Anthrax Cases in Pregnant and Postpartum Women: A Systematic Review

CDC Guidelines for the Prevention and Treatment of Anthrax, 2023

This report updates previous CDC guidelines and recommendations on preferred prevention and treatment regimens regarding naturally occurring anthrax. Also provided are a wide range of alternative regimens to first-line antimicrobial drugs for use if patients have contraindications or intolerances or after a wide-area aerosol release of

Bacillus anthracis spores if resources become limited or a multidrug-resistant B. anthracis strain is used (Hendricks KA, Wright ME, Shadomy SV, et al.; Workgroup on Anthrax Clinical Guidelines. Centers for Disease Control and Prevention expert panel meetings on prevention and treatment of anthrax in adults. Emerg Infect Dis 2014;20:e130687; Meaney-Delman D, Rasmussen SA, Beigi RH, et al. Prophylaxis and treatment of anthrax in pregnant women. Obstet Gynecol 2013;122:885-900; Bradley JS, Peacock G, Krug SE, et al. Pediatric anthrax clinical management. Pediatrics 2014;133:e1411-36). Specifically, this report updates antimicrobial drug and antitoxin use for both postexposure prophylaxis (PEP) and treatment from these previous guidelines best practices and is based on systematic reviews of the literature regarding 1) in vitro antimicrobial drug activity against B. anthracis; 2) in vivo antimicrobial drug efficacy for PEP and treatment; 3) in vivo and human antitoxin efficacy for PEP, treatment, or both; and 4) human survival after antimicrobial drug PEP and treatment of localized anthrax, systemic anthrax, and anthrax meningitis.

Changes from previous CDC guidelines and recommendations include an expanded list of alternative antimicrobial drugs to use when first-line antimicrobial drugs are contraindicated or not tolerated or after a bioterrorism event when first-line antimicrobial drugs are depleted or ineffective against a genetically engineered resistant

B. anthracis strain. In addition, these updated guidelines include new recommendations regarding special considerations for the diagnosis and treatment of anthrax meningitis, including comorbid, social, and clinical predictors of anthrax meningitis. The previously published CDC guidelines and recommendations described potentially beneficial critical care measures and clinical assessment tools and procedures for persons with anthrax, which have not changed and are not addressed in this update. In addition, no changes were made to the Advisory Committee on Immunization Practices recommendations for use of anthrax vaccine (Bower WA, Schiffer J, Atmar RL, et al. Use of anthrax vaccine in the United States: recommendations of the Advisory Committee on Immunization Practices, 2019. MMWR Recomm Rep 2019;68[No. RR-4]:1-14). The updated guidelines in this report can be used by health care providers to prevent and treat anthrax and guide emergency preparedness officials and planners as they develop and update plans for a wide-area aerosol release of B. anthracis.

Triage Algorithms for Mass-Casualty Bioterrorism: A Systematic Review

OBJECTIVES

To understand existing triage algorithms, propose improvement measures through comparison to better deal with mass-casualty incidents caused by bioterrorism.

STUDY DESIGN

Systematic review.

METHODS

Medline, Scopus and Web of Science were searched up to January 2022. The studies investigating triage algorithms for mass-casualty bioterrorism. Quality assessment was performed using the International Narrative Systematic Assessment tool. Data extractions were performed by four reviewers.

RESULTS

Of the 475 titles identified in the search, 10 studies were included. There were four studies on triage algorithms for most bioterrorism events, four studies on triage algorithms for anthrax and two studies on triage algorithms for mental or psychosocial problems caused by bioterrorism events. We introduced and compared 10 triage algorithms used for different bioterrorism situations.

CONCLUSION

For triage algorithms for most bioterrorism events, it is necessary to determine the time and place of the attack as soon as possible, control the number of exposed and potentially exposed people, prevent infection and determine the type of biological agents used. Research on the effects of decontamination on bioterrorism attacks needs to continue. For anthrax triage, future research should improve the distinction between inhalational anthrax symptoms and common disease symptoms and improve the efficiency of triage measures. More attention should be paid to triage algorithms for mental or psychosocial problems caused by bioterrorism events.

Clinical Features of Patients Hospitalized for All Routes of Anthrax, 1880-2018: A Systematic Review

BACKGROUND

Anthrax is a toxin-mediated zoonotic disease caused by Bacillus anthracis, with a worldwide distribution recognized for millennia. Bacillus anthracis is considered a potential biowarfare agent.

