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Motherisk Newsletters: Fall 1998, No. 9

Fall 1998, No. 9




HIGHLIGHTS FROM THE FIRST INTERNATIONAL CONFERENCE ON NAUSEA AND VOMITING OF PREGNANCY
On October 30 and 31, 1998, Motherisk hosted the first ever international meeting dedicated entirely to the topic of nausea and vomiting of pregnancy (NVP). With support from Duchesnay Inc., Motherisk was able to invite to Toronto the top researchers on NVP from Canada, Hong Kong, Israel, Sweden, the United Kingdom and United States.

Friday, October 30th the first day of this 2-day event was attended by over 150 physicians, midwives and other healthcare professionals. Presentations by a panel of 17 international experts described the latest findings on the etiology, epidemiology and management of NVP. On Saturday, October 31st the panel engaged in a day-long roundtable discussion of these and other topics, as well as the need for continuing research.
NVP Often Untreated
It appears that despite the availability of safe and effective drugs for NVP, in many countries such as the U.S. and U.K. the majority of women are not offered treatment. In fact, since the removal from the U.S. market of Bendectin, a drug that was prescribed through the 1960s and '70s for the treatment of NVP, there has been a three-fold increase in rates of hospitalization of women for management of severe forms of NVP. This grim statistic is explained by the fact that no other drug has replaced Bendectin on the American market to manage NVP. Given the litigious atmosphere in the U.S, it is also not common for physicians to treat NVP with drugs not specifically labeled for this indication.

The absurdity of the American situation was described by Dr. Anthony Scialli of Georgetown University who showed that while Bendectin (doxylamine plus vitamin B6) has been approved as safe by the FDA, the manufacturers of doxylamine (for allergies and insomnia) warn on the label not to use it in pregnancy. A recent study has also shown that half of all physicians surveyed would offer their patients a therapeutic abortion after exposure to doxylamine despite the huge amount of data showing it to be safe.

Other interesting studies showed that mild NVP is associated with better pregnancy outcomes, including lower risk of congenital malformations in general and cardiac malformations in particular. Conversely, severe forms of NVP, and in particular hyperemesis gravidarum, are associated with higher risk for lower birth weight and therapeutic abortion of otherwise wanted pregnancies. Very often, however, women suffering from hyperemesis are not offered appropriate drug therapy before experiencing dehydration and weight loss.

A Canadian Consensus on the Management of NVP discussed by Drs. Aurel Schofield of New Brunswick and Catherine MacKinnon of Ontario stresses the need for a patient-centered approach, taking into account not only the physical symptoms of the woman, but also the psychosocial consequences and overall quality of life. This Consensus document will be available shortly through the Motherisk Program.

More Research Required
The international panel concluded its 2-day meeting with a call for more research. "NVP is a medical condition and should not be ignored on grounds of being a 'normal' part of pregnancy," said Gideon Koren, M.D., Motherisk director and host of the conference.

NVP affects more than 100 million women close to 80% of pregnant women worldwide each year. In spite of this, it has been largely ignored in terms of new treatment modalities.

"It bothered us how 'blasČ ' people can be about women vomiting," continued Dr. Koren. "This meeting represents an important first step in rejecting outdated notions in the medical community about NVP and bringing the complications of this serious condition to light." The next step is continued research with particular focus on the etiology and management of NVP. Mr. Pierre Boivin, owner of Duchesnay, stated that his company will support future international collaborations in this field.

MOTHERISK HELPLINE FOR WOMEN SUFFERING FROM NAUSEA AND VOMITING OF PREGNANCY (NVP) 1-800-436-8477
Motherisk offers a toll-free phone counselling service in English and French, to assist women suffering from severe nausea and vomiting during pregnancy (NVP).

The NVP Helpline is staffed by an NVP counsellor, Monday to Friday from 9 a.m. to 5 p.m. (EST). Women in Toronto may also book an appointment for a clinic visit.

