- Email: [email protected]
The significance of cholera outbreak in the prognosis of pregnancy
ht. J, Gynaecol. Obstet., 1981,19:
403-407 0 International Federation of Gynaecology & Obstetrics
THE SIGNIFICANCE OF CHOLERA OUTBREAK IN THE PROGNOSIS OF PREGNANCY OKUN AYANGADE
Department of Obstetrics, Gynecology and Perinatology, Universityof Ife, Ile-Ife, Niger& (Received December 29th, 1981) (Accepted April llth, 1981)
Abstract Ayangade 0 (Dept of Obstetrics, Gynecology and Perinatology, University of Ife, IEe-Ife, Nigeria). The significance of cholera outbreak in the prognosis of pregnancy, Int J Gynaecol Obstet 19: 403-407, 1981 Five hundred sixty-one persons were treated in a comprehensive cholera unit during the 1979-1980 cholera outbreak at Ne-Ife. Sixty-one pregnant cholera patients were identified and followed up. Compared to the general female population, all female cholera patients in the 15-29 year age group show significantly more resistance to the disease than those aged 30 years and above. The pregnant cases, as well as all reproductiveyears age groups, showed significantly less mortality than both the non-pregnant patients and those at both extremes of age. Our findings show that pregnancy does not render the woman more susceptible and may, in fact, render her less susceptible after the first trimester, when prognosis brightens for both the mother and the fetus.
Key words: Pregnant cholera patients; Vibrio infections; Gastroenteritis vomiting; Profuse diarrhea; El Tor Vibrio chol-
cholerae erae
Introduction
Cholera as a life-threatening sporadic entity is an important cause of death in most parts of the world. In its untreated form not only
does it kill in large numbers, it does so with great rapidity. Outbreaks occur with near predictable regularity, particularly in areas where inadequate sanitation and inadequate distribution of purified water supply are prevalent. In Nigeria, sporadic outbreaks occur chiefly during the dry season [9], when a shortage of purified drinking water hits most communities. Characteristically, the outbreak starts in December, peaks in January and declines in February. The prognosis for the cholera-infected pregnant woman and her fetus is still a subject requiring more extensive study. Early workers claim cholera infection is aggravated by pregnancy resulting in heavy maternal and fetal losses. Pollitzer [ 101, in a classic work, remarks that cholera occurrence in pregnancy is fraught with particular danger. However, the degree of incapacity is likely to be determined by the stage of pregnancy and the promptness and specificity of the therapy instituted. The object of this prospective study is to analyze one cholera outbreak in the cholera unit of the University of Ife Teaching Hospital, Ile-Ife, Nigeria, that served as the only 24-h surveillance and treatment unit during the 1979- 1980 cholera outbreak. Our system of comprehensive case finding and referral determined the total number of victims, the number of pregnant females affected, their stage of pregnancy, and the outcome of the pregnancies, including both fetal and maternal losses. In contrast to previous studies chiefly based on hospital admissions, our system removes bias, thus Int J Gynaecol Obstet 19
404
Ayangade
enabling us to confirm if, in fact, pregnancy enhances susceptibility to Vibtio cholerae infections. Materials and methods The Ife Teaching Hospital, which serves a total population of about 350,000, during the last outbreak located the treatment unit for cholera patients on the grounds of its tertiary hospital - the Ife General Hospital. This was to afford the treatment team easy access to all life-support and diagnostic facilities. In addition to being the only hospital authority during the outbreak, it served as the sole agent for the provision of free medical care to cholera patients for the Oyo State Government. Between December 1979 and February 1980, 561 admissions were made with the clinical diagnosis of cholera infection. The diagnosis was based on acute onset of gastroenteritis vomiting and profuse diarrhea accompanied by prostration or shock. The diagnosis was strengthened by the awareness that many of the cholera patients shared the same drinking or sewage disposal system. All cases were treated with conventional fluids and regimens involving parenteral tetracycline. The excrements were disinfected and disposed of by the nursing staff who had been previously immunized. At the initial stages of the disease and prior to the institution of treatment, rectal