METHODS

We completed a systematic review for clinical and demographic characteristics of adults and children hospitalized with anthrax (cutaneous, inhalation, ingestion, injection [from contaminated heroin], primary meningitis) abstracted from published case reports, case series, and line lists in English from 1880 through 2018, assessing treatment impact by type and severity of disease. We analyzed geographic distribution, route of infection, exposure to anthrax, and incubation period.

RESULTS

Data on 764 adults and 167 children were reviewed. Most cases reported for 1880 through 1915 were from Europe; those for 1916 through 1950 were from North America; and from 1951 on, cases were from Asia. Cutaneous was the most common form of anthrax for all populations. Since 1960, adult anthrax mortality has ranged from 31% for cutaneous to 90% for primary meningitis. Median incubation periods ranged from 1 day (interquartile range [IQR], 0-4) for injection to 7 days (IQR, 4-9) for inhalation anthrax. Most patients with inhalation anthrax developed pleural effusions and more than half with ingestion anthrax developed ascites. Treatment and critical care advances have improved survival for those with systemic symptoms, from approximately 30% in those untreated to approximately 70% in those receiving antimicrobials or antiserum/antitoxin.

CONCLUSIONS

This review provides an improved evidence base for both clinical care of individual anthrax patients and public health planning for wide-area aerosol releases of B. anthracis spores.

Emergency Preparedness and Response: Highlights from the Division of Reproductive Health, 2011-2021

This report provides historical context and rationale for coordinated, systematic, and evidence-based public health emergency preparedness and response (EPR) activities to address the needs of women of reproductive age. Needs of pregnant and postpartum women, and infants-before, during, and after public health emergencies-are highlighted. Four focus areas and related activities are described: (1) public health science; (2) clinical guidance; (3) partnerships, communication, and outreach; and (4) workforce development. Finally, the report summarizes major activities of the Division of Reproductive Health's EPR Team at the Centers for Disease Control and Prevention.

Florid Bacillus cereus Infection of the Placenta Associated With Intrauterine Fetal Demise

Bacillus cereus is a gram-positive, rod-shaped bacterium that is commonly implicated in foodborne illness but has also become increasingly recognized as a source of serious non-gastrointestinal infections, including sepsis, meningitis, and pneumonia. Non-gastrointestinal B. cereus infections have been identified in children, especially in neonates; however, there are no previously described cases of fetal demise associated with B. cereus placental infection. We present a case of acute chorioamnionitis-related intrauterine fetal demise of twin A at 17 weeks gestation, noted two days after selective termination of twin B. Histological examination revealed numerous gram-positive bacilli in placental tissue, as well as fetal vasculature, in the setting of severe acute necrotizing chorioamnionitis and subchorionitis, intervillous abscesses, acute villitis, and peripheral acute funisitis. Cultures of maternal blood and placental tissue both yielded growth of B. cereus. This case underscores the importance of B. cereus as a human pathogen, and specifically demonstrates its potential as an agent of severe intraamniotic and placental infection with poor outcomes for the fetus.

Plague During Pregnancy: A Systematic Review

BACKGROUND

Yersinia pestis continues to cause sporadic cases and outbreaks of plague worldwide and is considered a tier 1 bioterrorism select agent due to its potential for intentional use. Knowledge about the clinical manifestations of plague during pregnancy, specifically the maternal, fetal, and neonatal risks, is very limited.

METHODS

We searched 12 literature databases, performed hand searches, and consulted plague experts to identify publications on plague during pregnancy. Articles were included if they reported a case of plague during pregnancy and at least 1 maternal or fetal outcome.

RESULTS

Our search identified 6425 articles, of which 59 were eligible for inclusion and described 160 cases of plague among pregnant women. Most published cases occurred during the preantibiotic era. Among those treated with antimicrobials, the most commonly used were sulfonamides (75%) and streptomycin (54%). Among cases treated with antimicrobials, maternal mortality and fetal fatality were 29% and 62%, respectively; for untreated cases, maternal mortality and fetal fatality were 67% and 74%, respectively. Five cases demonstrated evidence of Y. pestis in fetal or neonatal tissues.

CONCLUSIONS

Untreated Y. pestis infection during pregnancy is associated with a high risk of maternal mortality and pregnancy loss. Appropriate antimicrobial treatment can improve maternal survival, although even with antimicrobial treatment, there remains a high risk of pregnancy loss. Limited evidence suggests that maternal-fetal transmission of Y. pestis is possible, particularly in the absence of antimicrobial treatment. These results emphasize the need to treat or prophylax pregnant women with suspected plague with highly effective antimicrobials as quickly as possible.

