With the large outbreak of measles that has spread to more than a dozen states, questions from parents of children with cancer should be expected and encouraged. Parents should “talk to their physician about what the level of risk may be for their child who is undergoing cancer treatment (or has been previously treated) so that they have an understanding of how cocooned their child may or may not need to be,” Alison G. Freifeld, MD, told The ASCO Post.

“I don’t want people to overreact, but on the other hand, we are dealing with dealing with immunosuppressed children who may be very susceptible to measles and its complications,” she said. Dr. Freifeld is a specialist in infectious diseases in cancer patients and Professor, Internal Medicine at the University of Nebraska Medical Center in Omaha.

In allogeneic stem cell transplant recipients, measles (and other antigen-specific) antibody titers wane with time after transplant, and patients may become susceptible to measles. The degree of risk is probably fairly low, but cases of severe disease are reported.¹ Immunization against many vaccine-preventable diseases is standard after both autologous and allogeneic hematopoietic stem cell transplant. Dr. Freifeld noted.

Period of Vulnerability

“The guidelines state that patients who have had allogeneic stem cell transplant can be vaccinated 2 years after the transplant as long as they are not still on immunosuppression for graft-vs-host disease,” she continued. “At that point, live vaccines like measles, mumps, rubella are considered safe and most immunogenic.  Until then, these patients are considered vulnerable to acquiring measles.”

It is hard to guard against exposure to the measles virus. “It is such a contagious virus, and patients who develop measles are considered infectious between 4 days before the development of rash until 4 days after the rash actually appears. So it is difficult to predict who is going to be carrying the virus and shedding it. Even if a measles patient is in a room and then leaves, the virus can still linger on surfaces for a couple of hours,” Dr. Freifeld said.

If exposure to measles is suspected, patients with cancer who have not been vaccinated or revaccinated following a hematopoietic stem cell transplant should “strongly be considered for receiving postexposure prophylaxis with intravenous immunoglobulin given within 6 days of exposure,” Dr. Freifeld advised.

Measles can also be more difficult to diagnose in children with cancer because “sometimes immunocompromised patients don’t develop the rash at all,” she added. With or without the rash, if measles is a possible diagnosis, then a throat, nasal or nasopharyngeal swab should be sent for detection of measles RNA by real-time polymerase chain reaction (RT-PCR).

Dr. Freifeld advised physicians and parents to “be very aware of any outbreaks in their area. Pay attention to your local news.” And, she stressed, “be sure to vaccinate well children, because the vaccine is 97% effective.” ■

Disclosure: Dr. Freifeld reported no potential conflicts of interest.

Reference

1. Rubin LG, Levin MJ, Ljungman P, et al: 2013 IDSA clinical practice guideline for vaccination of the immunocompromised host. Clin Infect Dis 58:309-318, 2014.