Systematic Review of Tularemia During Pregnancy

Background Tularemia is caused by the gram-negative bacterium Francisella tularensis. Although rare, tularemia during pregnancy has been associated with pregnancy complications; data on efficacy of recommended antimicrobials for treatment are limited. We performed a systematic literature review to characterize clinical manifestations of tularemia during pregnancy and examine maternal, fetal, and neonatal outcomes with and without antimicrobial treatment.Methods We searched 9 databases, including Medline, Embase, Global Health, and PubMed Central, using terms related to tularemia and pregnancy. Articles reporting cases of tularemia with >= 1 maternal or fetal outcome were included.Results Of 5891 articles identified, 30 articles describing 52 cases of tularemia in pregnant patients met inclusion criteria. Cases were reported from 9 countries, and oropharyngeal and ulceroglandular tularemia were the most common presenting forms. A plurality (46%) of infections occurred in the second trimester. Six complications were observed: lymph node aspiration, lymph node excision, maternal bleeding, spontaneous abortion, intrauterine fetal demise, and preterm birth. No deaths among mothers were reported. Of 28 patients who received antimicrobial treatment, 1 pregnancy loss and 1 fetal death were reported. Among 24 untreated patients, 1 pregnancy loss and 3 fetal deaths were reported, including one where F. tularensis was detected in placental and fetal tissues.Conclusions Pregnancy loss and other complications have been reported among cases of tularemia during pregnancy. However, risk of adverse outcomes may be lower when antimicrobials known to be effective are used. Without treatment, transplacental transmission appears possible. These data underscore the importance of prompt recognition and treatment of tularemia during pregnancy. Tularemia has been associated with adverse outcomes in pregnancies where no effective antimicrobials were administered. Possible evidence of F. tularensis in placental and fetal tissues suggests that tularemia is transmissible from mother to fetus in the absence of effective treatment.