CORRESPONDENCE
Poliomyelitis resurfaced: another view To the editor: We fully agree that there should be a vigorous drive towards complete poliomyelitis immunization of the Canadian population and that sewage studies provide useful information about the circulation of enteroviruses in a community, but we are perturbed by the concluding statement of the editorial by Dr. D.M. McLean, "Poliomyelitis resurfaced" (Can Med Assoc J 116: 7, 1977), that there is a "continuing circulation of paralytogenic strains of poliovirus in Canadian urban communities". We know of no published evidence supporting this statement. With respect to the National Capital Region, the evidence quoted is, at best, circumstantial. In an Ontario urban community with a population of 500 000, it can be calculated1 from the data of MacLeod and colleagues2 that there are more than 40000 susceptible individuals in whom all three types of poliovirus may replicate, while at least 1300 to 2000 of them already excrete the virus before it becomes detectable in the community sewage. If such a level of infection is being continuously maintained in a given population - taking into account a ratio of clinical poliomyelitis to inapparent poliovirus infection of 1:100 or more - one would reasonably expect, over a course of several years, that a) virulent polioviruses would be isolated from time to time in the normal course of laboratory examinations of patients and b) isolated clinical cases of poliomyelitis would occur. Neither of these expectations has been realized in the National Capital Region. The last case of poliomyelitis in the Ottawa-Carleton region occurred in 1962. Since then a very careful surveillance of all enteroviruses isolated Contributions to the Correspondence section are welcomed and if considered suitable will be published as space permits. They should be typewritten double spaced and, except for case reports, should not exceed 1½ pages in length.
from human sources in this community has continued. Over the period 1965 to 1976, 395 strains of echoviruses and coxsackieviruses were isolated in our laboratory from 5500 clinical specimens from adults and children. Ten vaccine-like strains were recovered from patients living in Quebec, where Sabin vaccination is routinely administered. Not a single strain of poliovirus, vaccine-like or wild, was isolated from Ontario residents over the same period of time.
poliovirus vaccination programs be pursued with renewed vigour throughout Canada in order to protect all inhabitants of this nation against infection following sporadic introduction of unpredictably large amounts of virulent poliovirus.
E. RossIER, MD, DIP BACT (LOND) P.H. PHIPPS, M Sc
To the editor: Dr. Helen Cvejic and her colleagues (Follow-up of 50 adolescent girls 2 years after abortion. Can Med Assoc J 116: 44, 1976) imply that because 'there were no severe ill effects among the 38 girls 2 years after abortion... abortion can be considered with less hesitancy". This statement was supported by the evidence that, of 38 girls, 26 described "therapeutic abortion" as being a positive experience. However, who wouldn't feel better when an unwanted responsibility and resultant anxiety have been removed? What about the experience of the 36 or more baby girls and boys that died so that these subjects could have a "positive experience"?
Regional virology laboratory Children's Hospital of Eastern Ontario Ottawa, Ont.
References 1. Statistics Canada: Census of Canada, 1971 2. MACLEOn DRE, ING WK, BELCOURT RJ-P,
et al: Antibody status to poliomyelitis, measles, rubella, diphtheria and tetanus, Ontario, 1969-70: deficiencies discovered and remedies required. Can Med Assoc 1 113: 619, 1975
To the editor: Although the calculations of Dr. Rossier and Mr. Phipps presuppose the continual excretion of similar infective titres of virulent polioviruses by a constant proportion of the poliomyelitis-susceptible population, the amount of poliovirus excreted during natural infections varies widely from case to case. Furthermore, they overlook the sporadic introduction of a substantial number of poliovirus excretors from overseas countries where poliovirus remains highly endemic. The National Capital Region is one of several regions in Canada where these introductions may occur relatively frequently. Dr. Rossier and Mr. Phipps have observed the virtual absence of virulent or attenuated strains of poliovirus from patients examined virologically by them during the past decade, but these patients represent a highly selected group. Personal experience with comparable groups of patients in Toronto and Vancouver has revealed that these subjects excrete polioviruses rarely. For these reasons it is strongly recommended that
836 CMA JOURNAL/APRIL 23, 1977/VOL. 116
D.M. MCLEAN, MD, FRCP[C] University of British Columbia Vancouver, BC
Abortion - a positive experience?
