Middle East Respiratory Syndrome Coronavirus Antibodies in Dromedary Camels, Bangladesh, 2015

Serological evidence of bluetongue virus and associated factors in small ruminants of Bangladesh

Bluetongue (BT) is an infectious, vector-borne viral disease of animals having a substantial economic impact and it is endemic in the bordering states of the Indian subcontinent. Livestock enters frequently from India into Bangladesh without any screening. Hence, this study aimed to estimate the seroprevalence of Bluetongue virus (BTV) and associated risk factors in small ruminants of Bangladesh. We conducted a cross-sectional study in the Dhaka, Chattogram, and Faridpur districts of Bangladesh between 2017 and 2018. The team collected 333 serum samples from 123 goats and 210 sheep and tested them for the presence of antibodies against BTV using a competitive enzyme linked immunosorbent assay (c-ELISA). A mixed multivariable logistic regression model was built to identify risk factors. Sample collection location was included as a random effect and husbandry and demographic variables as fixed effects to identify the potential risk factors. The BTV seroprevalence was found to be 55.3% (n = 184; 95% CI: 49.74-60.68). In the mixed-effect logistic regression analysis, animal species (AOR: 4.69; 95% CI: 2.49-8.82; p = 0.001) and vector control measurement (AOR: 9.01; 95% CI: 4.01-20.00; p = 0.0001) were significantly associated with BTV seropositivity. However, no significant association was found in multivariable mixed-effect logistic regression for the variables age, body condition score (BCS), vaccination against PPR (p > 0.05). The study found evidence of high seroprevalence of BTV in both sheep and goats in different districts of Bangladesh, indicating natural exposure of the virus and the animals can serve as a potential threat for other animals. Further research is needed to isolate and identify the circulating virus serotype(s) of BTV in Bangladesh as well as longitudinal studies for epidemiological investigations to formulate sound control programs and to enhance the awareness about the possible impacts of this disease on the livelihood of the people.

Seroprevalence and risk factors of bluetongue virus in sheep of Chattogram, Bangladesh

Background and Aim:

Bluetongue (BT) is a non-contagious, infectious disease of wild and domestic ruminant animals caused by the BT virus (BTV). Bangladesh having a border with a BTV-endemic country, India and a substantial number of susceptible animals. Therefore, this study aimed to estimate BTV seroprevalence and potential risk factors.

Materials and Methods:

We collected 150 serum samples from indigenous sheep from Chattogram, Bangladesh. We screened the serum samples using a competitive enzyme-linked immunosorbent assay for detecting BTV-specific immunoglobulin.

Results:

We detected antibodies against BTV in 39.3% (59/150; 95% confidence interval: 31.5–47.6) of all sampled sheep. Factors like sampling site, sheep rearing location, rearing sheep with other farm species, and body condition score had a significant (p < 0.05) influence on the seroprevalence of BTV.

Conclusion:

The findings show that indigenous sheep have a higher BTV seroprevalence, necessitating sustained surveillance for early diagnosis and a better understanding of virus epidemiology in Bangladesh.

Major bat-borne zoonotic viral epidemics in Asia and Africa: A systematic review and meta-analysis

