ABSTRACT

Rubella disease occurs worldwide with seasonal variation and affects both the young and

elderly and may present as an acute, mild or asymptomatic illness. Infection during

early pregnancy may result in congenital rubella syndrome (CRS), stillbirth or miscarriage.

CRS often results in multiple birth defects such as heart problems, deafness and blindness

which makes rubella a leading cause of preventable congenital defects. This study aimed

to determine the seroprevalence of rubella-specific antibodies in school children 0-10 years

in Jos.

A cross-sectional descriptive study was done to determine the seroprevalence of rubella

specific antibodies, prevalence of recent rubella infection and factors associated with its

transmission in Jos. Children aged 0-10 in selected schools in Jos North and South were

studied. Serum was obtained from children and tested for IgG and IgM using ELISA.

A total of 405 children were studied with a mean age of 6.3 years (SD ± 2.5), out of which

220 (54.3%) were female and the age group, 7-8 had the most participants (113 [27.9%]).

336 (83.0%) children tested positive for rubella IgG while only 9 (2.2%) of children tested

werepositivefor IgM. Age≥5 years was significantlyassociated with rubellaseropositivity

with CI 1.01-3.08 at 95% CI and p value 0.043. There was no significant association

between sex of child and rubella seropositivity. Lack of Western education was

significantly associated with rubella seropositivity among children at 95% CI (1.21-4.25)

and p value 0.009. LGA of residence was also significantly associated with rubella

seropositivity as residents of Jos North were more 10 times more likely to be have rubella

specific antibodies than residents of Jos South. None of the study participants had ever

taken rubella vaccine.

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CHAPTER ONE

INTRODUCTION

1.1 BACKGROUND

Rubella disease occurs worldwide with seasonal variation and affects both the young and

elderly. It may present as an acute, mild or asymptomatic illness thus serological tests for

detection of specific rubella antibodies in suspected cases remain important. This infection,

also known as German measles or three-day measles, is caused by the Rubella virus (RV).

It is often mild especially in children with a lot of people not realizing that they are

sick. Infection during early pregnancy may result in a child born with congenital rubella

syndrome (CRS), stillbirth or miscarriage. Rubella is usually spread through contact with

people who are infected via coughing or sneezing.1 The incubation period is 14 to 21 days,

with the majority of individuals developing a rash 14 to 17 days after exposure. Individuals

with rubella are infectious from one week before symptoms appear to four days after the

onset of the rash. Babies with CRS may spread the virus for more than a year.2

Rubella reinfection following natural infection is very rare.3 Primary RV infections during

the first trimester of pregnancy have high teratogenic potential leading to severe

consequences- CRS which may occur in 80–85% of cases. It should be emphasized that

more than 50% of RV infections in non-immunized persons in the general population (and

in pregnant women) are subclinical.4

Naturally acquired rubella generally confers lifelong and usually high degree of immunity

against the disease for the majority of individuals.5,6 Rubella vaccination induces immunity

that confers protection from viraemia in the vast majority of vaccinees, which usually

persists for more than 16 years.5,6 A small fraction of the vaccinees fail to respond or