Indeed, who will speak for the dead children Who will mourn their passing Who will assess their reaction To the white-coat physicians! Sacrificing a life, to relieve anxiety Must be The epitome Of therapeutic medicine RALPH L. MATThEws Daihousie University Halifax, NS
To the editor: We agree wth Mr. Matthews that these are valid concerns to consider as part of the abortion experience; they are being expressed by physicians, theologians and patients. Nevertheless, we, with our limited ability and knowledge, considered it our
Poliomyelitis resurfaced: another view To the editor: We fully agree that there should be a vigorous drive towards complete poliomyelitis immunization of the Canadian population and that sewage studies provide useful information about the circulation of enteroviruses in a community, but we are perturbed by the concluding statement of the editorial by Dr. D.M. McLean, "Poliomyelitis resurfaced" (Can Med Assoc J 116: 7, 1977), that there is a "continuing circulation of paralytogenic strains of poliovirus in Canadian urban communities". We know of no published evidence supporting this statement. With respect to the National Capital Region, the evidence quoted is, at best, circumstantial. In an Ontario urban community with a population of 500 000, it can be calculated1 from the data of MacLeod and colleagues2 that there are more than 40000 susceptible individuals in whom all three types of poliovirus may replicate, while at least 1300 to 2000 of them already excrete the virus before it becomes detectable in the community sewage. If such a level of infection is being continuously maintained in a given population - taking into account a ratio of clinical poliomyelitis to inapparent poliovirus infection of 1:100 or more - one would reasonably expect, over a course of several years, that a) virulent polioviruses would be isolated from time to time in the normal course of laboratory examinations of patients and b) isolated clinical cases of poliomyelitis would occur. Neither of these expectations has been realized in the National Capital Region. The last case of poliomyelitis in the Ottawa-Carleton region occurred in 1962. Since then a very careful surveillance of all enteroviruses isolated Contributions to the Correspondence section are welcomed and if considered suitable will be published as space permits. They should be typewritten double spaced and, except for case reports, should not exceed 1½ pages in length.
from human sources in this community has continued. Over the period 1965 to 1976, 395 strains of echoviruses and coxsackieviruses were isolated in our laboratory from 5500 clinical specimens from adults and children. Ten vaccine-like strains were recovered from patients living in Quebec, where Sabin vaccination is routinely administered. Not a single strain of poliovirus, vaccine-like or wild, was isolated from Ontario residents over the same period of time.
poliovirus vaccination programs be pursued with renewed vigour throughout Canada in order to protect all inhabitants of this nation against infection following sporadic introduction of unpredictably large amounts of virulent poliovirus.
E. RossIER, MD, DIP BACT (LOND) P.H. PHIPPS, M Sc
To the editor: Dr. Helen Cvejic and her colleagues (Follow-up of 50 adolescent girls 2 years after abortion. Can Med Assoc J 116: 44, 1976) imply that because 'there were no severe ill effects among the 38 girls 2 years after abortion... abortion can be considered with less hesitancy". This statement was supported by the evidence that, of 38 girls, 26 described "therapeutic abortion" as being a positive experience. However, who wouldn't feel better when an unwanted responsibility and resultant anxiety have been removed? What about the experience of the 36 or more baby girls and boys that died so that these subjects could have a "positive experience"?
Regional virology laboratory Children's Hospital of Eastern Ontario Ottawa, Ont.
References 1. Statistics Canada: Census of Canada, 1971 2. MACLEOn DRE, ING WK, BELCOURT RJ-P,
et al: Antibody status to poliomyelitis, measles, rubella, diphtheria and tetanus, Ontario, 1969-70: deficiencies discovered and remedies required. Can Med Assoc 1 113: 619, 1975
To the editor: Although the calculations of Dr. Rossier and Mr. Phipps presuppose the continual excretion of similar infective titres of virulent polioviruses by a constant proportion of the poliomyelitis-susceptible population, the amount of poliovirus excreted during natural infections varies widely from case to case. Furthermore, they overlook the sporadic introduction of a substantial number of poliovirus excretors from overseas countries where poliovirus remains highly endemic. The National Capital Region is one of several regions in Canada where these introductions may occur relatively frequently. Dr. Rossier and Mr. Phipps have observed the virtual absence of virulent or attenuated strains of poliovirus from patients examined virologically by them during the past decade, but these patients represent a highly selected group. Personal experience with comparable groups of patients in Toronto and Vancouver has revealed that these subjects excrete polioviruses rarely. For these reasons it is strongly recommended that
836 CMA JOURNAL/APRIL 23, 1977/VOL. 116
D.M. MCLEAN, MD, FRCP[C] University of British Columbia Vancouver, BC
Abortion - a positive experience?
Indeed, who will speak for the dead children Who will mourn their passing Who will assess their reaction To the white-coat physicians! Sacrificing a life, to relieve anxiety Must be The epitome Of therapeutic medicine RALPH L. MATThEws Daihousie University Halifax, NS
To the editor: We agree wth Mr. Matthews that these are valid concerns to consider as part of the abortion experience; they are being expressed by physicians, theologians and patients. Nevertheless, we, with our limited ability and knowledge, considered it our
