Consequences of brucellosis infection during pregnancy: A systematic review of the literature

Human brucellosis and associated risk factors in the Middle East region: A comprehensive systematic review, meta-analysis, and meta-regression

Introduction

Human brucellosis, caused by the bacteria Brucella, is a significant infectious disease globally, also known as Mediterranean fever or Malta fever.

Methods

This meta-analysis and systematic review focuses on the prevalence rate, risk factors, and diagnostic methods of human brucellosis in Middle Eastern countries, where the disease remains a significant public health issue. The analysis included 92 studies conducted between 1993 and 2024, following specified inclusion and exclusion criteria among symptomatic patients across these countries. The prevalence rate was calculated by dividing positive samples by total samples. The I2 index and Chi-squared test assessed study heterogeneity. Significant heterogeneity occurred when I2 exceeded 50 %.

Results

The highest prevalence rate was observed in Oman, Lebanon, and Kuwait countries, emphasizing a notable burden of Brucella infection in these regions. Risk factors associated with human brucellosis were identified, with unpasteurized dairy consumption and close animal contact being predominant. Various professions such as farmers, dairy factory workers, and agriculture workers showed higher prevalence rate. Gender analysis indicated a prevalence rate of 18.02 % (95 % CI: 11.55-25.51 %) in males and 13.61 % (95 % CI: 10.8-16.68 %) in females, with no significant difference in hospitalization rates. The prevalence rate of Brucella spp. was varied across detection methods, with immunocapture agglutination assay (Brucellacapt) showing the highest estimated prevalence rate of (44.04 %, 95 % CI: 27.71-61.04), followed by PCR (39.84 %, 95 % CI: 20.14-61.39) and culture (29.22 %, 95 % CI: 17.89-42.03). Among Brucella species, Brucella melitensis (B. melitensis) and Brucella abortus (B. abortus) were the highest prevalence rate. Although statistically insignificant, the meta-analysis also revealed an upward trend in prevalence rate from 1993 to 2024, (P value = 0.277).

Discussion

This comprehensive review emphasizes the need for tailored strategies to control brucellosis in the Middle East, highlighting the importance of timely diagnosis, public awareness, and effective treatment protocols. These findings provide valuable insights for policymakers and healthcare professionals working to mitigate the impact of this disease in the region.

Brucellosis in Omani children: a multicenter experience over 15 years

BACKGROUND

Brucellosis, a common zoonotic disease worldwide, can lead to serious complications in humans. In Oman, the disease occurs most often in the south, but is increasing in the north.

OBJECTIVES

Describe brucellosis in children in the Northern Governorate in Oman.

DESIGN

Retrospective, observational.

SETTINGS

Hospitals in the Northern Governorate in Oman.

PATIENTS AND METHODS

We collected data on the demographics, distribution, common clinical presentations, risk factors, laboratory findings, therapy, and complications of confirmed cases of brucellosis. We included all brucellosis cases up to the age of 13 years at the Child Health Department in Royal, Suhar, Al Rustaq and Nizwa Hospitals over a 15-year period.

MAIN OUTCOME MEASURES

Descriptive findings of brucellosis.

SAMPLE SIZE

57 confirmed cases.

RESULTS

The 57 confirmed cases of Brucella had a mean age of 6 years. Most of the cases were from Dhakhiliya 21 (36.8%) and Batinah 18 (31.6%). Consumption of raw milk was documented in 75% and 41% had animal contact. From 2010, there was a marked rise of the cases with a maximum rise was noticed in 2019 with a total of 10 cases. The main clinical manifestations were fever (92%, n=52), arthritis (44%, n=25), which involved mainly knees and hips. Forty-two had bacteremia, 41% anemia, 10% osteomyelitis/septic arthritis, one case with congenital brucellosis and one case neurobrucellosis (1.8%). Forty cases had positive serology results of which 19 had positive cultures. Most cases had received cotrimoxazole and rifampin as the primary treatment regimen 22 (40%). Four patients relapsed (7%) after treatment completion.

