Serostatus of IgG antibody against mumps virus in adult population of Al Madinah Al Munawarah, Saudi Arabia

Abstract

Objectives: To determine the frequency and distribution of mumps-specific IgG antibodies among the healthy adult Saudi population in Al Madinah Al Munawarah, Saudi Arabia, where mandatory vaccination against measles-mumps-rubella (MMR) has been implemented for 30 years.

Methods: Qualitative and quantitative indirect enzyme-linked immunosorbent assay was performed to determine the mumps IgG antibody levels in sera collected from 429 individuals, including 224 men and 205 women. Participants were stratified into 3 age groups according to vaccination history (<20, 21-30, and >31 years).

Results: The overall seroprevalence of mumps antibodies in our population was 79.0%. The highest proportion of individuals with IgG antibody seropositivity, at 87.8% (95% confidence interval (95% CI): 84.7%-90.8%), was observed among the <20 years age group, who received 2 doses of vaccine. No significant relationships were observed between mumps seropositivity and age group or gender. The multivariable analysis identified the male gender and the age group >31 years as factors associated with an increased likelihood of seronegativity. Al Madinah Al Munawarah has achieved increased anti-mumps antibody seroprevalence since the implementation of the 2-dose MMR vaccination schedule.

Conclusions: Based on our study findings, we recommend that serological screening be performed to assess the need for mumps vaccination among adults at high risk for exposure and transmission.

Keywords: immunity; mumps; seropositivity; seroprevalence; vaccination.

Figure 1

- Concentrations of anti-mumps IgG antibodies among the 3 age groups. The median for each age group is shown by the horizontal line inside the box, which represents the 50% percentile. The 25% and 75% percentiles are indicated by the lower and the upper ends of each box, respectively. The distance between the 2 percentiles represents the interquartile range (IQR), which reflects the distribution of the values. The ends of the whiskers represent one and a half times the IQR. Extreme values that occur outside of the box and whiskers are considered outliers. Age group frequencies: <20 years (n=41), 21-30 years (n=171), and >31 years (n=217).

Figure 2

- Scatterplot showing age and anti-mumps IgG antibody concentrations.

Figure 3

- Box plot showing differences in the concentrations of anti-mumps IgG antibodies between men and women. Whiskers and box bands represent quartiles. Extreme values that occur outside of the box and whiskers are considered outliers. Gender frequency: men (n=224) and women (n=205).