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Bilharzia ova in cervical smears a possible additional route for the passage of ova into water
95 TRANSACTIONS OF THE ROYAL SOCIETY OF TROPICAL MEDICINE AND HYGIENE. Vol. 65. No. 1. 1971.
B I L H A R Z I A O V A IN CERVICAL S M E A R S A P O S S I B L E A D D I T I O N A L R O U T E F O R T H E P A S S A G E OF O V A INTO WATER D. W. S H E N N A N
Department of Histology, Harare Hospital, Salisbury AND MICHAEL GELFAND
University College of Rhodesia, Salisbury A t the end of 1968 it was noted that over the previous 18 months bilharzial ova had been found in a little over 2 % of all cervical smears. T h e occurrence of ova in 2-3% of smears in the postnatal clinic was almost double that from the o t h e r "well woman" clinic, the Family Planning Clinic at 1.3%. I t was decided to conduct a survey on 3 groups of patients from the Post-natal (PNC), Family Planning (FPC) and Gynaecological Out-patients (GOP) Clinics in order to determine whether a difference did in fact exist, and if so, wherein it lay. T h e following is a report on the first 5 months of the survey.
Method I n all three clinics a duckbill speculum was inserted to give clear view of the cervix, and a smear was taken through this from the squamo-columnar junction with a round-ended wooden spatula. No lubricants were used, and care was taken to avoid the possibility of contamination of the cervix by urinary bilharzial ova during the examination. T h e smears were screened routinely, and all smears from these clinics were charted under the subheadings: Source; age; stage of menstrual cycle; depth of epithelium (as judged from the type of cells found in the smear); parity; habitat; and presence or absence of Trichomonas. T h e numbers of ova and miracidia in positive smears were counted, and the viability or otherwise of ova was noted. Specimens of urine from as many of these patients as possible were also examined for ova and the results were correlated.
Results Over the 5 months 1,901 smears were examined. 44 were found to contain bilharzial ova and miracidia, ova being present in 40 and miracidia in 17. I n most slides terminalspined ova were identifiable as the infecting agent. S. mansoni was present in one, together with S. haematobium. I n 4 cases miracidia only were present. Ova 'were seen as viable and calcified forms and as empty shells. Viable ova were considered to be those in which the nuclei of the miracidium were clearly defined and showed no signs o f degeneration. T h e n u m b e r of ova found per positive smear ranged from 1 to over 200, with an average of 18.7. T h e patients' ages ranged from 16 to 41, average 25 years, with parities from 0 to 9, average 3"2. We acknowledge our indebtedness to the clinics concerned for providing data, and tO Miss S. Johnston and Mrs. D. Power for invaluable assistance in ecrrelating results. We also thank Dr. M. H. Webster, Secretary for Health for Rhodesia, for permission to publish this article.
96
B I L H A R Z I A OVA I N CERVICAL SMEARS
Urine results were available in 17 cases with positive smears, and in 6 of these the urine was negative. 3 patients had viable ova in the smear with a negative urine. Source The numbers and percentages of slides examined from each source were as follows: TABLE I. Source of slides Source Clinic
Number examined
Number positive
% Positive
Family planning
727
14
1.9
Gynaecological out-patients
292
6
2.0
Post-natal
882
24
2.7
1901
44
Totals
Patients were seen 6-8 weeks after childbirth in the Post-Natal Clinic, and it is interesting to note that 2 of the positive cases from the Family Planning Clinics were also 2 months post natal. Age We thought that the apparent higher occurrence in the Post Natal Clinic might be due to the fact that these women tend to be younger than Family Planning patients. Table I I gives a breakdown by ages, which shows that although there was little difference in the lower age groups, the groups between 25 and 40 still showed a higher occurrence rate in the Post Natal Clinic. This suggests a further cause in addition to the age difference. TABLE I I . Age groups f r o m each clinic giving total n u m b e r examined and n u m b e r of positive in each group in cervical smears
Group
U n d e r 20
20-24
25-29
30-34
35-39
26
182
225
161
83
2
6
1
3
4
34
70
56
3
1
403-
Age unknown
29
21
727
2
14
43
36
292
1
1
6
14
31
882
Total
FP Examined Positive
--
GOP Examined Positive
49
PNC Examined Positive Total Examined
161
303
200
112
61
6
8
3
5
2
24
--
191
519'
495
329
193
86
88
1901
Positive
8
14
7
9
2
1
3
44
Percentages
4.2
1"4
2"1
1.0
1.1
2"7
The percentage of the totals show," as expected, a falling off with increasing age from 4.2% under 20 years to 1.1% over 35.
