Mpox（猴痘）和 HIV
資料來源：Liz Highleyman/2023 年 1 月/aidsmap/財團法人台灣紅絲帶基金會編譯
圖片來源：弗拉德.奧爾洛夫/Shutterstock.com
關鍵點
• Mpox 通過密切的個人接觸傳播，包括性行為。
• 兩劑疫苗可以預防 mpox。
• 未經治療的 HIV 感染者罹患嚴重 mpox 的風險更大。
Mpox（猴痘）是由與天花有關的病毒引起的； 兩者都是正痘病毒家族的成員。 Mpox 通常會引起皮疹，並可能出現在身體的任何部位。 有時皮損伴有流感樣症狀和淋巴結腫大。
Mpox 不是一種新疾病。 它於 1958 年首次在實驗室猴子身上被發現，但在動物中它最常見於囓齒動物，例如大鼠。 1970 年在剛果民主共和國發現了第一例人類病例。在本次疫情爆發之前，mpox主要出現在中非和西非。但是，偶爾會在其他地方發現病例，主要是在旅行者中。
2022 年 5 月，猴痘（現更名為 mpox）爆發於英國，並很快蔓延至整個歐洲和北美。 截至 2022 年 12 月，全球已確認超過 83,000 例病例。 雖然病例已從 7 月和 8 月的高峰期大幅下降，但 mpox 仍然對某些人構成風險，例如那些未經治療的 HIV 感染者。
傳播
傳統上，猴痘病毒已經從動物傳播給人類——例如，透過咬傷或處理野味——以及透過密切接觸在人與人之間傳播。 然而，2022 年的爆發與性密切相關，尤其是與多個伴侶發生性關係者。
任何人都可以透過密切的個人接觸感染 mpox。然而，在這次疫情中受影響的大多數人都是性活躍的男同性戀者、雙性戀者和其他男男性行為者。當前爆發的一些病例也與家庭接觸有關。母嬰傳播可發生在懷孕、分娩或產後密切接觸期間。在醫療機構中透過職業接觸傳播的情況很少見。沒有與學校或日託中心有關的疫情。
傳播可能透過近距離的皮膚接觸、接吻和呼吸道飛沫（例如咳嗽產生的飛沫）發生。 但是，mpox 不像導致 COVID-19 的 SARS-CoV-2 冠狀病毒那樣透過空氣傳播。 目前尚不清楚 mpox 是否可以透過精液或陰道分泌物傳播，關於是否應將其稱為性傳播感染 (STI) 存在爭議。
接觸衣服、床單、毛巾或接觸過瘡液的表面也可能發生傳播。 然而，這似乎並不是當前爆發的主要因素。
症狀
您可以有 mpox在症狀開始之前最多達三週。 這種疾病通常會持續兩到四個星期。 然而，免疫力低下的人——包括那些感染晚期 HIV 的人——可能會經歷更嚴重的疾病或身體不適的時間更長。
該病毒通常以流感樣症狀開始，例如發燒、疲勞、頭痛和肌肉酸痛，以及淋巴結腫大。其典型特徵是皮疹，可出現在您的面部、生殖器、手掌、腳底或身體其他部位。有些人，尤其是接受過口交或肛交的人，會在喉嚨或直腸和直腸炎（直腸炎症）中出現疼痛性潰瘍。另一方面，有些人只有一個或幾個病變，可能不會出現其他症狀。
NAM aidsmap 的 Susan Cole 與 Harun Tulunay 和 BHIVA 主席 Laura Waters 博士就病毒進行了交談，Harun Tulunay 分享了他因嚴重猴痘住院的經歷。
潰瘍可能會疼痛或發癢，通常開始時是扁平的紅點，然後發展為堅硬、凸起的病變。 這些病變充滿高度傳染性的透明液體，然後是膿液（淡黃色液體）。 這些病變可能看起來像普通性傳播感染、水痘或其他皮膚病的病變，這會使診斷變得困難。 有些人同時檢測出 HIV、mpox 和其他 STI 陽性。專家建議那些有 mpox 症狀風險或出現症狀的人也應該接受 HIV 和其他 STI 檢測，並提供有關 HIV 暴露前預防 (PrEP) 的信息。
雖然大多數 mpox 患者無需治療即可康復，但瘡會留下疤痕，病情較嚴重的人可能會出現併發症。 這些包括病灶被細菌感染、敗血症（血液感染）、肺炎、腦炎（腦部炎症）和眼睛病灶導致的視力喪失。
嚴重的後果在兒童、孕婦和免疫力低下的人中更為常見。 接受抗反轉錄病毒治療且 HIV 控制良好的人似乎沒有更大的風險。然而，那些未經治療的 HIV、未抑制的病毒載量或低 CD4 計數的人可能會有更糟糕的結果。
非洲有兩種主要的猴痘病毒株，其中一種的死亡率約為 10%，另一種約為 1%。 在這次爆發中，較溫和的形式正在世界其他地方傳播，死亡率低於先前在非洲報告的死亡率。
預防
如果您患有 mpox，為降低傳播風險，請用衣服或繃帶蓋住您的瘡。 由於猴痘病毒可能會在面對面接觸時透過呼吸道飛沫傳播，因此咳嗽和打噴嚏時要遮住口鼻；戴上合適的口罩有助於防止傳播給密切接觸者。照顧 mpox 患者的醫護人員應使用標準的感染控制預防措施。
不要共用性玩具或牙刷等個人物品。避免共用衣服、床單或毛巾，並用熱水清洗。對與 mpox 瘡液接觸的表面進行消毒。目前尚不清楚 mpox 是否透過精液傳播，但保險套可以預防透過接觸生殖器或直腸的潰瘍來防止傳播。
有瘡或其他 mpox 症狀的人應避免性行為和其他密切接觸，接受檢查，如果症狀嚴重或持續時間較長，則應就醫。 那些認為自己可能接觸過 mpox 的人應該自我監測三週的症狀。
疫苗接種
由於病毒是相關的，因此接種天花疫苗也可以預防 mpox。常規天花疫苗接種在 1970 年代和 1980 年代結束，當時天花不再是公共衛生威脅，但這可能是最近 mpox 病例增加的原因之一。在英國，大多數 50 歲或以上的人以前都接種過天花疫苗。保護似乎是持久的，儘管免疫力可能會隨著時間的推移而緩慢下降。
英國和其他國家已經批准了一種名為 MVA-BN 的安全天花和 mpox 疫苗； 品牌名稱包括 Imvanex 和 Jynneos。它已經過測試並證明對 HIV 感染者是安全的。 一種稱為 ACAM2000 的較舊的活病毒疫苗會引起嚴重的副作用，尤其是對免疫力低下或皮膚狀況不佳的人，而且它被認為對 HIV 感染者不安全。
最初的 MVA-BN 方案包括兩次皮下注射，相隔 4 週。 然而，為了延長有限的疫苗供應，一些國家採用了一種節省劑量的皮內注射方法，即在皮膚表層下注射原始劑量的五分之一。使用任何一種方法，都需要兩次劑量才能獲得全面保護，大約在第二次劑量後兩周達到。
Mpox 可以透過所謂的環形疫苗接種或對感染者的密切接觸者進行有針對性的疫苗接種來控制。由於猴痘病毒的潛伏期較長，疫苗可在暴露後兩週內接種，但最好在四天內接種；這稱為暴露後預防。為獲得更廣泛的保護，有風險的人，例如有多個性伴侶的人，可以提前接種疫苗；這被稱為暴露前預防。專家不建議普通人群接種疫苗。
Mpox (monkeypox) and HIV
Liz Highleyman/January 2023/aidsmap
Vlad Orlov/Shutterstock.com
Key points
