After beginning surveillance of acute flaccid paralysis for overall poliomyelitis surveillance, one pediatric hospital requested evaluation of seven cases of Guillain-Barre Syndrome (GBS) that had been admitted over a three-month period. The progression of the paralysis was unusually rapid. Medical staff thought there was an unusual clustering of cases in this time period, since the hospital normally admits only three cases a year. We began an investigation of GBS diagnosed in children under 15 years of age in Riyadh city from July 1992 until June 1993. We sought to confirm whether these cases were GBS, to detect more cases in Riyadh city, and to evaluate the reporting system.
Methodology
We reviewed Riyadh surveillance records and medical records of GBS in children under 15 in three pediatric hospitals from July 1, 1992, to June 20, 1993. We interviewed parents of 86% of the affected children. We used the Poisson distribution to compute the monthly distribution of cases expected if cases were distributed randomly in time and compared that figure to the observed distribution.
Results
We detected 14 cases of GBS in Riyadh city and four cases in the rural Riyadh area, with incidence rates of 3.6/100,000 in Riyadh city and 0.4/100,000 in the rural area. Thirty-one percent of the cases had a history of URTI 14 days before onset. None had had recent vaccinations. All had symmetrical flaccid paralysis with ascending weakness, and 85% had intact sensation. An EMG done for three patients showed 100% with delayed nerve conduction. Thirty-eight percent had high CSF protein at the beginning of the illness, while four patients (100%) had high CSF protein on a repeated tap. No virus was isolated from stool or CSF in any patient. All improved within 10-45 days. We found no clustering by time (Chi square=1.01, 4 df). We found that only six cases had been reported to the Ministry of Health (MOH) from Riyadh city during the study period. We detected eight additional cases in Riyadh city not reported from hospitals to primary health care centers (PHCCs) and from there to the MOH.
Conclusion
Although they did not meet the full criteria for GBS diagnosis, 70% of the cases were diagnosed as GBS. No clustering by time, place or person was found. The high rate in the city compared with rural areas suggests that there is an additional risk factor for GBS in the city or that a similar neurologic disease is present. Improved diagnostic protocols and timely surveillance are needed.