Measles is sometimes considered a mild illness or “just a rash.” But the highly contagious virus can cause severe illness not only during initial infection, but years later, once patients appear to have fully recovered.
This delayed complication, a rare and almost invariably fatal brain disease known as subacute sclerosing panencephalitis (SSPE), is highlighted in a new report. published yesterday in Emerging infectious diseases.
For the report, researchers from the Centers for Disease Control and Prevention examined 20 children from the Philippines, where measles outbreaks occurred in 2010-2011, 2013 and 2018-2019. The most recent outbreak was the largest in the World Health Organization’s Western Pacific region. All the children mentioned in the report were admitted to the Quezon City Children’s Hospital from 2007 to 2022.
A bigger wave of SSPEs could be on the horizon
The four children whose measles infection dates match the 2018-2019 outbreak were hospitalized between 2020 and 2022, two to three years after their initial infections. Since SSPE is latent for years after initial infection, these cases “most likely represent the peak of a post-outbreak wave,” the report notes, and “additional cases may emerge in coming years.”
Ten of the 19 children in the study with an estimated age of infection contracted measles before they were old enough for routine vaccination at nine months (when the Philippines schedules its routine first dose). The median age at hospital admission for SSPE was 6.2 years.
Other cases could appear in the years to come.
Eighty-five percent of children had received at least one measles vaccine, but the report emphasizes that SSPE results from naturally circulating measles that spreads between people, not from the weakened measles virus used in vaccines.
In the Philippines, first dose vaccination coverage decreased from 92% in 2004-2007 to 64% in 2021. Reported measles cases increased from 2,428 in 2017 to 48,525 in 2019.
All 20 children admitted to hospital for SSPE had deterioration in brain function and nervous system. All 17 tested positive for measles antibodies in their spinal fluid, and all 13 tested positive for measles antibodies in their blood.
Diagnostic challenges and limitations
The researchers highlight certain limitations. Measles history was absent or unknown in a quarter of the observed children, and the researchers recommend enhanced measles surveillance for all children with signs of neurodegeneration, regardless of available measles history.
The study’s small, single-hospital sample could not establish national SSPE rates and infection dates, and vaccination history relied on caregiver recall and could not be verified.
Nevertheless, the results highlight the need for stronger measles and SSPE surveillance and sustained two-dose vaccination coverage, including additional vaccination during outbreaks, the authors conclude.
Gn Health