or fecal swabs were taken for definitive identification of the pathogen. Vibrio cholerae, El Tor bio-type, was isolated in most of the cases cultured. Although no difference in susceptibility for males and females has been proven 141, cholera, like other infections, imposes an additional risk on pregnancy and the fetus. As such, infected females were separately identified and studied in detail. A team of health workers conducted a health education session aimed at limiting the spread of the cholera outbreak. Female patients and/or relatives were interviewed to obtain data on parity and pregnancy age, occupation, status. The subsequent health of the infected Int J Gynaecol Obstet 19
women was ascertained by home visits at periodic intervals to determine and conduct follow-up on those who were pregnant at the time of the attack. Follow-up was completed in 88% of admitted cases. All index patients were followed throughout pregnancy and delivery to study the outcome of the pregnancy. Results Five hundred sixty-one clinically diagnosed cases of cholera during the 1979-1980 outbreak were recorded; of these, 270 female cases were studied and followed for a maximum of 7 months. The outbreak lasted a total of 12 weeks. Random cases picked for showed the bacteriologic identification isolation of El Tor Vi’ibrio cholerae in 90% of cases. Table I shows the age and sex distribution of the total group of cholera victims. It is obvious that 33% of patients were under the age of 15 years. A similarly striking number, 19% were between age 30 and 34 years. When the age distribution of the female cholera patients is compared to the total Ile-Ife female population (computed from the government-approved census figures), an obvious difference in distribution is noticed. Of the overall female population, 10.3% fall into the 30-34 year age category. An overrepresentation (19%) was found in cholerainfected females of the same age category. Age and sex distribution of cholera patients at IkTable I. Ife, 1979-1980.
(Years)
Male (N = 291)
Female (A’= 270)
Total (N =
>15 15-19 20-24 25-29 30-34 35-39 40-44 45-49 50+
95 19 18 20 53 32 24 15 15
88 18 17 19 49 29 22 14 14
183 37 35 39 102 61 46 29 29
Apegroup
561)
Cholera and pregnancy Table IL Fatality among female cholera patients followed up after the He-Ife outbreak, 1979-1980.
(years)
Female cholera patients followed up (N = 237)
Deaths (N = 46)
G15 15-19 20-24 25-29 30-34 35-39 40-44 45-49 50+
77 16 15 17 44 25 19 12 12
32 0 0 0 6 3 1 1 3
Agekmw
% Fatality
41.6 0 0 0 13.6 12.0 5.0 5.0 25.0 Mean 19.4
The difference between the two distributions was significant (P < 0.05). Table II shows mortality figures in the female cholera population. Table III shows a breakdown of the female cholera patients by pregnancy status and in comparison with the subgroup younger than 15 years of age. mortality the highest Proportionately, occurred among cholera patients who were under 15 years of age, followed by the non-pregnant patients. The least mortality was observed in the subgroup of pregnant cholera patients. Table IV shows the outcome of pregnancy in relation to the gestational age at the time the infection occurred. It can be seen that the chance of fetal loss decreases with increasing gestational age. An examination of these events in relation to blood volume does not readily explain this observation. However, better prognosis for the fetus is observed Table III. Analysis patients. Subgroups
pregnant Non-pregnant under 15 years
of
fatality
No. of cholera patients 61 176 77
among female
No. of deaths in subgroup 4 42 32
cholera
Stage of pregnancy when patient was infected Table IV. with cholera in relation to fetal outcome and blood volume. Stage of Pregnancy (months of gestation)
Live births as outcome
Fetal losses as outcome (%)
Blood volume (cc)
1 2 3 4 5 6 7+
1 3 8 5 5 15
ll(100) _ 4 (57) 3 (27) _ 1 (17) 1 (6)
4000 4000 4000 4000 4500 4750 5000
with increase in maternal blood volume. An examination of mortality in relation to various types of occupation is shown in Table V. As noted earlier, the disease occurs more in the very young and in the old, a group that constitute a dependant segment of the population. While only a little more than 50% died in this category, the number of deaths among the very young and the old women account for 74% of the total deaths resulting from cholera. This shows a significant degree of proneness. The numbers for women traders show relatively more vulnerability to the disease than for other occupations, most notable, however, is the fact that 14% of all women aged 30-34 years, irrespective of occupation, died of the disease. Table V. Mortality by occupation among female cholera patients followed up. Occupation
