Monkeypox Diagnosis

  • Diagnosis

    Monkeypox is a rare but potentially serious viral illness, characterized by a blister-like rash that resembles smallpox. Humans contract monkeypox by having close contact with animals or other people who have the virus.

    The first case of community-acquired monkeypox outside of Africa was reported in the United States in early June 2003. This case occurred in Wisconsin when a person became infected with monkeypox after handling an ill pet prairie dog. Investigators believe that the monkeypox virus was introduced into the U.S. by a shipment of animals from Africa that arrived in Texas on April 9, 2003. The virus likely spread from some of these animals to prairie dogs being kept by an animal vendor.

    As of July 8, 2003, 71 human cases of monkeypox had been reported in the United States, occurring in Illinois, Indiana, Kansas, Missouri, Ohio, and Wisconsin. Over 20% of those cases have required hospitalization to treat. Most of the patients appear to have caught monkeypox after coming in close contact with infected pet prairie dogs or by being in the same home as someone ill with monkeypox.

    Animals that are known to be able to carry the monkeypox virus include primates (monkeys, apes), rodents, and rabbits. So far in the U.S., only African rodents and prairie dogs have tested positive for monkeypox. However, it may be possible for other warm-blooded animals (including dogs and cats) to get it.

    Monkeypox illness in humans usually starts about 12 days after exposure to the virus. The first noticeable symptom is typically a fever. Within 1 to 3 days, a rash develops. Most people recover in 2 to 4 weeks.

    The period between exposure to the virus and the onset of monkeypox illness can be anywhere from a few days to 21 days. However, most people experience symptom onset about 12 days after exposure to the virus.

    A virus that is similar to the smallpox and cowpox viruses causes monkeypox.

    The monkeypox virus causes monkeypox. This virus is similar to the ones that cause smallpox and cowpox.

    Monkeypox is most commonly spread through close contact with warm-blooded exotic pets (such as prairie dogs, Gambian giant rats, and rope squirrels) that are ill with the virus Table 01.

    Researchers know that primates (monkeys, apes), rodents, and rabbits can catch monkeypox. However, they believe that most warm-blooded animals may also be able to contract the virus.

    You may be at risk for monkeypox exposure if the direct contact you've had with wild or exotic pets meets the following conditions:

    • You were within 6 feet of an animal that has or is suspected of having monkeypox.
    • The animal was acquired since April 15, 2003, from a distributor or a geographical area that is known to have monkeypox-infected animals Table 01.
    • The animal appeared tired, sick, or was not eating or drinking.
    • The animal had symptoms of a respiratory illness, such as a cough or discharge from the eyes or nose.
    • The animal had a rash or was missing parts of its fur.
    • You were bitten by an infected animal, handled housing or bedding of an infected animal, or came in direct contact with the blood, body fluids, or rash of an infected animal.

    If you have a pet that has been exposed to a sick animal and is showing signs of monkeypox, follow the recommendations made by the Centers for Disease Control and Prevention Table 01. If your veterinarian determines that your pet has monkeypox, euthanasia (humanely putting your pet to sleep) will be recommended. Euthanasia is necessary for monkeypox-infected animals so that the sick animal does not suffer and so that the virus does not spread to people, pets, or wild animals.

    Table 1.  What to Do If You Suspect Your Pet May Have Monkeypox

    To get monkeypox, your pet must first be exposed to an animal that has it. If you think your pet is at risk, follow these recommendations made by the Centers for Disease Control and Prevention:
    Keep people and other animals away from your pet. Shut it in a room that can easily be cleaned (such as the bathroom), or put it in a box or cage that is away from others.
    Consider your pet and objects it has come in close contact with (such as bedding or surfaces) to be contaminated. Wear single-use disposable gloves when handling your pet or objects in its environment. Wash your hands thoroughly with soap and water after handling your pet or contaminated objects.
    Keep in mind that your clothes and shoes may be contaminated with the monkeypox virus when you handle or care for your pet. Change your clothes immediately after pet contact.
    Take care not to contaminate yourself or objects when handling soiled bedding, linens, or clothing. A household washing machine is sufficient for decontaminating washable fabric items. Use detergent and hot water. On materials that can be bleached, use chlorine bleach.
    Notify your state or local health department that you have a pet that may have monkeypox. They may pick up the animal or tell you to seek veterinary attention.
    Before taking your animal to the vet, call ahead and warn the staff that you are bringing in an animal that may have monkeypox. The staff can then prepare for your arrival and take steps to be sure other people and animals in the clinic do not get monkeypox.
    Do not release your pet into the wild. A monkeypox outbreak among wild animals would create serious danger to wildlife, people, and other pets.
    Do not give your pet away or drop it off at an animal shelter. This would be dangerous to the shelter's animals, staff, and visitors. If you cannot afford veterinary care for your pet, contact your state or local health department and inform them of your situation.
    If the animal dies, do not throw the carcass in the trash or bury it in the backyard. Animals suspected of having monkeypox should be cremated. Place the carcass in at least two layers of plastic bags, seal them, and contact your veterinarian or local health department.
    Do not get rid of the animal's bedding, cage, toys, or food and water bowls with the household trash or at a dump or landfill. The monkeypox virus can survive on these items, potentially infecting people or animals. Contact your local health department for guidance in proper disposal of potentially infectious items.

