Multiplex PCR for rapid diagnosis and differentiation of pox and pox-like diseases in dromedary Camels

Pockenvirusinfektionen in der Dermatologie: Poxvirus infections in dermatology - the neglected, the notable, and the notorious

Die Familie Poxviridae umfasst derzeit 22 Gattungen, die Wirbeltiere infizieren können. Humanpathogene Pockenviren gehören den Gattungen Ortho‐, Para‐, Mollusci‐ und Yatapoxvirus an. Bis zur Eradikation der Variola vera im Jahr 1979 waren die Pocken, im Volksmund auch Blattern genannt, eine schwerwiegende Gesundheitsbedrohung für die Bevölkerung. Noch heute sind Dermatologen mit zahlreichen Pockenvirusinfektionen konfrontiert, wie den Bauernhofpocken, die als Zoonosen nach Tierkontakten in ländlichen Gebieten oder nach Massenversammlungen auftreten können. In den Tropen können Erkrankungen durch Tanapox‐ oder Vaccinia‐Viren zu den Differenzialdiagnosen gehören. Dellwarzen sind weltweit verbreitet und werden in bestimmten Fällen als sexuell übertragbare Pockenvirusinfektion angesehen. In jüngster Zeit hatten sich Mpox (Affenpocken) zu einer gesundheitlichen Notlage von internationaler Tragweite entwickelt, die eine rasche Identifizierung und angemessene Behandlung durch Dermatologen und Infektiologen erfordert. Fortschritte und neue Erkenntnisse über Epidemiologie, Diagnose, klinische Manifestationen und Komplikationen sowie Behandlung und Prävention von Pockenvirusinfektionen erfordern ein hohes Maß an Fachwissen und interdisziplinärer Zusammenarbeit in den Bereichen Virologie, Infektiologie und Dermatologie. Dieser CME‐Artikel bietet einen aktualisierten systematischen Überblick, um praktizierende Dermatologen bei der Identifizierung, Differenzialdiagnose und Behandlung klinisch relevanter Pockenvirusinfektionen zu unterstützen.

Poxvirus infections in dermatology - the neglected, the notable, and the notorious

The family Poxviridae currently comprises 22 genera that infect vertebrates. Of these, members of the Ortho-, Para-, Mollusci- and Yatapoxvirus genera have been associated with human diseases of high clinical relevance in dermatology. Historically, smallpox had been a notorious health threat until it was declared eradicated by the World Health Organization in 1979. Today, dermatologists are confronted with a variety of poxviral infections, such as farmyard pox, which occurs as a zoonotic infection after contact with animals. In the tropics, tanapox or vaccinia may be in the differential diagnosis as neglected tropical dermatoses. Molluscum contagiosum virus infection accounts for significant disease burden worldwide and is classified as a sexually transmitted infection in certain scenarios. Recently, mpox (monkeypox) has emerged as a public health emergency of international concern, requiring rapid recognition and appropriate management by dermatologists and infectious disease specialists. Advances and new insights into the epidemiology, diagnosis, clinical manifestations and complications, treatment, and prevention of poxviral infections require a high level of expertise and interdisciplinary skills from healthcare professionals linking virology, infectious diseases, and dermatology. This CME article provides a systematic overview and update to assist the practicing dermatologist in the identification, differential diagnosis, and management of poxviral infections.

The genetic identification of camel contagious ecthyma virus as the causative agent of contagious ecthyma in dromedary camels (Camelus dromedarius) in Qatar

Camel contagious ecthyma is a contagious viral disease of camels caused by either Orf virus (ORFV) or camel contagious ecthyma virus (CCEV). It has been previously reported and shown to cause economic losses in some camel-rearing countries in Asia and Africa, but has not been detected in Qatar. The purpose of this study was to identify and genetically characterize the contagious ecthyma causative agent in Qatari dromedary camels between 2017 and 2018. Accordingly, we made diagnoses of camel contagious ecthyma based on the clinical signs and genetic analysis of the entire major envelop protein (B2L) gene. The sequence analysis showed that CCEV was the infecting virus, and the B2L gene sequences were highly conserved between the locally infected camels with 100% similarity with isolates from Bahrain. This is the first study reporting the detection of CCEV in Qatar. We suggest that sequencing of the CCEV genome is necessary to determine the origin and relationship of this virus with other members of the parapoxvirus genus.