No. (N = 239)
Housewife Student Professional Trader
36 35 36 55
1 1 2 8
Farmer None (Children and older PeoPW
12 65
0 34
Deaths (N = 46)
Proportion
0.0656 0.2360 0.4156
405
Agegroup (years)
(30-34) (15) (30-34) I (30-34) (35-39) (40-49) _ (<15) = { (>50) =
= = = = = = 3 3
% total deaths 1 1 2 3 3 2
2.2 2.2 4.3 17.4
0 73.9
Int J Gynaecol Obstet I9
406
Ayangade
Discussion Epidemiologists [ 151 have recorded seven pandemics of cholera since 1800. The most recent one reportedly started in 196 1 in Indonesia and still persists today in most areas, including Africa. Most major cities in Nigeria experience sporadic outbreaks, usually during the dry seasons (December-February) with very high attendant human wastage. Cholera vaccination, therefore continues to be a requirement for international travel in and out of Nigeria. The inadequate state of sanitation and purified pipe-borne water shortages have made cholera outbreaks a predictable seasonal disease of urban dwellers. The outbreak of cholera in Ile-Ife in 1979-1980 resulted from El Tor Fibrio cholerue infection. Similar types were reported in other cities affected during the outbreak. The overall age and sex distribution in our study agrees with those of earlier workers [61 when all the cholera patients are examined. However, when the female patients are studied, the distribution shows a pattern different from the general female population. The underrepresentation among cholera patients 15-29 years of age coincides with the period of intense reproductive activity and, similarly, the overrepresentation in the 30-44 year age group coincides with the years of waning reproductive performance The significant level of (subfertility). difference demonstrated tends to prove that there is a differential age susceptibility. That the pregnant woman is more susceptible [4] is not shown in our experience. On the contrary, the pregnant woman is less likely to die from Vibrio cholerue infection than her non-pregnant counterpart. Moreover, females under 15 years of age appear particularly to be the most vulnerable. The reasons for the relative resistance in the reproductive prime may possibly result from the patients’ better attitudes to health matters. Further, systematic evaluation of stomach free acid -during the three trimesters of pregnancy is needed. A normal or high level Int J Gynaecol Obstet 19
of free acid may protect the pregnant woman from acid sensitive pathogens [ 81. As a result, some clinical infections may, therefore, either go unnoticed or may be treated early on account of the pregnancy-associated symptoms. No doubt the employment of a standard intravenous infusion technique [ 111 would have contributed to improved performance of this medically conscious subgroup. The four pregnancies that terminated during the third month of gestation constitute the highest amount of fetal loss when the first month is excluded. This is significantly higher than the probability figure of 80/ 1000 cited for spontaneous abortions from the Kauai pregnancy study [ 31. Overall, our data show that when complicated by cholera infection, 60% of pregnancies will result in a live born infant. This is lower than 88% quoted by Durfee [2]. Although more losses are experienced during the first trimester of pregnancy than during the latter stages, our number is too small to determine precisely the additional burden imposed by the infection on the first trimester. Hirschom et al. [4] studied 60 cases in Pakistan and reported 50% fetal mortality when infection occurs in the third trimester. In our study 16 third-trimester cases were diagnosed and out of these only one resulted in a stillbirth. However, four of 22 second-trimester cases in our study experienced fetal loss. The variance with the report of Hirschom et al. [3] is probably caused by premium placed on pregnancy and pregnancy related health matters. In our obstetric unit, less than 10% of the pregnant patients are registered by the end of the first trimester, and only 50% book in the third trimester, with 30% never having booked at all. The latter group are prompted to consult for a variety of health matters that do not respond to home treatments. remedies and less frequently, Home inadequate communication, jointly account for most of our maternal and fetal losses through delay in seeking medical attention.