Severe Coronavirus Infections in Pregnancy: A Systematic Review

OBJECTIVE

To inform the current coronavirus disease 2019 (COVID-19) outbreak, we conducted a systematic literature review of case reports of Middle East respiratory syndrome coronavirus (MERS-CoV), severe acute respiratory syndrome coronavirus (SARS-CoV), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19, during pregnancy and summarized clinical presentation, course of illness, and pregnancy and neonatal outcomes.

DATA SOURCES

We searched MEDLINE and ClinicalTrials.gov from inception to April 23, 2020.

METHODS OF STUDY SELECTION

We included articles reporting case-level data on MERS-CoV, SARS-CoV, and SARS-CoV-2 infection in pregnant women. Course of illness, indicators of severe illness, maternal health outcomes, and pregnancy outcomes were abstracted from included articles.

TABULATION, INTEGRATION, AND RESULTS

We identified 1,328 unique articles, and 1,253 articles were excluded by title and abstract review. We completed full-text review on 75, and 29 articles were excluded by full-text review. Among 46 publications reporting case-level data, eight described 12 cases of MERS-CoV infection, seven described 17 cases of SARS-CoV infection, and 31 described 98 cases of SARS-CoV-2 infection. Clinical presentation and course of illness ranged from asymptomatic to severe fatal disease, similar to the general population of patients. Severe morbidity and mortality among women with MERS-CoV, SARS-CoV, or SARS-CoV-2 infection in pregnancy and adverse pregnancy outcomes, including pregnancy loss, preterm delivery, and laboratory evidence of vertical transmission, were reported.

CONCLUSION

Understanding whether pregnant women may be at risk for adverse maternal and neonatal outcomes from severe coronavirus infections is imperative. Data from case reports of SARS-CoV, MERS-CoV, and SAR-CoV-2 infections during pregnancy are limited, but they may guide early public health actions and clinical decision-making for COVID-19 until more rigorous and systematically collected data are available. The capture of critical data is needed to better define how this infection affects pregnant women and neonates. This review was not registered with PROSPERO.

Plague and Pregnancy: Why Special Considerations Are Needed

Pregnant women are an important at-risk population to consider during public health emergencies. These women, like nonpregnant adults, may be faced with the risk of acquiring life-threatening infections during outbreaks or bioterrorism (BT) events and, in some cases, can experience increased severity of infection and higher morbidity compared with nonpregnant adults. Yersinia pestis, the bacterium that causes plague, is a highly pathogenic organism. There are 4 million births annually in the United States, and thus the unique needs of pregnant women and their infants should be considered in pre-event planning for a plague outbreak or BT event.

Maternal Immunization

Vaccines administered to women during pregnancy can provide protection against serious infectious diseases for the mother, for the newborn, or both. Maternal immunization boosts the concentration of maternal antibodies that can be transferred across the placenta to directly protect infants too young to be immunized. In addition, indirect protection through prevention of maternal infection and through breast milk antibodies can be achieved through maternal immunization. In general, inactivated vaccines are considered safe for pregnant women and their fetuses, whereas live vaccines are avoided owing to the theoretical potential risk to the fetus. However, the risks and benefits of vaccination must be carefully weighed and whenever possible, protection to the mother and her infant should be prioritized. Influenza and tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccines are routinely recommended for all pregnant women in the United States. Seasonal inactivated influenza vaccine is recommended for all pregnant women in any trimester of pregnancy, mainly to protect the mother, but there is growing evidence that infants benefit from passive antibody protection against influenza complications. The Tdap vaccine is recommended during the third trimester of each pregnancy to provide optimal protection to infants who are at particularly high risk of pertussis complications and mortality in the first 3 months of life. The effects of maternal immunization on the prevention of maternal and infant disease have been demonstrated in observational and prospective studies of influenza and pertussis disease in the United States and worldwide. Maternal immunization has the potential to improve the health of mothers and young infants and therefore, other diseases of relevance during this period are now targets of active research and vaccine development, including group B streptococcus and respiratory syncytial virus. Similarly, several vaccines can be administered during pregnancy in special circumstances, when maternal health, travel, or other special situations arise. This article reviews the current recommendations for vaccination of women during pregnancy.