More cell culture passaged Camelpox virus sequences found resembling those of vaccinia virus

BACKGROUND

Camelpox is the most infectious and economically important disease of camelids that causes significant morbidity and mortality rates. Several live attenuated vaccines against Camelpox virus (CMLV) are produced worldwide by passaging field isolates in cell culture. Sequence of a high passage Saudi isolate of CMLV was previously found closely resembled Vaccinia virus (VACV).

AIM

To determine whether other high cell culture passage CMLV isolates are genetically resemble VACV and further to explore the possible mechanism of the resemblance.

METHODS

We performed polymerase chain reaction and DNA sequence analysis of A-type inclusion body protein (ATIP), L1R, and open reading frame (ORF) 185 genes on different cell culture passage levels of a field isolate, two high passage vaccines, wild-type, and reference strains of CMLV.

RESULTS

We demonstrate that additional two high passage attenuated vaccine candidate from Sudan and UAE likewise contain sequences resembling VACV more than CMLV. Furthermore, sequence analysis of the ATIP gene of selected virus passages in cell culture revealed that the shift to VACV-like occurred between passage 11 and 20 and up to the 10th passage the genome still resembles wild-type virus. This observation was further confirmed by recombination analysis which indicated recombination events at ATIP and ORF185 genes occurred at higher passages.

CONCLUSION

We confirmed that the cell culture passage CMLV turns to resemble VACV after cell culture passage and concluded that the resemblance may not be a result of contamination or misidentification as previously thought but could be due to recombination events that occurred during the passage process.

First report of camel contagious ecthyma in Nigeria

Camel contagious ecthyma (CCE) is a viral disease of camelids that is caused by a Parapoxvirus (PPV) which is a DNA virus of the viral family: Poxviridae. Diseases affecting camels in Nigeria are scarcely reported. CCE or the laboratory detection of camel PPV (CPPV) has not been reported in Nigeria. This study investigated and described the clinical presentation of CCE and molecular detection of CPPV in Nigeria. Suspected cases of CCE were reported in a farm, live animal market and abattoir, in three different states (Bauchi, Plateau and Zamfara) in Northern Nigeria. Skin scabs, lungs, liver and intestine samples were collected. Polymerase chain reaction (PCR) was carried out using the primers which targets the RPO30 gene fragment of the genus PPV. The clinical signs observed from the suspected cases of CCE were proliferative skin lesions, papules, scabs on the lips and nares. CPPV was detected in 80.0% (4/5) of the samples collected by PCR. CCE was diagnosed based on clinical signs and PCR results. This is the first report of CCE in Nigeria. Further studies should be carried out to genetically characterize the CPPV circulating in Nigeria.

First Diagnosed Case of Camelpox Virus in Israel

An outbreak of a disease in camels with skin lesions was reported in Israel during 2016. To identify the etiological agent of this illness, we employed a multidisciplinary diagnostic approach. Transmission electron microscopy (TEM) analysis of lesion material revealed the presence of an orthopox-like virus, based on its characteristic brick shape. The virus from the skin lesions successfully infected chorioallantoic membranes and induced cytopathic effect in Vero cells, which were subsequently positively stained by an orthopox-specific antibody. The definite identification of the virus was accomplished by two independent qPCR, one of which was developed in this study, followed by sequencing of several regions of the viral genome. The qPCR and sequencing results confirmed the presence of camelpox virus (CMLV), and indicated that it is different from the previously annotated CMLV sequence available from GenBank. This is the first reported case of CMLV in Israel, and the first description of the isolated CMLV subtype.