CONCLUSION

This study showed the distribution and clinical characteristics of brucellosis in different regions in the Northern Governorate in Oman. Although the numbers of cases remained low, the gradual increase is concerning for public health and preventive strategies. Further studies are needed to compare this data with the Southern region.

LIMITATION

Retrospective study with small sample size.

High Seropositivity of Brucella melitensis Antibodies among Pregnant Women Attending Health Care Facilities in Mwanza, Tanzania: A Cross-Sectional Study

Background

Brucellosis is one of the most prevalent zoonotic neglected tropical diseases across the globe. Brucella melitensis (B. melitensis), the most pathogenic species is responsible for several pregnancy adverse outcomes in both humans and animals. Here, we present the data on the magnitude of B. melitensis antibodies among pregnant women in Mwanza, Tanzania, the information that might be useful in understanding the epidemiology of the disease and devising appropriate control interventions in this region. Methodology. A hospital-based cross-sectional study involving pregnant women was conducted at two antenatal clinics in Mwanza between May and July 2019. The pretested structured questionnaire was used for data collection. Blood samples were collected aseptically from all consenting women followed by the detection of B. melitensis antibodies using slide agglutination test. Descriptive data analysis was done using STATA version 17.

Results

A total of 635 pregnant women were enrolled with the median age of 25 (interquartile range (IQR): 16-48) years and median gestation age of 21 (IQR: 3-39) weeks. Seropositivity of B. melitensis antibodies was 103 (16.2 (95% CI:13.3-19.1)). On the multivariate logistic regression analysis, as the gestation age increases, the odds of being seropositive decreases (aOR:0.972 (95% CI: 0.945-0.999), P = 0.045). Furthermore, being a housewife (aOR:3.902 (95% CI:1.589-9.577), P = 0.003), being employed (aOR:3.405 (95% CI:1.412-8.208), P = 0.006), and having history of miscarriage (aOR:1.940 (95% CI:1.043-3.606), P = 0.036) independently predicted B. melitensis seropositivity among pregnant women in Mwanza.

Conclusion

High seropositivity of B. melitensis was observed among employed and housewife pregnant women in Mwanza. This calls for the need of more studies in endemic areas that might lead to evidence-based control interventions.

Public Knowledge, Attitudes, and Practices Regarding Brucellosis in Taif City, Saudi Arabia

BACKGROUND

Brucellosis is a serious zoonotic infectious disease. Humans contract the disease by coming into contact with infected animals or their products. In Saudi Arabia, brucellosis is considered to be an endemic disease, with an annual incidence of 15.34 per 100,000 population from 2003 to 2018. Because of the devastating consequences for human health, raising awareness is an essential component in preventing brucellosis. Our study aims to assess the knowledge, awareness, and attitudes regarding brucellosis among the residents of Taif City, Saudi Arabia.

METHODS

A descriptive, cross-sectional survey conducted in June-October 2022 targeted the population of Taif City, Saudi Arabia. The data were collected by an online questionnaire, which included questions on sociodemographic characteristics, awareness regarding brucellosis, behavior and attitude toward animals, and consuming animal-based products.

RESULTS

A total of 743 participants were included. The participants were 18-70 years old, 63.4% were females, and 79.4% had a university education. Only 450 participants answered yes to the first question: "Do you know about brucellosis or have you heard about it?" Therefore, they were asked to answer knowledge questions. It was found that out of 450 participants, 46.9% demonstrated a "poor" knowledge level. Participants aged 26-55 years old demonstrated significantly more "good" knowledge than the other age groups (p = 0.001). Males demonstrated significantly more "good" knowledge (30.6%) than females (14.9%) (p < 0.001). The practices and attitudes of animal breeder participants (16.2%) were satisfactory because more than half of them did not participate in the birth of animals (53.4%), 50.7% did not participate in the birth with abortion, and approximately 61% used gloves when taking care of animals. The practices were unsatisfactory because 53.4% of the participants reported that they "always" eat the meat of animals they keep, and 64.4% reported that they personally slaughter sheep or cows from the herd.