Cholera and pregnancy
Apart from difficulties with communication and home remedy trials, the prevailing positive attitude to pregnancy in general predisposes to purposeful and prompt attention to health matters. This contrasts with situations in the very young and the older where both mortality and age group morbidity figures reflect the compounding effect of both factors. Although current mortality figures are put at 0.6% 171, the higher mortality in our study reflects non-selection and/or delays in seeking medical care. The biggest contributors to the high mortality are the dependent-age group (children and older adults). Among female deaths in the reproductive years, 50% occurred in the 30-34 year age group. Among pregnant cholera patients, the three maternal deaths occurred in women who were between 30 and 39 years of age, with two of these (67%) being between 30 and 34 years. The reason for this age susceptibility cannot be readily explained. It was not feasible to perform cultures in every case. Judging by the high degree of correlation between the symptom complex and the I/ibrio Cholerue isolation in those cultured, it is rational to conclude noncultured cases were certainly genuine cholera cases. This assertion is buttressed by the fact that a negative culture does not disprove the diagnosis, as most negative cultures belong to cases partially treated preadmission. Furthermore, Hirschom et al. [4] did show the incidence of non-choleraic diarrhea with pregnancy to be as low as 3%. We feel safe in stating that Nigerian women aged 15-29 years show relatively more resistance to cholera infection than their older counterparts. Mortality figures show a sparing of the same group of women while the three maternal losses recorded were in the 30-39 age group. The overall maternal mortality in this study was 6.6%. In view of the above findings, more intensive public health education and/or vaccination during the precholera season can help prevent fatalities in both extremes of age.
401
Fetal losses in the first trimester can be prevented by early registration, while maternal mortality (ages 30-39) can be substantially reduced or prevented by identifying the older pregnant woman for intensive supervision during cholera outbreaks. Acknowledgement
The author is indebted to Dr. 0.0. Ladipo of the Department of Agricultural Economics for his help in statistical analysis and to Mr. Wogugu of the Medical Records for his assistance in ensuring complete case findings. References 1 Cholera in 1978. Weekly Epidemiology Rec. 54(17): 129, 1919. 2 Durfee RB: Complications of pregnancy. .In Current Obstetrics and Gynecologic Diagnosis and Treatment (cd Raph C Benson) 2nd edn, p. 648. Lange, 1978. French RE, Bierman JM: Probabilities of fetal mortality. Public Health Rep. 77: 835,1962. Hirschorn N, Chowdhury AKMA, Lindenbaum J: Cholera in pregnant women. Lancet 1: 1230, 1969. Kamal AM: The 7th pandemic of cholera. In Cholera (ed D Barua, N Burroes) pp l-4. WB Saunders, Philadelphia, 1974. 6 Lewis EA, Francis TI, Montefiore D, Okubadejo OA, Oyediran ABOO, Ayoola EA, Mohammed I, Onyetwotu II, Vincent R, McSweeney PL, Molloy MR, Sheehan JC, Coke AR, Wright EA: Cholera in Ibadan, 1971. J Trop Med Hyg 21(3): 307,1972. 1 Mackay DM, Symposium in cholera - Cholera: Present world situation. Trans R Sot Trop Med Hyg 73(l): 1, 1979. 8 Mackay DM: Trop Dis Bull 76(7): 1979. 9 Mosley WH: Epidemiology of cholera. WHO Public Health Pap No. 40: 23,197O. 10 Pollitzer R: In Cholera. Geneva, 1959. 11 Watten RH, Morgan FM, Songkhla YM, Vanikati B, Phillips RA: J Clii Invest 38: 1879,1959. Address for reprints: S.O. Ayangsde Dept of Obstetrics and Gynecology Faculty of Health Sciences Uniwrsity of Ife Ile-Ife, Nigeria
Int J Gynaecol Obstet 19
403-407 0 International Federation of Gynaecology & Obstetrics
THE SIGNIFICANCE OF CHOLERA OUTBREAK IN THE PROGNOSIS OF PREGNANCY OKUN AYANGADE
Department of Obstetrics, Gynecology and Perinatology, Universityof Ife, Ile-Ife, Niger& (Received December 29th, 1981) (Accepted April llth, 1981)