ALDARA PREGNANCY HEALTHLINE - 1-800-670-6126
Aldara is a new and effective therapy for genital warts. Have you used, or are you planning to use Aldara in pregnancy or while planning a pregnancy? If so, we would like tohear from you. Please call us at our toll free number. All calls are strictly confidential.

NEW TOLL-FREE HELPLINE 1-877-FAS-INFO
ALCOHOL AND SUBSTANCE USE IN PREGNANCY


Callers throughout Canada will soon be able to call Motherisk's new toll-free number for information and counselling about Alcohol and Substance Use in Pregnancy. With support from the Brewers Association of Canada, this new clinical program is scheduled to begin in November. Serviced by two specially trained counsellors, the Alcohol and Substance Use Helpline will be "open" from 9 a.m. to 5 p.m. in each time zone across Canada.

Alcohol
It has been estimated that up to 0.5 to 2 in 1000 babies born are developmentally delayed due to maternal use of alcohol. Much larger numbers are affected to smaller degrees by Fetal Alcohol Effects. At the present time, very little is available to help prevent, diagnose and manage fetal alcohol damage in Canada. Yet diagnosis in early life is vitally important if parents, physicians, psychologists, teachers and others are to understand and manage the range of neurobehavioural problems associated with fetal alcohol syndrome, and thus prevent secondary damage commonly leading to delinquent or illegal activities in adolescence.

Other substances
An estimated 10 to 45 percent of women cared for at urban teaching hospitals in large US cities use cocaine in pregnancy. In the Metropolitan Toronto area, there has been a steady increase in the number of newborns affected by maternal drug use. The damaging effects include prematurity, growth retardation and developmental delay. Appropriate diagnosis, treatment and perinatal care depend on accurate and timely classification of "exposed" infants.

The new Alcohol and Substance Use Helpline will:
  • provide evidence-based information and counselling to women who have engaged in high risk behaviour in pregnancy and/or prior to learning that they were pregnant;
  • offer access to support and treatment in the caller's area;
  • alert callers to the possible need for specialized care for their newborn, and increase the likelihood that more infants with substantially higher risks for significant perinatal complications will be identified before they are sent home.
Through meetings, regional workshops and publications the Motherisk team will share its findings with healthcare providers, community groups and government representatives. Motherisk will also contribute to a comprehensive database on all issues related to alcohol in pregnancy and during lactation.

The program's objective is to get the facts straight about alcohol and other substances in pregnancy and lactation.

"I am delighted that the Brewers Association of Canada is able to assist Motherisk in expanding its highly respected program offering research-based information about alcohol and substance use during pregnancy," said Mr. Sandy Morrison, President of the Brewers Association of Canada. "The new national helpline will be a useful tool for both pregnant and breastfeeding women, as well as for medical professionals. We are pleased that through our funding Motherisk will be able to provide free access to its specialized knowledge and counselling to all regions of Canada."

A MOTHERISK HIV HEALTHLINE UPDATE 1-888-246-5840

THE USE OF COMBINATION ANTIRETROVIRAL THERAPY IN PREGNANCY
Therapy for HIV infection is rapidly evolving with many new agents becoming available for use in combination therapy. Most of these drugs have not been studied in pregnant women, so there is very little information on the fetal safety for these agents singly or in combination. Many of these agents have caused carcinogenic, mutagenic, reproductive or teratogenic effects in animal studies. For example, a new non-nucleoside reverse transcriptase inhibitor, efavirenz, caused major malformations in 3 of 20 monkey fetuses, including anencephaly, unilateral anophthalmia, microphthalmia and cleft palate. Therefore, in order for women to be able to make informed decisions on antiretrovirals for themselves and their unborn child, more reliable information is needed on the benefits and risks of these drugs in pregnancy.