Bats are the natural reservoir host for many pathogenic and non‐pathogenic viruses, potentially spilling over to humans and domestic animals directly or via an intermediate host. The ongoing COVID‐19 pandemic is the continuation of virus spillover events that have taken place over the last few decades, particularly in Asia and Africa. Therefore, these bat‐associated epidemics provide a significant number of hints, including respiratory cellular tropism, more intense susceptibility to these cell types, and overall likely to become a pandemic for the next spillover. In this systematic review, we analysed data to insight, through bat‐originated spillover in Asia and Africa. We used STATA/IC‐13 software for descriptive statistics and meta‐analysis. The random effect of meta‐analysis showed that the pooled estimates of case fatality rates of bat‐originated viral zoonotic diseases were higher in Africa (61.06%, 95%CI: 50.26 to 71.85, l²% = 97.3, p < 0.001). Moreover, estimates of case fatality rates were higher in Ebola (61.06%; 95%CI: 50.26 to 71.85, l²% = 97.3, p < 0.001) followed by Nipah (55.19%; 95%CI: 39.29 to 71.09, l²% = 94.2, p < 0.001), MERS (18.49%; 95%CI: 8.19 to 28.76, l²% = 95.4, p < 0.001) and SARS (10.86%; 95%CI: 6.02 to 15.71, l²% = 85.7, p < 0.001) with the overall case fatality rates of 29.86 (95%CI: 29.97 to 48.58, l²% = 99.0, p < 0.001). Bat‐originated viruses have caused several outbreaks of deadly diseases, including Nipah, Ebola, SARS and MERS in Asia and Africa in a sequential fashion. Nipah virus emerged first in Malaysia, but later, periodic outbreaks were noticed in Bangladesh and India. Similarly, the Ebola virus was detected in the African continent with neurological disorders in humans, like Nipah, seen in the Asian region. Two important coronaviruses, MERS and SARS, were introduced, both with the potential to infect respiratory passages. This paper explores the dimension of spillover events within and/or between bat–human and the epidemiological risk factors, which may lead to another pandemic occurring. Further, these processes enhance the bat‐originated virus, which utilises an intermediate host to jump into human species.

Serological exposure in Bactrian and dromedary camels in Kazakhstan to a MERS or MERS-like coronavirus

Middle East respiratory syndrome coronavirus (MERS-CoV) is a camel-borne zoonotic virus endemic across Eastern Africa and the Middle East, with evidence of circulation in Bangladesh and Mongolia. To determine if MERS-CoV was present in Kazakhstan, in 2017-2018 we collected swabs and sera from Bactrian camels (n = 3124) and dromedary (n = 5083). The total seropositivity was 0.54% in Bactrian camels and 0.24% in dromedaries, however we did not detect MERS-CoV RNA in swab samples. There was no difference in the probability of infection between species or sex, but younger camels had a higher probability of being seropositive, suggesting a recent introduction of the virus to Kazakhstan. The infection of both camel species indicates that they both may play a role as natural reservoirs. These results reinforce the need for continual surveillance, especially at the camel-human interface to understand the risk of zoonotic exposure. This article is protected by copyright. All rights reserved.

Longitudinal and abattoir-based surveillance of MERS-CoV in camels in Jordan, 2018-2020

To generate baseline information to help better understand the antibody kinetics and nasal shedding dynamics of MERS-CoV in camels in Jordan, a longitudinal surveillance study was conducted in two phases; phase 1 was between December, 2018 and January, 2019 and phase 2 between August and December 2020. In each phase, two camel herds were studied. These herds were located in Al-azraq and in Al-ramtha area and were named Al-azraq and Al-ramtha herds, respectively. The same camel herd of Al-zarqa area was sampled in both phases while two different camel herds, one in each phase, were sampled in Al-ramtha area. Blood and nasal swabs were collected from same selected animals in all visits to each herd in both phases. Additionally, nasal swabs and retropharyngeal lymph node tissue samples were collected from sixty-one camels slaughtered at Al-ramtha abattoir during phase 2 to enhance virus isolation opportunities and phylogenetic analysis. All sampled animals from Al-azraq camel herd were either borderline or seropositive on spike 1 based ELISA assay and negative on quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) in both phases. In Al-ramtha camel herds, an unsteady pattern prevailed in animals' seropositivity in both phases and viral RNA was detected in all animals in the end of phase 1 and in one animal during phase 2. For the seroconversion, anti-MERS-CoV spike 1 antibodies were detected in two animals in phase 1 in the first collection only. While, in phase 2, intermittent seroconversion pattern was observed in several samples over time of collections that ended with all animals became seropositive in the last collection (after nineteen days from viral RNA detection). In addition, viral RNA was detected in nasal swabs of 3 slaughtered camels. Phylogenetic analysis of a partial fragment of spike 1 gene sequences of all MERS-CoV isolates clustered together with clade B of MERS-CoV. This cluster contains all MERS-CoV sequences obtained either from camels or human sources in the Arabian Peninsula indicating the continuous circulation of this clade also in Jordan.

