Leptospirosis in pregnancy: A systematic review

Leptospirosis

Leptospirosis is a zoonotic bacterial infection that is prevalent across all continents and is caused by pathogenic spirochaetes of the genus Leptospira. Although infection can be asymptomatic, symptomatic disease can vary in severity from mild to severe illness, the latter characterized by icterus and/or multi-organ dysfunction and potentially death. An estimated one million cases of leptospirosis occur globally each year, resulting in ~60,000 deaths. The pathogenesis of severe leptospirosis is poorly understood but is believed to involve an interplay between genetic predisposition, pathogen virulence and dysregulated immune responses that trigger a cytokine storm with associated immunoparesis. Leptospira are susceptible to several low-cost antibiotics, including benzyl penicillin, doxycycline, cephalosporins and macrolides, when used in the early phase of infection. Late disease with organ dysfunction is treated with supportive care, and the benefit of antibiotics during late disease is doubtful. Very few countries have licensed a vaccine for human leptospirosis, and available vaccines only protect against rodent-associated serogroups. Exposure control by behavioural modifications and personal protective measures are the major preventative measures in leptospirosis, and the efficacy of prophylactic antibiotics has not been confirmed in clinical trials. Future research is needed to accurately estimate leptospirosis disease burden across the globe, to understand the pathophysiology of severe leptospirosis to inform the design of targeted immunotherapies and vaccines, and to develop cost-effective and accurate point-of-care diagnostics.

Molecular Characterization of Gene Encoding Outer Membrane Protein loa22 in Pathogenic Leptospira Serovars in Iran

The loa22 protein is highly conserved among pathogenic Leptospira serovars and it is expressed during both acute and chronic infections. The aim of this study was to clone and sequence of the loa22 protein-encoding gene of Leptospira serovars. In this study, 23 pathogenic Leptospira serovars and two nonpathogenic Leptospira serovars were used. These serovars were obtained from the microbial culture collection of Leptospira Reference Laboratory, Department of Microbiology, Razi Vaccine and Serum Research Institute, Karaj, Iran. Three serovars, including L. Sejroe Hardjo-bovis, L. Grippotyphosa, L. Canicola, are used in the preparation of the trivalent vaccine. The loa22 gene was amplified by specific primers and the PCR products were then purified using kit and were cloned into a pTZ57R/T vector and transformed in competent E. coli DH5α cells. The cells were then plated onto LB agar containing ampicillin and recombinant colonies subjected to colony PCR to confirm the presence of the Leptospiral gene. Positive colonies plasmid vector was isolated from cells by High Pure Plasmid Isolation Kit. The loa22 gene was detected in all 23 pathogenic serovars, while this gene was not observed in nonpathogenic L. biflexa. It was determined that the similarity percentage of the sequenced pathogenic serovars is between 95.5% and 100%. The results concluded that the loa22 gene was highly conserved among various pathogenic Leptospira serovars and can be used to develop an effective recombinant vaccine.

Foetal outcome of Leptospira and Rickettsial infections during pregnancy: a systematic review

BACKGROUND

Leptospirosis and rickettsial infections are bacterial zoonoses prevalent in different geographical locations and presents with overlapping symptoms.

OBJECTIVE

To identify foetal outcomes in pregnant women diagnosed with rickettsial infections, including scrub typhus and leptospirosis, along with their associated factors.

METHODS

A comprehensive search was conducted in MEDLINE/PubMed, Scopus, CENTRAL (Cochrane), Web of Science, PsycINFO, Academic Search Premier, CINAHL, and Embase using defined search terms. Studies involving pregnant women with diagnosed leptospirosis and rickettsial infections, including scrub typhus, were selected. Two independent reviewers screened titles and abstracts using the Rayyan Web interface. Data extraction was performed in Microsoft Excel, with Zotero for reference management. Study quality was assessed using Joanna Briggs Institute Critical Appraisal tools. Data synthesis included narrative analysis.

RESULTS

Fifty-four studies were included: 22 on scrub typhus, 14 on rickettsial infection, 16 on leptospirosis, and 2 on all three infections. Of 176 scrub typhus cases, 53 resulted in foetal loss and 3 in neonatal death. Among 38 rickettsial infection cases, 4 had foetal loss. Out of 63 leptospirosis cases, 13 experienced foetal loss. Six maternal deaths occurred due to scrub typhus and one due to Rocky Mountain spotted fever.

CONCLUSION

Leptospirosis and rickettsial infections, including scrub typhus, are important causes of pregnancy loss. Further research is needed to better understand and mitigate these risks in pregnant women.

