National surveillance for Guillain-Barré syndrome: January 1978-March 1979.

Between January 1, 1978, and March 31, 1979, 1,034 cases of Guillain-Barré syndrome (GBS) were reported to the Centers for Disease Control by the 1,813 American Academy of Neurology sentinel physicians who participated in the national GBS surveillance program. A direct correlation was observed between increasing age and the age-specific attack (incidence) rates. Based on the cases observed and the total US population, age-adjusted attack rates were statistically higher in males (0.52 per 100,000) than in females (0.40). Rates for whites were 0.44 and those for blacks 0.28 per 100,000; although the difference is statistically significant, uncertainties as to the true denominators by race preclude acceptance of these differences as valid. Sixty-seven percent, or 682 of the patients, reported that they had had an antecedent illness within 8 weeks before onset of GBS, and among them the peak period of onset of GBS was in the second week after the onset of the prior illness. There were also 52 patients (5%) who had undergone surgery and 45 (4.5%) who had received vaccinations, both within the 8 weeks before onset of GBS. However, the high proportions of antecedent illness in these groups (45% of those operated and 53% of those vaccinated) made attribution of GBS to the procedures tenuous. Risk of GBS in patients who reported receiving a swine influenza vaccination in 1976 was no greater than in those who reported that they did not receive this vaccine.