97
D. W. SHENNAN AND MICHAEL GELFAND
Stage o f menstrual cycle This is charted only with respect to Family Planning patients, the only women in whom dates of last menstrual period were available. 3 of the 14 positive subjects were post-natal, and no date of last menstrual period was given for 2 others. Of the remainder, 6 of 9 were within the first 7 days of the cycle (Table III). TABLE I I I . Smears found at different stages of the menstrual c rcle
Number examined
Menstrual (1-4 days)
Postmenstrual (5-7 days)
Proliferative
Ovulatory (12-14 days)
Secretory (15-24 days)
Premenstrual (25-28 days)
Overdue (28 days plus)
75
89
87
66
151
48
58
Number examined
]
2
I
Depth of epithelium Most smears showed an intermediate epithelium, and ova were found in all depths of epithelium. There appeared to be no tendency towards increased shedding of ova from an atrophic epithelium. Parity Bilharzia of the upper genital tract has been associated by some workers with subfertility (CHARLEWOODet al., 1949; YOUSSEF and ABDINE, 1958), but in this series cervical bilharziasis appears to have had no effect on fertility (BOULE and NOTELWlTZ, 1964). One nulliparous patient presented at Gynaecological Out-patients' Department with a complaint of infertility--a common complaint in this department and not necessarily associated with bilharzia; 28 patients had parities ranging from 2 to 9 and only one single-para subject was over 21 years. Habitat did not appear to affect the rate of bilharziasis. Associated smear constituents Trichomonas was found in about a quarter of all women examined, and in association with bilharzia in 18 of 44. In this series bilharzia was never found in association with dyskaryosis or malignancy. Although YOUSErF et al. (1962) suggest a specific cytological picture of epithelial drying and infection in their vaginal series, no such specific picture was found here--possibly because the cervix is not as prone to drying as the vagina, and because non:specific infective changes are common in our patients. Correlation with urine results 641 urines were examined: TABLE IV. Source of urines examined
Total
Family Planning
Gynaecological Out-Patients
P6st-Natal
Number examined
641
95
65
481
Number positive
100
8
5
87
8'2
7-7
18"1
% Positive
15-6
98
BILHARZIA OVA IN CERVICAL SMEARS
These results were subdivided by age, and also by habitat, and percentage of positives of post-natal women in each subgroup was compared with that of the total. It was found that in each subgroup by age, except that under 20, and in every subgroup by habitat, the percentage of positives of post-natal women was highcr than that of the total number. Comment In a region where urinary bilharziasis is endemic, terminal-spincd ova arc commonly discharged through the cervical epithelium, being found in about 2~o of all our cervical smears. It is not known whether the factors governing this excretion are similar to those affecting excretion of ova through the bladder. The presence of viable ova and miracidia was demonstrated in smears, as has been previously shown by other workers (BERRY, 1966; BOULEand NOTELWITZ,1964; YOUSSEF and ABDINE, 1958). This raises the possibility that water may be contaminated in this way when infected women bathe in streams. Until now it has been our impression that the only important methods of transmission were through urine and faeces, but though the number of ova excreted through the cervix is small in comparison with other routes, the efficacy of this route is probably increased by the fact that the ova are deposited directly in a favourable environment and frequently near to the intermediate hosts. It has yet to be shown, however, how important this minor method of transmission may be. Contamination of water by urine remains the main method of transmission, though it seems possible that on rare occasions ova may be passed via the cervix while not being simultaneously passed via the bladder. We compared 3 groups of women for the presence of bilharziasis in cervical smears. The results suggest that the post-natal group includes on average younger women who normally have a higher rate of bilharziasis. But even in the older women most cases were found to occur among post-natal patients. The urine results similarly showed a higi~er rate of positives among post-natal patients in all age groups except under the age of 20. A possible explanation is the increase in vascularity in all pelvic organs associated with pregnancy, encouraging the migration of worms to these areas and facilitating the excretion of ova. Further study along these lines is needed. S. mansoni rarely occurs in cervical smears. Although considerably less common than S. haematobium in the genital tract, it has been shown by Gelfand to occur in the uterus, cervix and vagina. 3 further smears containing S. mansoni have been screened since the period covered by this study. One contained S. mansoni only, the other 2 contained both S. mansoni and S. haematobium. A further point worthy of mention is that 6 of 9 positives among Family Planning patients were found within the first week of the cycle. The work of VOGELand MINNING (1953) suggests that in monkeys, eggs arc secreted 2-3 weeks after being laid, and it is interesting to speculate whether the same applied to man, and if so, whether the worm is sensitive to the host's hormones, tending to ovulate at the samc time as the host. CLARK (1966) showed, in a very extensive series, that though peak of egg production in heavily infected areas occurs between 7 and 12 years of age, there is a second minor peak between 13 and 20. The above speculation, hardly to be dignified as a "theory" on the strength of 9 cases, offers a temptingly neat explanation of this minor peak, and also of the higher apparent incidence in women. It can be accepted from clinical and pathological studies that at timcs the cervix is the site of granulomatous reaction so severe as to rcsemble carcinoma, and discovery of ova in the tissue is an important finding in such cases becausc effective treatment is available. Thus exfoliative cytology in Rhodesia has the additional advantage of not only
D. W. SHENNAN AND MICHAEL GELFAND
99
uncovering unsuspected disease, but also offers an easy test to differentiate between bilharzial granuloma and carcinoma of the cervix. Occasionally the two coincide, but there appears to be no convincing evidence to show that they are connected.
