Infectious mononucleosis is one of the most common infections worldwide. However, people don’t usually know: is mono contagious?
Learn the causes, symptoms, and complications of mono. Also, there will be a thorough answer to the question, is mono contagious? Be ready to identify if you or your family need medical attention directly from a doctor in the lines below.
What is infectious mononucleosis?
Infectious mononucleosis (or glandular fever) is a viral infection. Epstein Barr Virus (EBV) is the cause of this disease. However, additional viruses like cytomegalovirus, adenovirus, or others can produce a very similar condition. The latter is called mononucleosis syndrome.
EBV is a member of the herpes virus family. The same group affects humans and causes different diseases like cold sores, genital herpes, or chickenpox. Like almost all viruses, EBV infection is self-limited by the body.
Most times, the first infection happens during childhood, and by adulthood, most people have it. Estimates say that around 90% of the adult human population has had this infection.
Inside the body, the virus affects a specific type of cell from the immune system. This system comprises cells of the blood, the spleen, and the lymph nodes or glands. The immune system is in charge of fighting off threats like viruses or bacteria that could damage the body.
Specifically, EBV infects B lymphocyte cells. These B lymphocytes are in charge of producing antibodies. And the latter are proteins that neutralize viruses and bacteria to protect people from diseases.
It is common for the Epstein Barr virus infection to occur without symptoms in children, where most primary infections occur. After this, the virus remains in the body, living inside B lymphocytes for life.
In adults, primary EBV infection or infectious mononucleosis can affect the liver, the spleen, and the lymph nodes. It can also cause muscle aches and fatigue. In teenagers and young adults, the primary infection can be more complicated than usual. After the first infection, a person can suffer from mild periods of bothering symptoms called reactivations. Reactivations in people with a weak immune system can also be very serious.
How do you contract mononucleosis, and how frequent is this disease?
Is mono contagious? Well, The common transmission mode of infectious mononucleosis (or mono) is from one person to another through saliva. That’s why it is also known commonly as the kissing disease.
Besides kissing, people can also contract the infection from sharing cups, forks, or knives. Less likely but also probable is when talking closely in closed unventilated areas.
So, in general, Is mono contagious? Yes, but it is not a very contagious disease. Symptoms may appear 4-6 weeks after direct contact with the virus.
During a lifetime, people who have had infectious mononucleosis became infected and more commonly than not without any symptoms. This means that they can have the virus in their saliva without knowing. This condition receives the name of “asymptomatic shedder.”
Most new infections occur from an asymptomatic shedder and less than 1 out of 10 from asymptomatic acute infection. Even though it is extremely rare, sexual fluids (like semen or vaginal fluids) can transmit EBV infection. Also, blood transfusion is another possible form of transmission.
Mono is a frequent disease, but most times, we’re not aware of it. Approximately half of all children get mono by the time they become five years old. And for adults, about 90% have had the infection by 35 years of age, but many don’t develop symptoms.
What are the symptoms of infectious mononucleosis?
The majority of patients with EBV infection will remain without symptoms, while a smaller part will develop infectious mononucleosis.
The most common symptoms include fatigue, muscle aches, headache, fever, swollen lymph nodes, and a sore throat. Fatigue and muscle aches can be present for months after your body has controlled the infection.
Swollen glands can be the only symptom in some patients. They usually involve lymph nodes on both sides of the neck, the armpits, or the groin.
A sore throat can become very painful and can show white patches that resemble a bacterial infection. EBV is one of the most common causes of viral sore throat, and it could be the only symptom in reactivations.
Some patients can also have their spleen affected. It is an important organ for the immune system, located on the upper-left side of your abdomen. The spleen is a fragile organ, and it can be severe if it gets critically inflamed in mono.
The liver can also be affected by EBV. The liver is an organ in the upper-right side of your abdomen. It has many functions, and when it gets inflamed, it is something doctors take into account. The liver can also become tender during a physical examination, and it is essential to let the doctor know.
