MONKEY POX
Epidemiology of Monkeypox (Mpox)
Mpox is a viral zoonotic disease caused by the Monkeypox virus (MPXV), which belongs to the Orthopoxvirus genus. It was first discovered in 1958 in monkeys used for research, but human cases were first identified in 1970 in the Democratic Republic of Congo (DRC) during smallpox eradication efforts. Since then, it has become endemic in several Central and West African countries, especially in rural areas near tropical rainforests(
In recent years, the disease has spread beyond endemic regions. The 2022-2024 global outbreaks saw a significant number of cases in non-endemic countries across Europe, North America, and parts of Asia. As of July 2024, over 100,000 cases have been reported globally, with clade II responsible for most of the outbreaks outside Africa
Mode of Transmission
Mpox is transmitted through both animal-to-human and human-to-human contact:
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Animal-to-Human Transmission:
- Contact with infected animals, including rodents, squirrels, and monkeys, remains a primary source of infection. The virus can spread through bites, scratches, or direct contact with the blood, bodily fluids, or skin lesions of infected animals
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Human-to-Human Transmission:
- Close contact: Transmission between humans occurs mainly through close physical contact with an infected person’s skin lesions, respiratory droplets, or contaminated materials (e.g., bedding or clothing).
- Respiratory secretions: Prolonged face-to-face exposure can lead to transmission via respiratory droplets, especially in settings like households or healthcare facilities.
- Sexual transmission: In recent outbreaks, sexual contact, particularly among men who have sex with men (MSM), has been a key factor in the spread of mpox, particularly through close skin-to-skin contact during sexual activities
- Vertical transmission (mother to fetus) and contact during or after birth can also spread the virus.
Clinical Features
Mpox typically begins with non-specific symptoms followed by more distinct features:
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Incubation Period: The incubation period generally lasts 5 to 21 days (average: 7-14 days)
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Initial Symptoms (Prodromal Phase):
- Fever
- Severe headache
- Lymphadenopathy (enlarged lymph nodes, a key distinguishing feature from smallpox)
- Muscle aches
- Fatigue
- Back pain
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Rash (Exanthem Phase):
- The rash appears 1-3 days after the fever onset, progressing from macules (flat lesions) to papules (raised lesions), vesicles (fluid-filled), pustules (pus-filled), and finally scabs.
- The lesions typically start on the face and spread to other parts of the body, including the palms, soles, and genital areas
- Lesions can vary in number, from a few to thousands, and evolve synchronously, which is characteristic of orthopoxvirus infections.
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Duration: The illness usually lasts for 2-4 weeks, and most patients recover without specific treatment. However, severe cases can occur, especially in individuals with weakened immune systems(
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Complications: In some cases, complications such as secondary bacterial infections, respiratory distress, sepsis, encephalitis, or corneal infections can develop. The case fatality rate is generally low but higher in immunocompromised patients and children
Treatment of Mpox (Monkeypox)
Currently, no specific treatment exists for mpox, but supportive care and management of complications are essential. Antiviral treatments are available for severe cases or those at high risk.
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Supportive Care:
- Management of fever, pain, and hydration.
- Secondary infections should be treated with appropriate antibiotics
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Antiviral Medications:
- Tecovirimat (TPOXX): This antiviral is recommended for treating severe mpox cases, especially in immunocompromised individuals or those at high risk of severe disease. It inhibits the viral protein responsible for the egress of the virus from infected cells
- Cidofovir and Brincidofovir: These antivirals may be used in severe cases, especially in individuals with complications like encephalitis or other life-threatening conditions. However, their use is generally limited due to potential side effects
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Vaccination:
- The JYNNEOS vaccine can be used post-exposure to reduce disease severity, ideally administered within 4 days of exposure. It’s also recommended for pre-exposure prophylaxis in high-risk populations, such as healthcare workers and MSM communities
Isolation Period
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Isolation Guidelines:
- Patients with mpox should be isolated immediately after diagnosis to prevent transmission. Isolation should continue until all lesions have scabbed over and a fresh layer of skin has formed.
- This typically takes 2 to 4 weeks depending on the severity of the infection and immune status
- Infected individuals should avoid close contact with others, especially vulnerable populations such as immunocompromised individuals and pregnant women, during this period
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Infection Control:
- In healthcare settings, patients should be placed in a private room with airborne and contact precautions. Healthcare workers should use personal protective equipment (PPE) including gloves, gowns, and N95 masks(
- At home, the patient should stay in a separate room, avoid sharing personal items, and wear a mask when in contact with others.
Prognosis
The prognosis for mpox is generally good, with most patients recovering fully after 2-4 weeks. However, certain groups may experience more severe disease and complications:
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Factors Influencing Prognosis:
- Immunocompromised individuals: People with weakened immune systems, such as those with HIV, or undergoing immunosuppressive therapy, are at higher risk of severe illness and complications like pneumonia, sepsis, encephalitis, or death(
- Children and pregnant women: These groups are more prone to complications and higher mortality rates(
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Mortality Rates:
- The case fatality rate (CFR) for mpox is relatively low, around 1% to 3%, depending on the viral clade. The Central African clade (clade I) is associated with higher mortality, whereas the West African clade (clade II) tends to be less severe
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