Immune Cells and Infectious Diseases in Preeclampsia Susceptibility

Preeclampsia is a severe pregnancy disorder, affecting approximately 10% of pregnancies worldwide, characterised by hypertension and proteinuria after the 20th week of gestation. The condition poses significant risks to both maternal and fetal health, including cardiovascular complications and impaired fetal development. Recent trends indicate a rising incidence of preeclampsia, correlating with factors such as advanced maternal age and cardiovascular comorbidities. Emerging evidence also highlights a notable increase in the association between autoimmune and infectious diseases with preeclampsia. Autoimmune conditions, such as type 1 diabetes and systemic lupus erythematosus, and infections triggered by global health challenges, including leptospirosis, Zika, toxoplasmosis, and Chagas disease, are now recognised as significant contributors to preeclampsia susceptibility by affecting placental formation and function. This review focuses on the immunologic mechanisms underpinning preeclampsia, exploring how immune system dysregulation and infectious triggers exacerbate the condition. It also discusses the pathologic mechanisms, including galectins, that preeclampsia shares with autoimmune and infectious diseases, and their significant risk for adverse pregnancy outcomes. We emphasise the necessity for accurate diagnosis and vigilant monitoring of immune and infectious diseases during pregnancy to optimise management and reduce risks. By raising awareness about these evolving risks and their impact on pregnancy, we aim to enhance diagnostic practices and preventive strategies, ultimately improving outcomes for pregnant women, especially in regions affected by environmental changes and endemic diseases.

Laboratory diagnosis and epidemiological features of leptospirosis cases in a tribal region of Western Maharashtra, India: A retrospective study

PURPOSE

Palghar district, located in the coastal region of the Konkan division of Maharashtra, has a predominantly tribal population. Leptospirosis is a major neglected public health problem and is highly underreported in Palghar district. The study aimed to evaluate the seropositivity of Leptospira infection and its associated epidemiological factors in tribal areas of the Palghar district of Maharashtra.

METHODS

The present retrospective study included 94 samples of patients clinically suspected of leptospirosis during a period of one year (2021-2022) tested at Model Rural Health Research Unit (MRHRU) Dahanu. The serum sample testing was done for the presence of specific Leptospira IgM antibodies using the Panbio™ Leptospira IgM ELISA kit. Leptospirosis seropositivity was correlated with various epidemiological risk factors.

RESULTS

A total of 12 samples of patients tested positive for specific IgM antibodies by ELISA method, indicating an overall positivity of 12.8%. Among those who tested positive, fever (83.3%), headache (58.3%), myalgia (50%), redness of the eyes (50%), and calf tenderness (16.7%) were the common symptoms observed. Subjects with redness of the eyes were significantly associated with leptospirosis (p = 0.018). The highest positivity (50%) was reported from the Ganjad area of Dahanu taluka. Farmers and animal handlers were most affected by leptospirosis.

CONCLUSION

The high proportion of Leptospirosis cases reflects the endemic nature of the disease in the Palghar district. This study shows seasonal trends in leptospirosis incidence over the year. The clinical presentation of leptospirosis may vary from sub-clinical to mild illness to severe and potentially fatal. The findings of this study will be important for achieving the overarching goal of One Health.

Leptospirosis-Associated Acute Respiratory Distress Syndrome (ARDS) in Pregnancy: A Rare Presentation

Leptospirosis, a zoonotic disease caused by spirochetes of the genus Leptospira, poses unique challenges in pregnancy due to its varied clinical presentation and potential adverse outcomes for both mother and fetus. We present a case of a 24-year-old primigravida at 35 weeks of gestation who presented with fever, dyspnea, and abdominal pain, and was ultimately diagnosed with leptospirosis complicated by acute respiratory distress syndrome (ARDS). Prompt initiation of antibiotic therapy, supportive care, and timely delivery via emergency cesarean section led to favorable maternal and neonatal outcomes. This case report underscores the importance of considering leptospirosis in pregnant patients presenting with similar symptoms, particularly in endemic regions, and highlights the critical role of multidisciplinary management in optimizing outcomes.

Gender differences in the perception of leptospirosis severity, behaviours, and Leptospira exposure risk in urban Brazil: a cross-sectional study

Background

Vulnerability to climate hazards and infectious diseases are not gender-neutral, meaning that men, women, boys, girls, and other gender identities experience different health risks. Leptospirosis, a zoonotic climate sensitive infectious disease, is commonly transmitted to humans via contact with animals and the environment, particularly soil and flood water. Gender differences in leptospiral infection risk are reported globally, with men consistently found to be at higher risk than women. However, the drivers of this difference in risk are poorly understood. Previous studies suggest that the interplay of knowledge, perceptions, and behaviours may shape differential infection risk among genders.

Methodology/Principal Findings

To examine gender differences in Leptospira exposure risk we conducted a cross-sectional serosurvey among adult participants (n = 761) in four urban, marginalised, informal settlements in the city of Salvador, Brazil. We found that seroprevalence was 14.6% and 9.4% across men and women respectively. We then applied causal inference methodology to a two-part sex-disaggregated analysis to investigate: 1) the association of perceptions and behaviours with Leptospira seropositivity and 2) the association of perceptions with behaviours. We found that men who perceived leptospirosis as extremely serious had lower odds of seropositivity, walking through sewage water, or walking barefoot, suggesting an important link between perceptions, behaviours, and exposure risk. These associations were not found in women, and these behaviours were not associated with seropositivity in men or women.

Conclusions

Our results highlight perceived severity of disease as a potential driver of behaviour in men, and perceptions of disease may be an important target for health education programs. Furthermore, our study identifies evidence gaps in the understanding of infection risks in women. As the first sex-disaggregated study investigating Leptospira infection risks, we advocate for a gendered lens in future studies to further understand risks specific to different gender identities.