•Mpox is transmitted during close personal contact, including sex.
•A two-dose vaccine can prevent mpox.
•People with untreated HIV are at greater risk for severe mpox.
Mpox (monkeypox) is caused by a virus related to smallpox; both are members of the orthopox virus family. Mpox typically causes a rash with sores that can appear anywhere on the body. Sometimes the skin lesions are accompanied by flu-like symptoms and swollen lymph nodes.
Mpox is not a new disease. It was first discovered in laboratory monkeys in 1958, though in animals it’s most common in rodents, such as rats. The first human case was identified in 1970 in the Democratic Republic of Congo. Before the current outbreak, mpox was mostly seen in central and west Africa. However, cases have occasionally been found elsewhere, mostly among travellers.
In May 2022, an outbreak of monkeypox – now renamed mpox – began in the UK and soon spread throughout Europe and North America. As of December 2022, more than 83,000 cases have been identified worldwide. While cases have declined dramatically from their peak in July and August, mpox still poses a risk for some people, such as those living with untreated HIV.
Transmission
Traditionally, the monkeypox virus has been transmitted from animals to people – for example, via bites or handling wild game – and from person to person through close contact. However, the 2022 outbreak is strongly linked to sex, especially having sex with multiple partners.
Anyone can get mpox through close personal contact. However, most of those affected in this outbreak have been sexually active gay, bisexual and other men who have sex with men. Some cases in the current outbreak have also been linked to household contact. Mother-to-child transmission can occur during pregnancy, delivery or close contact after birth. Transmission via occupational exposure in healthcare settings is rare. There have been no outbreaks linked to schools or day care centres.
Transmission may happen via skin-to-skin contact, kissing and respiratory droplets (such as those from coughing) at close range. However, mpox is not airborne like the SARS-CoV-2 coronavirus that causes COVID-19. It is not clear whether mpox can be transmitted in semen or vaginal fluid, and there is debate about whether it should be called a sexually transmitted infection (STI).
Transmission may also happen through contact with clothing, bed linens, towels or surfaces that have come in contact with fluid from sores. However, this does not appear to be a major factor in the current outbreak.
Symptoms
You can have mpox for up to three weeks before symptoms start. The illness usually lasts two to four weeks. However, people with compromised immunity – including those with advanced HIV – may experience more severe illness or be unwell for longer.