Jaundice, a yellow coloring of the skin, is also a sign that the liver might not be working correctly. Jaundice is also noticeable in the white part of the eye. Patients also experience mild fever, but it is not very common. Some people experience a skin rash (made of flat pink spots) in any body part.
Is mono contagious before symptoms? How long is a person contagious with mono?
Now, when is mono contagious? Mono can be contagious before the onset of the symptoms. However, it is hard to determine how long before symptoms onset is EBV infection contagious because of the lack of testing.
Another particularity that makes it difficult to know is the long incubation period. Incubation periods are the time it takes for the infection to manifest after the exposure. This means, after kissing someone with mono, it can take 4-6 weeks for a person to develop the disease.
After symptoms appear, mono takes 2-4 weeks to heal, and usually, people are contagious for 1-3 months more. Although that is a common way, some have found contagious patients after 18 months.
After primary infection, scientists have found that people with asymptomatic reactivations (virus growing and no symptoms) can also transmit the disease without notice. A vast majority of new infections occur from asymptomatic people.
Are there different stages of mono?
Like most diseases, mono has different stages or phases. For some people, differentiating between one phase and the other may not be evident.
Generally, the first phase is the incubation period. This stage starts with the moment a person has contact with the virus. During the incubation period, the patient has the infection but is not sick. Patients do not exhibit symptoms, but the virus is active inside the body and is, in some cases, infective (or can pass the infection to other people).
After the incubation period comes to the prodromal phase. This phase involves symptoms that are not specific to mono and lasts about five days. It includes fatigue, general malaise, and muscle aches.
The acute symptomatic phase starts with a sore throat, fever, and swollen glands and overlaps with prodromal symptoms. A sore throat can take up to 10 days to resolve, but the acute illness takes about 2-6 weeks to finish. This means the body has controlled the infection, and people enter the convalescent stage.
The virus still lives in the body in the convalescent stage, where it remains dormant or latent. Fatigue can persist during the convalescent stage.
Some people cannot properly control the infection and go into a chronic active EBV (CAEBV). This is a serious mortal condition where acute symptoms can persist for a longer than usual period. Chronic active mononucleosis is more common in people with a weak immune system, but young adults are also at risk.
Does mono weaken the immune system?
It is not a common complication of EBV infection, but an immune deficiency could happen. Immune deficiencies are the name of the conditions where your immune system is weak. Low neutrophils are a recognized complication of EBV infection around the second week after the onset of symptoms.
Neutrophils are a type of blood cells that fight off bacterial infections. If they are low, people could have a slightly higher risk of infections. EBV doesn’t normally cause significantly low neutrophils, so the risk isn’t high.
In very rare cases, mono could cause severe neutropenia (low neutrophils), which could lead to severe infections. There are other cases in which the virus could weaken your immune system.
Mono causes your immune system to weaken in a genetic condition called X-linked lymphoproliferative disease 1 (XLP-1). XLP-1 patients who suffer from EBV become more likely to have other infections that could be life-threatening.
Before having the Epstein Barr virus infection, people with XLP-1 live normal lives and do not react to other viruses. About half of all patients with XLP-1 experience different forms of immune deficiency.
Survival rates from these complications have improved a lot since their discovery. The most common immune deficiency in XLP-1 patients with EBV is hemophagocytic lymphohistiocytosis (HLH).
In HLH, some cells start destroying each other, making them unable to fight infections. In addition to HLH, hypogammaglobulinemia is another common form of immune deficiency in XLP-1.
Hypogammaglobulinemia means low production of antibodies. Antibodies are proteins from your body that help your immune system. Other genetic conditions exist but are even more uncommon.
What are the complications of infectious mononucleosis?
There are two types of complications: those that happen during the acute primary infection and those that can appear during a lifetime.
Acute disease complications are both common and uncommon. Let’s review them. The common ones are airway obstruction, central nervous system infection, strep infection, and blood changes.
Airway obstruction happens mainly because of throat inflammation. Central nervous system infection can cause inflammation of the brain and its protective layers. This receives the name of meningoencephalitis, and it is a very serious condition.