Abstract Ayangade 0 (Dept of Obstetrics, Gynecology and Perinatology, University of Ife, IEe-Ife, Nigeria). The significance of cholera outbreak in the prognosis of pregnancy, Int J Gynaecol Obstet 19: 403-407, 1981 Five hundred sixty-one persons were treated in a comprehensive cholera unit during the 1979-1980 cholera outbreak at Ne-Ife. Sixty-one pregnant cholera patients were identified and followed up. Compared to the general female population, all female cholera patients in the 15-29 year age group show significantly more resistance to the disease than those aged 30 years and above. The pregnant cases, as well as all reproductiveyears age groups, showed significantly less mortality than both the non-pregnant patients and those at both extremes of age. Our findings show that pregnancy does not render the woman more susceptible and may, in fact, render her less susceptible after the first trimester, when prognosis brightens for both the mother and the fetus.
Key words: Pregnant cholera patients; Vibrio infections; Gastroenteritis vomiting; Profuse diarrhea; El Tor Vibrio chol-
cholerae erae
Introduction
Cholera as a life-threatening sporadic entity is an important cause of death in most parts of the world. In its untreated form not only
does it kill in large numbers, it does so with great rapidity. Outbreaks occur with near predictable regularity, particularly in areas where inadequate sanitation and inadequate distribution of purified water supply are prevalent. In Nigeria, sporadic outbreaks occur chiefly during the dry season [9], when a shortage of purified drinking water hits most communities. Characteristically, the outbreak starts in December, peaks in January and declines in February. The prognosis for the cholera-infected pregnant woman and her fetus is still a subject requiring more extensive study. Early workers claim cholera infection is aggravated by pregnancy resulting in heavy maternal and fetal losses. Pollitzer [ 101, in a classic work, remarks that cholera occurrence in pregnancy is fraught with particular danger. However, the degree of incapacity is likely to be determined by the stage of pregnancy and the promptness and specificity of the therapy instituted. The object of this prospective study is to analyze one cholera outbreak in the cholera unit of the University of Ife Teaching Hospital, Ile-Ife, Nigeria, that served as the only 24-h surveillance and treatment unit during the 1979- 1980 cholera outbreak. Our system of comprehensive case finding and referral determined the total number of victims, the number of pregnant females affected, their stage of pregnancy, and the outcome of the pregnancies, including both fetal and maternal losses. In contrast to previous studies chiefly based on hospital admissions, our system removes bias, thus Int J Gynaecol Obstet 19
404
Ayangade
enabling us to confirm if, in fact, pregnancy enhances susceptibility to Vibtio cholerae infections. Materials and methods The Ife Teaching Hospital, which serves a total population of about 350,000, during the last outbreak located the treatment unit for cholera patients on the grounds of its tertiary hospital - the Ife General Hospital. This was to afford the treatment team easy access to all life-support and diagnostic facilities. In addition to being the only hospital authority during the outbreak, it served as the sole agent for the provision of free medical care to cholera patients for the Oyo State Government. Between December 1979 and February 1980, 561 admissions were made with the clinical diagnosis of cholera infection. The diagnosis was based on acute onset of gastroenteritis vomiting and profuse diarrhea accompanied by prostration or shock. The diagnosis was strengthened by the awareness that many of the cholera patients shared the same drinking or sewage disposal system. All cases were treated with conventional fluids and regimens involving parenteral tetracycline. The excrements were disinfected and disposed of by the nursing staff who had been previously immunized. At the initial stages of the disease and prior to the institution of treatment, rectal or fecal swabs were taken for definitive identification of the pathogen. Vibrio cholerae, El Tor bio-type, was isolated in most of the cases cultured. Although no difference in susceptibility for males and females has been proven 141, cholera, like other infections, imposes an additional risk on pregnancy and the fetus. As such, infected females were separately identified and studied in detail. A team of health workers conducted a health education session aimed at limiting the spread of the cholera outbreak. Female patients and/or relatives were interviewed to obtain data on parity and pregnancy age, occupation, status. The subsequent health of the infected Int J Gynaecol Obstet 19
