Measles in the Immunocompromised Host

Introduction

On June 8, 2023, 11 different locations reported a combined total of 16 cases of measles. Even though an effective and safe vaccine is available against the measles virus, the world has witnessed an absolute surge in measles-related death (approximately three lakh fifty thousand) worldwide in the year 2018. The reduction in vaccination coverage contributed to this increase. The severity of the disease is influenced by multiple factors, and certain vulnerable populations are at a heightened risk.

What Is an Immunocompromised Host?

Individuals with a compromised immune system experience a diminished capacity to fight diseases and other infections. This can arise due to the existence of various diseases or conditions such as AIDS, cancer, diabetes, malnutrition, and specific genetic disorders. Moreover, individuals who are on specific medications for a prolonged time (for example, steroidal medications), are undergoing therapy such as chemotherapy or radiation therapy, or have had organ transplantation, may have a compromised immune system and are more prone to other infections and diseases.

Normally, individuals have a well-integrated, complex defense mechanism. This defense system includes the following:

• Physical Barrier - For example, the skin, acid present in the stomach, mucus in the respiratory tract, lysosomal enzymes in saliva, and more

• Innate Immunity - This is present from birth and does not require prior exposure to a particular pathogen to offer protection from the disease. Natural killer cells, phagocytic cells, neutrophils, etc., are examples of innate immunity.

• Adaptive Immunity - This is a targeted immune response that develops on exposure to a particular pathogen and tries to provide immunity to the specific pathogen.

Each component of the immune system has a specific role in the defense system, and a disruption to this system can cause increased susceptibility to diseases and infections.

What Is Measles?

Measles is a viral, highly contagious, infectious disease that primarily affects children. However, individuals of all ages are susceptible to developing measles if not immunized against the measles virus, which belongs to the paramyxovirus family. There are no measles-targeted antiviral medications. The treatment measures aim to prevent complications associated with the infection by maintaining a balanced nutrition-rich diet, good hydration, and adequate rest. Timely vaccination and booster doses are key for the prevention of measles.

Why Is the Measles Vaccine Contraindicated for Immunocompromised Hosts?

The measles vaccine (MMR) should not be given to severely immunocompromised individuals.

Some of the contraindicated scenarios are as follows:

• HIV-infected individuals who are not severely immunosuppressed can receive the MMR vaccine. HIV- infection individuals may receive the vaccine once the CD4+ T lymphocyte count is more than 200 cells/µL.

• It is recommended to avoid pregnancy for four weeks after receiving measles vaccination. It is also advised that pregnant women should not receive the vaccine.

• High-dose corticosteroid therapy and recent administration of blood products or immune globulin may require delaying MMR vaccination for approximately a month after cessation of therapy.

The measles vaccine is generally contraindicated for immunocompromised individuals due to the live nature of the vaccine. The measles vaccine contains a weakened form of the measles virus that stimulates the immune system to produce a protective immune response (adaptive immunity). In individuals with weakened immune systems, instead of creating immunity against measles, the virus present in the vaccine can replicate in the body and may pose a risk of causing measles itself or lead to severe complications. Furthermore, the immunocompromised individuals may not be able to clear the live virus from their system efficiently, and the virus may persist and potentially be transmitted to other unvaccinated vulnerable individuals.

What Are the Symptoms of Measles in Immunocompromised Hosts?

The symptoms of measles in immunocompromised individuals are generally similar to those in immunocompetent individuals, but they can be more severe and prolonged due to the compromised immune response. Common symptoms of measles include:

• The fever associated with measles may last longer and be more persistent in immunocompromised individuals.

• Measles typically begins with a red, brownish-red rash that may be flat or blister-like, filled with fluid, and it usually starts to appear on the face and then spreads to the rest of the body. However, there are studies that state rashes are not necessarily present in immunocompromised individuals.

• Cough.

• Runny nose.

• Red, watery eyes (conjunctivitis).

• Muscle aches and pains.

• Fatigue and weakness.

• Loss of appetite.

• Individuals with a compromised immune system are more prone to developing complications such as pneumonia, bronchitis, encephalitis (brain inflammation), and even death.

The overall duration of the illness may be extended in immunocompromised individuals, with a longer recovery period required.

How to Manage Immunocompromised Individuals Who Are Exposed to Measles?

If individuals are known to have been exposed to the measles virus, then the first step is to test for measles antibodies since the measles antibody count will differ for three to eleven months once treatment is initiated for the individual. For individuals above sixty-six pounds of weight, intravenous or intramuscular immunoglobulin therapy is advised within six days of being exposed to the measles virus. They must also be closely monitored for approximately twenty-eight days for any signs of complications following the therapy. Such individuals are also advised to remain isolated from other prone individuals and to remain masked when in public environments.

What Are the Recommendations for Immunocompromised Hosts to Prevent Measles?

• Practicing proper hygiene measures for self and surrounding helps prevent most infectious diseases for healthy as well as compromised individuals.

• Immunocompromised individuals should avoid traveling to areas with an ongoing measles outbreak or have the potential risk for the same.

• Practice social distancing in communities with active measles cases.

• Wearing a mask can help with isolation and social distancing.

• Ensure close family members or friends who visit often have received the age-appropriate measles vaccination.

• If one fears having been exposed to measles, it is recommended to call and consult with the doctor at the earliest.

Conclusion

With proper proactive and precautionary measures, it is possible to protect immunocompromised individuals against measles and improve overall health for them. One must be isolated and under a doctor’s care if exposed to the virus and avoid public environments in areas with ongoing measles outbreaks. While measles poses a significant risk for immunocompromised individuals, following such strategies can help minimize the impact of the disease.