Streptococcus (or strep) is the name of the bacteria that commonly cause sore throat. In infectious mono, strep can over-infect the tonsils.
Lastly, blood changes include anemia and low platelet count. Anemia means low hemoglobin concentration, and hemoglobin is the protein that transports oxygen in the blood. The platelets are a type of blood cell that helps with the formation of clots to stop bleedings.
Common complications are such because they are more common than the uncommon ones, but remember that overall mono complications are not usual.
Rare complications include conjunctivitis, heart diseases, neurologic disorders, pancreatitis, pneumonitis, immune deficiencies, and splenic rupture.
Conjunctivitis is the inflammation of the part that covers the eyeball and the internal part of the eyelid. Rare neurologic complications are a lot of diseases other than meningoencephalitis.
Pancreatitis is the inflammation of the pancreas, an organ that is in the central abdomen, behind the stomach—finally, one of the most feared (but still uncommon) complications: splenic rupture.
A ruptured spleen happens when a patient has an enlarged spleen and engages in tough physical activities. Generally, uncommon complications happen in less than 1% of the people with infectious mono. In the long term, EBV is related to some cancer types, but this is also very uncommon.
How is infectious mononucleosis diagnosed?
Usual diagnostic tests are a full blood count, heterophile antibodies, and specific EBV antibodies.
Let’s talk a little bit more about each test. A full blood count reports some of the main characteristics of the blood. This includes hemoglobin concentration, red blood cells (RBC) count, white blood cells (WBC) count, and platelets.
RBCs are the cells that carry hemoglobin, and they both can be low in EBV infection. There are five main types of WBC: neutrophils, basophils, eosinophils, lymphocytes, and monocytes. The most common alteration in mono is a high lymphocyte count.
Lab technicians can also perform a peripheral blood smear (PBS). In a PBS, they drop blood and put it under a microscope to see the components. A full blood count can also find a low platelet count.
These findings are not very specific and may help the diagnosis, but it is hard to be sure with this information only.
Heterophile antibodies test measures the presence of a more specific type of antibody (immune system protein) that rises during mononucleosis. Nevertheless, heterophile antibodies are not very specific.
For example, they are positive in only half of the kids <5 years with EBV infection. In teens and young adults, they are positive in around 90% of primary infections.
High heterophile antibody values occur in the second week after symptoms appear. This means that if the test is not positive, it might be appropriate to repeat it after 7-10 days.
The specific EBV antibody test is relatively accurate. It measures antibodies against the mononucleosis virus, which will be present if the infection is there. EBV DNA is one of the most accurate tests available. It identifies the presence of the virus directly through a method called PCR. Still, false negatives are possible in this test.
How can you get rid of mono fast? What are the treatments?
There is no medication to prevent or treat the primary EBV infection. Usual measures include resting, drinking plenty of water to stay hydrated, and medications to relieve discomfort.
It includes acetaminophen or ibuprofen for muscle aches, headache, or general malaise. Acetaminophen and ibuprofen belong to a group called Non-Steroidal Anti-Inflammatory Drugs (NSAIDs).
All NSAIDs act the same way, but acetaminophen and ibuprofen are the safest ones, with fewer side effects. Other common NSAIDs like naproxen, aspirin, diclofenac or ketoprofen, are not always safe to use in mono. Such medications will not reduce the acute phase or improve overall recovery.
Other medications that might be helpful are topical anesthetics to relieve a sore throat. Sore throat anesthetics come in different presentations. The most common ones are sprays and pills with different flavors. A pharmacist can support the choice of the right topical anesthetic.
Acyclovir, the medicine used to treat cold sores (another herpesvirus infection), reduces the number of virus particles in infected saliva. However, it has not proven to be effective in the treatment and overall symptoms of EBV infection.
Mono complications could require further treatment with a potent anti-inflammatory medication (corticosteroids). It is essential not to take medications without the advice of a physician.