Preparing for biological threats: Addressing the needs of pregnant women

Intentional release of infectious agents and biological weapons to cause illness and death has the potential to greatly impact pregnant women and their fetuses. We review what is known about the maternal and fetal effects of seven biological threats: Bacillus anthracis (anthrax); variola virus (smallpox); Clostridium botulinum toxin (botulism); Burkholderia mallei (glanders) and Burkholderia pseudomallei (melioidosis); Yersinia pestis (plague); Francisella tularensis (tularemia); and Rickettsia prowazekii (typhus). Evaluating the potential maternal, fetal, and infant consequences of an intentional release of an infectious agent requires an assessment of several key issues: (1) are pregnant women more susceptible to infection or illness compared to the general population?; (2) are pregnant women at increased risk for severe illness, morbidity, and mortality compared to the general population?; (3) does infection or illness during pregnancy place women, the fetus, or the infant at increased risk for adverse outcomes and how does this affect clinical management?; and (4) are the medical countermeasures recommended for the general population safe and effective during pregnancy? These issues help frame national guidance for the care of pregnant women during an intentional release of a biological threat. Birth Defects Research 109:391-398, 2017.© 2017 Wiley Periodicals, Inc.

CDC Online Course: Reproductive Health in Emergency Preparedness and Response

In an emergency, the needs of women of reproductive age, particularly pregnant and postpartum women, introduce unique challenges for public health and clinical care. Incorporating reproductive health issues and considerations into emergency preparedness and response is a relatively new field. In recent years, several resources and tools specific to reproductive health have been developed. However, there is still a need for training about the effects of emergencies on women of reproductive age. In an effort to train medical and public health professionals about these topics, the CDC Division of Reproductive Health developed Reproductive Health in Emergency Preparedness and Response, an online course that is available across the United States.

Cutaneous Anthrax on Eyelid in a Pregnant Woman

A 32-year-old patient who was 17 weeks of pregnant referred to our hospital due to a lesion on the eyelid and swelling on her face. Patient's history revealed that she helped her husband for slaughtering of a sick animal and contacted with the meat. A scabby lesion was detected on the inferior eyelid with hyperaemia around, central necrotic appearance and swelling. The diagnosis of anthrax was performed based on her epidemiological data, physical examination findings, and Bacillus anthracis were seen on direct preparation. This case was considered worthy to present since she was pregnant, the disease was located on the inferior eyelid, which is a rare place for location, and caused no complication or sequel either in mother or in baby.

Antitoxin Treatment of Inhalation Anthrax: A Systematic Review

Concern about use of anthrax as a bioweapon prompted development of novel anthrax antitoxins for treatment. Clinical guidelines for the treatment of anthrax recommend antitoxin therapy in combination with intravenous antimicrobials; however, a large-scale or mass anthrax incident may exceed antitoxin availability and create a need for judicious antitoxin use. We conducted a systematic review of antitoxin treatment of inhalation anthrax in humans and experimental animals to inform antitoxin recommendations during a large-scale or mass anthrax incident. A comprehensive search of 11 databases and the FDA website was conducted to identify relevant animal studies and human reports: 28 animal studies and 3 human cases were identified. Antitoxin monotherapy at or shortly after symptom onset demonstrates increased survival compared to no treatment in animals. With early treatment, survival did not differ between antimicrobial monotherapy and antimicrobial-antitoxin therapy in nonhuman primates and rabbits. With delayed treatment, antitoxin-antimicrobial treatment increased rabbit survival. Among human cases, addition of antitoxin to combination antimicrobial treatment was associated with survival in 2 of the 3 cases treated. Despite the paucity of human data, limited animal data suggest that adjunctive antitoxin therapy may improve survival. Delayed treatment studies suggest improved survival with combined antitoxin-antimicrobial therapy, although a survival difference compared with antimicrobial therapy alone was not demonstrated statistically. In a mass anthrax incident with limited antitoxin supplies, antitoxin treatment of individuals who have not demonstrated a clinical benefit from antimicrobials, or those who present with more severe illness, may be warranted. Additional pathophysiology studies are needed, and a point-of-care assay correlating toxin levels with clinical status may provide important information to guide antitoxin use during a large-scale anthrax incident.

The importance of studying antimicrobials in pregnancy

Pregnant women and their unborn fetuses are a population with unique and heightened risks from a variety of infectious conditions. Sizable percentages of pregnant women receive antimicrobials during pregnancy for various indications. Despite this, many of the available antimicrobials in current use have inadequate data to fully inform evidence-based dosage recommendations to optimize clinical impact. Because of non-inclusion of pregnant women in clinical trials this situation exists and challenges the obstetric providers' ability to provide evidence-based treatment. Examples of the impact of the current status of exclusion of pregnant women from participation in clinical trials will be highlighted. In addition, successful models of research permitting safe and informative investigations of various antimicrobials in pregnancy will be discussed.

Clinical management of potential bioterrorism-related conditions

The agents most likely to be used in bioterrorism attacks are reviewed, along with the clinical syndromes they produce and their treatment.