In Canada, in the early 1980s women accounted for 5% of new HIV infections, but the proportion has increased to 21.8% in 1997 ( 1 ). Over 90% of HIV-infected females are of child-bearing age. The prevalence of HIV-infection in pregnant women in Canada is in the range of 3 to 6 per 10,000 pregnant women. An increasing proportion of women who are aware of their HIV-infection are choosing to have children ( 2 ). These decisions are influenced in part, by the availability of improved antiretroviral therapy (ART) which has led women to be more optimistic about their own health and the outcome for their children. As health care providers adopt the practice of offering HIV testing routinely in pregnancy, it is expected that the number of the HIV-infected pregnant women who are aware of their status and seeking medical care for HIV in pregnancy will increase.

In keeping with the Motherisk philosophy, therapy for HIV in pregnancy should aim to optimize the health of the mother and her unborn child ( 3,4 ). Since combination antiretroviral therapy is the currently recommended standard treatment for HIV-infected adults, then pregnancy should not preclude the use of such therapeutic regimens. Currently in Canada, some HIV-positive pregnant women are being offered ART with one, two or three drugs ( 5 ). Zidovudine (AZT) monotherapy was initially the most frequently prescribed therapy but the frequency of use of combinations is increasing. Some of the more commonly prescribed combinations are AZT + lamivudine (3TC) or AZT + 3TC + a protease inhibitor (PI). No single PI seems preferred by the clinicians who treat HIV-positive women. Since the guidelines for ART in pregnancy indicate that therapy should be individualized, it is appropriate that a variety of options have been used in practice ( > 3,4 ).

To date there have been no published results on trials using combination ART in pregnancy. However, when counselling an HIV-positive pregnant woman there are several pieces of information for which there is good evidence:

  • combination ART is likely the best therapy to reduce her own HIV viral load (3,4)
  • there is an association between a high viral load and an increased risk of transmission from mother to baby (6-9)
  • zidovudine alone will reduce the risk of transmission from mother to baby ( 10,11 )
  • combination ART lowers the viral load more than zidovudine alone, therefore it is hypothesized that combination ART would further reduce the risk of transmission from mother to baby ( 3,4 )
  • HIV infection itself does not cause malformations in babies ( 12 )
  • zidovudine alone in pregnancy has not been associated with malformations but does cause transient anemia in the newborn ( 9 )
  • although no toxicity has been reported from the use of other ART in pregnancy the numbers are too small to draw any conclusions on safety (13)
  • all children exposed to ART in pregnancy should be followed for assessment of short and long term sequelae of exposure.
Last year, Motherisk and the HIV program at The Hospital for Sick Children formed a collaborative team to provide information and counselling to women and their health care providers on HIV and pregnancy. The Motherisk-HIV Healthline and Network was launched on December 1, 1997. This is the only such program in Canada. Few other countries are able to provide this level of counselling.

Thanks to the cooperation and commitment of HIV Network members, the program has enrolled mother-infant pairs from several provinces in its national HIV pregnancy registry. Many more cases are needed if we are to obtain good evidence on the fetal safety and toxicity of ART through prospective follow-up of exposed infants. Clinicians involved in the care of an HIV-positive pregnant woman may join the Network at any time and enroll cases in the registry. The HIV-positive pregnant woman herself may also enroll. For more information please call 1-888-246-5840 Fax: (416) 813-7562; E-mail: momrisk@sickkids.ca .