Major zoonotic diseases of public health importance in Bangladesh

Zoonotic diseases cause repeated outbreaks in humans globally. The majority of emerging infections in humans are zoonotic. COVID‐19 is an ideal example of a recently identified emerging zoonotic disease, causing a global pandemic. Anthropogenic factors such as modernisation of agriculture and livestock farming, wildlife hunting, the destruction of wild animal habitats, mixing wild and domestic animals, wildlife trading, changing food habits and urbanisation could drive the emergence of zoonotic diseases in humans. Since 2001, Bangladesh has been reporting many emerging zoonotic disease outbreaks such as nipah, highly pathogenic avian influenza, pandemic H1N1, and COVID‐19. There are many other potential zoonotic pathogens such as Ebola, Middle East respiratory syndrome coronavirus, Kyasanur forest disease virus and Crimean–Congo haemorrhagic fever that may emerge in the future. However, we have a limited understanding of zoonotic diseases’ overall risk in humans and associated factors that drive the emergence of zoonotic pathogens. This narrative review summarised the major emerging, re‐emerging, neglected and other potential zoonotic diseases in Bangladesh and their associated risk factors. Nipah virus and Bacillus anthracis caused repeated outbreaks in humans. More than 300 human cases with Nipah virus infection were reported since the first outbreak in 2001. The highly pathogenic avian influenza virus (H5N1) caused more than 550 outbreaks in poultry, and eight human cases were reported so far since 2007. People of Bangladesh are frequently exposed to zoonotic pathogens due to close interaction with domestic and peri‐domestic animals. The rapidly changing intensified animal–human–ecosystem interfaces and risky practices increase the risk of zoonotic disease transmission. The narrative review's findings are useful to draw attention to the risk and emergence of zoonotic diseases to public health policymakers in Bangladesh and the application of one‐health approach to address this public health threat.

Middle East Respiratory Syndrome Coronavirus (MERS-CoV): State of the Science

Coronaviruses belong to a large family of viruses that can cause disease outbreaks ranging from the common cold to acute respiratory syndrome. Since 2003, three zoonotic members of this family evolved to cross species barriers infecting humans and resulting in relatively high case fatality rates (CFR). Compared to Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV, CFR = 10%) and pandemic Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2, CFR = 6%), the Middle East Respiratory Syndrome Coronavirus (MERS-CoV) has scored the highest CFR (approximately 35%). In this review, we systematically summarize the current state of scientific knowledge about MERS-CoV, including virology and origin, epidemiology, zoonotic mode of transmission, and potential therapeutic or prophylactic intervention modalities.

A single dose of ChAdOx1 MERS provides protective immunity in rhesus macaques

Developing a vaccine to protect against the lethal effects of the many strains of coronavirus is critical given the current global pandemic. For Middle East respiratory syndrome coronavirus (MERS-CoV), we show that rhesus macaques seroconverted rapidly after a single intramuscular vaccination with ChAdOx1 MERS. The vaccine protected against respiratory injury and pneumonia and reduced viral load in lung tissue by several orders of magnitude. MERS-CoV replication in type I and II pneumocytes of ChAdOx1 MERS-vaccinated animals was absent. A prime-boost regimen of ChAdOx1 MERS boosted antibody titers, and viral replication was completely absent from the respiratory tract tissue of these rhesus macaques. We also found that antibodies elicited by ChAdOx1 MERS in rhesus macaques neutralized six different MERS-CoV strains. Transgenic human dipeptidyl peptidase 4 mice vaccinated with ChAdOx1 MERS were completely protected against disease and lethality for all different MERS-CoV strains. The data support further clinical development of ChAdOx1 MERS.

Cross-sectional prevalence study of MERS-CoV in local and imported dromedary camels in Saudi Arabia, 2016-2018