Molecular characterization of Camelpox virus isolates from Bikaner, India: Evidence of its endemicity

Camelpox is an important viral disease of camels, which may produce mild skin lesions or severe systemic infections. Camelpox virus (CMLV) isolates retrieved from an incidence of camelpox in camels at Bikaner, India were characterized on the basis of genotype and pathotype. Histopathological examination of the CMLV scab revealed intracytoplasmic-eosinophilic inclusion bodies. The phylogenetic analysis of all eight CMLV isolates for C18L gene nucleotide sequence revealed its clustering with its strains M-96 from Kazakhstan and CMS from Iran. The study will help to understand the transmission chain, pathobiology, and epidemiology of circulating CMLV strains. The full genome sequencing of some of the exemplary samples of CMLV is recommended in order to plan and implement a suitable control strategy.

Identification and phylogenetic analysis of contagious ecthyma virus from camels (<i>Camelus dromedarius</i>) in Iran

Contagious ecthyma is a highly contagious disease affecting domestic and wild ruminants such as sheep, goats and camels. The identification and characterisation of a parapoxvirus (PPV) infecting camels is described here. The virus was detected in dromedary camels (Camelus dromedarius) from Kerman and Shiraz in Iran. PPV-specific amplification by polymerase chain reaction (PCR) further confirmed that the disease was associated with PPV infection. Phylogenetic analysis of ORF011 (B2L) gene sequences showed 99.79% and 82.13% similarity of the PPV identified in this study with the Jodhpur isolate and the bovine papular stomatitis virus (BPSV) isolates (CE41), respectively. Moreover, phylogenetic analysis of the ORF045 gene indicated that the Shiraz sample was in all probability closely related to VR634 and to F00.120R and PCPV776. In conclusion, the results suggest that camel PPV (CPPV) is a likely cause of contagious ecthyma in dromedary camels in Iran.

Investigation on papillomavirus infection in dromedary camels in Al-Ahsa, Saudi Arabia

We investigated two outbreaks of papillomatosis between 2013 and 2015 in Al Ahsa region of eastern Saudi Arabia involving fourteen dromedary camels. The disease affected both young and adult animals and occurred in coincidence with demodectic mange infestation. Diagnosis was made based on gross and histopathological characteristics of the wart lesion and was confirmed by PCR. Rolling circle amplification followed by degenerate primer PCR and sequencing of the amplicons revealed the presence of both Camelus dromedarius papillomavirus types 1 and 2, previously identified in infected dromedaries in Sudan.

Genetic characterization of poxviruses in Camelus dromedarius in Ethiopia, 2011-2014

Camelpox and camel contagious ecthyma are infectious viral diseases of camelids caused by camelpox virus (CMLV) and camel contagious ecthyma virus (CCEV), respectively. Even though, in Ethiopia, pox disease has been creating significant economic losses in camel production, little is known on the responsible pathogens and their genetic diversity. Thus, the present study aimed at isolation, identification and genetic characterization of the causative viruses. Accordingly, clinical case observations, infectious virus isolation, and molecular and phylogenetic analysis of poxviruses infecting camels in three regions and six districts in the country, Afar (Chifra), Oromia (Arero, Miyu and Yabello) and Somali (Gursum and Jijiga) between 2011 and 2014 were undertaken. The full hemagglutinin (HA) and partial A-type inclusion protein (ATIP) genes of CMLV and full major envelope protein (B2L) gene of CCEV of Ethiopian isolates were sequenced, analyzed and compared among each other and to foreign isolates. The viral isolation confirmed the presence of infectious poxviruses. The preliminary screening by PCR showed 27 CMLVs and 20 CCEVs. The sequence analyses showed that the HA and ATIP gene sequences are highly conserved within the local isolates of CMLVs, and formed a single cluster together with isolates from Somalia and Syria. Unlike CMLVs, the B2L gene analysis of Ethiopian CCEV showed few genetic variations. The phylogenetic analysis revealed three clusters of CCEV in Ethiopia with the isolates clustering according to their geographical origins. To our knowledge, this is the first report indicating the existence of CCEV in Ethiopia where camel contagious ecthyma was misdiagnosed as camelpox. Additionally, this study has also disclosed the existence of co-infections with CMLV and CCEV. A comprehensive characterization of poxviruses affecting camels in Ethiopia and the full genome sequencing of representative isolates are recommended to better understand the dynamics of pox diseases of camels and to assist in the implementation of more efficient control measures.