An Overview of Tickborne Infections in Pregnancy and Outcomes in the Newborn: The Need for Prospective Studies

Infection by Tickborne Bacterium Candidatus Midichloria Associated with First Trimester Pregnancy Loss, Tennessee, USA

A previously healthy 26-year-old woman in middle Tennessee, USA, experienced a first trimester pregnancy loss after multiple tick bites. Histopathology, 16S rRNA sequencing, and electron microscopy examination of the products of conception revealed an infection by a bacterium within the Candidatus Midichloria genus.

A Day in the Woods in Pregnancy: Fetal and Neonatal Implications

Borrelia miyamotoi disease (BMD), also known as hard-tick relapsing fever, is an emerging tick-borne illness caused by the bacterium Borrelia miyamotoi. This pathogen is transmitted primarily by Ixodes ticks, also known as deer ticks or black-legged ticks. BMD poses significant public health concerns because of its potential to cause severe hemodynamic and hematologic disturbances, particularly in vulnerable populations such as pregnant individuals. BMD often presents with symptoms like other tick-borne infections, including fever, chills, headache, and muscle aches, but often lacks the characteristic rash seen in Lyme disease and does not typically have a greater-than-24-hour tick attachment period for transmission. A high index of suspicion in the late spring and summer months in the Northern hemisphere is essential for early diagnosis of BMD and treatment to prevent maternal and neonatal morbidity and mortality.

Pregnancy Among Reported Lyme Disease Cases-United States, 1992-2019

BACKGROUND

Lyme disease (LD), the most common vector-borne disease in the United States, typically presents with a localised erythema migrans rash (EM). Left untreated, infection can disseminate to cause severe heart, joint or nervous system manifestations. Summaries of LD surveillance data have been published previously but did not include the frequency, demographic or clinical characteristics of LD cases during pregnancy.

METHODS

We summarised confirmed and probable LD cases by pregnancy status as reported to the U.S. Centers for Disease Control and Prevention during 1992-2019. We defined an LD case during pregnancy as one with (1) female sex, (2) age 14-49 years and (3) positive pregnancy indication. We evaluated the frequency, seasonality, age distribution, race and ethnicity, geographic distribution and clinical manifestations of LD cases during pregnancy and cases among non-pregnant females. We compared proportions using chi-squared tests.

RESULTS

Among 698,876 reported LD cases, 112,002 (16%) were confirmed or probable cases among females aged 14-49 years; 32,301 (29%) were specifically reported as non-pregnant and 643 (0.6%) (568 confirmed and 75 probable cases) reported as pregnant. Illness onset peaked in June among LD cases during pregnancy, but in July for cases among non-pregnant females. A higher proportion of confirmed LD cases during pregnancy had only EM rash than did cases among non-pregnant females (66% vs. 60%, p = 0.019).

CONCLUSIONS

LD cases during pregnancy are rare. Compared to non-pregnant females, cases among pregnant females more commonly involve early clinical manifestations. These patterns could suggest earlier detection or more complete reporting of LD cases during pregnancy than their non-pregnant counterparts. Earlier detection could be due to frequent contact with healthcare or increased self-advocacy during pregnancy. Prompt antimicrobial treatment is critical for preventing severe disease and reducing risk of adverse pregnancy or birth outcomes.

Examining Infant and Child Neurodevelopmental Outcomes After Lyme Disease During Pregnancy

Lyme disease is the most common vector-borne disease in the United States. Recent environmental and socioecological changes have led to an increased incidence of Lyme and other tick-borne diseases, which enhances the urgency of identifying and mitigating adverse outcomes of Lyme disease exposure. Lyme disease during pregnancy, especially when untreated, may lead to adverse pregnancy and neonatal outcomes; however, long-term child outcomes following utero exposure to Lyme disease have not yet been systematically assessed. This concise review describes the current state of knowledge of Lyme disease as a congenital infection and the potential effects of in utero exposure to Lyme disease infection on the neurodevelopment of infants and children. We highlight the importance of distinguishing between acute Lyme disease and a chronic condition termed Post-Treatment Lyme Disease Syndrome, as the impacts of both conditions on the developing fetus and subsequent child development may differ. The importance of placental pathology for patients with acute or chronic symptoms of Lyme disease in pregnancy is explored. Future research aiming to understand and protect neurodevelopment after antenatal Lyme disease must carefully collect potentially confounding variables such as symptomatology and treatment, use clear and standard case definitions, and follow children into school-age and beyond.

