| Abstract|| |
Background: Rubella is traditionally considered a childhood disease but has the potential to cause outbreaks in hospital set ups. It is important to know the susceptibility status of health care workers (HCWs) as to frame guidelines for their immunization and thus prevent hospital outbreaks. Participants: The rubella susceptibility status of 313 HCWs working in the institute was assessed. This study was initiated after we reported an outbreak due to rubella among HCWs of our institute. Materials and Methods: The serum samples were tested to determine Rubella IgG titres by enzyme linked immunosorbent assay (ELISA). Results: Overall, 48 (15.3%) subjects were found to be negative, thereby indicating their susceptibility to infection. Out of them, 29 (60.5%) were in contact with pregnant women during the course of their employment. There is a risk of nosocomial transmission of rubella from affected HCWs to their contacts especially pregnant women as many of the rubella infections are asymptomatic. Conclusion: Hence, we stress the need for vaccinating the HCWs at the start of their employment to contain the spread of infection and also to reduce the risk of outbreaks in work place.
Keywords: Health care workers, immunization, rubella
|How to cite this article:|
Singh MP, Chatterjee SS, Singh R, Goyal K, Ratho RK. Rubella seronegativity among health care workers in a tertiary care north Indian hospital: Implications for immunization policy. Indian J Pathol Microbiol 2013;56:148-50
|How to cite this URL:|
Singh MP, Chatterjee SS, Singh R, Goyal K, Ratho RK. Rubella seronegativity among health care workers in a tertiary care north Indian hospital: Implications for immunization policy. Indian J Pathol Microbiol [serial online] 2013 [cited 2014 Aug 31];56:148-50. Available from: http://www.ijpmonline.org/text.asp?2013/56/2/148/118704
| Introduction|| |
Rubella virus, a member of family Togaviridae is well known for its teratogenic potential. Disastrous consequences can occur if the infection is contracted by a woman during her pregnancy leading to congenital rubella syndrome (CRS). As per the World Health Organization (WHO) estimate, worldwide more than 100,000 children are born with CRS.  Rubella is endemic in India and CRS contributes significantly to the morbidity and mortality among the live births. The incidence of rubella in many countries has reduced drastically over the past few years as rubella vaccine has been incorporated in their immunization schedule. The immunity to rubella is defined by the presence of rubella-specific IgG (≥10 International Units/ml) either following vaccination or natural infection. 
Rubella has the potential to cause institutional outbreaks and also outbreaks in day care centers or hospitals when susceptible population accumulates over years. This was well demonstrated during a rubella outbreak, which occurred in the pediatric center of our institute.  Previous studies among health care workers (HCWs) revealed that a substantial proportion (2.4-36.3%) of them may be seronegative at any particular time. , However, only limited literature is available regarding rubella serostatus among HCWs in India. , The present study was aimed to assess the rubella-specific IgG serostatus among HCWs working in our institute so as to formulate a vaccination policy among HCWs.
| Materials and Methods|| |
The study was carried out between April 2009 and March 2010 in a tertiary care 1410 bedded hospital in North India. Three hundred and thirteen HCWs including both the medical and the nursing staff working in various wards were included in the study. The HCWs were given adequate background information about the study and only those volunteers who gave a written consent were included. Approximately 2 ml blood samples were collected from each participant aseptically by trained health care personnel. Serum was separated and stored in aliquots in -20°C till tested. A standard questionnaire was administered on demographic characteristics, marital history, vaccination history and type and duration of employment. The study was approved by the Institute Ethics Committee as per national guidelines. Rubella-specific IgG was estimated using commercially available ELISA kit (Adaltis, Italy) as per the manufacturer's instructions. The standard controls from 1 to 1000 International unit (IU) were provided with the kit and these were used during every test run. The optical density (OD) was measured at 450 nm using ELISA reader. The absorbance values of the standard controls provided in the kit and test was plotted on a graph. Samples that showed an IgG antibody titre >10 IU/ml were taken as positive, and those ≤10 IU/ml as negative as per international guidelines.  All the participants were duly informed of the results. The seronegative patients for IgG were advised rubella vaccination. The serum samples were also tested for the presence of rubella IgM antibodies by commercially available ELISA kits as per the manufacturer's instructions (Adaltis, Italy). Student's t-test was performed to find out the significance of differences in data among various groups.
