2 organism is being shed [12]. However, tests using ELISA or direct ﬂuorescent antibody to detect antigen in the stool are more sensitive than microscopy and are now commonly available and used in the United States. In 2005, a survey was conducted by The American Col- lege of Obstetricians and Gynecologists (ACOG) in collabo- ration with CDC on knowledge about common parasitic dis- eases [27]. The survey showed that many practitioners were not certain how to correctly prescribe medication for many of these diseases, especially which medications are safe for pregnant women [27]. The current study takes the previous survey a step further to determine knowledge about how to diagnose and treat cases of giardiasis. Malabsorption and di- arrhea in pregnant women caused by giardiasis may be harm- ful to the fetus [28]. Along with correct diagnosis, correct treatment helps to ensure the safety of the fetus. In addition, some medications used for giardiasis may have side eﬀects that could aﬀect fetal development [1, 29]. 2. METHODS A questionnaire about two common parasitic diseases (giar- diasis and toxoplasmosis) and their diagnosis and treatment by obstetrician-gynecologists was developed by ACOG and CDC and was distributed nationally by ACOG. For the pur- pose of this paper, we will focus on the giardiasis portion of the survey. The survey was pilot-tested by obstetrician- gynecologists in the Washington, DC, area in December 2005. ACOG mailed the survey to a random sample of 1200 out of 33 354 fellows in February 2006. To ensure the highest response rate possible, four mailing cycles were completed ending in June 2006. Data from returned surveys were as- sembled at the ACOG facility in Washington, DC, using SPSS [30]. Data analysis was performed at the CDC using SAS 9.1 [31]. Frequencies with conﬁdence intervals using bino- mial proportions were used to convey the percentages for the survey’s multiple-choice answers. The mean ages of the to- tal population and survey sample were compared with the Z test; other demographic variable proportions were compared with the chi-square. The survey was reviewed and exempted by human subjects staﬀ at ACOG and CDC. 3. RESULTS Of the 1200 ACOG fellows who were mailed the survey, 502 responded for a response rate of 42%. Table 1 displays the de- mographics for the participants including gender, location, and type of practice, as well as statistical diﬀerences between the survey population and the ACOG member population. The survey population had a slightly lower mean age than the ACOG member population (46 years versus 47 years, resp., P = .001). Generally, the participants answered the survey questions correctly, although for a few questions there was a lot of uncertainty. Medication used for the treatment of giardia- sis was one area where fewer of the participants indicated the most correct answer. Approximately half (49.6%) of the participants chose metronidazole, which is used for treat- Infectious Diseases in Obstetrics and Gynecology ment of giardiasis; however many participants did not rec- ognize that mebendazole is not a primary treatment of gi- ardiasis, and that tinidazole and nitazoxanide can also be used for treatment. The participants also did not usually se- lect the safest medication to use for pregnant women in the ﬁrst trimester. The majority (75.8%) believed metronida- zole to be the safest, while in actuality paromomycin is the safest treatment in the ﬁrst trimester (although less eﬀective). The practitioners (66.8%) also believed that the treatment of asymptomatic carriers is recommended, however it is not the recommended practice in most cases. Table 2 shows the dis- tributions for each survey question. 4. DISCUSSION The objective of this study was to create a concise sur- vey that would cover the basics in knowledge about giar- diasis. Through this survey, we found that the majority of obstetrician-gynecologists provided correct information re- garding giardiasis; however, the survey also showed areas where further education is needed. Most physicians correctly answered questions about how the disease is transmitted, prevention methods, and outcomes of the disease. However, one of the most important issues concerning the disease is treatment and many of the participants might beneﬁt from further education in this area (Table 2). 5. MEDICATIONS USED FOR TREATMENT OF GIARDIASIS Gardner and Hill [1] provide a thorough review of drugs for treatment of giardiasis including medications for the use in pregnant women. The largest class of agents to treat Giar- dia is the nitroimidazoles, which includes metronidazole and tinidazole. Metronidazole is the most common drug used to treat giardiasis worldwide [1]. It has been found to have an eﬃcacy of 85%–90% in adult and pediatric patients [1, 32]. Tinidazole is one of the drugs with potential for the great- est compliance since it has a longer half-life and can be taken in one dose [1, 33, 34]. In 2004, tinidazole was approved for use in the United States [35]. Studies have shown the drug to have a median eﬃcacy of 92%, and up to 100% for a one- dose regimen [1, 36]. Nitazoxanide was approved for treat- ment of Giardia in the US in 2003 [16]. A study in Mex- ico found nitazoxanide to have an eﬃcacy rate of 56%-74%, while other studies have found eﬃcacy rates as high as 80% [16]. An in vitro study showed that nitazoxanide is more po- tent than albendazole and metronidazole, 2.5 and 50 times, respectively [37]. Clinical trials with mebendazole have given varying results, and thus other therapies are preferentially recommended [1, 38–41]. Trials comparing mebendazole to metronidazole showed that mebendazole was less eﬀective against giardial infections [38–40]. In the survey, the best answer was to recognize that mebendazole is not the pre- ferred method of treatment (in Table 2 “all except meben- dazole” was chosen by 45.7%). However, many participants (49.6%) chose metronidazole as the medication to use for treatment, which is correct, as well as tinidazole (chosen by