CONCLUSION

Our study showed that most of the participants were aware of brucellosis; however, at the same time, the knowledge level regarding brucellosis was not satisfactory.

Spontaneous preterm birth: Involvement of multiple feto-maternal tissues and organ systems, differing mechanisms, and pathways

Survivors of preterm birth struggle with multitudes of disabilities due to improper in utero programming of various tissues and organ systems contributing to adult-onset diseases at a very early stage of their lives. Therefore, the persistent rates of low birth weight (birth weight < 2,500 grams), as well as rates of neonatal and maternal morbidities and mortalities, need to be addressed. Active research throughout the years has provided us with multiple theories regarding the risk factors, initiators, biomarkers, and clinical manifestations of spontaneous preterm birth. Fetal organs, like the placenta and fetal membranes, and maternal tissues and organs, like the decidua, myometrium, and cervix, have all been shown to uniquely respond to specific exogenous or endogenous risk factors. These uniquely contribute to dynamic changes at the molecular and cellular levels to effect preterm labor pathways leading to delivery. Multiple intervention targets in these different tissues and organs have been successfully tested in preclinical trials to reduce the individual impacts on promoting preterm birth. However, these preclinical trial data have not been effectively translated into developing biomarkers of high-risk individuals for an early diagnosis of the disease. This becomes more evident when examining the current global rate of preterm birth, which remains staggeringly high despite years of research. We postulate that studying each tissue and organ in silos, as how the majority of research has been conducted in the past years, is unlikely to address the network interaction between various systems leading to a synchronized activity during either term or preterm labor and delivery. To address current limitations, this review proposes an integrated approach to studying various tissues and organs involved in the maintenance of normal pregnancy, promotion of normal parturition, and more importantly, contributions towards preterm birth. We also stress the need for biological models that allows for concomitant observation and analysis of interactions, rather than focusing on these tissues and organ in silos.

Integrated mRNA-seq and miRNA-seq analysis of goat fibroblasts response to Brucella Melitensis strain M5-90

Brucellosis is a globally zoonotic bacterial disease of humans and various animals including goats, sheep, and cattle. Brucella melitensis M5-90, a live attenuated vaccine strain, has been widely used to prevent brucellosis in goats and sheep. However, the molecular mechanisms governing protective immunity response in non-professional phagocytes infected with B. melitensis M5-90 have not been fully investigated, especially in goats. In our research, goat fibroblasts were used as in vitro models to determine these mechanisms by transcriptome analysis. After incubating with B. melitensis M5-90 3 h, the infected goat fibroblasts were collected at 0 h, 4 h, 24 h, 48 h and 72 h for RNA-seq. The results indicated that there were totally 11,819 differentially expressed genes (DEGs) and 777 differentially expressed (DE) miRNAs found in experiment groups compared with the control groups (|log2(Foldchange)|≥1, FDR<0.05). GO and KEGG enrichment analyses revealed that down-regulated genes were involved in the riboflavin metabolism and positive regulation of IL-8 secretion pathway. The up-regulated genes were mainly involved in adaptive immunity, including TNF signaling pathway, MAPK signaling pathway and JAK/STAT pathway. Additionally, cytokine-cytokine receptor interaction, natural killer cell mediated cytotoxicity and toll-like receptor signaling pathway, which associated with innate immunity pathways, were also induced. Based on the Pearson correlation coefficients and prediction results of TargetScan and miRanda, the miRNA-mRNA networks of NFKB1, IFNAR2 and IL10RB were constructed and verified in goat fibroblasts by qPCR, which demonstrated that goat fibroblasts displayed immunomodulatory properties. Our findings provide a deeper insight into the host miRNA-driven B. melitensis defense mechanism and reveal the transcriptome changes involved in the innate and adaptive immune response of the goats to B. melitensis infection.