Susan King, MD, Msc, FRCPC

REFERENCES
  1. Health Canada. HIV and AIDS among women in Canada. HIV/AIDS Epi Update Bureau of HIV/AIDS, STD and TB, LCDC. May 1998
  2. Delmas MC, Anzen B, Pena JM et al. Incidence and outcome of pregnancies in HIV-infected women. Conference Record of 12th World AIDS Conference, Geneva, 1998, Abstract #24194
  3. Center for Disease Control and Prevention. Public Health Service task force recommendations for the use of antiretroviral drugs in pregnant women infected with HIV-1 for maternal health and for reducing perinatal HIV-1 transmission in the United States. MMWR 1998; 47: RR-2
  4. Minkoff H, Augenbraun M. Antiretroviral therapy for pregnant women. Am J Obstet Gynecol 1997; 176: 478-89
  5. Singer J, Lapointe N, Forbes J, King SM, et al. Antiretroviral therapy in pregnant women in Canada: Access and outcome 1995-1996. Conference Record of the 12th World AIDS Conference, Geneva, 1998. Abstract # 23315.
  6. Cao Y, Krogstad P, Korber BT, et al. Maternal viral load and vertical transmission of the infection: The Ariel Project for the prevention of HIV transmission from mother to infant. Nature Medicine 1997; 3: 549-52
  7. Dickover RE, Garatty EM, Horman SA, et al. Identification of levels of maternal HIV-1 RNA associated with risk of perinatal transmission from mother to infant. JAMA 1996;275:599-605
  8. Mayaux M-J, Dussaix E, Isopet J, et al. Maternal viral load during pregnancy and the mother-to -child transmission of human immunodeficiency virus type-1: the French perinatal Cohort Studies. J Infect Dis 1997; 175:172-5
  9. Thea DM, Steketee RW, Pliner V, et al. The effect of maternal viral load on the risk of perinatal transmission of HIV-1. J Infect Dis 1997; 175:707-11
  10. Connor EM, Sperling RS, Gelber R, et al. Reduction of maternal-infant transmission of human immunodeficiency virus type I with zidovudine treatment. New Engl J Med 1994; 331: 1173-80
  11. Taneepanichskul S. Sirinavin S. Phuapradit W. Chaturachinda K. Effect of zidovudine treatment in late pregnancy on HIV-1 in utero transmission. Australian & New Zealand J Obstet & Gynaecol 1997; 37:329-31
  12. Abrams EJ, Matheson PB, Thomas PA, et al. Neonatal predictors of infection status and early death among 332 infants at risk of HIV-1 infection monitored prospectively from birth. Pediatrics 1995; 96: 451-8
  13. Report of the Antiretroviral Pregnancy Registry , Pharmaresearch Corporation. Interim Report January 1989 to December 1997

ADVANCED HAIR TESTING TECHNIQUES AND APPLICATIONS EXPLORED AT MOTHERISK WORKSHOP

Hair testing for drugs of abuse, particularly in the neonatal population, is the single most accurate biomarker for gestational exposure to these drugs. As a leader in this field, as well as Canada's only academic laboratory to conduct routine analysis of neonatal and adult hair, Motherisk was pleased to host the Second International Hair Testing Workshop on October 1 and 2. The 2-day program of lectures, practical demonstrations and panel discussions was attended by physicians and forensic toxicologists from around the world.

Capillary Electrophorisis
Day one of the workshop featured a practical demonstration of capillary electrophoresis by Dr. Giulia Manetto of the Institute of Forensic Medicine, University of Verona, Italy. Capillary electrophoresis is a new, alternative method of hair analysis. Traditionally, the initial screening of the hair samples is performed by an immunoassay. The immunoassay is later confirmed by a more specific assay, such as gas chromatography with a mass spectrum detector (GC-MS). While capillary electrophoresis does not have the sensitivity of GC-MS, it has the advantage of being cheaper and much easier to interpret. In the future, it has the potential to become a routinely used method not only for hair testing but for testing of any biological fluid.

Testing Neonatal Hair
Neonatal hair testing was a key topic throughout the 2-day event. Julia Klein of Motherisk discussed the differences between neonatal and adult hair. She stressed that because of the sparsity of neonatal hair in comparison with adult hair, neonatal hair analysis must be conducted using extremely sensitive methods. Ms. Klein described a method developed in the Motherisk laboratory to test for both cocaine and nicotine and their respective metabolites in the same neonatal sample. She also noted that since maternal cigarette smoking can be a confounding factor in studying the effects of gestational cocaine exposure, it is extremely important to establish with certainty whether the mother of the newborn smoked and/or used cocaine during pregnancy. Testing the neonatal hair for the presence of these two xenobiotics provides an accurate answer to these question.