women was ascertained by home visits at periodic intervals to determine and conduct follow-up on those who were pregnant at the time of the attack. Follow-up was completed in 88% of admitted cases. All index patients were followed throughout pregnancy and delivery to study the outcome of the pregnancy. Results Five hundred sixty-one clinically diagnosed cases of cholera during the 1979-1980 outbreak were recorded; of these, 270 female cases were studied and followed for a maximum of 7 months. The outbreak lasted a total of 12 weeks. Random cases picked for showed the bacteriologic identification isolation of El Tor Vi’ibrio cholerae in 90% of cases. Table I shows the age and sex distribution of the total group of cholera victims. It is obvious that 33% of patients were under the age of 15 years. A similarly striking number, 19% were between age 30 and 34 years. When the age distribution of the female cholera patients is compared to the total Ile-Ife female population (computed from the government-approved census figures), an obvious difference in distribution is noticed. Of the overall female population, 10.3% fall into the 30-34 year age category. An overrepresentation (19%) was found in cholerainfected females of the same age category. Age and sex distribution of cholera patients at IkTable I. Ife, 1979-1980.
(Years)
Male (N = 291)
Female (A’= 270)
Total (N =
>15 15-19 20-24 25-29 30-34 35-39 40-44 45-49 50+
95 19 18 20 53 32 24 15 15
88 18 17 19 49 29 22 14 14
183 37 35 39 102 61 46 29 29
Apegroup
561)
Cholera and pregnancy Table IL Fatality among female cholera patients followed up after the He-Ife outbreak, 1979-1980.
(years)
Female cholera patients followed up (N = 237)
Deaths (N = 46)
G15 15-19 20-24 25-29 30-34 35-39 40-44 45-49 50+
77 16 15 17 44 25 19 12 12
32 0 0 0 6 3 1 1 3
Agekmw
% Fatality
41.6 0 0 0 13.6 12.0 5.0 5.0 25.0 Mean 19.4
The difference between the two distributions was significant (P < 0.05). Table II shows mortality figures in the female cholera population. Table III shows a breakdown of the female cholera patients by pregnancy status and in comparison with the subgroup younger than 15 years of age. mortality the highest Proportionately, occurred among cholera patients who were under 15 years of age, followed by the non-pregnant patients. The least mortality was observed in the subgroup of pregnant cholera patients. Table IV shows the outcome of pregnancy in relation to the gestational age at the time the infection occurred. It can be seen that the chance of fetal loss decreases with increasing gestational age. An examination of these events in relation to blood volume does not readily explain this observation. However, better prognosis for the fetus is observed Table III. Analysis patients. Subgroups
pregnant Non-pregnant under 15 years
of
fatality
No. of cholera patients 61 176 77
among female
No. of deaths in subgroup 4 42 32
cholera
Stage of pregnancy when patient was infected Table IV. with cholera in relation to fetal outcome and blood volume. Stage of Pregnancy (months of gestation)
Live births as outcome
Fetal losses as outcome (%)
Blood volume (cc)
1 2 3 4 5 6 7+
1 3 8 5 5 15
ll(100) _ 4 (57) 3 (27) _ 1 (17) 1 (6)
4000 4000 4000 4000 4500 4750 5000
with increase in maternal blood volume. An examination of mortality in relation to various types of occupation is shown in Table V. As noted earlier, the disease occurs more in the very young and in the old, a group that constitute a dependant segment of the population. While only a little more than 50% died in this category, the number of deaths among the very young and the old women account for 74% of the total deaths resulting from cholera. This shows a significant degree of proneness. The numbers for women traders show relatively more vulnerability to the disease than for other occupations, most notable, however, is the fact that 14% of all women aged 30-34 years, irrespective of occupation, died of the disease. Table V. Mortality by occupation among female cholera patients followed up. Occupation
No. (N = 239)
Housewife Student Professional Trader