Multidrug-resistant tuberculosis during pregnancy and adverse birth outcomes: a systematic review and meta-analysis

BACKGROUND

Multidrug-resistant tuberculosis (MDR-TB) is a major global public health concern. However, there is a dearth of literature on whether MDR-TB and its medications impact maternal and perinatal outcomes, and when such evidence exists the findings are conflicting.

OBJECTIVES

This systematic review and meta-analysis aimed to examine the impact of MDR-TB and its medications during pregnancy on maternal and perinatal outcomes.

SEARCH STRATEGY

PubMed, Scopus and Web of Science databases were searched from earliest to February 2020.

SELECTION CRITERIA

Records were screened based on pre-defined selection criteria and assessed for quality by two independent reviewers.

DATA COLLECTION AND ANALYSIS

A meta-analysis was performed using the random effects model to calculate pooled prevalence for each outcome.

MAIN RESULTS

Of the 72 records identified, 12 were included in the systematic review and meta-analysis, consisting of 174 pregnant women with MDR-TB and 110 adverse outcomes. Maternal death, pregnancy loss, preterm birth and low birthweight were the most common maternal and perinatal adverse outcomes reported in the studies. The overall pooled prevalence was 7.5% (95% CI 3.2-12.8) for maternal death, 10.6% (95% CI 6.0-16.3) for pregnancy loss, 12.9% (95% CI 0.0-38.0) for preterm birth and 23.7% (95% CI 17.0-31.0) for low birthweight.

CONCLUSIONS

The findings suggest that MDR-TB is associated with a high risk of adverse maternal and perinatal outcomes, but these should be interpreted cautiously because the evidence is largely preliminary. Adequately powered prospective cohort studies are urgently required to corroborate these findings.

TWEETABLE ABSTRACT

Multidrug-resistant tuberculosis may increase the risk of adverse maternal and perinatal outcomes.

Human brucellosis in pregnancy - an overview

Human brucellosis during pregnancy is characterized by significantly less pronounced adverse obstetric outcomes than in animals, but with remarkably more adverse obstetric outcomes when compared to healthy pregnant women. Seroprevalence of brucellosis in pregnancy and cumulative incidence of brucellosis cases per 1000 delivered obstetrical discharges in endemic regions were reported to be 1.5–12.2% and 0.42–3.3, respectively. Depending on the region, the frequency of pregnant women in the cohorts of patients with brucellosis was from 1.5% to 16.9%. The most common and the most dramatic unfavorable outcomes during brucellosis in pregnancy are the obstetric ones, manifested as abortions (2.5–54.5%), intrauterine fetal death (0–20.6%), or preterm deliveries (1.2–28.6%), depending on the stage of pregnancy. Other unfavorable outcomes due to brucellosis are addressed to infant (congenital/neonatal brucellosis, low birth weight, development delay, or even death), the clinical course of disease in mother, and delivery team exposure. When diagnosed in pregnant women, brucellosis should be treated as soon as possible. Early administration of adequate therapy significantly reduces the frequency of adverse outcomes. Rifampicin in combination with trimethoprim-sulfamethoxazole for 6 weeks is the most commonly used and recommended regimen, although monotherapies with each of these two drugs are also widely used while waiting for the results from prospective randomized therapeutic trials. As no effective human vaccine exists, screening of pregnant women and education of all women of childbearing age about brucellosis should be compulsory preventive measures in endemic regions.

