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Erythema infectiosum in a primary school: Investigation of an outbreak in bury
Public Health
(1989), 103, 391-393
Erythema I n f e c t i o s u m in a Primary School: Investigation of an O u t b r e a k in Bury A n d r e w T u r n e r 1 and Olu O l o j u g b a 2
Public Health Laboratory Service, Manchester, 2Bury Health Authority. 21 Silver Street. Bury, Lancashire
Between January and April 1987, 97 of 302 (32%) children attending a primary school in Bury, Lancashire, were affected by an exanthematous illness. The duration and extent of the episode caused considerable local interest and anxiety. Examination of 6 serum specimens obtained during the subsequent investigation demonstrated evidence of recent Human Parvovirus B19 infection in 3 children and 1 teacher. No evidence of recent rubella virus infection was found. The investigation of the episode is discussed in the context of problems which may occur in the management of similar outbreaks. Introduction In late March 1987 the Medical Officer for Environmental Health ( M O E H ) for Bury was informed o f an exanthematous illness affecting children at a local primary school. Several of the children had been seen by their family doctors who had m a d e various diagnoses including allergy, Scarlet Fever, Rubella and Fifth Disease or 'Slapped Cheek Syndrome'. Some parents had been advised to keep their children off school, others had been advised that this was unnecessary. This variation in opinion and advice, and the continued occurrence o f cases led the H e a d m a s t e r of the school to report the outbreak. A n investigation was started by the M O E H and the Environmental Health Department, and subsequently the local Public Health L a b o r a t o r y (PHL) was invited to assist. Methods The school was visited and class registers and sickness records examined. With the help o f the Headmaster, a list of affected pupils and staff was compiled. Details of pregnant staff were also obtained. Mothers o f recently affected pupils were contacted by telephone where possible and h o m e visits made. A brief history was taken, and with parental consent, a blood sample taken by t h u m b prick. Ill or pregnant staff were advised to contact their family doctors who were written to by the M O E H informing them o f the investigation and the preliminary results, and requesting that they submit serum specimens to the PHL. Six sera were examined for IgM antibody to H u m a n Parvovirus B19 and Rubella virus by standard antibody capture methods. ~,2 Results A total of 302 children attended the school and there were 16 full-time and 8 part-time staff, 22 of w h o m were female. One m e m b e r of staff was k n o w n to be pregnant. Altogether 97 o f the 302 (32%) children were affected by the illness. The attack rate was highest in the infant classes, in 2 of which it reached 50%. Three of the staff were affected, none o f w h o m was pregnant. The first cases presented during the second week o f January, and cases continued © The Society of Community Medicine, 1989
A. Turner and O. Olojugba
392
to occur until the half-term holiday in April. There were no new cases after the pupils returned from holiday. Detailed clinical records were not available, but 17 of 18 mothers who were interviewed by an Environmental Health Officer described a rash affecting their children, mostly on the face, particularly the cheeks. Sera were obtained in April from 3 symptomatic children and 3 teachers; 2 of the teachers had been symptomatic, 1 was pregnant but asymptomatic. IgM antibody to H u m a n Parvovirus B19 was detected in the sera from all 3 children and 1 of the symptomatic staff, consistent with recent Parvovirus B19 infection. N o n e of the sera contained Rubella-specific IgM. Discussion and Conclusion
The illness in the children at the school was benign and self-limiting and in some cases typical o f Fifth Disease, or Erythema Infectiosum (EI), and cases continued to occur for a number of weeks until the outbreak was interrupted by the school half-term holiday (Figure 1). Although this pattern is similar to that previously reported in other school outbreaks of Fifth Disease, 3 it was nevertheless decided to investigate the episode further to try and confirm the clinical diagnosis. There were 2 reasons for this. (i) A similar rash m a y occur with RubeUa, 4 and at least one female staff m e m b e r was known to be pregnant. (ii) There was local concern that the rash was due to allergy to a spray used on the school lawns. The investigation was limited because the outbreak was reported to the Medical Officer for Environmental Health late on in its course and few recent cases were readily identifiable. There was felt to be insuffÉcient justification for taking blood specimens from a larger n u m b e r of children when they were only mildly affected. However, results of those tested confirmed the clinical diagnosis of EI, which has recently been shown to be caused by infection with H u m a n Parvovirus B19. 5 Although it is possible that some of the other 25
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9th 16th 23rd 30th January
7th 13th 20th 27th February
Dates
6th
13th 20th 27th March
3rd 10th April
(1987)
Figure 1 Histogram showing numbers of pupils absent from school due to exanthematous illness January to April 1987.