    Rarely, monkeypox is spread by person-to-person contact with an individual who has monkeypox.

    To become infected with monkeypox from another human, you will need to have come in intimate or close contact with them. You may be at risk for monkeypox exposure if the direct contact you've had with infected persons meets the following conditions:

    • You were within 6 feet of an infected person for 3 or more hours; you had close, face-to-face exposure to them; or you were exposed to their coughs and sneezes.
    • You were exposed to the body fluids of an infected person (saliva, stool, or urine).
    • You were exposed to the monkeypox lesions of an infected person or to fluid from the monkeypox lesions.

    The most common symptoms of monkeypox are fever, rash, swollen lymph glands, and feeling generally unwell (malaise). These symptoms are similar to those of other viral illnesses, such as chickenpox Figure 01.

    The first noticeable symptom of monkeypox is usually fever. The fever usually starts 12 days after exposure to the monkeypox virus but can begin 7 to 21 days after exposure.

    The most common symptoms of monkeypox include:

    • Cough or nasal congestion
    • Fever of 99.3° F (37.4° C) or above
    • Rash
    • Swollen lymph glands in the neck, armpits, or groin
    • Feeling tired or generally unwell

    Other symptoms that may occur include:

    • Chills or sweats
    • Sore throat
    • Headache, backache, or muscle aches
    • Nausea/vomiting
    • Shortness of breath

    The rash of monkeypox starts as a discolored spot on the skin that starts out flat, but becomes raised. The lesions then become filled with fluid (pus) and may resemble a blister. Later, the lesions crust over. The rash can cover a wide area of the body, or it can be limited to a small area Figure 01.

    Click to enlarge: Monkeypox lesions of a child

    Figure 01. Monkeypox lesions of a child

    You are at risk of contracting monkeypox if you have been in close contact with an infected exotic pet.

    If you have been exposed to an ill exotic pet that was obtained after April 15, 2003, contact your clinician. Exotic pets that may carry monkeypox include:

    • Prairie dogs
    • Tree squirrels
    • Rope squirrels
    • Dormice
    • Gambian giant pouched rats
    • Brush-tailed porcupines
    • Striped mice
    The owners of sick animals should contact their veterinarian immediately.

    Monkeypox can be dangerous, especially for pregnant women and children under the age of 1.

    It is important for anyone who thinks they have monkeypox to seek medical attention. However, children and pregnant women are especially at risk for contracting monkeypox and having serious consequences from it. Children and pregnant women should avoid contact with exotic pets that may have the virus, and should not be in a house that has an animal or a person suffering from monkeypox.

    When seeking medical attention, it is important that you notify your clinician in advance that you have been exposed to the monkeypox virus.

    Special precautions need to be taken by the medical staff to prevent transmission of the virus to others. Precautions may include isolating you from other patients, having you wear a surgical mask, and having visitors and medical personnel wear special protective equipment.

    Your clinician will ask you about recent exposure to wild or exotic animals, or to individuals that may be ill with monkeypox. You will also need to tell your clinician about your smallpox vaccination history.

    Since health departments must track monkeypox cases, it is important that you give your clinician the details of your possible monkeypox exposure. Your clinician will also need to know about any smallpox vaccinations you have received in your lifetime. If possible, take your vaccination records with you to your medical appointment.

    Your clinician will perform a physical exam.

    Your clinician will listen to your heart, lungs, and chest through a stethoscope. Your clinician will also check your temperature, pulse rate, blood pressure, and breathing speed. The information gathered during your physical examination may help your clinician determine if your illness is mild or serious.

    Your clinician will also look at any rash areas you may have on your body. The monkeypox rash usually starts within 1 to 3 days of the onset of fever. Let your clinician know when you first noticed your fever.

    Laboratory tests can confirm a diagnosis of monkeypox.

    Your clinician can take a scraping or some fluid from a skin lesion to test for monkeypox. A blood test or a swab of your throat can also be used for monkeypox testing.

    It is especially important that clinicians determine the cause of illness in pregnant women and children under the age of 1. Monkeypox can mimic chickenpox, and it is important for your clinician to select the appropriate vaccine if one is required.

    If you received the smallpox vaccine in the past, you may be protected against monkeypox.

    Although information is limited, some data suggests that having received the smallpox vaccination in the past may protect at least 85% of people that are exposed to monkeypox. The vaccine may prevent you from becoming ill with monkeypox or may lessen the severity of the illness if you do get monkeypox.

    Your clinician may consider giving you the smallpox vaccination if you have been exposed to the monkeypox virus or are at high risk of coming into contact with the virus.