36 35 36 55
1 1 2 8
Farmer None (Children and older PeoPW
12 65
0 34
Deaths (N = 46)
Proportion
0.0656 0.2360 0.4156
405
Agegroup (years)
(30-34) (15) (30-34) I (30-34) (35-39) (40-49) _ (<15) = { (>50) =
= = = = = = 3 3
% total deaths 1 1 2 3 3 2
2.2 2.2 4.3 17.4
0 73.9
Int J Gynaecol Obstet I9
406
Ayangade
Discussion Epidemiologists [ 151 have recorded seven pandemics of cholera since 1800. The most recent one reportedly started in 196 1 in Indonesia and still persists today in most areas, including Africa. Most major cities in Nigeria experience sporadic outbreaks, usually during the dry seasons (December-February) with very high attendant human wastage. Cholera vaccination, therefore continues to be a requirement for international travel in and out of Nigeria. The inadequate state of sanitation and purified pipe-borne water shortages have made cholera outbreaks a predictable seasonal disease of urban dwellers. The outbreak of cholera in Ile-Ife in 1979-1980 resulted from El Tor Fibrio cholerue infection. Similar types were reported in other cities affected during the outbreak. The overall age and sex distribution in our study agrees with those of earlier workers [61 when all the cholera patients are examined. However, when the female patients are studied, the distribution shows a pattern different from the general female population. The underrepresentation among cholera patients 15-29 years of age coincides with the period of intense reproductive activity and, similarly, the overrepresentation in the 30-44 year age group coincides with the years of waning reproductive performance The significant level of (subfertility). difference demonstrated tends to prove that there is a differential age susceptibility. That the pregnant woman is more susceptible [4] is not shown in our experience. On the contrary, the pregnant woman is less likely to die from Vibrio cholerue infection than her non-pregnant counterpart. Moreover, females under 15 years of age appear particularly to be the most vulnerable. The reasons for the relative resistance in the reproductive prime may possibly result from the patients’ better attitudes to health matters. Further, systematic evaluation of stomach free acid -during the three trimesters of pregnancy is needed. A normal or high level Int J Gynaecol Obstet 19
of free acid may protect the pregnant woman from acid sensitive pathogens [ 81. As a result, some clinical infections may, therefore, either go unnoticed or may be treated early on account of the pregnancy-associated symptoms. No doubt the employment of a standard intravenous infusion technique [ 111 would have contributed to improved performance of this medically conscious subgroup. The four pregnancies that terminated during the third month of gestation constitute the highest amount of fetal loss when the first month is excluded. This is significantly higher than the probability figure of 80/ 1000 cited for spontaneous abortions from the Kauai pregnancy study [ 31. Overall, our data show that when complicated by cholera infection, 60% of pregnancies will result in a live born infant. This is lower than 88% quoted by Durfee [2]. Although more losses are experienced during the first trimester of pregnancy than during the latter stages, our number is too small to determine precisely the additional burden imposed by the infection on the first trimester. Hirschom et al. [4] studied 60 cases in Pakistan and reported 50% fetal mortality when infection occurs in the third trimester. In our study 16 third-trimester cases were diagnosed and out of these only one resulted in a stillbirth. However, four of 22 second-trimester cases in our study experienced fetal loss. The variance with the report of Hirschom et al. [3] is probably caused by premium placed on pregnancy and pregnancy related health matters. In our obstetric unit, less than 10% of the pregnant patients are registered by the end of the first trimester, and only 50% book in the third trimester, with 30% never having booked at all. The latter group are prompted to consult for a variety of health matters that do not respond to home treatments. remedies and less frequently, Home inadequate communication, jointly account for most of our maternal and fetal losses through delay in seeking medical attention.