Summary 1,901 slides from 3 clinics were examined for bilharzial ova and miracidia and 44 were found to be positive. The percentage of positives was higher in the Post-Natal group than in Family Planning or Gynaecological Out-Patients groups. This difference may be partly because of increased vascularity associated with pregnancy. The presence of viable ova as well as miracidia in some of the cases was demonstrated and their importance as a further possible mode of transmission of the disease is emphasized. This applies to both S. haematobium and S. mansoni. Some variation in the degree of excretion of ova, depending on the stage of the menstrual cycle, was noted in a small number of cases on which data on the menstrual cycle were available. Further work is being carried out on this point. REFERENCES BERRY, A. (1966). J. Path. Bact., 91, 325. BOULE, P. & NOTELWITZ,M. (1964). S. Afr. ~. Obstet. Gynaec., 2, 48. CHARLEWOOD,G. P., SHIPPEL, S. & RENTON, H. (1949). J. Obstet. Gynaec. Br. Commonw., 56, 367. CLARKE, V. DE V. (1966). Cent. Afr. J. Med., 12, 6. Supplement. GELFAND, M. (1950). Schistosomiasis. Cape Town: Jura. VOGEL, H. & MINNING, W. (1953). Z. Tropenmed. Parasit., 4, 418. YOUSEFF, A. F. & ABDINE, (1958). ~. Obstet. Gynaec. Br. Commonw., 65, 991. ----, FAYED, M. M. & SH~FEEK, M. A. (1962). Am. J. Obstet. Gynec., 83, 710.
B I L H A R Z I A O V A IN CERVICAL S M E A R S A P O S S I B L E A D D I T I O N A L R O U T E F O R T H E P A S S A G E OF O V A INTO WATER D. W. S H E N N A N
Department of Histology, Harare Hospital, Salisbury AND MICHAEL GELFAND
University College of Rhodesia, Salisbury A t the end of 1968 it was noted that over the previous 18 months bilharzial ova had been found in a little over 2 % of all cervical smears. T h e occurrence of ova in 2-3% of smears in the postnatal clinic was almost double that from the o t h e r "well woman" clinic, the Family Planning Clinic at 1.3%. I t was decided to conduct a survey on 3 groups of patients from the Post-natal (PNC), Family Planning (FPC) and Gynaecological Out-patients (GOP) Clinics in order to determine whether a difference did in fact exist, and if so, wherein it lay. T h e following is a report on the first 5 months of the survey.
Method I n all three clinics a duckbill speculum was inserted to give clear view of the cervix, and a smear was taken through this from the squamo-columnar junction with a round-ended wooden spatula. No lubricants were used, and care was taken to avoid the possibility of contamination of the cervix by urinary bilharzial ova during the examination. T h e smears were screened routinely, and all smears from these clinics were charted under the subheadings: Source; age; stage of menstrual cycle; depth of epithelium (as judged from the type of cells found in the smear); parity; habitat; and presence or absence of Trichomonas. T h e numbers of ova and miracidia in positive smears were counted, and the viability or otherwise of ova was noted. Specimens of urine from as many of these patients as possible were also examined for ova and the results were correlated.
Results Over the 5 months 1,901 smears were examined. 44 were found to contain bilharzial ova and miracidia, ova being present in 40 and miracidia in 17. I n most slides terminalspined ova were identifiable as the infecting agent. S. mansoni was present in one, together with S. haematobium. I n 4 cases miracidia only were present. Ova 'were seen as viable and calcified forms and as empty shells. Viable ova were considered to be those in which the nuclei of the miracidium were clearly defined and showed no signs o f degeneration. T h e n u m b e r of ova found per positive smear ranged from 1 to over 200, with an average of 18.7. T h e patients' ages ranged from 16 to 41, average 25 years, with parities from 0 to 9, average 3"2. We acknowledge our indebtedness to the clinics concerned for providing data, and tO Miss S. Johnston and Mrs. D. Power for invaluable assistance in ecrrelating results. We also thank Dr. M. H. Webster, Secretary for Health for Rhodesia, for permission to publish this article.