Dr. Gideon Koren, Director of the Motherisk Program, lectured on the ethical and medico-legal issues of testing neonates. Often pediatricians ask if parental consent is needed to cut a small amount of the infant's hair. While consent is desirable, if the physician has a strong suspicion of gestational drug exposure, confirmation of the exposure should not depend on parental consent, especially in light of the fact that when compared to drawing blood for a blood test, taking a hair sample is a relatively non-invasiveness procedure.

The topic of neonatal hair testing was developed further in a presentation by Dr. Manetto. Work performed at the Pediatric Clinic of The University of Verona, Italy, used neonatal hair analysis to investigate possible maternal thyroxine supply to the congenital hypothyroid fetus.

Day two of the workshop featured lectures by other international experts on the results of hair analysis for toxic environmentals such as methyl mercury, and the use of hair testing to assess patient therapeutic compliance.

Controversal Issues
The highlight of the workshop was a panel discussion of controversial issues surrounding the application and interpretation of hair analysis and its results. Dr. Richard Newel from the Center for Healthy Mothers and Babies, College of Public Health, University of South Florida discussed the potential for race and sex bias in the interpretation of hair test results. Their study concluded that hair testing is in good agreement with urine testing and self- reported drug use when the data are analyzed either by race or by gender, indicating an absence of bias. A separate study to test the possibility of contamination of the hair by passive exposure (as opposed to active drug use), supported previous findings by Motherisk that passively contaminated hair can be cleaned by repeated washings, but hair from active users cannot be cleaned even by repeated washings.

Panelists also discussed the application of hair analysis in Canadian criminal and civil law, as well as its utility in child protection and custody cases. The floor was then opened to questions from the physicians, laboratory technicians, lawyers, and child protection workers who attended this lively, 3-hour session.

Workshop presenters submitted abstracts describing their research and findings. To receive a listing of abstracts, please contact susan.santiago@sickkids.ca

Julia Klein, MSc


TOXOPLASMOSIS - A TRUE DANGER TO THE FETUS

Q: A 28-year-old woman is 3 months pregnant with her first child. She has heard about toxoplasmosis from her friends and asks you if it is safe to keep her cat.

The causative agent of toxoplasmosis is toxoplasma gondii, an intracellular parasite. Infection in humans usually occurs by ingestion of raw meat such a lamb, pork or beef. It is estimated that up to 25% of fresh pork and lamb contain cysts (1). Less commonly transmission can occur through the ingestion of poorly washed raw vegetables contaminated with oocysts or unpasteurized goat's milk or cheese. Infection can also occur by ingestion of the oocysts in cat feces ( 2 ). Waterborne transmission was suspected in a recent outbreak in Victoria, British Columbia, although there has been only one other report of this type of transmission in the literature ( 3,4 ). In immunocompetent hosts infection is usually symptomatic. Symptoms when they do occur are mild and non-specific (e.g., lymphadenopathy, fatigue, malaise and myalgia, etc.).

The risk to the pregnant woman depends on whether she has previously acquired immunity. This varies from country to country primarily dependent on cultural practices. In Canada only 32% to 40% of women of child-bearing age have protective immunity against toxoplasmosis ( 5 , 21 ). Although pregnant women are at no higher risk than the general population to become infected, an asymptomatic infection during pregnancy can result in an infant who is severely affected. The overall rate of transmission from an infected mother to her fetus is 30% to 40 % (6). There is an inverse relationship between the stage when the fetus is infected and the severity of disease. The lowest rate of transmission (15%) and the highest severity of disease (spontaneous abortions, stillbirths, perinatal deaths and severe neurologic sequelae) occur in the first trimester. Conversely in the third trimester the rate of transmission is approximately 60%, however the fetus tends to be mildly affected ( 6, 7 ). Rarely fetal transmission has been reported when infection occurs in the 6 month period immediately prior to pregnancy (8).

