Amy Krueger et al. Gender (N = 502) Age (mean; years) (N = 500) ACOG districts∗ (N = 468) Practice type (N = 502) Table 1: Demographics for the survey sample of obstetrician-gynecologists and the American College of Obstetricians and Gynecologists (ACOG), 2006. Characteristic Number Study (N = 502) (%) ACOG members (N = 33 354) (%) Male Female District 1 District 2 District 3 District 4 District 5 District 6 District 7 District 8 District 9 Solo Military OB/GYN partnership/group University Other including HMO 254 248 500 27 14 50 77 63 34 105 48 50 95 11 286 61 49 50.6 49.4 46 5.8 3.0 10.7 16.4 13.5 7.3 22.4 10.3 10.7 18.9 2.2 57.0 12.2 9.8 51.8 48.2 47 6.2 6.5 7.3 20.6 10.3 10.2 19.3 10.2 9.0 21.5 5.8 48.9 13.4 10.5 ∗US states and territories in districts are deﬁned as follows: District 1: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, Vermont; District 2: New York; District 3: Delaware, New Jersey, Pennsylvania; District 4: District of Columbia, Florida, Georgia, Maryland, North Carolina, South Carolina, Virginia, West Virginia, Puerto Rico, US West Indies; District 5: Indiana, Kentucky, Ohio, Michigan; District 6: Illinois, Iowa, Minnesota, Nebraska, North Dakota, South Dakota, Wisconsin; District 7: Alabama, Arkansas, Kansas, Louisiana, Mississippi, Missouri, Oklahoma, Tennessee, Texas; District 8: Alaska, Arizona, Colorado, Hawaii, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, Wyoming, American Samoa; District 9: California. 0.2%). Therefore, 95.6% of participants indicated at least one of the correct medications for treatment of giardiasis. 6. SAFEST MEDICATIONS TO USE DURING FIRST TRIMESTER OF PREGNANCY Metronidazole has been found to be carcinogenic in rats and mice but has not been proven so in humans [1, 32]. Metron- idazole rapidly enters the fetal circulation after absorption by the mother, which raises concerns about the use during preg- nancy [1]. Some studies have shown no harmful eﬀects to the fetus [42], and the drug falls in FDA pregnancy category B for teratogenic eﬀects [27]. Many studies have found metron- idazole to be safe for treatment during the second and third trimesters [1, 32, 42]. Over 75% of the participants believed metronidazole to be the safest medication for use in the ﬁrst trimester. Since tinidazole is in the same family as metronida- zole, it displays similar side eﬀects [1]. A case-control study of oral tinidazole treatment has shown placental transfer; it is not generally recommended for use in the ﬁrst trimester of pregnancy much like its relative, metronidazole [43]. Of the respondents in our survey 6.7% considered tinidazole to be the safest treatment in the ﬁrst trimester. Albendazole is in the same family as mebendazole and has also shown inconsistencies in its eﬀectiveness when used alone [1]. Albendazole has been found to be teratogenic in mice and rats and is not generally recommended for use in pregnant women, especially during the ﬁrst trimester [1, 29]. In the current survey, 1.3% of the participants considered al- bendazole to be the safest medication for treatment in preg- nant women. Paromomycin is considered the safest to use for treatment in the ﬁrst trimester because it is poorly absorbed from the intestine and nearly 100% is excreted unchanged; therefore, little if any of the drug reaches the fetus [1, 36]. In addition, no teratogenicity has been found with this treat- ment [36]. Paromomycin has been found to have an eﬃcacy of 55%–90% [1]. Approximately 16% of respondents indi- cated that paramomycin was the safest medication to use in the ﬁrst trimester of pregnancy. Although paromomycin is theoretically the safest treatment in the ﬁrst trimester, it is not necessarily the least expensive or most available. 7. TREATMENT OF ASYMPTOMATIC CARRIERS Screening and treatment of asymptomatic carriers is not gen- erally recommended but depends on the speciﬁc situation in which the patient resides. It is often not desirable to treat Population comparison P-value 0.9056 0.001 0.9081 0.6825 3