Erythema Infectiosum in a Primary School
393
children who were affected actually had Rubella, the only pregnant teacher was immune to Rubella infection. The effect of Rubella in pregnancy is well established, 6 as has the importance of investigating contacts o f p r e g n a n t ' w o m e n with rubelliform illness. 7 Therefore, where there are female staffofchild-bearing age, school outbreaks such as this merit investigation to exclude Rubella infection. The outcome o f infection with H u m a n Parvovirus B19 in pregnancy is less well understood and m o r e informed m a n a g e m e n t will depend on the findings of prospective studies such as that being carried out by the P H L S Working Party on Fifth Disease) Having established the cause of the illness, keeping children with a rash off school would not have been appropriate because the illness was mild, immunity in adult life m a y be beneficial and it would not have interrupted the transmission of infection as cases of E1 are no longer infectious by the time the rash appears. 9 Finally, early reporting of similar outbreaks should be encouraged as it enables m o r e timely and relevant investigation.
Acknowledgements We thank Mrs Cath Hignett and Mr Gwyn Pritchard for their help with the investigation, Mrs Margaret Ridehalgh for the Parvovirus-specific IgM tests, Dr J.E. Cradock-Watson and Dr I. Greatorex for helpful discussions, and Mrs Kath McGagh and Mrs Brenda White for the manuscript.
References 1. Tedder, R. S., Yao, J. L. & Anderson, M. J. (1982). The production of monoclonal antibodies to Rubella haemagglutinin and their use in antibody-captive radioimmunoassays for Rubellaspecific IgM. Journal of Hygiene, 88, 335-350. 2. Cohen, B.J., Mortimer, P.P. & Pereira, M.S. (1983). Diagnostic assays with monoclonal antibodies for the human serum parvovirus-like virus (SPLV). Journal of Hygiene, 91, 113-130. 3. Lauer, B.A., MacCormack, J.N. & Wilfert, C. (1976). Erythema infectiosum: an elementary school outbreak. American Journal of the Disease of Children, 130, 252-254. 4. Best, J. M. & Banatvala, J.E. (1987). Rubella. In: Principles and Practice of Clinical Virology, Zuckerman, A. J., Banatvala, J. E. & Pattison, J. R. (eds). Chichester: Wiley Medical. 324 pp. 5. Anderson, M.J., Lewis, E., Kidd, I.M., Hall, S.M. & Cohen, B.J. (1984). An outbreak of Erythema Infectiosum associated with Human Parvovirus infection. Journal of Hygiene, 93, 8593. 6. Miller, E., Cradock-Watson, J. E. & Pollock, T. M. (1982). Consequences of confirmed maternal Rubella at successive stages of pregnancy. Lancet, ii, 781-784. 7. Morgan-Capner, P. (1983). The detection of Rubella-specific antibody. Public Health Laboratory Service Microbiology Digest, 1, 6-11. 8. Hall, S., Anderson, M., Caul, O., Cohen, B., Cradock-Watson, J., Kaye, P., Mortimer, P., Peto, T., Shirley, J. & Vurdien, J. (1987). The outcome of Human Parvovirus (B19) infection in pregnancy: a prospective study conference proceedings of the Joint Meeting of The European Society Against Virus Diseases and European Group for Rapid Viral Diagnosis. Davos. 9. Anderson, M.J. (1987). Human Parvoviruses. In: Principles and Pract&e of Clinical Virology. Zuckerman, A. J., Banatvala, J. E. & Pattison, J. R. (eds). Chichester: Wiley Medical. 516 pp.