Special considerations for prophylaxis for and treatment of anthrax in pregnant and postpartum women

Clinical recommendations for the prevention and treatment of anthrax among pregnant women are updated.

In August 2012, the Centers for Disease Control and Prevention, in partnership with the Association of Maternal and Child Health Programs, convened a meeting of national subject matter experts to review key clinical elements of anthrax prevention and treatment for pregnant, postpartum, and lactating (P/PP/L) women. National experts in infectious disease, obstetrics, maternal fetal medicine, neonatology, pediatrics, and pharmacy attended the meeting, as did representatives from professional organizations and national, federal, state, and local agencies. The meeting addressed general principles of prevention and treatment for P/PP/L women, vaccines, antimicrobial prophylaxis and treatment, clinical considerations and critical care issues, antitoxin, delivery concerns, infection control measures, and communication. The purpose of this meeting summary is to provide updated clinical information to health care providers and public health professionals caring for P/PP/L women in the setting of a bioterrorist event involving anthrax.

Prophylaxis and treatment of anthrax in pregnant women

OBJECTIVE

To review the safety and pharmacokinetics of antimicrobials recommended for anthrax postexposure prophylaxis and treatment in pregnant women.

DATA SOURCES

Articles were identified in the PubMed database from inception through December 2012 by searching the keywords (["pregnancy]" and [generic antibiotic drug name]). Additionally, we searched clinicaltrials.gov and conducted hand searches of references from REPROTOX, TERIS, review articles, and Briggs' Drugs in Pregnancy and Lactation.

METHODS OF STUDY SELECTION

Articles included in the review contain primary data related to the safety and pharmacokinetics among pregnant women of 14 antimicrobials recommended for anthrax postexposure prophylaxis and treatment (amoxicillin, ampicillin, chloramphenicol, clindamycin, ciprofloxacin, doripenem, doxycycline, levofloxacin, linezolid, meropenem, moxifloxacin, penicillin, rifampin, and vancomycin).

TABULATION, INTEGRATION, AND RESULTS

The PubMed search identified 3,850 articles for review. Reference hand searching yielded nine additional articles. In total, 112 articles met the inclusion criteria.

CONCLUSIONS

Overall, safety and pharmacokinetic information is limited for these antimicrobials. Although small increases in risks for certain anomalies have been observed with some antimicrobials recommended for prophylaxis and treatment of anthrax, the absolute risk of these antimicrobials appears low. Given the high morbidity and mortality associated with anthrax, antimicrobials should be dosed appropriately to ensure that antibiotic levels can be achieved and sustained. Dosing adjustments may be necessary for the β-lactam antimicrobials and the fluoroquinolones to achieve therapeutic levels in pregnant women. Data indicate that the β-lactam antimicrobials, the fluoroquinolones, and, to a lesser extent, clindamycin enter the fetal compartment, an important consideration in the treatment of anthrax, because these antimicrobials may provide additional fetal benefit in the second and third trimesters of pregnancy.

Inhibitors of Bacillus anthracis edema factor

Edema factor (EF) is a calmodulin (CaM)-activated adenylyl cyclase (AC) toxin from Bacillus anthracis that contributes to anthrax pathogenesis. Anthrax is an important medical problem, but treatment of B. anthracis infections is still unsatisfying. Thus, selective EF inhibitors could be valuable drugs in the treatment of anthrax infection, most importantly shock. The catalytic site of EF, the EF/CaM interaction site and allosteric sites constitute potential drug targets. To this end, most efforts have been directed towards targeting the catalytic site. A major challenge in the field is to obtain compounds with high selectivity for AC toxins relative to mammalian membranous ACs (mACs). 3'-(N-methyl)anthraniloyl-2'-deoxyadenosine-5'-triphosphate is the most potent EF inhibitor known so far (Ki, 10nM), but selectivity relative to mACs needs to be improved (currently ~5-50-fold, depending on the specific mAC isoform considered). AC toxin inhibitors can be identified in virtual screening studies based on available EF crystal structures and examined in cellular test systems or at the level of purified toxin using classic radioisotopic or non-radioactive fluorescence assays. Binding of certain MANT-nucleotides to AC toxins elicits large direct fluorescence- or fluorescence resonance energy transfer signals upon interaction with CaM, and these signals can be used to identify toxin inhibitors in competition binding studies. Collectively, potent EF inhibitors are available, but before they can be used clinically, selectivity against mACs must be improved. However, several methodological approaches, complementing each other, are now available to direct the development of potent, selective, orally applicable and clinically useful EF inhibitors.