The Middle East Respiratory Syndrome-Coronavirus (MERS-CoV) is an endemic virus in dromedaries. Annually, Saudi Arabia imports thousands of camels from the Horn of Africa, yet the epidemiology of MERS-CoV in these animals is largely unknown. Here, MERS-CoV prevalence was compared in imported African camels and their local counterparts. A total of 1399 paired sera and nasal swabs were collected from camels between 2016 and 2018. Imported animals from Sudan (n = 829) and Djibouti (n = 328) were sampled on incoming ships at Jeddah Islamic seaport before unloading, and local camels were sampled from Jeddah (n = 242). Samples were screened for neutralizing antibodies (nAbs) and MERS-CoV viral RNA. The overall seroprevalence was 92.7% and RNA detection rate was 17.2%. Imported camels had higher seroprevalence compared to resident herds (93.8% vs 87.6%, p <0.01) in contrast to RNA detection (13.3% vs 35.5%, p <0.0001). Seroprevalence significantly increased with age (p<0.0001) and viral RNA detection rate was ~2-folds higher in camels <2-year-old compared to older animals. RNA detection was higher in males verses females (24.3% vs 12.6%, p<0.0001) but seroprevalence was similar. Concurrent positivity for viral RNA and nAbs was found in >87% of the RNA positive animals, increased with age and was sex-dependent. Importantly, reduced viral RNA load was positively correlated with nAb titers. Our data confirm the widespread of MERS-CoV in imported and domestic camels in Saudi Arabia and highlight the need for continuous active surveillance and better prevention measures. Further studies are also warranted to understand camels correlates of protection for proper vaccine development.

Global status of Middle East respiratory syndrome coronavirus in dromedary camels: a systematic review

Dromedary camels have been shown to be the main reservoir for human Middle East respiratory syndrome (MERS) infections. This systematic review aims to compile and analyse all published data on MERS-coronavirus (CoV) in the global camel population to provide an overview of current knowledge on the distribution, spread and risk factors of infections in dromedary camels. We included original research articles containing laboratory evidence of MERS-CoV infections in dromedary camels in the field from 2013 to April 2018. In general, camels only show minor clinical signs of disease after being infected with MERS-CoV. Serological evidence of MERS-CoV in camels has been found in 20 countries, with molecular evidence for virus circulation in 13 countries. The seroprevalence of MERS-CoV antibodies increases with age in camels, while the prevalence of viral shedding as determined by MERS-CoV RNA detection in nasal swabs decreases. In several studies, camels that were sampled at animal markets or quarantine facilities were seropositive more often than camels at farms as well as imported camels vs. locally bred camels. Some studies show a relatively higher seroprevalence and viral detection during the cooler winter months. Knowledge of the animal reservoir of MERS-CoV is essential to develop intervention and control measures to prevent human infections.

A novel luciferase immunosorbent assay performs better than a commercial enzyme-linked immunosorbent assay to detect MERS-CoV specific IgG in humans and animals

The Middle East respiratory syndrome (MERS) is a lethal zoonosis caused by MERS coronavirus (MERS-CoV) and poses a significant threat to public health worldwide. Therefore, a rapid, sensitive, and specific serologic test for detecting anti-MERS-CoV antibodies in both humans and animals is urgently needed for the successful management of this illness. Here, we evaluated various novel luciferase immunosorbent assays (LISA) based on nucleocapsid protein (NP) as well as fragments derived from spike protein (S) including subunit 1 (S1), N terminal domain (NTD), receptor-binding domain (RBD) and subunit 2 (S2) of S for the detection of MERS-CoV-specific IgG. Fusion proteins, including nanoluciferase (NLuc) and various fragments derived from the NP or S protein of MERS-CoV, were expressed in human embryonic kidney 293 T cells. LISAs that detected anti-MERS-CoV IgG were further developed using cell lysates expressing various fusion proteins. Panels of human or animal samples infected with MERS-CoV were used to analyze the sensitivity and specificity of various LISAs in reference to a MERS-CoV RT-PCR, commercial S1-based ELISA, and pseudovirus particle neutralization test (ppNT). Our results showed that the S1-, RBD-, and NP-LISAs were more sensitive than the NTD- and S2-LISAs for the detection of anti-MERS-CoV IgG. Furthermore, the S1-, RBD-, and NP-LISAs were more sensitive (by at least 16-fold) than the commercially available S1-ELISA. Moreover, the S1-, RBD-, and NP-LISA specifically recognized anti-MERS-CoV IgG and did not cross-react with samples derived from other human CoV (OC43, 229E, HKU1, NL63)-infected patients. More importantly, these LISAs proved their applicability and reliability for detecting anti-MERS-CoV IgG in samples from camels, monkeys, and mice, among which the RBD-LISA exhibited excellent performance. The results of this study suggest that the novel MERS-CoV RBD- and S1- LISAs are highly effective platforms for the rapid and sensitive detection of anti-MERS-CoV IgG in human and animal samples. These assays have the potential to be used as serologic tests for the management and control of MERS-CoV infection.