    Since the smallpox virus and the monkeypox virus are so similar, the smallpox vaccine may likely benefit those exposed to monkeypox. If you think you have been exposed to monkeypox, it is important to contact your clinician as soon as possible. Vaccination may be most effective when given within 4 days of exposure to the virus. If you work around animals, work in the healthcare setting, or are caring for someone with monkeypox, ask your clinician if you should receive a smallpox vaccination.

    It may be dangerous for certain people to receive the smallpox vaccine. Be sure to tell your clinician if you:

    • Have a problem with your immune system
    • Have HIV
    • Have received a marrow, tissue, or organ transplant
    • Are receiving immunosuppressive therapy
    • Have a blood disorder
    • Are allergic to rubber or latex
    • Are allergic to the smallpox vaccine or any of its components (polymyxin B, streptomycin, chlortetracycline, neomycin)

    If you have monkeypox, you need to take measures to prevent spreading your monkeypox to others Table 02.

    If you or your clinician suspect that you are ill due to the monkeypox virus, it is important that you stay home so that you don't make other people sick. Monkeypox can be dangerous to other people and animals. Take steps to protect other household members from catching monkeypox from you Table 02.

    Table 2.  Steps to Take to Prevent Spreading Your Monkeypox to Others

    Stay home until your rash has healed and you no longer have symptoms of illness. Do not allow visitors into your house until your clinician says that you are no longer contagious.
    If you do have to leave the house (to receive medical care, for example), wear a surgical mask over your nose and mouth and wear clothing that covers your rash.
    Establish an isolation area to prevent those within your household from becoming sick. This area should be a part of the house that is away from others as much as possible. Household members should wear surgical masks when entering the area, and you should wear a mask if you have to go outside the area.
    Household members should wear single-use disposable gloves if they need to come in direct contact with you, your laundry, your eating utensils, or surfaces that may have come in contact with respiratory droplets, bodily fluids, or monkeypox lesions. Hand washing after glove removal is always necessary.
    Wash your hands often, using warm water and soap; everyone else in your household should do the same. An alcohol-based antibacterial hand rub can be used to cleanse hands when water is not available. Good hand washing should always be done after touching body sites, laundry, eating utensils, or surfaces that may have been in contact with respiratory droplets or skin lesions.
  • Prevention and Screening

    If you received the smallpox vaccine in the past, you may be protected against monkeypox.

    Although information is limited, some data suggests that having received the smallpox vaccination in the past may protect at least 85% of people that are exposed to monkeypox. The vaccine may prevent you from becoming ill with monkeypox or may lessen the severity of the illness if you do get monkeypox.

    Your clinician may consider giving you the smallpox vaccination if you have been exposed to the monkeypox virus or are at high risk of coming into contact with the virus.

    Since the smallpox virus and the monkeypox virus are so similar, the smallpox vaccine may likely benefit those exposed to monkeypox. If you think you have been exposed to monkeypox, it is important to contact your clinician as soon as possible. Vaccination may be most effective when given within 4 days of exposure to the virus. If you work around animals, work in the healthcare setting, or are caring for someone with monkeypox, ask your clinician if you should receive a smallpox vaccination.

    It may be dangerous for certain people to receive the smallpox vaccine. Be sure to tell your clinician if you:

    • Have a problem with your immune system
    • Have HIV
    • Have received a marrow, tissue, or organ transplant
    • Are receiving immunosuppressive therapy
    • Have a blood disorder
    • Are allergic to rubber or latex
    • Are allergic to the smallpox vaccine or any of its components (polymyxin B, streptomycin, chlortetracycline, neomycin)

    If you have monkeypox, you need to take measures to prevent spreading your monkeypox to others Table 02.

    If you or your clinician suspect that you are ill due to the monkeypox virus, it is important that you stay home so that you don't make other people sick. Monkeypox can be dangerous to other people and animals. Take steps to protect other household members from catching monkeypox from you Table 02.

    Table 2.  Steps to Take to Prevent Spreading Your Monkeypox to Others

    Stay home until your rash has healed and you no longer have symptoms of illness. Do not allow visitors into your house until your clinician says that you are no longer contagious.
    If you do have to leave the house (to receive medical care, for example), wear a surgical mask over your nose and mouth and wear clothing that covers your rash.
    Establish an isolation area to prevent those within your household from becoming sick. This area should be a part of the house that is away from others as much as possible. Household members should wear surgical masks when entering the area, and you should wear a mask if you have to go outside the area.
    Household members should wear single-use disposable gloves if they need to come in direct contact with you, your laundry, your eating utensils, or surfaces that may have come in contact with respiratory droplets, bodily fluids, or monkeypox lesions. Hand washing after glove removal is always necessary.
    Wash your hands often, using warm water and soap; everyone else in your household should do the same. An alcohol-based antibacterial hand rub can be used to cleanse hands when water is not available. Good hand washing should always be done after touching body sites, laundry, eating utensils, or surfaces that may have been in contact with respiratory droplets or skin lesions.

Recommended Reading

Meet the Pharmacists

I'm Kristen Dore, PharmD. Welcome to PDR Health!

Check out my latest blog post on heartburn medication

Monkeypox Related Drugs

    Monkeypox Related Conditions