|Year : 2004 | Volume
| Issue : 1 | Page : 61-63
The seroepidemiology of rubella in Amritsar (Punjab)
N Singla, N Jindal, A Aggarwal
Department of Microbiology, Government Medical College, Amritsar - 143 001, Punjab, India
Department of Microbiology, Government Medical College, Amritsar - 143 001, Punjab, India
Seroprevalence of Rubella was determined in 580 women including 80 women of medical community of district Amritsar, by ELISA test. The overall Rubella IgG seropositivity was 68.8% while in women of medical community it was 80%. Maximum number of women were seropositive (77.2%) in age group 26-35 years. Significantly higher rates were observed in women of urban areas and those belonging to lower socioeconomic class. Although the incidence of seropositivity was more in women with history of adverse pregnancy outcome than those with normal obstetric performance, the difference was statistically not significant (p > 0.05). Serologically, immune status showed poor correlation with history of past Rubella virus like infection.
|How to cite this article:|
Singla N, Jindal N, Aggarwal A. The seroepidemiology of rubella in Amritsar (Punjab). Indian J Med Microbiol 2004;22:61-3
|How to cite this URL:|
Singla N, Jindal N, Aggarwal A. The seroepidemiology of rubella in Amritsar (Punjab). Indian J Med Microbiol [serial online] 2004 [cited 2014 Apr 24];22:61-3. Available from: http://www.ijmm.org/text.asp?2004/22/1/61/8066
Rubella is a mild exanthematous disease of worldwide distribution. However, there is risk of infection to the foetus and subsequent congenital defects when it infects susceptible pregnant women. Since Rubella is not notifiable in many countries and its clinical diagnosis is frequently inaccurate, serosurveys are used to assess the epidemiologic pattern of Rubella in a community. India is a vast country but only a few such surveys,, have been conducted so far. It was therefore considered worthwhile to study the Rubella seroprevalence rates and to analyze them according to the age, geographical distribution, socioeconomic status, previous history of immunization and adverse pregnancy outcome in the female population of Amritsar (Punjab).
| ~ Materials and Methods|| |
The present study was conducted on 580 women of different age groups. These women were selected at random and belonged to different geographical areas and to different socioeconomic classes. A detailed history with special reference to past Rubella virus like infection, immunization against Rubella and adverse pregnancy outcomes if any, was recorded.
Blood samples were collected from all women, sera was separated and stored at 4°C until analyzed. IgG antibodies against Rubella were detected using Pathozyme Rubella IgG ELISA kit (Omega Diagnostics). The results were interpreted as seropositive if the antibody titer was more than 11 IU/mL and seronegative if less than 9 IU/mL. Samples with titer between 9-11 IU/mL were considered equivocal and were retested after 2 weeks.
| ~ Results|| |
Of the 580 women, 380 (65.5%) were in the reproductive age group of 16-45 years and 200 (34.5%) were in prefertility age (10-15 years). Three hundred and thirty four (57.6%) belonged to urban areas and 246 (42.4%) to rural area. Majority of them (365, 62.9%) were from lower socioeconomic class and only 68 (11.7%) belonged to upper class. Past history of Rubella like infection could only be obtained in two while none of the women gave history of immunization against Rubella.
Considering all age groups Rubella IgG seropositivity was found to be 68.8% in our study. In 80 women of medical community seropositivity was 80% (64/80). There was an increasing trend in seropositivity from 64% in prepubertal age to the maximum incidence of 77.2% in the age group 26-35 years (peak fertility age). This was followed by a conspicuous decline to 59.3% beyond 35 years [Table].
The prevalence of Rubella seropositive women was more in those residing in urban areas (76.6%) as compared to those of rural areas (58.1%) Statistically the difference was significant (p<0.05). A decline in the immune status with rising socioeconomic status was also observed and the difference in seropositivity between upper and lower class was found to be statistically significant (p<0.05%).
Of the 380 women of reproductive age group, 233 (61.3%) were pregnant and the prevalence of seropositivity in them was 67.8% which was less than that observed in nonpregnant women (76.9%). However, the difference between the two was not statistically significant (p>0.05). One hundred and eighty three of the 380 women who presented with history of adverse pregnancy outcomes showed higher prevalence of seropositivity (73.2%) than in women with normal obstetric performance (69.5%), the difference between the two being insignificant (p>0.05).
| ~ Discussion|| |
There is considerable variation in the prevalence of Rubella antibodies among women of childbearing age. European women have relatively higher prevalence of Rubella immunity (93.2%) as compared to women of African (86.7%) and Asian origin (78.4%). In India the reported figures vary from 53% to 94.1%.,,, Our finding of 71.3% falls within this range, leaving about one third of women still susceptible to Rubella infection as they enter childbearing age. The reason for this difference in immunity is difficult to explain. However, factors such as net birth rate, population density, opportunities for entry of virus, level of herd immunity at the time of virus introduction and ethnicity of the population may be responsible for this variation.
Occupational exposure (doctors, nurses, school teachers) is another factor that increases the chances of contracting Rubella infection. In our study, 80% women of medical community were found to be seropositive which implies that 20% of them are still susceptible and are at potential risk of acquiring Rubella infection.
Analysis of antibody levels among rural and urban populations showed that seropositivity rate was much higher (76.6%) in urban women as compared to those residing in rural areas (58.1%) which is in accordance to the finding of other authors.,, Although women in both the areas are exposed to Rubella infection at an early age, the chances of exposure are less in rural areas owing to a lower population density. Rubella seropositivity rates were also found to be higher in women of lower socioeconomic class (71.8%) than in women of upper class (55.9%) as was also reported by Yadav et al. Crowded living conditions in lower class population might increase the chances of exposure to Rubella infection.
Past history of Rubella virus like infection was given by only two of the 580 women, although the prevalence of Rubella seropositivity by serological studies was found to be much higher. Brown et al have also reported the poor correlation of past history of Rubella with immune status serologically. None of the women included in this study gave history of immunization against Rubella. Even the school girls of prepubertal age were found not to be vaccinated against Rubella. Similar observations have been made by Chakravarti from New Delhi. This indicates that the need for immunization to control Rubella has not been duly recognized in India.
Higher incidence of seropositivity observed in women presenting with adverse pregnancy outcomes suggests that Rubella could be a cause of repeated pregnancy wastage in these women.
It is evident from the present study that Rubella virus infection is prevalent in our population. However, a substantial number of women including those of medical community reach childbearing age without acquiring natural immunity to Rubella. Hence, there is need to formulate an effective Rubella immunization programme to prevent repeated pregnancy wastage and birth of infants with congenital Rubella syndrome.
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