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Scientific question

This study evaluated novel luciferase immunosorbent assays (LISAs) based on nucleocapsid protein (NP) as well as fragments derived from spike protein (S) for detection of MERS-CoV-specific IgG in humans and animals.

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Evidence before this study

Enzyme-linked immunosorbent assay (ELISA), microneutralization (MN), immunofluorescence assay (IFA), and pseudovirus particle neutralization test (ppNT) have been performed to detect serum antibodies against MERS-CoV. There remains a need to develop novel serological assays independent of protein purification, special secondary antibody, virus cultivation and Biosafety Level 3 (BSL-3) laboratory.

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New findings

In this study, novel LISAs based on the MERS-CoV S fragments and NP were developed. Human and animal samples infected with MERS-CoV were measured by the newly developed LISAs as well as reference methods including commercial S1-ELISA and ppNT. The results showed that the S1-, RBD-, and NP-LISAs were able to specifically distinguish MERS-CoV-infected samples from samples infected by other HCoV as consistent as the reference methods. Comparing with the commercially available S1-ELISA, the S1- and RBD-LISAs were 64-folds more sensitive. Moreover, the applicability and reliability of the LISAs were verified by detecting anti-MERS-CoV IgG in samples from camels, monkeys, and mice. The RBD-LISA exhibited superior sensitivity and specificity.

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Significance of the study

The novel MERS-CoV RBD- and S1-LISAs were developed independent of protein purification and special secondary antibody, and showed super specificity and efficiency for the detection of anti-MERS-CoV IgG in human and animal samples. These assays are recommended for serological diagnosis of MERS-CoV infection in the investigation of epidemic characteristic, origin tracing and vaccine study of MERS-CoV, they would contribute to the scientific control and prevention of MERS.

A database of geopositioned Middle East Respiratory Syndrome Coronavirus occurrences

As a World Health Organization Research and Development Blueprint priority pathogen, there is a need to better understand the geographic distribution of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) and its potential to infect mammals and humans. This database documents cases of MERS-CoV globally, with specific attention paid to zoonotic transmission. An initial literature search was conducted in PubMed, Web of Science, and Scopus; after screening articles according to the inclusion/exclusion criteria, a total of 208 sources were selected for extraction and geo-positioning. Each MERS-CoV occurrence was assigned one of the following classifications based upon published contextual information: index, unspecified, secondary, mammal, environmental, or imported. In total, this database is comprised of 861 unique geo-positioned MERS-CoV occurrences. The purpose of this article is to share a collated MERS-CoV database and extraction protocol that can be utilized in future mapping efforts for both MERS-CoV and other infectious diseases. More broadly, it may also provide useful data for the development of targeted MERS-CoV surveillance, which would prove invaluable in preventing future zoonotic spillover.

Measurement(s)	Middle East Respiratory Syndrome • geographic location
Technology Type(s)	digital curation
Factor Type(s)	geographic distribution of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) • year
Sample Characteristic - Organism	Middle East respiratory syndrome-related coronavirus
Sample Characteristic - Location	Earth (planet)

Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.11108801

A systematic review of MERS-CoV seroprevalence and RNA prevalence in dromedary camels: Implications for animal vaccination

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Most adult dromedaries in Africa and the Middle East have been infected with MERS-CoV.

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Seroprevalence increases with age, while active infection is more common in calves.

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Prevalence is higher at sites where different dromedary populations mix.

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Further study is needed to determine if prevalence of infection varies seasonally.

