Mary Wilson
Well-known member
Published: July 29, 2022
David O Ulaeto, Jake Dunning, Miles W Carroll
DOI:https://doi.org/10.1016/S2666-5247(22)00194-X
The international outbreak of monkeypox that was recognised in May, 2022 represents a new transmission route for monkeypox virus. Since it was first recognised as a zoonotic pathogen in the 1970s, this virus has frequently jumped from its rodent reservoir hosts into people, predominantly in the Democratic Republic of the Congo. Such zoonotic events are estimated at several thousand per year, but are characterised by low human-to-human transmission.[SUP]1[/SUP][SUP], [/SUP] [SUP]2[/SUP] In the Democratic Republic of the Congo, zoonosis is predominantly seen in school-age boys in rural areas, who engage in hunting small game.[SUP]3[/SUP] By contrast, the outbreak that began in Nigeria in 2017 predominantly involved men aged 25–40 years in urban or periurban areas, with no obvious connection to suspected animal reservoirs.[SUP]4[/SUP]
The presentation of monkeypox in the current outbreak is also new. Traditionally, human monkeypox presents as a generalised monomorphic pustular rash, and genital lesions are rare.[SUP]5[/SUP][SUP], [/SUP] [SUP]6[/SUP][SUP], [/SUP] [SUP]7[/SUP] In the current international outbreak, including in Nigeria, an ulcerating genital rash develops in the majority of cases. For clinical presentations outside Africa, the genital rash precedes the generalised pustular rash, which is often minor.[SUP]4[/SUP][SUP], [/SUP] [SUP]8[/SUP][SUP], [/SUP] [SUP]9[/SUP][SUP], [/SUP] [SUP]10[/SUP][SUP], [/SUP] [SUP]11[/SUP][SUP], [/SUP] [SUP]12[/SUP] This presentation suggests that the genital area is a site of primary infection, giving rise to a localised rash, which is then sometimes followed by a secondary disseminated infection. Interestingly, reports from Nigeria up to 2020 and the USA in 2003 describe most patients as having monomorphic lesions, whereas in the current outbreak clinicians in the UK anecdotally report predominantly pleiomorphic lesions at different stages of eruption at the same time.
In the current outbreak, monkeypox virus seems to be transmitting via a primary localised rash (appendix). Transmission via primary rash (primary transmission) removes the requirement for the virus to establish a general disseminated infection, and this could facilitate the evolution of variants. Such a transmission route could also facilitate the co-transmission of multiple variants, as primary lesions avoid the bottleneck of secondary dissemination. If monkeypox virus is adapting to human transmission by this novel route, the adaptations should most readily be seen in genomes that are sequenced from primary rash lesions. ...
https://www.thelancet.com/journals/...5247(22)00194-X/fulltext#.YuS4u-R7ja8.twitter
David O Ulaeto, Jake Dunning, Miles W Carroll
DOI:https://doi.org/10.1016/S2666-5247(22)00194-X
The international outbreak of monkeypox that was recognised in May, 2022 represents a new transmission route for monkeypox virus. Since it was first recognised as a zoonotic pathogen in the 1970s, this virus has frequently jumped from its rodent reservoir hosts into people, predominantly in the Democratic Republic of the Congo. Such zoonotic events are estimated at several thousand per year, but are characterised by low human-to-human transmission.[SUP]1[/SUP][SUP], [/SUP] [SUP]2[/SUP] In the Democratic Republic of the Congo, zoonosis is predominantly seen in school-age boys in rural areas, who engage in hunting small game.[SUP]3[/SUP] By contrast, the outbreak that began in Nigeria in 2017 predominantly involved men aged 25–40 years in urban or periurban areas, with no obvious connection to suspected animal reservoirs.[SUP]4[/SUP]
The presentation of monkeypox in the current outbreak is also new. Traditionally, human monkeypox presents as a generalised monomorphic pustular rash, and genital lesions are rare.[SUP]5[/SUP][SUP], [/SUP] [SUP]6[/SUP][SUP], [/SUP] [SUP]7[/SUP] In the current international outbreak, including in Nigeria, an ulcerating genital rash develops in the majority of cases. For clinical presentations outside Africa, the genital rash precedes the generalised pustular rash, which is often minor.[SUP]4[/SUP][SUP], [/SUP] [SUP]8[/SUP][SUP], [/SUP] [SUP]9[/SUP][SUP], [/SUP] [SUP]10[/SUP][SUP], [/SUP] [SUP]11[/SUP][SUP], [/SUP] [SUP]12[/SUP] This presentation suggests that the genital area is a site of primary infection, giving rise to a localised rash, which is then sometimes followed by a secondary disseminated infection. Interestingly, reports from Nigeria up to 2020 and the USA in 2003 describe most patients as having monomorphic lesions, whereas in the current outbreak clinicians in the UK anecdotally report predominantly pleiomorphic lesions at different stages of eruption at the same time.
In the current outbreak, monkeypox virus seems to be transmitting via a primary localised rash (appendix). Transmission via primary rash (primary transmission) removes the requirement for the virus to establish a general disseminated infection, and this could facilitate the evolution of variants. Such a transmission route could also facilitate the co-transmission of multiple variants, as primary lesions avoid the bottleneck of secondary dissemination. If monkeypox virus is adapting to human transmission by this novel route, the adaptations should most readily be seen in genomes that are sequenced from primary rash lesions. ...
https://www.thelancet.com/journals/...5247(22)00194-X/fulltext#.YuS4u-R7ja8.twitter