| Results|| |
Out of 313 HCWs included in the present study, 97 HCW were from obstetrics, 84 from general medical wards and intensive care units, 44 from pediatrics, 34 from psychiatry, 28 from community medicine, 21 from laboratory and 5 from surgery speciality. The age range of the participants was 18-40 years (mean ± SD = 23.8 ± 5 years); 284 were females and 29 were males. Overall, 48 (15.3%) were negative for rubella IgG antibody (95% confidence interval = 13.6%-17.0%). The age-wise distribution of seronegative HCW is shown in [Figure 1]. Of them, 44 were females (91.7%) and 4 males (8.3%). Five (5/48, 10.41%) of the seronegative workers were married. There was no significant difference between seropositive and seronegative HCWs in terms of age (24.3 years vs. 23.25 years, P value >0.5). Age distribution of protected and unprotected HCWs is shown in [Figure 1]. The proportion of seronegative workers was not significantly (P > 0.5) higher among the married workers (11.1%) than among single workers (16.0%). A history of contact with pregnant women during the course of their employment was given by 187 subjects; of them, 29 (15.5%) did not have protective antibodies. The place of posting of the seronegative HCWs is shown in [Table 1]. Of the 313 participants, only 15 reported previous receipt of rubella vaccine, further 14 of these 15 individuals (93.3%) had protective antibody levels.
| Discussion|| |
Our work for the first time describes the susceptible status of HCWs to rubella in a north Indian tertiary care hospital. The HCWs are at increased risk of contracting rubella from patients especially in pediatric set ups where they come in contact with CRS cases. It is well known that the infants with CRS shed rubella virus for long periods in nasopharyngeal secretions and urine and close contact with such infants can lead to rubella infection. Majority of such rubella infections are subclinical and hence there is a risk that infected HCWs may unknowingly transmit the virus to other patients or staff. Typically in developing countries like India, nursing staff, students and resident doctors have rotational duties in different sections of the hospital; hence the spread of rubella may occur far and wide leading to institutional outbreaks as has been reported from Bangalore, Vellore and also from Chandigarh. ,, Previous studies from different countries have shown varying rubella seronegativity (1.4%-33.8%) among HCWs. ,,,,
In India, the information on rubella in health care personnel is scanty.  Our hospital being a premier teaching and research institute of India, typically attracts resident doctors and nursing students from all over the country. Two studies carried out on HCWs from south Indian eye hospitals have demonstrated similar rates of seronegativity (11.4% and 15%). , Thus it seems that these rates possibly reflect the general rubella sero-status of HCWs across India. However, a recent study by Valsan et al.  carried out in medical and nursing students in south India has reported a much higher seronegativity of 33.8%. Thus it necessitates the need for large-scale multicentric studies to find out the status of rubella IgG antibodies in health care professionals so as to formulate a vaccination policy for HCWs in the country.
The key elements to prevent rubella outbreak is to ensure a high level of rubella immunity through effective immunization as is done in the developed nations. As per guidelines of Indian Academy of Pediatrics,  Measles Mumps Rubella (MMR) vaccine should be given to seronegative hospital staffs that frequently come in contact with pregnant mothers. In the health care set up, vaccination of both female and male HCWs is desirable at the time of employment both for self protection and also to restrict further spread of the virus in the hospital and in the community at large. It is worthwhile to have an institutional policy on rubella vaccination among hospital staff, medical and nursing students following routine screening for serostatus at the time of their employment to prevent hospital-based outbreaks. This will also reduce the risk of CRS in children born to immunized HCW as presence of maternal rubella specific IgG antibodies is protective.
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Mini P Singh
Department of Virology, Postgraduate Institute of Medical Education and Research, Chandigarh - 160 012