Although the classic triad of congenital toxoplasmosis includes chorioretinitis, intracranial calcifications and hydrocephalus, most infected infants are asymptomatic at birth. It is important to remember although asymptomatic at birth most infants with untreated disease will go on to develop some manifestation of the disease. In particular up to 85% will develop chorioretinitis (blindness, impaired vision), 20% to 75% will have some form of developmental delay, and 10% to 30% will have moderate hearing loss ( 9, 10, 11, 12 ). Hence appropriate follow-up is very important.

The impact of congenital toxoplasmosis in Canada is largely unknown ( 5 ). In Ontario, the provincial health lab has tested >14,500 specimens since 1980 with positive antibodies. From this it can be estimated that there are 250 new cases of toxoplasmosis per year of which approximately 10 of these might be from congenital transmission ( 21 ). Problems associated with prenatal screening include the need for multiple screens throughout pregnancy and the fact that IgM antibody may remain positive for as long as 2 years after infection which may unnecessarily result in heightened patient anxiety, further testing or even abortion of non-infected fetuses. A related concern is that since the prevalence of disease in countries such as Canada and the United States is low, the predictive value of a positive test (18% to 37%) is much lower than for countries like France (92%) where the prevalence of disease is high. Hence in Canada many women would have to be screened with invasive tests such as amniocentesis or cordocentesis to identify a single case of an infected fetus. This would impose a major economic burden on our healthcare system as well as being a source of morbidity to those pregnant women who would abort a non-infected fetus as a result of an invasive diagnostic procedure. In light of all of these factors routine prenatal screening is not recommended in most Canadian centres.

The prevention of congenital toxoplasmosis takes three major approaches. Primary prevention or prevention of maternal infection is the preferred approach ( Table 1 ) ( 13 ). All women should be educated about these precautions preferably at the planning stage before conception but realistically at the earliest opportunity possible. A pregnant woman should not consider her risk to be directly related to cat ownership and should be counselled regarding other likely unrecognized means of transmission such as ingestion of raw or poorly cooked lamb or pork. The highest risk of transmission from cat to human is from kittens, since young cats have often not yet acquired immunity to the disease. Ideally, a nonpregnant immunocompetent individual should be responsible for changing the cat litter. However, it is important to realize that it takes 2 to 3 days for the toxoplasmosis oocysts to sporulate or become infectious at room temperature ( 7 ). Therefore, if the cat litter is changed every day, the potential for transmission of infection through cat feces is extremely low.

Another approach is secondary prevention, which involves diagnosis of early maternal infection and treatment in an attempt to prevent fetal transmission. Spiramycin is a macrolide antibiotic, which may concentrate in placenta and therefore may prevent transmission to the fetus ( 7 ). One study estimated that spiramycin decreases transmission of toxoplasmosis by about 60% ( 14 ). However, when fetal transmission occurred clinical disease was no less severe in the group who received spiramycin.

The third approach or tertiary prevention involves identification of infection in the fetus or newborn and instituting early treatment to ameliorate clinical disease. Techniques for prenatal diagnosis of toxoplasmosis include ultrasound, which is only sensitive for gross and severe disease, amniocentesis and polymerase chain reaction for toxoplasma gondii and cordocentesis and fetal blood sampling for serological testing (e.g., IgA) performed at reference centres ( 15, 16, 17 ). Although polymerase chain reaction on amniotic fluid has recently been shown to have excellent sensitivity and specificity, this test is also not routinely available and samples must be sent to reference centres ( 17 ). Spiramycin is generally employed in the first trimester or when fetal infection has not been proven. The drug regimen of choice for proven fetal or congenital toxoplasmosis is pyrimethamine, sulfadiazine and folinic acid. Because of concerns regarding teratogenicity, this combination is used in the second and third trimesters after infection has been confirmed by pcr on amniotic fluid or serology on fetal blood. A French study of 52 pregnancies treated with pyrimethamine/sulfadiazine alternating with spiramycin compared with 72 untreated historical controls suggested that treated mothers had infants with less severe disease at birth ( 18 ). In addition, accumulating evidence suggests that early identification and prolonged treatment (1 year) of infants with congenital toxoplasmosis decreases the severity of acute and long-term morbidity, such as impairment of vision and hearing, and neurodevelopmental delay ( 10 , 19 ). Screening for toxoplasmosis is currently not part of routine neonatal screening in Canada. Proponents of this approach argue that the low incidence of congenital toxoplasmosis (1:1000 to 1:10,000) is comparable to other diseases such as congenital hyperthyroidism (1:5000) and phenylketonuria (1:12,000). Although this is currently an unresolved issue for most countries in the developed world, the apparent positive impact of treatment on long-term neurological sequelae suggest that neonatal screening may prove to be cost-effective ( 19 ).

