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EYE HOSPITAL EYE
1308 EYE HOSPITAL EYE
SIR,—We read your Nov 5 editorial with special interest because have recently experienced a large hospital outbreak of epidemic keratoconjunctivitis due to adenovirus type 8 which illustrates many of the points you emphasise. In one respect, however, our experience differed. Whereas you state that "the virus seldom spreads to family members" we found domestic transmission was frequent and serious. Of 161 virologically proven cases where an epidemiological history was available, 26 (16%) resulted from transmission within the family. This figure underestimates the true extent of domestic transmission since by no means all the secondary cases attended the eye hospital and so were not investigated virologically. Transmission to spouses, children, and grandchildren was recorded, and transmission was not restricted just to those relatives who helped to put drops into an infected person’s eyes. It is very important for every patient with possible adenovirus keratoconjunctivitis to be warned by the examining ophthalmologist, as early in the infection as possible, of the possibility of family spread. Patients should be told how the virus may spread from eye to eye in ocular secretions and advise on we
daughters, which attach to aerosol particles in indoor air,such as cigarette smoke, and radon daughter exposure is a well-established risk factor for lung cancer among miners.6In support of this view, we wish to present some preliminary studies of indoor radon daughter concentrations as influenced by cigarette smoke. The accompanying figure shows the build-up of radon daughters in a room after the mechanical ventilation has been turned off and the additional concentrations obtained by burning cigarettes. Radon daughter concentrations seem to almost double. The instrument we used was a WLM-300 (EDA Instruments, Canada) and twelve cigarettes were passively burned in a room of 24 m3, with no-one
present.
hygienic measures such as the use of separate towels and pillowslips, use and careful disposal of paper tissues rather than handkerchiefs, and the need for thorough handwashing after the the
infected eye has been touched. Whilst control of an epidemic depends, as you emphasised, on preventing the spread of virus within the eye hospital, effort should also be directed towards avoiding transmission at home. However, despite medical advice to an individual about hygienic measures, transmission may still occur within the family, because of the infectivity of the virus under conditions of close domestic contact. North Manchester
Regional Laboratory, Booth Hall Hospital,
Virus
SHIRLEY RICHMOND CHRISTOPHER L. DODD
Manchester M9 2AA Manchester
Royal Eye Hospital
SIR,—Your editorial correctly indicates the dominant importance of hospitals and ambulance rooms in the spread of eye infections and the value of thorough washing with soap and water for preventing spread. Without decrying the value of hypochlorite and chloramine T, it is worth emphasising that the simple measure of thorough washing of hands and instruments with soap and running water can arrest hospital outbreaks. Transmission within the home and in other non-hospital, non-industrial settings can also occur when hygiene is inadequate. Several examples of this were seen during epidemics of keratoconjunctivitis on Clydeside, with a secondary attack rate of 2% in family contacts surveyed during the 1971-72 outbreak.2 Department of Infectious Diseases, Communicable Diseases (Scotland) Unit, and Regional Virus Laboratory, Ruchill Hospital, Glasgow G20 9NB
NORMAN R. GRIST DANIEL REID ELEANOR J. BELL
PASSIVE SMOKING AND INDOOR RADON DAUGHTER CONCENTRATIONS
SIR,—Professor Correa and colleagues (Sept 10, p 595) have provided further evidence that passive smoking is a risk factor for lung cancer, but even more interesting was the association of lung cancer and maternal smoking only among smokers. Observations about passive smoking should be considered against a background of naturally occurring radioactivity in dwellings-ie, radon emanating into houses from the ground and from building materials.3,4 The decay of radon results in a-emitting radon 1
Wegman DH, Guinee VF, Millian SJ. Epidemic keratoconjunctivitis. Am J Publ Hlth
1970; 60: 1230-37. 2. Reid D, Bell EJ, Grist NR, Taylor JC, Ellis JR Epidemic keratoconjunctivitis West of Scotland, 1967-72. J Hyg Camb 1974; 73: 157-63. 3 Cliff KD Assessment of airborne radon
the
daughter concentrations in dwellings in Great
Britain. Phys Med Biol 1978; 23: 696-711. 4. Stranden E, Berteig L, Ugletveit F. A study on radon 36: 413-21.
in
in
dwellings. Health Phys 1979;
Mean and upper and lower curves for radon daughter concentrations in four experiments with ( - - - - ) and three experiments without (-) cigarette smoke.
Mechanical ventilation started again at the end.
was
turned off at the
beginning of experiment and
Stirring the air tends to cause the radon daughters to attach to walls and furniture and aerosols provide additional surfaces for attachment-ie, there could be even greater differences in radon daughter concentrations in the absence and the presence of cigarette smoke under normal home conditions, when people move around causing some circulation of the air. Although we turned off the ventilation to increase the background of radon daughters and to facilitate the measurements, the concentrations found are by no means remarkable; the Swedish standard permits up to 400 Bq/m3 EER (equilibrium equivalent radon), and thousands of homes have even
7
higher concentrations.
A comparison of the attachment of the decay products of radon-220 and radon-222 to monodispersed aerosols. J Aerosol Sci 1979; 10: 571-79 6. Committee on the Biological Effects of Ionizing Radiations. The effects on populations of exposure to low levels of ionizing radiation (BEIR III). Washington, DC: National Academy of Sciences, 1980. 7 Akerblom G, Wilson C. Radon: geological aspects of an environmental problem. Uppsala: Geological Survey of Sweden, 1982. report 30. 5.