An Unusual Case of Serologically Confirmed Post-Partum Lyme Disease Following an Asymptomatic Borrelia burgdorferi Infection Acquired during Pregnancy and Lacking Vertical Transmission in Utero

In this report, we describe a 23-year-old female who, while pregnant, was exposed to Borrelia burgdorferi but did not develop significant signs or symptoms (joint pain, arthritis) of Lyme disease until shortly after delivering a healthy child at term. Serologic testing confirmed infection with B. burgdorferi. A 3-week course of treatment with doxycycline was completely curative. There was no evidence for congenital or perinatal transmission of this pathogen at any point pre-term or postnatally. The key reasons that could account for this unique clinical scenario are discussed in the context of previously published related reports.

Perinatal transmission of Lyme disease: A qualitative study investigating the research priorities of patients with Lyme disease in pregnancy

INTRODUCTION

Lyme disease is one of the most prevalent vector-borne disease in North America, yet its implications during pregnancy are poorly understood. Our knowledge of perinatal transmission of Lyme disease is limited due to the lack of robust epidemiological studies and longitudinal follow-up.

OBJECTIVES

This study aimed to understand the research priorities of people who have experienced Lyme disease in pregnancy and the feasibility of recruiting this population for future studies on perinatal transmission of Lyme disease. We also sought to understand the barriers and enablers to participating in research on perinatal transmission of Lyme disease.

METHODS

We conducted a qualitative study using focus groups and interviews with people who had experienced Lyme disease during pregnancy. English speaking participants were recruited through an online survey. There was no geographic restriction on participation. The focus groups and the interview were recorded and transcribed. Data were analyzed using interpretive content analysis.

RESULTS

Twenty people participated in four semi-structured focus groups and one semi-structured individual interview. The majority of participants were from North America. Participants' research priorities fell into five categories: transmission, testing, treatment, disease presentation, and education. All study participants expressed interest in future participation in research on Lyme disease in pregnancy and highlighted barriers and enablers to participation that could be addressed to facilitate future study recruitment.

CONCLUSION

The research priorities identified in this research would be well addressed through prospective research. People who experience Lyme disease in pregnancy are invested in continued research into perinatal transmission of Lyme disease.

Developing a Prospective Gestational Lyme Disease Study

Lyme disease in pregnancy is understudied. The few available reports of Borrelia infection during pregnancy collecting clinical outcomes, with or without confirmed fetal infection both in utero and neonatal, are limited to case reports and small series. Population-based studies are not available. We propose a prospective study of Borrelia infection during pregnancy based in obstetrical practices in both endemic and nonendemic areas, with long term follow-up of pregnancy outcomes and development assessment of offspring infected or exposed to Borrelia in utero using current serological, microscopic, culture, and molecular techniques. In addition to detection of Borrelia burgdorferi sensu stricto, additional Borrelia species and other pathogens known to be transmitted by ticks will be tested. Serial biospecimens including maternal and cord blood, maternal peripheral blood mononuclear cells and urine, and, when clinically indicated, amniotic fluid, chorionic villi, intrauterine cord blood, will be collected with clinical data, imaging, and for infections treatment medications. Offspring will be followed until age 5 years with annual developmental assessments to assess pregnancy outcomes. The study will require parallel development of a biorepository with strategies for management, data security and data sharing. A public-private partnership will be required to support the study.

Lyme borreliosis in pregnancy and associations with parent and offspring health outcomes: An international cross-sectional survey

Background

Lyme disease (LD) is a complex tick-borne pathology caused by Borrelia burgdorferi sensu lato bacteria. Currently, there are limited data regarding the health outcomes of people infected during pregnancy, the potential for perinatal transmission to their fetus, and the long-term effects on these children. Therefore, the primary objective of this survey study was to investigate the impact of LD in pregnancy on both the parent and their offspring.

Methods

A seven-section survey was developed and administered in REDCap. Although recruitment was primarily through LD-focused organizations, participation was open to anyone over the age of 18 who had been pregnant. Participant health/symptoms were compared across those with “Diagnosed LD,” “Suspected LD,” or “No LD” at any time in their lives. The timing of LD events in the participants’ histories (tick bite, diagnosis, treatment start, etc.) were then utilized to classify the participants’ pregnancies into one of five groups: “Probable Treated LD,” “Probable Untreated LD,” “Possible Untreated LD,” “No Evidence of LD,” and “Unclear.”