A recent outbreak of toxoplasmosis which peaked in December 1994 and March 1995 in Victoria, British Columbia shed some light on the epidemiology of this disease ( 3 , 20 ). An outbreak was suspected when the provincial laboratory noticed an increase in positive toxoplasmosis serology. Two Victoria ophthalmologists also diagnosed seven cases of acute toxoplasmosis with retinitis in immunocompetent hosts, a rare disease in Canada. When attempts to link the outbreak to a common food source failed it was noted that cases were linked to the Humpback reservoir, one of two plants in Greater Victoria supplying unfiltered surface water. In a case-control study 83/94 outbreak cases lived in the area supplied by the Humpback reservoir ( 3 ). A massive screening program was initiated in pregnant women. Of 37 women identified to be serologically positive 12 infants were infected. Of the 12 infants infected, 5 had eye lesions and two had brain calcifications. It is suspected that the outbreak occurred due to contamination of unfiltered surface water with toxoplasmosis oocysts from wild (e.g., cougars) and domestic cats. The cluster of cases occurring during run-off supports this.

Table 1: Primary Prevention of Congenital Toxoplasmosis: Prevention of Infection in Pregnant Women
FOOD CATS/ENVIRONMENT
  • Eat meat that is well cooked
  • Wash utensils and counters well after meat preparation
  • Wash hands after handling raw meat and before eating
  • Avoid contact with eyes and mucous membranes while preparing uncooked meat
  • Wash foods such as vegetables and fruits well before eating
  • Wash hands after handling raw vegetables and fruits
  • Avoid unpasteurized milk products
  • Empty cat litter daily
  • Wear gloves while handling cat litter
  • Wash hands after handling cat litter
  • Use boiling water to disinfect cat litter box
  • Avoid feeding cat uncooked meat
  • Wear gloves while gardening and wash hands well after contact with soil or sand

A: Your patient should be reassured that she does not have to give up her cat. She should be educated as to the primary preventive measures outlined in Table 1 . She should be counseled about the limitations of prenatal serologic tests for toxoplasmosis that are routinely available in Canada. If prenatal screening is performed in a pregnant woman perceived to be at high risk, the first test should be performed as early as possible in the first trimester. A single positive IgM test may reflect disease occurring before conception or a false positive. A negative test does not preclude early infection or infection later in pregnancy. Either of these situations entails serial serologic testing and may unnecessarily result in heightened patient anxiety.

