

RESULTS

A total of 29 cases were identified; 20 males (69%) and nine females (31%), age 45±12years. The death rate was higher for men (52%) than for women (23%). Initial presentation was fever in 22 (75%) cases, cough in 20 (69%) cases, and shortness of breath in 20 (69%) cases. Associated comorbidities were diabetes mellitus in nine (31%) patients and chronic kidney disease (CKD) in eight (27%) patients. Duration of symptoms before hospitalization ranged from 2.9days to 5days. Elevated liver enzymes were present in 14 (50%) patients and impaired renal profile present in eight (27%) patients. We also describe in this study radiological patterns and factors associated with mortality.

CONCLUSION

MERS-CoV infection transmission continues to occur as clusters in healthcare facilities. The frequency of cases and deaths is higher among men than women and among patients with comorbidities.

Middle East respiratory syndrome coronavirus (MERS-CoV): what lessons can we learn?

The Middle East Respiratory Coronavirus (MERS-CoV) was first isolated from a patient who died with severe pneumonia in June 2012. As of 19 June 2015, a total of 1,338 MERS-CoV infections have been notified to the World Health Organization (WHO). Clinical illness associated with MERS-CoV ranges from mild upper respiratory symptoms to rapidly progressive pneumonia and multi-organ failure. A significant proportion of patients present with non-respiratory symptoms such as headache, myalgia, vomiting and diarrhoea. A few potential therapeutic agents have been identified but none have been conclusively shown to be clinically effective. Human to human transmission is well documented, but the epidemic potential of MERS-CoV remains limited at present. Healthcare-associated clusters of MERS-CoV have been responsible for the majority of reported cases. The largest outbreaks have been driven by delayed diagnosis, overcrowding and poor infection control practices. However, chains of MERS-CoV transmission can be readily interrupted with implementation of appropriate control measures. As with any emerging infectious disease, guidelines for MERS-CoV case identification and surveillance evolved as new data became available. Sound clinical judgment is required to identify unusual presentations and trigger appropriate control precautions. Evidence from multiple sources implicates dromedary camels as natural hosts of MERS-CoV. Camel to human transmission has been demonstrated, but the exact mechanism of infection remains uncertain. The ubiquitously available social media have facilitated communication and networking amongst healthcare professionals and eventually proved to be important channels for presenting the public with factual material, timely updates and relevant advice.

Middle East respiratory syndrome coronavirus (MERS-CoV): what lessons can we learn?

The Middle East Respiratory Coronavirus (MERS-CoV) was first isolated from a patient who died with severe pneumonia in June 2012. As of 19 June 2015, a total of 1,338 MERS-CoV infections have been notified to the World Health Organization (WHO). Clinical illness associated with MERS-CoV ranges from mild upper respiratory symptoms to rapidly progressive pneumonia and multi-organ failure. A significant proportion of patients present with non-respiratory symptoms such as headache, myalgia, vomiting and diarrhoea. A few potential therapeutic agents have been identified but none have been conclusively shown to be clinically effective. Human to human transmission is well documented, but the epidemic potential of MERS-CoV remains limited at present. Healthcare-associated clusters of MERS-CoV have been responsible for the majority of reported cases. The largest outbreaks have been driven by delayed diagnosis, overcrowding and poor infection control practices. However, chains of MERS-CoV transmission can be readily interrupted with implementation of appropriate control measures. As with any emerging infectious disease, guidelines for MERS-CoV case identification and surveillance evolved as new data became available. Sound clinical judgment is required to identify unusual presentations and trigger appropriate control precautions. Evidence from multiple sources implicates dromedary camels as natural hosts of MERS-CoV. Camel to human transmission has been demonstrated, but the exact mechanism of infection remains uncertain. The ubiquitously available social media have facilitated communication and networking amongst healthcare professionals and eventually proved to be important channels for presenting the public with factual material, timely updates and relevant advice.

Contact tracing the first Middle East respiratory syndrome case in the Philippines, February 2015

BACKGROUND

Middle East respiratory syndrome (MERS) is an illness caused by a coronavirus in which infected persons develop severe acute respiratory illness. A person can be infected through close contacts. This is an outbreak investigation report of the first confirmed MERS case in the Philippines and the subsequent contact tracing activities.

METHODS

Review of patient records and interviews with health-care personnel were done. Patient and close contacts were tested for MERS-coronavirus (CoV) by real time-polymerase chain reaction. Close contacts were identified and categorized. All traced contacts were monitored daily for appearance of illness for 14 days starting from the date of last known exposure to the confirmed case. A standard log sheet was used for symptom monitoring.

RESULTS

The case was a 31-year-old female who was a health-care worker in Saudi Arabia. She had mild acute respiratory illness five days before travelling to the Philippines. On 1 February, she travelled with her husband to the Philippines while she had a fever. On 2 February, she attended a health facility in the Philippines. On 8 February, respiratory samples were tested for MERS-CoV and yielded positive results. A total of 449 close contacts were identified, and 297 (66%) were traced. Of those traced, 15 developed respiratory symptoms. All of them tested negative for MERS.

DISCUSSION

In this outbreak investigation, the participation of health-care personnel in conducting vigorous contact tracing may have reduced the risk of transmission. However, being overly cautious to include more contacts for the outbreak response should be further reconsidered.