96
B I L H A R Z I A OVA I N CERVICAL SMEARS
Urine results were available in 17 cases with positive smears, and in 6 of these the urine was negative. 3 patients had viable ova in the smear with a negative urine. Source The numbers and percentages of slides examined from each source were as follows: TABLE I. Source of slides Source Clinic
Number examined
Number positive
% Positive
Family planning
727
14
1.9
Gynaecological out-patients
292
6
2.0
Post-natal
882
24
2.7
1901
44
Totals
Patients were seen 6-8 weeks after childbirth in the Post-Natal Clinic, and it is interesting to note that 2 of the positive cases from the Family Planning Clinics were also 2 months post natal. Age We thought that the apparent higher occurrence in the Post Natal Clinic might be due to the fact that these women tend to be younger than Family Planning patients. Table I I gives a breakdown by ages, which shows that although there was little difference in the lower age groups, the groups between 25 and 40 still showed a higher occurrence rate in the Post Natal Clinic. This suggests a further cause in addition to the age difference. TABLE I I . Age groups f r o m each clinic giving total n u m b e r examined and n u m b e r of positive in each group in cervical smears
Group
U n d e r 20
20-24
25-29
30-34
35-39
26
182
225
161
83
2
6
1
3
4
34
70
56
3
1
403-
Age unknown
29
21
727
2
14
43
36
292
1
1
6
14
31
882
Total
FP Examined Positive
--
GOP Examined Positive
49
PNC Examined Positive Total Examined
161
303
200
112
61
6
8
3
5
2
24
--
191
519'
495
329
193
86
88
1901
Positive
8
14
7
9
2
1
3
44
Percentages
4.2
1"4
2"1
1.0
1.1
2"7
The percentage of the totals show," as expected, a falling off with increasing age from 4.2% under 20 years to 1.1% over 35.
97
D. W. SHENNAN AND MICHAEL GELFAND
Stage o f menstrual cycle This is charted only with respect to Family Planning patients, the only women in whom dates of last menstrual period were available. 3 of the 14 positive subjects were post-natal, and no date of last menstrual period was given for 2 others. Of the remainder, 6 of 9 were within the first 7 days of the cycle (Table III). TABLE I I I . Smears found at different stages of the menstrual c rcle
Number examined
Menstrual (1-4 days)
Postmenstrual (5-7 days)
Proliferative
Ovulatory (12-14 days)
Secretory (15-24 days)
Premenstrual (25-28 days)
Overdue (28 days plus)
75
89
87
66
151
48
58
Number examined
]
2
I
Depth of epithelium Most smears showed an intermediate epithelium, and ova were found in all depths of epithelium. There appeared to be no tendency towards increased shedding of ova from an atrophic epithelium. Parity Bilharzia of the upper genital tract has been associated by some workers with subfertility (CHARLEWOODet al., 1949; YOUSSEF and ABDINE, 1958), but in this series cervical bilharziasis appears to have had no effect on fertility (BOULE and NOTELWlTZ, 1964). One nulliparous patient presented at Gynaecological Out-patients' Department with a complaint of infertility--a common complaint in this department and not necessarily associated with bilharzia; 28 patients had parities ranging from 2 to 9 and only one single-para subject was over 21 years. Habitat did not appear to affect the rate of bilharziasis. Associated smear constituents Trichomonas was found in about a quarter of all women examined, and in association with bilharzia in 18 of 44. In this series bilharzia was never found in association with dyskaryosis or malignancy. Although YOUSErF et al. (1962) suggest a specific cytological picture of epithelial drying and infection in their vaginal series, no such specific picture was found here--possibly because the cervix is not as prone to drying as the vagina, and because non:specific infective changes are common in our patients. Correlation with urine results 641 urines were examined: TABLE IV. Source of urines examined
Total
Family Planning
Gynaecological Out-Patients
P6st-Natal
Number examined
641
95
65
481
Number positive
100
8
5
87
8'2
7-7
18"1
% Positive
15-6
98
BILHARZIA OVA IN CERVICAL SMEARS
These results were subdivided by age, and also by habitat, and percentage of positives of post-natal women in each subgroup was compared with that of the total. It was found that in each subgroup by age, except that under 20, and in every subgroup by habitat, the percentage of positives of post-natal women was highcr than that of the total number. Comment In a region where urinary bilharziasis is endemic, terminal-spincd ova arc commonly discharged through the cervical epithelium, being found in about 2~o of all our cervical smears. It is not known whether the factors governing this excretion are similar to those affecting excretion of ova through the bladder. The presence of viable ova and miracidia was