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Measles in bone marrow transplant recipients during an outbreak in São Paulo, Brazil
Clarisse M Machado1, Flávio B Gonçalves, Cláudio S Pannuti
1Virology Laboratory, Instituto de Medicina Tropical de São Paulo, University of São Paulo Medical School, SP, Brazil. clarimm@usp.br
Abstract:
In 1997, a measles outbreak was identified in São Paulo. Between February and December, 20 185 cases were confirmed. From April to July 1997, a seroepidemiologic survey was conducted to identify the recipients of bone marrow (BM) transplants who were susceptible to measles and the occurrence of measles in this population. A total of 156 patients were screened by enzyme immunoassay (EIA). Patients with IgG titers more than 100 mIU/mL were considered immune. Measles reimmunization records were also reviewed. Thirty-two vaccinated patients underwent serologic evaluation. Six of 22 patients (27.3%) within 3 years after vaccination lost measles immunity, in contrast to 7 of 10 patients (70%) vaccinated longer than 3 years previously (P =.049). Among the 122 nonvaccinated patients, 41 (33.6%) were susceptible to measles: 4 of 47 patients (8.5%) within the first year after BM transplantation (BMT), and 37 of the 75 patients (49.3%) after the first year after BMT (P <.001). Eight recipients acquired measles, confirmed by serology (EIA). High-avidity IgG antibodies were observed in the acute phase of measles, suggesting a secondary immune response. Measles interstitial pneumonia was observed in one patient. Seven patients had mild symptoms. Exanthema was present in all patients. All but one patient had fever and nonproductive cough. Koplik spots could be observed in 5 patients. Measles can be mild in BM transplant recipients. Exanthema is frequently present but not often typical. Immunity to measles decreases after day +365 after BMT. Additional studies are needed to evaluate the safety of measles vaccine after the first year of BMT, mostly during outbreaks.
Insights
Measles immunity wanes after bone marrow transplantation (BMT), increasing susceptibility. Re-evaluation of vaccine strategies is crucial, especially post-transplant and during outbreaks.
Area of Science:
- Immunology
- Infectious Diseases
- Hematology
Background:
- A 1997 measles outbreak in São Paulo highlighted potential risks for immunocompromised populations.
- Bone marrow transplant (BMT) recipients may have altered immune responses to infections and vaccinations.
Purpose of the Study:
- To assess measles immunity and susceptibility in bone marrow transplant recipients during an outbreak.
- To evaluate the duration of measles immunity after vaccination and BMT.
Main Methods:
- A seroepidemiologic survey using enzyme immunoassay (EIA) screened 156 BMT patients for measles IgG antibodies.
- Measles reimmunization records were reviewed for 32 vaccinated patients.
- Susceptibility was analyzed based on time since vaccination and time since BMT.
Main Results:
- 33.6% of unvaccinated BMT patients were susceptible to measles, with susceptibility increasing significantly after one year post-BMT (49.3%).
- 27.3% of patients vaccinated within 3 years lost immunity, compared to 70% vaccinated over 3 years prior.
- Eight BMT recipients contracted measles, exhibiting mild symptoms and frequent exanthema; one developed pneumonia.
Conclusions:
- Measles immunity diminishes significantly after one year post-BMT, necessitating careful monitoring.
- Measles infection can be mild in BMT recipients, but complications like pneumonia can occur.
- Further research is needed on the safety and efficacy of measles re-vaccination in BMT patients, particularly after the first year and during outbreaks.