The virus often starts with flu-like symptoms, such as fever, fatigue, headache, and muscle aches, as well as swollen lymph nodes. Its characteristic feature is a rash that can appear on your face, genitals, the palms of your hands, the soles of your feet or elsewhere on your body. Some people, especially those who had receptive oral or anal sex, develop painful sores in their throat or rectum and proctitis (rectal inflammation). On the other hand, some people have only one or a few lesions and may not develop other symptoms.
NAM aidsmap’s Susan Cole talks to Harun Tulunay, who shares his experience of being hospitalised with severe monkeypox, and BHIVA Chair Dr Laura Waters, about the virus.
The sores, which may be painful or itchy, typically start out as flat red spots and progress to firm, raised lesions. These lesions fill with highly infectious clear fluid and then pus (yellowish fluid). The lesions may look like those of common STIs, chickenpox or other skin conditions, which can make diagnosis difficult. Some people have tested positive for HIV, mpox, and other STIs at the same time. Experts recommend that those at risk for, or presenting with, symptoms of mpox should also be tested for HIV and other STIs and given information on HIV pre-exposure prophylaxis (PrEP).
While most people with mpox recover without treatment, the sores can leave scars, and people with more severe disease may develop complications. These include infection of the lesions by a bacteria, sepsis (blood infection), pneumonia, encephalitis (brain inflammation) and vision loss due to lesions in the eyes.
Severe outcomes are more common among children, pregnant women and immunocompromised people. People on antiretroviral therapy with well-controlled HIV do not appear to be at greater risk. However, those with untreated HIV, unsuppressed viral load or a low CD4 count may have worse outcomes.
There are two main monkeypox virus strains in Africa, one of which has a death rate of around 10% and the other around 1%. The milder form is circulating elsewhere in the world in this outbreak, and mortality is lower than previously reported in Africa.
Prevention
To reduce the risk of transmission if you have mpox, cover your sores with clothing or bandages. Because the monkeypox virus may be transmitted through respiratory droplets during face-to-face contact, cover your coughs and sneezes; wearing a well-fitted mask can help prevent transmission to close contacts. Healthcare workers caring for people with mpox should use standard infection control precautions.
Don’t share sex toys or personal items such as toothbrushes. Avoid sharing clothes, bed linens or towels, and wash them in hot water. Disinfect surfaces that come in contact with fluid from mpox sores. It is not yet known whether mpox is passed on in semen, but condoms may prevent transmission via contact with sores on the genitals or in the rectum.
People with sores or other mpox symptoms should avoid sex and other close contact, get tested, and seek medical care if symptoms are severe or prolonged. Those who think they might have been exposed to mpox should self-monitor for symptoms for three weeks.
Vaccination
Because the viruses are related, smallpox vaccination can prevent mpox as well. Routine smallpox vaccination ended in the 1970s and 1980s when smallpox was no longer a public health threat, but this may be one reason for the recent rise in cases of mpox. Most people around age 50 or older in the UK were previously vaccinated against smallpox. Protection appears to be long-lasting, though immunity may slowly decline over time.
The UK and other countries have approved a safe, smallpox and mpox vaccine known as MVA-BN; brand names include Imvanex and Jynneos. It has been tested and shown to be safe for people living with HIV. An older live virus vaccine known as ACAM2000 can cause serious side effects, especially in people with compromised immunity or skin conditions, and it is not considered safe for people with HIV.
The original MVA-BN regimen consisted of two doses administered by subcutaneous injection four weeks apart. However, in an effort to stretch limited vaccine supplies, some countries adopted a dose-sparing intradermal method in which one-fifth of the original dose is administered under the top layer of skin. With either method, two doses are needed for full protection, which is reached around two weeks after the second dose.
Mpox can be contained through so-called ring vaccination, or targeted vaccination of close contacts of an infected person. Because the monkeypox virus has a long incubation period, the vaccine can be administered up to two weeks after exposure, though it works best if given within four days; this is known as post-exposure prophylaxis. For broader protection, people at risk, such as those with multiple sex partners, can receive the vaccine in advance; this is known as pre-exposure prophylaxis. Experts do not recommend vaccination for the general population.
Treatment
People with mild or moderate mpox symptoms usually do not need treatment beyond supportive care, such as bed rest, keeping lesions clean and over-the-counter medications (to manage pain, fever and itches). Some people may need stronger pain management. For more severe cases, antiviral medications used to treat smallpox can also be used for mpox, including tecovirimat (TPOXX), cidofovir (Vistide) and brincidofovir (Tembexa). Vaccinia immune globulin (smallpox antibodies) is another option.
Tecovirimat has not been well studied in people living with HIV. However, it does not have known drug interactions with antiretrovirals that would limit its use in HIV-positive people on treatment or HIV-negative people on PrEP. Some experts recommend that people with HIV should be considered for earlier mpox treatment because they are prone to more severe disease. Starting and staying on effective antiretroviral therapy and maintaining an undetectable HIV viral load reduces the risk of adverse mpox outcomes.
While recovering, health officials advise that people with mpox should isolate for three weeks. Sex partners and household members are at the greatest risk. Mpox is infectious until the sores heal completely and scabs fall off. Many experts think transmission happens mainly when people are symptomatic, but research is ongoing.
This page was last reviewed in January 2023. It is due for review in January 2024.