LONDON -- The effects of bacterial meningitis in infancy persist as learning disabilities through young adulthood, suggested investigators here.
LONDON, March 22 --The effects of bacterial meningitis in infancy persist in the form of learning disabilities through young adulthood, suggested investigators here.
In a study of adolescents in England and Wales, 25% of those who had had bacterial meningitis in infancy failed to pass any of their high school certification exams in five key subject areas, compared with only 6.6% of controls, reported John de Louvois, M.D., and colleagues of Hammersmith Hospital.
"As far as we know, this is the largest study into the effects of meningitis in infancy on educational achievement at age 16, and the only one based on a national cohort," the authors reported online in the Archives of Diseases in Childhood, a BMJ publication. "It demonstrates for the first time the full extent of learning disability among survivors, even those who had previously appeared to be unscathed."
A pediatric infectious disease specialist who was not involved in the study said that the results as reported are "disturbing." But Blaise Congeni, M.D., of the Akron (Ohio) Children's Hospital added that in his experience children with meningitis generally have better outcomes.
"There are obviously children who are identified early on to have catastrophic consequences, but long-term cognitive problems that show up later in patients who appear to be normal--that's not my experience or what I thought the literature showed," Dr. Congeni said in an interview.
The students were part of a long-term case control cohort of children who were infected with bacterial meningitis in infancy during an outbreak of the disease in England and Wales from 1985 to 1987. The children had been evaluated for meningitis-associated disability at age five, and for behavioral problems at age 13.
In the current study, the authors looked at 461 teens and 289 controls who had been matched with the cases by generalists a decade or so earlier.
The study focused on the results of General Certificate of Secondary Education (GCSE) exams. The tests are taken by 16-year-olds in England and Wales, with results graded from A to E. The national standard is a passing grade of C or higher in five subjects.
To determine whether bacterial meningitis in infancy would have an effect on later academic performance, the authors compared cases and controls by type of school attended (special or regular), the number of GCSE examinations attempted, the number of examinations passed, and achievement in five key subjects: English language, English literature, mathematics, science, and a modern foreign language. The authors also stratified examination results by the age at which the students developed meningitis.
They found that 7.8% of the cases (36 of 461) were enrolled in special education programs or schools, compared with none of the controls; the rate of special school attendance for the overall population in England is 1.7%.
In all 25.4% of all index cases (117 of 461) did not pass any of their certification exams, compared with just 6.6% (19 of 289) controls.
Among those students attending regular comprehensive (secondary) schools, 9.4% of those who had been infected with meningitis in infancy took fewer than five GCSE exams, compared with 4.7% of controls (odds ratio 2.1, 95% CI, 1.0 to 4.2, P=0.04)
In addition nearly half of all index cases attending comprehensive schools failed to achieve the national standard of at least five passes at grade C or above (47.8% vs. 25.5% of controls, odds ratio 2.7, 95% CI, 1.9 to 3.8, P<0.0001)
The numbers were nearly identical when they looked only at those children who had no signs of meningitis-associated disability at age 5. In this subgroup, 48.9% of the index cases did not achieve the five-pass standard, compared with 25.4% of controls. (odds ratio=2.8, 95% CI, 1.95 to 4.02, P<0.0001).
When they looked at the five key subject areas in the subgroup, they found similar results, with 56.9% of index cases failing to pass all five subjects, compared with 34.9% of controls (odds ratio for passing all five 0.4, 95% CI 0.3 to 0.6, P<0.0001).
More than half of all former meningitis patients (54.3%) failed their English language and math exams, compared with 33.6% of controls (odds ratio 0.4, 95% CI 0.3 to 0.6).
There were no significant differences in educational achievement between pupils who had meningitis as neonates and those who were infected from the ages of two to 12 months, however.
"It is alarming that children who appeared to have escaped meningitis unscathed when assessed at age 5 did no better in their GCSE examinations than those with recognized disabilities," the authors wrote. "This emphasizes the need not only for a full post-infection medical assessment but also for continuing educational support throughout the school years. The results of this study show that this support is not at present being given."
The authors noted that since the 1985-87 meningitis outbreak, there have been substantial improvements in the management and treatment of meningitis in infancy, resulting in a decline in acute phase mortality from 25.5% then to 6.6% just a decade later, but little difference in the incidence of moderate to severe disability at age five between patients treated in the mid-to-late 1980s and those treated in the late 1990s.
"Almost a third of the 16 year olds who attended special schools had had meningitis due to H. influenzae," the authors noted. "The virtual eradication of H. influenzae as a cause of infantile meningitis, after the introduction of the HIB vaccine, should in itself improve the overall outcome of infantile meningitis. Raising parental awareness of the long term consequences of meningitis in infancy might also improve the uptake of immunization."