demonstrated in smears, as has been previously shown by other workers (BERRY, 1966; BOULEand NOTELWITZ,1964; YOUSSEF and ABDINE, 1958). This raises the possibility that water may be contaminated in this way when infected women bathe in streams. Until now it has been our impression that the only important methods of transmission were through urine and faeces, but though the number of ova excreted through the cervix is small in comparison with other routes, the efficacy of this route is probably increased by the fact that the ova are deposited directly in a favourable environment and frequently near to the intermediate hosts. It has yet to be shown, however, how important this minor method of transmission may be. Contamination of water by urine remains the main method of transmission, though it seems possible that on rare occasions ova may be passed via the cervix while not being simultaneously passed via the bladder. We compared 3 groups of women for the presence of bilharziasis in cervical smears. The results suggest that the post-natal group includes on average younger women who normally have a higher rate of bilharziasis. But even in the older women most cases were found to occur among post-natal patients. The urine results similarly showed a higi~er rate of positives among post-natal patients in all age groups except under the age of 20. A possible explanation is the increase in vascularity in all pelvic organs associated with pregnancy, encouraging the migration of worms to these areas and facilitating the excretion of ova. Further study along these lines is needed. S. mansoni rarely occurs in cervical smears. Although considerably less common than S. haematobium in the genital tract, it has been shown by Gelfand to occur in the uterus, cervix and vagina. 3 further smears containing S. mansoni have been screened since the period covered by this study. One contained S. mansoni only, the other 2 contained both S. mansoni and S. haematobium. A further point worthy of mention is that 6 of 9 positives among Family Planning patients were found within the first week of the cycle. The work of VOGELand MINNING (1953) suggests that in monkeys, eggs arc secreted 2-3 weeks after being laid, and it is interesting to speculate whether the same applied to man, and if so, whether the worm is sensitive to the host's hormones, tending to ovulate at the samc time as the host. CLARK (1966) showed, in a very extensive series, that though peak of egg production in heavily infected areas occurs between 7 and 12 years of age, there is a second minor peak between 13 and 20. The above speculation, hardly to be dignified as a "theory" on the strength of 9 cases, offers a temptingly neat explanation of this minor peak, and also of the higher apparent incidence in women. It can be accepted from clinical and pathological studies that at timcs the cervix is the site of granulomatous reaction so severe as to rcsemble carcinoma, and discovery of ova in the tissue is an important finding in such cases becausc effective treatment is available. Thus exfoliative cytology in Rhodesia has the additional advantage of not only
D. W. SHENNAN AND MICHAEL GELFAND
99
uncovering unsuspected disease, but also offers an easy test to differentiate between bilharzial granuloma and carcinoma of the cervix. Occasionally the two coincide, but there appears to be no convincing evidence to show that they are connected.
Summary 1,901 slides from 3 clinics were examined for bilharzial ova and miracidia and 44 were found to be positive. The percentage of positives was higher in the Post-Natal group than in Family Planning or Gynaecological Out-Patients groups. This difference may be partly because of increased vascularity associated with pregnancy. The presence of viable ova as well as miracidia in some of the cases was demonstrated and their importance as a further possible mode of transmission of the disease is emphasized. This applies to both S. haematobium and S. mansoni. Some variation in the degree of excretion of ova, depending on the stage of the menstrual cycle, was noted in a small number of cases on which data on the menstrual cycle were available. Further work is being carried out on this point. REFERENCES BERRY, A. (1966). J. Path. Bact., 91, 325. BOULE, P. & NOTELWITZ,M. (1964). S. Afr. ~. Obstet. Gynaec., 2, 48. CHARLEWOOD,G. P., SHIPPEL, S. & RENTON, H. (1949). J. Obstet. Gynaec. Br. Commonw., 56, 367. CLARKE, V. DE V. (1966). Cent. Afr. J. Med., 12, 6. Supplement. GELFAND, M. (1950). Schistosomiasis. Cape Town: Jura. VOGEL, H. & MINNING, W. (1953). Z. Tropenmed. Parasit., 4, 418. YOUSEFF, A. F. & ABDINE, (1958). ~. Obstet. Gynaec. Br. Commonw., 65, 991. ----, FAYED, M. M. & SH~FEEK, M. A. (1962). Am. J. Obstet. Gynec., 83, 710.