Dr. Elizabeth Phillips

REFERENCES
  1. Jacobs, L, Remington JS, Melton ML. The resistance of the encysted form of toxoplasma gondii. Journal of Parasitology 1960;46:11-21.
  2. Teutsch SM, Juranek DD, Sulzer A, et al. Epidemic toxoplasmosis associated with infected cats. New England Journal of Medicine 1979;300:695-99.
  3. Bowie WR, King AS, Werker DH, et al. Outbreak of toxoplasmosis associated with municipal drinking water. The Lancet 1997;350:173-7.
  4. Benenson MV, Takafuji ET, Lemon SM et al. Oocyst-transmitted toxoplasmosis associated with the ingestion of contaminated water. New England Journal of Medicine 1983;307:666-9.
  5. Carter AO, Frank JW. Congenital toxoplasmosis: Epidemiologic features and control. Canadian Medical Association Journal 1986;135:618-23.
  6. Desmonts G, Couvreur J. Congenital toxoplasmosis: A prospective study of the offspring of 542 women who acquired toxoplasmosis during pregnancy. Pathophysiology of congenital disease, in Thalhammer O, Baumgarten K, Pollak A. (Eds): Perinatal Medicine. Sixth European Congress, Stuttgart, Germany, Thieme, 1979, p.51.
  7. Remington JS, McLeod R, Desmonts G. Toxoplasmosis. In Remington JS, Klein JO (Eds): Infectious Diseases of the Fetus and Newborn, ed 4. Philadelphia, WB Saunders, 1994, pp. 140-267.
  8. Desmonts G, Couvreur J, Thulliez P. Congenital toxoplasmosis: Five cases with mother-to-child transmission of pre-pregnancy infection. Presse Med. 1990;19:1445-9.
  9. Koppe JG, Kloosterman GJ, deRoever-Bonnet H et al. Toxoplasmosis and pregnancy, with a long-term follow-up of the children. European J of Obstet. Gynecol Reprod Biology 1974;413:101-10.
  10. McAuley JB, Boyer KM, Patel D et al. Early and longitudinal evaluation of treated infants and children and untreated historical patients with congenital toxoplasmosis: The Chicago Collaborative Treatment Trial. Clinical Infectious Disease 1994;18:38-72.
  11. Koppe JG, Loewer-Sieger DH, deRoever-Bonnet H. Results of 20-year follow-up of congenital toxoplasmosis. Lancet 1986;1:254-6.
  12. Wilson CB, Remington JS, Stagno S et al. Development of adverse sequelae in children born with subclinical congenital toxoplasma infection. Pediatrics 1980;66:767-74.
  13. Wilson CB, Remington JS. What can be done to prevent congenital toxoplasmosis? American Journal of Obstetrics and Gynecology 1980;138:357-63.
  14. Couvreur J, Desmonts G, Thulliez P. Prophylaxis of congenital toxoplasmosis: Effect of spiramycin on placental infection. Journal of Antimicrobial Chemotherapy 1988;22 Suppl B:193-200.
  15. Hohlfeld P, MacAleese J, Capell-Pavlovsky M et al. Fetal toxoplasmosis: Ultrasonographic signs. Ultrasound Obstet. Gynecol 1991;1:241-4.
  16. Daffos F, Capella-Pavlovsky M, Forestier F. Fetal blood sampling during pregnancy with use of a needle guided by ultrasound: A study of 606 consecutive cases. American Journal of Obstetrics and Gynecology 1985;153:655-60.
  17. Hohlfeld P, Daffos F, Costa JM et al. Prenatal diagnosis of congenital toxoplasmosis with a polymerase-chain-reaction test on amniotic fluid. New England Journal of Medicine 1994;331:695-9.
  18. Hohlfeld P, Daffos F, Thulliez P et al. Fetal toxoplasmosis: Outcome of pregnancy and infant follow-up after in utero treatment. Journal of Pediatrics 1989;115:765-9.
  19. Guerina NG, Hsu HW, Meissner C. et al. Neonatal serologic screening and early treatment for congenital toxoplasma gondii infection. New England Journal of Medicine 1994;330:1858-63.
  20. Mullen A. "I think we have a problem in Victoria: MDs respond quickly to toxoplasmosis outbreak in BC." Canadian Medical Association Journal 1996;154:1721-4.
  21. Proctor EM, Banerjee S. The seroepidemiology of toxoplasmosis in the lower Fraser Valley of British Columbia. Canadian Journal of Infectious Diseases 1994;5:218-23.
  22. denHollander N, LeBer C. Toxoplasma gondii in Ontario and water-borne toxoplasmosis in Victoria, BC 1996. http://ourworld.compuserve.com/homepages/rschabas/toxo.htm .

This Issue of the Motherisk Newsletter is Supported by THE MOTHERISK RESEARCH FUND AND FRIENDS OF MOTHERISK.

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