Stillbirth and fulminant postpartum haemolysis: COVID-19 or leptospirosis or both?

We report the case of a female patient with a SARS-CoV-2 infection first diagnosed at 32 2/7 weeks of gestation, resulting in stillbirth at 33 5/7 weeks of gestation. Post partum the patient presented with severe and persistent haemolysis, mild thrombocytopaenia, renal insufficiency and proteinuria as well as elevated liver enzymes and jaundice. Further investigations revealed a positive IgM for Leptospira interrogans and proof of infection by PCR in the urine. The patient was treated with penicillin for 7 days and received a total of 23 units of red blood cells within 11 days. Haemolysis diminished over time and haemoglobin, proteinuria and transaminases normalised within 23 days after delivery. We suppose an acute leptospirosis as underlying cause for the haemolysis, mimicking pregnancy-associated thrombotic microangiopathy. Whether stillbirth was related to leptospirosis or SARS-CoV-2 infection remains unclear.

Leptospirosis Manifesting as HELLP (Hemolysis, Elevated Liver Enzymes, and Low Platelets) Syndrome: A Rare Case of Leptospirosis During Pregnancy

Pregnancy is characterized by a reduced immune response, making pregnant women more susceptible to infections. We present a case of a 24-year-old woman in her second pregnancy who arrived at the hospital at 36 weeks gestation in active labor. The patient had received regular antenatal care including routine prenatal check-ups, screenings, and appropriate vaccinations. She complained of abdominal pain for 5-6 hours, sudden onset of hematuria, and a history of low-grade fever for two days. Physical examination revealed paleness, grade three pedal edema, and elevated blood pressure. Diagnostic tests showed mild anemia, thrombocytopenia, proteinuria, elevated liver enzymes, and kidney dysfunction. The patient was admitted to the labor ward, and a tentative diagnosis of hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome was made. Shortly after arrival, she spontaneously delivered a healthy baby. However, post-delivery, her fever profile indicated the presence of leptospira IgM antibodies, leading to a diagnosis of leptospirosis mimicking HELLP syndrome. Immediate medical treatment resulted in symptom resolution within two weeks and normal biochemical values within a month. Leptospirosis, caused by the gram-negative spirochete bacteria leptospira, is a zoonotic infection rarely observed during pregnancy and can be misdiagnosed due to its atypical presentation. It can mimic other pregnancy-related conditions such as viral hepatitis, obstetric cholestasis, HELLP syndrome, and acute fatty liver of pregnancy. Early detection and treatment are crucial as this disease can have serious consequences for both the mother and fetus. Therefore, leptospirosis should be considered a potential differential diagnosis, particularly in endemic areas.

Diving into the complexity of the spirochetal endoflagellum

Spirochaetes, a phylum that includes medically important pathogens such as the causative agents of Lyme disease, syphilis, and leptospirosis, are in many ways highly unique bacteria. Their cell morphology, subcellular organization, and metabolism reveal atypical features. Spirochetal motility is also singular, dependent on the presence of periplasmic flagella or endoflagella, inserted subterminally at cell poles and not penetrating the outer membrane and elongating outside the cell as in enterobacteria. In this review we present a comprehensive comparative genomics analysis of endoflagellar systems in spirochetes, highlighting recent findings on the flagellar basal body and filament. Continued progress in understanding the function and architecture of spirochetal flagella is uncovering paradigm-shifting mechanisms of bacterial motility.

Tropical Infections Induced Fulminant Hepatitis in Peripartum Managed Successfully: Tales of Fate

Tropical diseases such as malaria, dengue, intestinal helminths, schistosomiasis, leishmaniasis, and filariasis have an essential influence on the reproductive health of patients.

Various cases of pregnancy loss in unexplained circumstances are a result of underdiagnosed tropical diseases. Term pregnancy complicated by tropical diseases is a challenge for the treating clinicians as these infections tend to mimic HELLP (Hemolysis, Elevated Liver enzymes, and Low Platelets) syndrome and increase the chances of perinatal complications and maternal mortality. Except for tropical diseases, ever since the conception of the COVID-19 pandemic, the differentials for fever pregnancy have become extensive, and the treating clinicians need to solve the puzzle of the etiology behind these symptoms that are non-specific and might be due to both COVID-19 and tropical Infections. Prophylactic treatment for malaria is pivotal in pregnancy as immunity is decreased during pregnancy, making the patient susceptible to developing malaria-related complications. Dengue is one of the most common mosquito-borne infections found around the globe. Complications of dengue during pregnancy include pregnancy loss as well as vertical transmission of infection to the fetus. Leptospirosis, even though rare, has a wide range of complications in pregnancy ranging from fetal loss to congenital infection and oligohydramnios, thereby requiring close monitoring and prompt management during pregnancy.

We report a case series of three cases where patients presented during the period of pregnancy with fulminant hepatic failure, which turned out to be a consequence of tropical diseases. All the cases were treated successfully and discharged in stable condition.