Results

A total of 691 eligible people participated in the survey, of whom 65% had Diagnosed LD, 6% had Suspected LD, and 29% had No LD ever. Both the Diagnosed LD and Suspected LD groups indicated a high symptom burden (p < 0.01). Unfortunately, direct testing of fetal/newborn tissues for Borrelia burgdorferi only occurred following 3% of pregnancies at risk of transmission; positive/equivocal results were obtained in 14% of these cases. Pregnancies with No Evidence of LD experienced the fewest complications (p < 0.01) and were most likely to result in a live birth (p = 0.01) and limited short- and long-term offspring pathologies (p < 0.01). Within the LD-affected pregnancy groups, obtaining treatment did not decrease complications for the parent themselves but did ameliorate neonatal health status, with reduced rates of rashes, hypotonia, and respiratory distress (all p < 0.01). The impact of parent LD treatment on longer-term child outcomes was less clear.

Conclusion

Overall, this pioneering survey represents significant progress toward understanding the effects of LD on pregnancy and child health. A large prospective study of pregnant people with LD, combining consistent diagnostic testing, exhaustive assessment of fetal/newborn samples, and long-term offspring follow-up, is warranted.

Tick-borne encephalitis in pregnant women – a mini narrative review

Tick-borne encephalitis (TBE) incidence has been increasing in Europe the last decades, but very few cases in pregnant women have been described. We present two cases and describe the serology of both mother and infant at the time of diagnosis and delivery, as well as at months 3, 6, 9, and 12 of follow-up. In both cases, pregnancies and infants developed normally. The mothers had moderate-to severe symptoms of TBE and were positive for IgM and IgG at the time of diagnosis, and throughout the follow up period whilst both infants were PCR- and IgM-negative and positive for IgG during their first months in life. Declining IgG titres were seen in the infants during follow-up until they became negative at the age of nine months. TBE IgG was vertically transmitted in these two cases of infants born to TBE-infected mothers.

Case Report: Lyme Borreliosis and Pregnancy - Our Experience

Lyme Borreliosis (LB) is an infection transmitted by Ixodes sp. ticks. Its early manifestation includes erythema migrans rash. Since the discovery of LB in 1975, the question arose as to whether this infection could be vertically transmitted from mother to fetus during pregnancy, as transplacental transmission has already been known for other spirochetoses, such as syphilis, relapsing fever and leptospirosis. The first confirmed case with positive Lyme serology was described in 1985 in a 28-year- old mother who had acquired Lyme in the first trimester and then developed an erythema migrans rash. Subsequently, transmission of Borrelia burgdorferi sl. in humans from mother to fetus has been documented through identification of Borrelia spirochetes in fetal tissues/and or placenta by various methods including culture, PCR and indirect immunofluorescence. Adverse birth outcomes, which are limited in case of prompt LB treatment, included spontaneous miscarriage, preterm birth and hyperbilirubinemia, but also cardiac involvement and cutaneous angiomas have been documented although rarely. No significant associations were found between adverse outcomes at birth and the trimester of infection. Patients treated for gestational LB had a lower frequency of miscarriages and premature births, as also the frequency of congenital malformations was similar to that observed in the normal population. The recommended treatment for LB in pregnancy is Amoxicillin, 1 g 3 times a day for 14-21 days. In the present study, we report our case series, which includes 11 pregnant women, 6 of which developed erythema migrans during pregnancy (between week 8 and 34), 3 had myoarticular or neurological symptoms and 2 had positive serology, but did not develop any clinical symptoms. Our data stress on the importance of early antibiotic treatment also in seropositive gestating women without symptoms in order to avoid any possible complication to fetus and newborns.