Cholera and pregnancy
Apart from difficulties with communication and home remedy trials, the prevailing positive attitude to pregnancy in general predisposes to purposeful and prompt attention to health matters. This contrasts with situations in the very young and the older where both mortality and age group morbidity figures reflect the compounding effect of both factors. Although current mortality figures are put at 0.6% 171, the higher mortality in our study reflects non-selection and/or delays in seeking medical care. The biggest contributors to the high mortality are the dependent-age group (children and older adults). Among female deaths in the reproductive years, 50% occurred in the 30-34 year age group. Among pregnant cholera patients, the three maternal deaths occurred in women who were between 30 and 39 years of age, with two of these (67%) being between 30 and 34 years. The reason for this age susceptibility cannot be readily explained. It was not feasible to perform cultures in every case. Judging by the high degree of correlation between the symptom complex and the I/ibrio Cholerue isolation in those cultured, it is rational to conclude noncultured cases were certainly genuine cholera cases. This assertion is buttressed by the fact that a negative culture does not disprove the diagnosis, as most negative cultures belong to cases partially treated preadmission. Furthermore, Hirschom et al. [4] did show the incidence of non-choleraic diarrhea with pregnancy to be as low as 3%. We feel safe in stating that Nigerian women aged 15-29 years show relatively more resistance to cholera infection than their older counterparts. Mortality figures show a sparing of the same group of women while the three maternal losses recorded were in the 30-39 age group. The overall maternal mortality in this study was 6.6%. In view of the above findings, more intensive public health education and/or vaccination during the precholera season can help prevent fatalities in both extremes of age.
401
Fetal losses in the first trimester can be prevented by early registration, while maternal mortality (ages 30-39) can be substantially reduced or prevented by identifying the older pregnant woman for intensive supervision during cholera outbreaks. Acknowledgement
The author is indebted to Dr. 0.0. Ladipo of the Department of Agricultural Economics for his help in statistical analysis and to Mr. Wogugu of the Medical Records for his assistance in ensuring complete case findings. References 1 Cholera in 1978. Weekly Epidemiology Rec. 54(17): 129, 1919. 2 Durfee RB: Complications of pregnancy. .In Current Obstetrics and Gynecologic Diagnosis and Treatment (cd Raph C Benson) 2nd edn, p. 648. Lange, 1978. French RE, Bierman JM: Probabilities of fetal mortality. Public Health Rep. 77: 835,1962. Hirschorn N, Chowdhury AKMA, Lindenbaum J: Cholera in pregnant women. Lancet 1: 1230, 1969. Kamal AM: The 7th pandemic of cholera. In Cholera (ed D Barua, N Burroes) pp l-4. WB Saunders, Philadelphia, 1974. 6 Lewis EA, Francis TI, Montefiore D, Okubadejo OA, Oyediran ABOO, Ayoola EA, Mohammed I, Onyetwotu II, Vincent R, McSweeney PL, Molloy MR, Sheehan JC, Coke AR, Wright EA: Cholera in Ibadan, 1971. J Trop Med Hyg 21(3): 307,1972. 1 Mackay DM, Symposium in cholera - Cholera: Present world situation. Trans R Sot Trop Med Hyg 73(l): 1, 1979. 8 Mackay DM: Trop Dis Bull 76(7): 1979. 9 Mosley WH: Epidemiology of cholera. WHO Public Health Pap No. 40: 23,197O. 10 Pollitzer R: In Cholera. Geneva, 1959. 11 Watten RH, Morgan FM, Songkhla YM, Vanikati B, Phillips RA: J Clii Invest 38: 1879,1959. Address for reprints: S.O. Ayangsde Dept of Obstetrics and Gynecology Faculty of Health Sciences Uniwrsity of Ife Ile-Ife, Nigeria
Int J Gynaecol Obstet 19