Human infection with Middle East Respiratory Syndrome Coronavirus (MERS-CoV) is driven by recurring dromedary-to-human spill-over events, leading decision-makers to consider dromedary vaccination. Dromedary vaccine candidates in the development pipeline are showing hopeful results, but gaps in our understanding of the epidemiology of MERS-CoV in dromedaries must be addressed to design and evaluate potential vaccination strategies. We aim to bring together existing measures of MERS-CoV infection in dromedary camels to assess the distribution of infection, highlighting knowledge gaps and implications for animal vaccination. We systematically reviewed the published literature on MEDLINE, EMBASE and Web of Science that reported seroprevalence and/or prevalence of active MERS-CoV infection in dromedary camels from both cross-sectional and longitudinal studies. 60 studies met our eligibility criteria. Qualitative syntheses determined that MERS-CoV seroprevalence increased with age up to 80–100% in adult dromedaries supporting geographically widespread endemicity of MERS-CoV in dromedaries in both the Arabian Peninsula and countries exporting dromedaries from Africa. The high prevalence of active infection measured in juveniles and at sites where dromedary populations mix should guide further investigation – particularly of dromedary movement – and inform vaccination strategy design and evaluation through mathematical modelling.

Diversity and prevalence of parasitic infestation with zoonotic potential in dromedary camel ( ) and fat-tailed sheep (dhumba) in Bangladesh

OBJECTIVE

Parasitic infestation is a major cause of losses in livestock production in tropical regions. A cross-sectional study was conducted to determine the prevalence of Gastro-intestinal (GI) parasites of dromedary camel (Camelus dromedarius) and fat-tailed sheep (dhumba), and the prevalence of hemoparasites in camel from Dhaka, Bangladesh.

MATERIALS AND METHODS

A total of 87 fecal samples (32 dhumba and 55 camel) and 55 camel blood samples were collected during September-October 2015. Fecal samples were examined by direct smear, sedimentation method, flotation technique, and McMaster technique for GI parasite. Giemsa stained blood smears were examined under microscope for hemoparasite detection.

RESULTS

62% camel (n = 34; 95% confidence interval (CI): 47.7-74.6) were infected with at least one genus of parasite. 15% camel were harboring more than one genus of parasite. The prevalence of GI parasite and hemoparasite in camel were recorded as Trichuris spp. (n = 16; 29%; 95% CI: 17.6-42.9), Balantidium coli (n = 12; 22%; 95% CI: 11.8-35.0), Trichostrongylus spp. (n = 7; 13%; 95% CI: 5.3-24.5), Strongyloides spp. (n = 5; 9%; 95% CI: 3.0-20.0), Anaplasma spp. (n = 5; 9%; 95% CI: 3.02-20.0), Paragonimus spp. (n = 1; 2%; 95% CI: 0.05-9.7), Schistosoma spp. (n = 1; 2%; 95% CI: 0.05-9.7), Hymenolepis spp. (n = 1; 2%; 95% CI: 0.05-9.7), Moniezia spp. (n = 1; 2%; 95% CI: 0.05-9.7), and Babesia spp. (n = 1; 2%; 95% CI: 0.05-9.7). Mean EPG feces of camel was 291.76 ± 42.03 with a range of 0-1,400. Total 59.4% dhumba (n = 19; 95% CI: 41-76) were positive for GI parasite, including Trichostrongylus spp. (n = 10; 31.3%; 95% CI: 16.1-50), Strongyloides spp. (n = 9; 28%; 95% CI: 13.8-46.8), B. coli (n = 5; 15.6%; 95% CI: 5.3-32.8), and Trichuris spp. (n = 4; 12.5%; 95% CI: 3.5-28.9).

CONCLUSIONS

High percentage of parasitic infestation in camel and dhumba in the present study refers to the necessity of use of anthelmintic for health and production improvement and to prevent zoonotic parasite transmission to animal handler and workers.

MERS: Progress on the global response, remaining challenges and the way forward

This article summarizes progress in research on Middle East Respiratory Syndrome (MERS) since a FAO-OIE-WHO Global Technical Meeting held at WHO Headquarters in Geneva on 25-27 September 2017. The meeting reviewed the latest scientific findings and identified and prioritized the global activities necessary to prevent, manage and control the disease. Critical needs for research and technical guidance identified during the meeting have been used to update the WHO R&D MERS-CoV Roadmap for diagnostics, therapeutics and vaccines and a broader public health research agenda. Since the 2017 meeting, progress has been made on several key actions in animal populations, at the animal/human interface and in human populations. This report also summarizes the latest scientific studies on MERS since 2017, including data from more than 50 research studies examining the presence of MERS-CoV infection in dromedary camels.