Tick borne relapsing fever - a systematic review and analysis of the literature

Tick borne relapsing fever (TBRF) is a zoonosis caused by various Borrelia species transmitted to humans by both soft-bodied and (more recently recognized) hard-bodied ticks. In recent years, molecular diagnostic techniques have allowed to extend our knowledge on the global epidemiological picture of this neglected disease. Nevertheless, due to the patchy occurrence of the disease and the lack of large clinical studies, the knowledge on several clinical aspects of the disease remains limited. In order to shed light on some of these aspects, we have systematically reviewed the literature on TBRF and summarized the existing data on epidemiology and clinical aspects of the disease. Publications were identified by using a predefined search strategy on electronic databases and a subsequent review of the reference lists of the obtained publications. All publications reporting patients with a confirmed diagnosis of TBRF published in English, French, Italian, German, and Hungarian were included. Maps showing the epidemiogeographic mosaic of the different TBRF Borrelia species were compiled and data on clinical aspects of TBRF were analysed. The epidemiogeographic mosaic of TBRF is complex and still continues to evolve. Ticks harbouring TBRF Borrelia have been reported worldwide, with the exception of Antarctica and Australia. Although only molecular diagnostic methods allow for species identification, microscopy remains the diagnostic gold standard in most clinical settings. The most suggestive symptom in TBRF is the eponymous relapsing fever (present in 100% of the cases). Thrombocytopenia is the most suggestive laboratory finding in TBRF. Neurological complications are frequent in TBRF. Treatment is with beta-lactams, tetracyclines or macrolids. The risk of Jarisch-Herxheimer reaction (JHR) appears to be lower in TBRF (19.3%) compared to louse-borne relapsing fever (LBRF) (55.8%). The overall case fatality rate of TBRF (6.5%) and LBRF (4-10.2%) appears to not differ. Unlike LBRF, where perinatal fatalities are primarily attributable to abortion, TBRF-related perinatal fatalities appear to primarily affect newborns.

Less common bacterial, fungal and viral infections: review of management in the pregnant patient

This review is a comprehensive summary of treatment options for pregnant patients with less common bacterial, fungal, and viral infections. It offers guidance to clinicians based on the most recently published evidence-based research and expert recommendations. A search of MEDLINE (inception to March 2021) and the CDC website was performed. Liposomal amphotericin B is the preferred therapy for cryptococcosis, histoplasmosis, oesophageal candidiasis, and coccidioidomycosis, especially during the first trimester due to teratogenic concerns with azole antifungals. For oral candidiasis, clotrimazole troches or miconazole mucoadhesive buccal tablets are recommended. A β-lactam antimicrobial is preferred over doxycycline for various manifestations of Lyme disease and the drug of choice for Pneumocystis pneumonia is trimethoprim/sulfamethoxazole. Acyclovir is the preferred antiviral for varicella zoster virus. Fluoroquinolones, macrolides, and aminoglycosides should be avoided if possible and there are alternate agents available for an effective treatment regimen. There is a scarcity of clinical data in pregnant patients with less common bacterial, fungal and viral infections. This population lacks definitive recommendations in many clinical practice guidelines. The key to optimizing therapy is a comprehensive review of the available evidence and a careful balance of risks and benefits before final treatment decisions.

Protein and DNA Biosynthesis Demonstrated in Host Cell-Free Phagosomes Containing Anaplasma phagocytophilum or Ehrlichia chaffeensis in Axenic Media

Rickettsiae belong to the Anaplasmataceae family, which includes mostly tick-transmitted pathogens causing human, canine, and ruminant diseases. Biochemical characterization of the pathogens remains a major challenge because of their obligate parasitism.

Rickettsiae belong to the Anaplasmataceae family, which includes mostly tick-transmitted pathogens causing human, canine, and ruminant diseases. Biochemical characterization of the pathogens remains a major challenge because of their obligate parasitism. We investigated the use of an axenic medium for growth of two important pathogens—Anaplasma phagocytophilum and Ehrlichia chaffeensis—in host cell-free phagosomes. We recently reported that the axenic medium promotes protein and DNA biosynthesis in host cell-free replicating form of E. chaffeensis, although the bacterial replication is limited. We now tested the hypothesis that growth on axenic medium can be improved if host cell-free rickettsia-containing phagosomes are used. Purification of phagosomes from A. phagocytophilum- and E. chaffeensis-infected host cells was accomplished by density gradient centrifugation combined with magnet-assisted cell sorting. Protein and DNA synthesis was observed for both organisms in cell-free phagosomes with glucose-6-phosphate and/or ATP. The levels of protein and DNA synthesis were the highest for a medium pH of 7. The data demonstrate bacterial DNA and protein synthesis for the first time in host cell-free phagosomes for two rickettsial pathogens. The host cell support-free axenic growth of obligate pathogenic rickettsiae will be critical in advancing research goals in many important tick-borne diseases impacting human and animal health.