Kruger J, Nöthling JF.
SIR,—We read your Nov 5 editorial with special interest because have recently experienced a large hospital outbreak of epidemic keratoconjunctivitis due to adenovirus type 8 which illustrates many of the points you emphasise. In one respect, however, our experience differed. Whereas you state that "the virus seldom spreads to family members" we found domestic transmission was frequent and serious. Of 161 virologically proven cases where an epidemiological history was available, 26 (16%) resulted from transmission within the family. This figure underestimates the true extent of domestic transmission since by no means all the secondary cases attended the eye hospital and so were not investigated virologically. Transmission to spouses, children, and grandchildren was recorded, and transmission was not restricted just to those relatives who helped to put drops into an infected person’s eyes. It is very important for every patient with possible adenovirus keratoconjunctivitis to be warned by the examining ophthalmologist, as early in the infection as possible, of the possibility of family spread. Patients should be told how the virus may spread from eye to eye in ocular secretions and advise on we
daughters, which attach to aerosol particles in indoor air,such as cigarette smoke, and radon daughter exposure is a well-established risk factor for lung cancer among miners.6In support of this view, we wish to present some preliminary studies of indoor radon daughter concentrations as influenced by cigarette smoke. The accompanying figure shows the build-up of radon daughters in a room after the mechanical ventilation has been turned off and the additional concentrations obtained by burning cigarettes. Radon daughter concentrations seem to almost double. The instrument we used was a WLM-300 (EDA Instruments, Canada) and twelve cigarettes were passively burned in a room of 24 m3, with no-one
present.
hygienic measures such as the use of separate towels and pillowslips, use and careful disposal of paper tissues rather than handkerchiefs, and the need for thorough handwashing after the the
infected eye has been touched. Whilst control of an epidemic depends, as you emphasised, on preventing the spread of virus within the eye hospital, effort should also be directed towards avoiding transmission at home. However, despite medical advice to an individual about hygienic measures, transmission may still occur within the family, because of the infectivity of the virus under conditions of close domestic contact. North Manchester
Regional Laboratory, Booth Hall Hospital,
Virus
SHIRLEY RICHMOND CHRISTOPHER L. DODD
Manchester M9 2AA Manchester
Royal Eye Hospital
SIR,—Your editorial correctly indicates the dominant importance of hospitals and ambulance rooms in the spread of eye infections and the value of thorough washing with soap and water for preventing spread. Without decrying the value of hypochlorite and chloramine T, it is worth emphasising that the simple measure of thorough washing of hands and instruments with soap and running water can arrest hospital outbreaks. Transmission within the home and in other non-hospital, non-industrial settings can also occur when hygiene is inadequate. Several examples of this were seen during epidemics of keratoconjunctivitis on Clydeside, with a secondary attack rate of 2% in family contacts surveyed during the 1971-72 outbreak.2 Department of Infectious Diseases, Communicable Diseases (Scotland) Unit, and Regional Virus Laboratory, Ruchill Hospital, Glasgow G20 9NB
NORMAN R. GRIST DANIEL REID ELEANOR J. BELL
PASSIVE SMOKING AND INDOOR RADON DAUGHTER CONCENTRATIONS
SIR,—Professor Correa and colleagues (Sept 10, p 595) have provided further evidence that passive smoking is a risk factor for lung cancer, but even more interesting was the association of lung cancer and maternal smoking only among smokers. Observations about passive smoking should be considered against a background of naturally occurring radioactivity in dwellings-ie, radon emanating into houses from the ground and from building materials.3,4 The decay of radon results in a-emitting radon 1
Wegman DH, Guinee VF, Millian SJ. Epidemic keratoconjunctivitis. Am J Publ Hlth
1970; 60: 1230-37. 2. Reid D, Bell EJ, Grist NR, Taylor JC, Ellis JR Epidemic keratoconjunctivitis West of Scotland, 1967-72. J Hyg Camb 1974; 73: 157-63. 3 Cliff KD Assessment of airborne radon
the
daughter concentrations in dwellings in Great
Britain. Phys Med Biol 1978; 23: 696-711. 4. Stranden E, Berteig L, Ugletveit F. A study on radon 36: 413-21.
in
in
dwellings. Health Phys 1979;
Mean and upper and lower curves for radon daughter concentrations in four experiments with ( - - - - ) and three experiments without (-) cigarette smoke.
Mechanical ventilation started again at the end.
was
turned off at the
beginning of experiment and
Stirring the air tends to cause the radon daughters to attach to walls and furniture and aerosols provide additional surfaces for attachment-ie, there could be even greater differences in radon daughter concentrations in the absence and the presence of cigarette smoke under normal home conditions, when people move around causing some circulation of the air. Although we turned off the ventilation to increase the background of radon daughters and to facilitate the measurements, the concentrations found are by no means remarkable; the Swedish standard permits up to 400 Bq/m3 EER (equilibrium equivalent radon), and thousands of homes have even
7
higher concentrations.
A comparison of the attachment of the decay products of radon-220 and radon-222 to monodispersed aerosols. J Aerosol Sci 1979; 10: 571-79 6. Committee on the Biological Effects of Ionizing Radiations. The effects on populations of exposure to low levels of ionizing radiation (BEIR III). Washington, DC: National Academy of Sciences, 1980. 7 Akerblom G, Wilson C. Radon: geological aspects of an environmental problem. Uppsala: Geological Survey of Sweden, 1982. report 30. 5.
Kruger J, Nöthling JF.