D Goh1, F Chew, S Khor, B Lee. 1. Department of Paediatrics, National University of Singapore.
Abstract
OBJECTIVE: To ascertain the profile of cases of measles seen at a general hospital during a recent outbreak that occurred despite a measles vaccination program. METHODOLOGY: A retrospective study from January 1991 to March 1998. All patients with measles (ICD code 055. 9) seen at the emergency unit or as inpatients were included. RESULTS: There were 87 cases identified. The diagnosis was clinical in all and proven serologically in 71%. Eighty-five per cent of the cases occurred between January 1997 and March 1998. There was a bi-modal age distribution with peaks in the very young (</= 18 months) and those aged 16-20 years. The majority was unvaccinated (58/87). A proportion (11/87) demonstrated vaccine failure, most likely primary failures. CONCLUSION: This changing measles epidemiology suggests lowering of herd immunity. 'Catch up' vaccinations in July- October 1997 given to school children aged 12-18 years (200 000 individuals or 82% of cohort), may have helped contain the outbreak. These results substantiated the need for a two-dose policy and 'catch-up' immunization program.
OBJECTIVE: To ascertain the profile of cases of measles seen at a general hospital during a recent outbreak that occurred despite a measles vaccination program. METHODOLOGY: A retrospective study from January 1991 to March 1998. All patients with measles (ICD code 055. 9) seen at the emergency unit or as inpatients were included. RESULTS: There were 87 cases identified. The diagnosis was clinical in all and proven serologically in 71%. Eighty-five per cent of the cases occurred between January 1997 and March 1998. There was a bi-modal age distribution with peaks in the very young (</= 18 months) and those aged 16-20 years. The majority was unvaccinated (58/87). A proportion (11/87) demonstrated vaccine failure, most likely primary failures. CONCLUSION: This changing measles epidemiology suggests lowering of herd immunity. 'Catch up' vaccinations in July- October 1997 given to school children aged 12-18 years (200 000 individuals or 82% of cohort), may have helped contain the outbreak. These results substantiated the need for a two-dose policy and 'catch-up' immunization program.
Authors: Wanhan See; Yi Kai Ng; Lin Cui; Yuske Kita; Steven Peng-Lim Ooi; Vernon Lee; Derrick Mok Kwee Heng; Raymond Tzer Pin Lin Journal: Western Pac Surveill Response J Date: 2021-07-12