Tetanus in Southern Vietnam: Current Situation.

Area of Science:

• * Epidemiology
• * Immunology
• * Public Health

Background:

• * Accurate data on tetanus incidence and disease burden in Vietnam are lacking.
• * Tetanus prevention programs, including the Expanded Program on Immunization (EPI) and Maternal and Neonatal Tetanus (MNT) initiative, have been implemented.
• * Understanding the impact of these programs on tetanus incidence and population immunity is crucial.

Purpose of the Study:

• * To analyze the age structure of tetanus cases in Vietnam over an 18-year period.
• * To assess the impact of the EPI and MNT initiatives on tetanus prevention.
• * To evaluate the serological status of anti-tetanus antibodies in men and women.

Main Methods:

• * Retrospective analysis of 786 tetanus cases admitted to a tertiary referral center in Vietnam across three separate years (1994, 2003, 2012).
• * Examination of patient age structure and birth-year distribution.
• * Enzyme-linked immunosorbent assay (ELISA) to measure anti-tetanus antibody levels in 180 individuals (90 men, 90 women) covered by MNT but not EPI.

Main Results:

• * The median age of tetanus cases increased significantly from 33 in 1994 to 46 in 2012, with most cases born before EPI initiation.
• * The birth-year distribution of cases remained unchanged across the study years, indicating consistent presentation from older birth cohorts.
• * Serological analysis revealed that 73.3% of women had protective anti-tetanus antibody levels compared to only 24.4% of men, indicating significant vulnerability in older men.

Conclusions:

• * Tetanus prevention programs in Vietnam have not fully eliminated the disease, particularly in older populations.
• * Older men represent a vulnerable group with low anti-tetanus antibody levels, suggesting a need for targeted vaccination strategies.
• * Continued surveillance and evaluation of vaccination program efficacy are essential for controlling tetanus incidence in Vietnam.