(1989), 103, 391-393
Erythema I n f e c t i o s u m in a Primary School: Investigation of an O u t b r e a k in Bury A n d r e w T u r n e r 1 and Olu O l o j u g b a 2
Public Health Laboratory Service, Manchester, 2Bury Health Authority. 21 Silver Street. Bury, Lancashire
Between January and April 1987, 97 of 302 (32%) children attending a primary school in Bury, Lancashire, were affected by an exanthematous illness. The duration and extent of the episode caused considerable local interest and anxiety. Examination of 6 serum specimens obtained during the subsequent investigation demonstrated evidence of recent Human Parvovirus B19 infection in 3 children and 1 teacher. No evidence of recent rubella virus infection was found. The investigation of the episode is discussed in the context of problems which may occur in the management of similar outbreaks. Introduction In late March 1987 the Medical Officer for Environmental Health ( M O E H ) for Bury was informed o f an exanthematous illness affecting children at a local primary school. Several of the children had been seen by their family doctors who had m a d e various diagnoses including allergy, Scarlet Fever, Rubella and Fifth Disease or 'Slapped Cheek Syndrome'. Some parents had been advised to keep their children off school, others had been advised that this was unnecessary. This variation in opinion and advice, and the continued occurrence o f cases led the H e a d m a s t e r of the school to report the outbreak. A n investigation was started by the M O E H and the Environmental Health Department, and subsequently the local Public Health L a b o r a t o r y (PHL) was invited to assist. Methods The school was visited and class registers and sickness records examined. With the help o f the Headmaster, a list of affected pupils and staff was compiled. Details of pregnant staff were also obtained. Mothers o f recently affected pupils were contacted by telephone where possible and h o m e visits made. A brief history was taken, and with parental consent, a blood sample taken by t h u m b prick. Ill or pregnant staff were advised to contact their family doctors who were written to by the M O E H informing them o f the investigation and the preliminary results, and requesting that they submit serum specimens to the PHL. Six sera were examined for IgM antibody to H u m a n Parvovirus B19 and Rubella virus by standard antibody capture methods. ~,2 Results A total of 302 children attended the school and there were 16 full-time and 8 part-time staff, 22 of w h o m were female. One m e m b e r of staff was k n o w n to be pregnant. Altogether 97 o f the 302 (32%) children were affected by the illness. The attack rate was highest in the infant classes, in 2 of which it reached 50%. Three of the staff were affected, none o f w h o m was pregnant. The first cases presented during the second week o f January, and cases continued © The Society of Community Medicine, 1989
A. Turner and O. Olojugba
392
to occur until the half-term holiday in April. There were no new cases after the pupils returned from holiday. Detailed clinical records were not available, but 17 of 18 mothers who were interviewed by an Environmental Health Officer described a rash affecting their children, mostly on the face, particularly the cheeks. Sera were obtained in April from 3 symptomatic children and 3 teachers; 2 of the teachers had been symptomatic, 1 was pregnant but asymptomatic. IgM antibody to H u m a n Parvovirus B19 was detected in the sera from all 3 children and 1 of the symptomatic staff, consistent with recent Parvovirus B19 infection. N o n e of the sera contained Rubella-specific IgM. Discussion and Conclusion
The illness in the children at the school was benign and self-limiting and in some cases typical o f Fifth Disease, or Erythema Infectiosum (EI), and cases continued to occur for a number of weeks until the outbreak was interrupted by the school half-term holiday (Figure 1). Although this pattern is similar to that previously reported in other school outbreaks of Fifth Disease, 3 it was nevertheless decided to investigate the episode further to try and confirm the clinical diagnosis. There were 2 reasons for this. (i) A similar rash m a y occur with RubeUa, 4 and at least one female staff m e m b e r was known to be pregnant. (ii) There was local concern that the rash was due to allergy to a spray used on the school lawns. The investigation was limited because the outbreak was reported to the Medical Officer for Environmental Health late on in its course and few recent cases were readily identifiable. There was felt to be insuffÉcient justification for taking blood specimens from a larger n u m b e r of children when they were only mildly affected. However, results of those tested confirmed the clinical diagnosis of EI, which has recently been shown to be caused by infection with H u m a n Parvovirus B19. 5 Although it is possible that some of the other 25
-6 O t-
20
O
E 0
75
zz
_Q rc~ o Z
~- lo
O .lz
•
-6 o
Z c.,9
0
9th 16th 23rd 30th January
7th 13th 20th 27th February
Dates
6th
13th 20th 27th March
3rd 10th April
(1987)
Figure 1 Histogram showing numbers of pupils absent from school due to exanthematous illness January to April 1987.
