Monkeypox: Clinical Features, Diagnosis & Management Review

A recent review in JAMA examines monkeypox clinical presentation and treatment options.

Background

Monkeypox virus (MPXV) is a double-stranded DNA virus with two clades: Clade I, which is endemic to Central African countries, and Clade II, which is endemic to Western African states.

The haplogroup IIb MPXV pandemic spread rapidly over 118 countries, resulting in a global population health emergency between July 2022 and May 2023. The outbreak affected around 99,000 people worldwide, caused more than 33,000 illnesses, and claimed 60 lives in the United States.

A recent study in eastern DRC found a new developing strain known as clade Ib, stressing the importance of greater surveillance and global vaccination equity in addressing the ongoing public health concern.

Regarding the review
The current study focuses on the clinical aspects, diagnostic procedures, and treatment regimens for monkeypox infections.

The researchers searched the PubMed database for monkeypox records from January 1, 1975 to September 13, 2024, focusing on high-quality randomized clinical trials (RCTs) and longitudinal observation studies.

They also examined the government’s websites for new instructions. The analysis cited 111 sources, including one RCT, 59 longitudinal studies, 23 reviews, 13 government websites, fundamental science publications, four case reports, and one press release.

Clinical Presentation of Monkeypox
Humans are most likely to develop monkeypox from direct contact with the virus, which can spread through infected lesions, bodily fluids, bites, scratches, contaminated fomites, and respiratory droplets.

Clade IIb infections are common among homosexuals, bisexuals, and men who have sex with men. Clade Ia MPXV transmission is primarily driven by zoonotic exposure and household distribution, with a large proportion of infections occurring in children.

MPXV targets immunological cells and surrounding lymph nodes. It grows rapidly, spreading throughout the lymphatic and circulatory systems, infecting numerous organs and causing injury to the host. The median incubation time is between seven and ten days.

After the asymptomatic incubation period, prodromal symptoms such fever, lymphadenopathy, headaches, myalgias, and malaise emerge before or after the rash appears.

Painful skin lesions include macules, papules, vesicles, and pustular lesions. The last stage is crusty and desquamate. These lesions may develop concurrently. Patients with mpox are infectious until all lesions re-epithelialize, which can take up to four weeks.

The Mpox rash, which frequently affects the face, torso, and limbs, can cause vaginal, anogenital, oral, and perioral lesions after sexual intercourse. Few lesions (median, less than 10) may occur and progress unevenly.

Mpox can cause proctitis, pharyngitis, urethritis, and ophthalmic disease. It can also cause necrotizing skin lesions, bacterial superinfection, pneumonia, and encephalitis, especially in immunocompromised persons.

Monkeypox Diagnosis and Treatment
Clinicians should look for Mpox in patients with skin lesions and a history of MPXV exposure. Polymerase chain reaction (PCR) confirms Mpox.

Secondary syphilis, herpes simplex virus, impetigo, and cellulitis are all possible differential diagnosis. Secondary syphilis lesions are painless. Herpes simplex, impetigo, and cellulitis are characterized by painful pustular or vesicular lesions comparable to monkeypox.

The first line of therapy for mpox is supportive care, which includes analgesic pain relief and wound care. Lidocaine gel and nonsteroidal anti-inflammatory medications are used to provide supportive treatment for skin and genital lesions. The lesions should be clean and dry. If the lesions are infected, they should be debrided with wet-to-dry dressings and treated with antibiotics.

The US Food and Drug Administration (FDA) has not approved antiviral therapies for Mpox sufferers. However, numerous medicines, including vaccinia immune globulin intravenous (VIGIV), brincidofovir, and tecovirimat, are available through clinical trials and expanded access programs. VIGIV is administered in a single dose of 6,000 to 9,000 units/kg.

Brincidofovir is taken orally once a week for two weeks in a dose of 200 mg, but it can cause liver enzyme elevations. Tecovirimat is administered orally (600 mg) and intravenously (200 mg), but it is not recommended for individuals with creatinine clearance less than 30 mL/min.

The Modified Vaccinia Ankara-Bavarian Nordic (MVA-BN) vaccination is 66% to 86% efficacious in high-incidence adults. The Advisory Committee on Immunization Practices (AICP) recommends the MVA-BN vaccine as a preexposure prophylaxis for nonoccupational-risk adults, such as gay, bisexual, transgender, nonbinary, newly diagnosed, multiple-sex partners, or those who have sex at commercial venues or public events in areas with high MPXV transmission.

MVA-BN vaccine is recommended by the Centers for Disease Control and Prevention (CDC) as post-exposure prophylactic therapy for persons who have known or suspected exposure. It is best taken after four days of MPXV exposure, but can be given up to 14 days later.

Conclusion
According to the research, monkeypox is a viral disease spread by direct skin contact. It causes self-resolving sickness but can lead to serious morbidity and mortality in immunocompromised people.

Although supportive care is the initial line of treatment, healthcare practitioners may consider sophisticated therapies in severe situations.

Monkeypox immunizations are effective, and high-risk persons should have them. Clinicians must be able to recognize the unique signs and symptoms of monkeypox in order to diagnose and treat it appropriately.

For more information: Mpox Clinical Presentation, Diagnostic Approaches, and Treatment Strategies: A Review, JAMA Network, doi:10.1001/jama.2024.21091