猴痘：被忽視的老對手
猴痘是一種人畜共通疾病，由一種屬於正痘病毒屬的病毒引起，在非洲西部和中部流行。由於北美以及歐洲和大洋洲國家報告的病例越來越多，這種疾病正在成為全球頭條新聞。截至 6 月 2 日，780 例實驗室確診的猴痘病例已向世衛組織報告或確認了，這些病例來自非猴痘病毒流行地區之世衛組織四個區署的 27 個成員國。雖然沒有報告死亡（但在流行國家繼續發生死亡），但人們擔心在以前沒有報告過這種疾病的國家和沒有去過流行國家的個人中出現非典型的猴痘。可能受到持續的 COVID-19 大流行的影響，媒體對猴痘爆發的報導錯誤地暗示它可能是下一次大流行，這與現實相去甚遠。
1970 年報告了第一例人類猴痘病例，在過去的 5 年中，幾個非洲國家爆發了猴痘。就在今年，世衛組織已收到來自五個非洲流行國家的 1,365 例病例和 69 人死於該病毒的報告。該疾病的死亡率在 1% 到 10% 之間，具體取決於不同進化枝，兒童、孕婦和免疫功能低下的個體出現負面結果的風險很高。由於天花疫苗接種對猴痘提供了部分保護，40 多年前天花被根除後停止接種意味著 50 歲以下的任何人都無法從這種保護中受益，事實上，非流行國家最近的病例是最年輕的年齡族群。到目前為止，遏制猴痘爆發的策略依賴於對人們進行疾病教育並及早發現病例以減少他們傳播病毒的可能性。但是，正如Hugh Adler 及其同事在 5 月 24 日於刺胳針期刊發表的的一篇文章中所述，使用抗病毒藥物治療猴痘病例的一些經驗正在出現中。
儘管對當前全球爆發猴痘的調查仍在進行中，但病毒傳播似乎可能是在西班牙和比利時擁擠的公共活動中開始的。非洲已有人傳人的報導，但在非流行國家大規模發生，卻令世界大吃一驚。然而，非洲國家流行地區的研究人員對似乎明顯的雙重標準表示失望：雖然猴痘只是撒哈拉以南非洲的一個問題，但這種疾病並沒有受到任何關注，但一旦病例開始出現高收入國家，世界其他地區便注意到了這一點。非洲人群與猴痘病毒共存了幾十年，現在是時候進行研究以解決流行國家的需求了。此外，新的人畜共通疾病的出現及其在全球範圍內的潛在傳播是我們需要做好準備的。隨著森林砍伐、遷徙和衝突，人類與野生動物之間的接觸變得越來越普遍，這種接近將有利於人畜共通疾病病原體的外溢。目前缺少的是對可能出現的病原體的了解以及對監測的充分投資。
6 月 2 日至 3 日，由世衛組織所組織來自世界各地的專家進行了一次磋商，以確定管理當前猴痘疫情的優先領域和未來研究的主要目標。更好的診斷工具、更好地與當地社區的接觸、更全面的健康一體 (One Health) 之方法以及對疫苗和治療劑的研究被確定為優先事項。
對猴痘的突然關注是否也會給流行國家帶來一些好處？有希望是這種情況。剛果民主共和國正在進行一項關於天花疫苗接種對醫護人員猴痘病例影響的研究，另一項研究將監測中非共和國唯一獲得許可用於治療猴痘的抗病毒藥物 tecovirimat 的擴大使用情況。與此同時，應該承認非洲醫生在處理猴痘方面的長期經驗，並成為未來討論的一個組成部分。 ■ 刺胳針傳染病
www.thelancet.com/infection Vol 22 July 2022
Monkeypox: a neglected old foe
Monkeypox is a zoonosis caused by a virus belonging to the genus orthopoxvirus and endemic to western and central Africa. The disease is making headlines worldwide because of a growing number of cases being reported from North America and countries in Europe and Oceania. As of June 2, 780 laboratoryconfirmed cases of monkeypox had been reported to or identified by WHO from 27 member states across four WHO regions that are not endemic for monkeypox virus. Although no deaths have been reported (but deaths continue to occur in endemic countries), there is concern for the atypical emergence of monkeypox in countries where the disease had not been reported before and in individuals who have not travelled to endemic countries. Probably scarred by the ongoing COVID-19 pandemic, the media coverage of the monkeypox outbreak has incorrectly suggested that it might be the next pandemic, which is far from reality.
The first human monkeypox case was reported in 1970 and over the past five decades, several African countries have seen monkeypox outbreaks. Just this year, WHO has received reports of 1365 cases and 69 deaths due to the virus from five endemic African countries. The disease has a mortality that varies between 1% and 10%, depending on the clade, and children, pregnant women, and immunocompromised individuals are at high risk for negative outcomes. Since smallpox vaccination provides partial protection against monkeypox, its cessation over 40 years ago when smallpox was eradicated means that anyone younger than 50 years is not benefitting from that kind of protection and in fact the recent cases in non-endemic countries have been in the youngest age bracket. So far, the strategy to contain monkeypox outbreaks has relied on educating people on the disease and finding cases early to reduce the likelihood they transmit the virus. But, as described in an Article by Hugh Adler and colleagues that we published on May 24, some experience in the use of antivirals in managing monkeypox cases is emerging.
Although the investigation on the current global oubreak of monkeypox is still ongoing, it seems likely that viral transmission might have started in crowded public events in Spain and Belgium. Human-to-human transmission had already been reported in Africa, but its occurrence at a large scale in non-endemic countries caught the world by surprise. Researchers in endemic African countries have, however, expressed dismay for what appears to be an obvious double standard: whilst monkeypox was a just problem of sub-Saharan Africa, the disease had not received any attention, but as soon as cases started appearing in high-income countries, the rest of the world took note. African populations have coexisted with monkeypox virus for decades and it is time that research is done to address the needs of endemic countries. Moreover, the emergence of new zoonoses and their potential spread at the global level is something we need to be prepared for. With deforestation, migration, and conflict, the contact between human populations and wildlife is becoming more common and such proximity will favour spillover of zoonotic pathogens. What is currently missing is knowledge of what pathogens might emerge and an adequate investment in surveillance.
On June 2–3, WHO organised a consultation of experts from all over the world to define priority areas for the management of the current outbreak of monkeypox and key objectives for future research. Better diagnostic tools, better engagement with local communities, a more comprehensive One Health approach, and research on vaccines and therapeutic agents were identified as priorities.
Will the sudden attention given to monkeypox bring some benefits also for endemic countries? There is hope that this is the case. A study on the impact of smallpox vaccination on monkeypox cases among health-care workers is ongoing in DR Congo, and another study will monitor expanded access to tecovirimat, the only antiviral drug licensed for treating monkeypox, in the Central African Republic. In the meantime, the long experience in dealing with monkeypox from African doctors should be acknowledged and be an integral part of the discussion moving forward. ■ The Lancet Infectious Diseases
www.thelancet.com/infection Vol 22 July 2022