Erythema Infectiosum in a Primary School
393
children who were affected actually had Rubella, the only pregnant teacher was immune to Rubella infection. The effect of Rubella in pregnancy is well established, 6 as has the importance of investigating contacts o f p r e g n a n t ' w o m e n with rubelliform illness. 7 Therefore, where there are female staffofchild-bearing age, school outbreaks such as this merit investigation to exclude Rubella infection. The outcome o f infection with H u m a n Parvovirus B19 in pregnancy is less well understood and m o r e informed m a n a g e m e n t will depend on the findings of prospective studies such as that being carried out by the P H L S Working Party on Fifth Disease) Having established the cause of the illness, keeping children with a rash off school would not have been appropriate because the illness was mild, immunity in adult life m a y be beneficial and it would not have interrupted the transmission of infection as cases of E1 are no longer infectious by the time the rash appears. 9 Finally, early reporting of similar outbreaks should be encouraged as it enables m o r e timely and relevant investigation.
Acknowledgements We thank Mrs Cath Hignett and Mr Gwyn Pritchard for their help with the investigation, Mrs Margaret Ridehalgh for the Parvovirus-specific IgM tests, Dr J.E. Cradock-Watson and Dr I. Greatorex for helpful discussions, and Mrs Kath McGagh and Mrs Brenda White for the manuscript.
References 1. Tedder, R. S., Yao, J. L. & Anderson, M. J. (1982). The production of monoclonal antibodies to Rubella haemagglutinin and their use in antibody-captive radioimmunoassays for Rubellaspecific IgM. Journal of Hygiene, 88, 335-350. 2. Cohen, B.J., Mortimer, P.P. & Pereira, M.S. (1983). Diagnostic assays with monoclonal antibodies for the human serum parvovirus-like virus (SPLV). Journal of Hygiene, 91, 113-130. 3. Lauer, B.A., MacCormack, J.N. & Wilfert, C. (1976). Erythema infectiosum: an elementary school outbreak. American Journal of the Disease of Children, 130, 252-254. 4. Best, J. M. & Banatvala, J.E. (1987). Rubella. In: Principles and Practice of Clinical Virology, Zuckerman, A. J., Banatvala, J. E. & Pattison, J. R. (eds). Chichester: Wiley Medical. 324 pp. 5. Anderson, M.J., Lewis, E., Kidd, I.M., Hall, S.M. & Cohen, B.J. (1984). An outbreak of Erythema Infectiosum associated with Human Parvovirus infection. Journal of Hygiene, 93, 8593. 6. Miller, E., Cradock-Watson, J. E. & Pollock, T. M. (1982). Consequences of confirmed maternal Rubella at successive stages of pregnancy. Lancet, ii, 781-784. 7. Morgan-Capner, P. (1983). The detection of Rubella-specific antibody. Public Health Laboratory Service Microbiology Digest, 1, 6-11. 8. Hall, S., Anderson, M., Caul, O., Cohen, B., Cradock-Watson, J., Kaye, P., Mortimer, P., Peto, T., Shirley, J. & Vurdien, J. (1987). The outcome of Human Parvovirus (B19) infection in pregnancy: a prospective study conference proceedings of the Joint Meeting of The European Society Against Virus Diseases and European Group for Rapid Viral Diagnosis. Davos. 9. Anderson, M.J. (1987). Human Parvoviruses. In: Principles and Pract&e of Clinical Virology. Zuckerman, A. J., Banatvala, J. E. & Pattison, J. R. (eds). Chichester: Wiley Medical. 516 pp.