Mono, most of the time, resolves by itself, and some medications (like antibiotics) can make the condition much worse. Do not give antibiotics to a person with infectious mononucleosis unless indicated by a doctor. Plenty of home remedies exist, but they lack scientific evidence to support them. Everyone should eat a healthy diet even without mono.
What health care specialists treat infectious mono?
Since the disease heals on its own, a general practitioner is the one who diagnoses and monitors the condition. Other specialists are not needed for the majority of the people with infectious mono.
In the case of complications, the doctors who treat the condition are internal medicine (IM) doctors or infectious medicine physicians. Acute infection complications might require hospital management. Also, depending on the type of complication a person has, different doctors might have to treat them.
For instance, if a person develops neurological complications, a neurologist could consult—neurologic complications. The same happens with cardiac consequences and cardiologists. If you develop myocarditis or pericarditis, your IM doctor might consult a cardiologist. Myocarditis and pericarditis are the inflammation of the heart muscle and its covering. They can become serious conditions if left untreated.
In children, the ideal doctor to treat mononucleosis is the pediatrician. Some countries also have pediatricians with a specialty in infectious diseases.
Is the whole family at risk? What can a person do to minimize the spread of infectious mononucleosis?
Is mono contagious? If a member of the family has mono, the actual risk of contagion is very low. The most probable source of that infection is from an asymptomatic shedder.
Most likely, all adults in the household have had the infection and have protective immunity, which means that if they get in contact with the virus their body neutralizes it. Therefore, for them, it is difficult to pass it to their children.
Notably, in the case of an infected kid, the risk of severe disease is really low. The standard measures of rest and plenty of liquid are important no matter the age.
Now, to avoid transmission between children, they should avoid contact with infected saliva. Prevent kids from sharing toys if they tend to take them to their mouths. Avoid them sharing cups or eating utensils and make them wash their hands frequently and thoroughly.
In the case of teens and young adults, an infection most commonly occurs from kissing with asymptomatic shedders. It is hard to determine the risk of kissing someone with asymptomatic mononucleosis. When caring for an adult with mono, basically, the same measures apply. In families where there are people with a weak immune system, further care should be given to all members for reassurance.
Can mono kill a child?
Although it is not common, glandular fever can be deadly, both in children and adult patients. Children tend to experience fewer complications, therefore less chance of death.
Causes of death vary from person to person, but some complications are more likely to cause life loss. Virtually all complications can be like threatening without proper treatment.
The most common complications to cause death are splenic rupture, sepsis, and airway obstruction. Splenic rupture is uncommon, but its severity places it as a frequent cause of death.
Prevention is crucial. Rest and avoidance of physical activity are extremely important in all patients, particularly those with a swollen spleen. Sepsis mostly occurs from the complication of a strep infection. The bacteria that infect the tonsils can go into the bloodstream without treatment. This causes your body to attack in an uncontrolled way that ends up causing death. Other bacteria besides strep can cause the condition of sepsis but are less frequent.
Lastly, airway obstruction can arise from the throat inflammation that is common in EBV infection. Tonsils and other parts of the throat become very inflamed. Extreme inflammation doesn’t allow air to pass for the person to breathe. This condition requires specific treatment by a doctor.
Can you kiss your girlfriend with a mono?
In couples living together where a partner has mono, and the other has had it, kissing is not a risk. The primary infection produces antibodies that protect you from further infection.
However, couples should avoid sexual activity if one has mono at that moment. If one of the partners hasn’t had mononucleosis, they should not kiss the infected person.
The time a person is contagious es variable, but kissing restriction should apply for approximately six weeks. The restriction also applies to sharing cups or eating utensils. Sharing a bed doesn’t significantly raise the risk of infection.
Do you have symptoms of this disease?
This tool is an Infectious Mononucleosis Symptoms Checker. It gathers the most important symptoms, signs, and risk factors for this disease. Therefore, it will help anybody who uses it to determine if their symptoms are because of mononucleosis. This tool is free and would only take a few minutes.