Effects of Embryonic Inflammation and Adolescent Psychosocial Environment on Cognition and Hippocampal Staufen in Middle-Aged Mice

Accumulating evidence has indicated that embryonic inflammation could accelerate age-associated cognitive impairment, which can be attributed to dysregulation of synaptic plasticity-associated proteins, such as RNA-binding proteins (RBPs). Staufen is a double-stranded RBP that plays a critical role in the modulation of synaptic plasticity and memory. However, relatively few studies have investigated how embryonic inflammation affects cognition and neurobiology during aging, or how the adolescent psychosocial environment affects inflammation-induced remote cognitive impairment. Consequently, the aim of this study was to investigate whether these adverse factors can induce changes in Staufen expression, and whether these changes are correlated with cognitive impairment. In our study, CD-1 mice were administered lipopolysaccharides (LPS, 50 μg/kg) or an equal amount of saline (control) intraperitoneally during days 15–17 of gestation. At 2 months of age, male offspring were randomly exposed to stress (S), an enriched environment (E), or not treated (CON) and then assigned to five groups: LPS, LPS+S, LPS+E, CON, and CON+S. Mice were evaluated at 3-month-old (young) and 15-month-old (middle-aged). Cognitive function was assessed using the Morris water maze test, while Staufen expression was examined at both the protein and mRNA level using immunohistochemistry/western blotting and RNAscope technology, respectively. The results showed that the middle-aged mice had worse cognitive performance and higher Staufen expression than young mice. Embryonic inflammation induced cognitive impairment and increased Staufen expression in the middle-aged mice, whereas adolescent stress/an enriched environment would accelerated/mitigated these effects. Meanwhile, Staufen expression was closely correlated with cognitive performance. Our findings suggested embryonic inflammation can accelerate age-associated learning and memory impairments, and these effects may be related to the Staufen expression.

Congenital brucellosis in a Chinese preterm neonate: A case report

Although extremely rare, congenital brucellosis can occur via perinatal transmission. We report a case of an infant born prematurely at 34–36 weeks' gestation who had pyrexia, shortness of breath, hepatosplenomegaly and thrombocytopenia. Blood cultures were positive for Gram-negative coccobacilli and Brucella infection was suspected. While, serological tests were negative for Brucella antibodies, B. melitensis infection was confirmed by polymerase chain reaction (PCR). Serology of the parents’ blood confirmed the presence of Brucella. The family did not live in an endemic area but had ridden a camel 12 months before the pregnancy. The bacteria may have been sexually transmitted from father to mother and then to foetus via an intrauterine infection. In endemic areas or where the family has been in close contact with infected animals, brucellosis should be suspected in a severely ill neonate with an unknown infection. Thorough medical histories from the family are essential as early diagnosis and prompt therapy will almost certainly improve neonatal outcome.

Infection by Brucella melitensis or Brucella papionis modifies essential physiological functions of human trophoblasts

Brucellosis is a zoonosis caused by bacteria of the Brucella genus. In ruminants, brucellosis causes abortion, followed by chronic infection and secretion of bacteria in milk. In humans, it usually presents as flu-like symptoms, with serious complications if untreated. Epidemiological studies have only recently established that brucellosis can also cause pregnancy complications in women, but the pathogenic mechanisms are unknown. Pioneering studies in ruminants showed that Brucella infect trophoblasts and then colonise the placenta where they grow to high density. A recent study showed that the main zoonotic Brucella species can infect human cytotrophoblasts (CTB) and extravillous trophoblasts (EVT). In this work, we show that Brucella papionis (associated with stillbirth in primates) also infects human trophoblasts. However, it replicates actively in CTB, whereas its replication is very restricted within EVT. We also observed alteration of several trophoblastic functions upon infection by B. papionis or Brucella melitensis (the most prevalent species in human brucellosis). Infection altered the production of hormones, the ability of CTB to form syncytiotrophoblasts, and the invasion capacity of EVT. We also found that infection can spread between different types of trophoblasts. These findings constitute a new step in understanding how Brucella infection causes adverse pregnancy outcomes.

Current Resources for Evidence-Based Practice, March 2019

A review of new resources to support the provision of evidence-based care for women and infants.