Human-to-human transmission of Brucella - a systematic review

Role of myeloid-derived suppressor cells in chronic brucellosis

Introduction

Human brucellosis, a Brucella infection caused most common zoonosis in the world, remains a serious public health burden in China. Brucella chronic infection always causes immunosuppressive status and results in severe organ or tissue damages. The aim of this work was to study the role of the myeloid-derived suppressor cells (MDSCs) in human chronic brucellosis.

Methods

Fifty cases of chronic brucellosis and 40 healthy individual controls were enrolled in this study. We analyzed the frequency and subsets of MDSCs in PBMC between the chronic brucellosis and healthy control groups by flow cytometry. Furthermore, we also measured the inflammatory-related cytokines in serum samples and the MDSCs inhibition ability to the proliferation of T cells in vitro.

Results

We found that the frequency of MDSCs in peripheral blood and the level of IL-6 and IL-10 Th2 cytokines and Arginase-1 were significantly increased in chronic brucellosis patients. In addition, we also found that the T cell function was suppressed in vitro by co-culturing with MDSCs from brucellosis patients.

Conclusion

Our study described an increase of immunosuppressive MDSCs in peripheral blood of chronic brucellosis patients. These results contribute to the understanding of Brucella persistent infection, which may provide an insight for effective treatment of chronic brucellosis patients in clinical practice.

The Reasons Behind Long-Term Endemicity of Brucellosis in Low and Middle-Income Countries: Challenges and Future Perspectives

Brucellosis is a neglected worldwide zoonotic disease with more than 500,000 new human cases each year. Direct contact with infected animals and consumption of undercooked animal origin foods are the main routes of brucellosis transmission to humans. Although long endeavor has been applied to control and eliminate brucellosis from animal and human populations in developing countries especially in low- and middle-income countries (LMICs), the disease is still endemic in these regions. Many common or unique factors including raw milk consumption, unhygienic slaughter of livestock, extensive husbandry, budgetary limitations, misdiagnosis, and other conditions play a role in long-term endemicity of brucellosis in these locations. It has been shown that One Health is the only practical approach to control brucellosis; however, applying such methods is challenging in low-resource areas. In such conditions, brucellosis is continuously maintained in animals and repeatedly spread to human populations. In this article, factors playing a critical role in brucellosis endemicity, and the real conditions challenging the application of One Health approach in control of brucellosis are highlighted.

Brucella Spondylitis: Current Knowledge and Recent Advances

The most prevalent zoonotic disease is brucellosis, which poses a significant threat for worldwide public health. Particularly in endemic areas, spinal involvement is a major source of morbidity and mortality and can complicate the course of the disease. The diagnosis of Brucella spondylitis is challenging and should be suspected in the appropriate epidemiological and clinical context, in correlation with microbiological and radiological findings. Treatment depends largely on the affected parts of the body. Available treatment options include antibiotic administration for an adequate period of time and, when appropriate, surgical intervention. In this article, we examined the most recent data on the pathophysiology, clinical manifestation, diagnosis, and management of spinal brucellosis in adults.

Brucellosis Seropositivity Using Three Serological Tests and Associated Risk Factors in Abattoir Workers in Gauteng Province, South Africa

Abattoir workers are liable to zoonotic infections from animals and animal products, primarily to diseases with asymptomatic and chronic clinical manifestations in animals, such as brucellosis. No published reports exist on the seroprevalence of brucellosis in abattoir workers in South Africa. Therefore, this cross-sectional study was conducted to estimate the occurrence and risk factors for Brucella exposure in abattoir workers in Gauteng Province. A total of 103 abattoir workers and managers from 6 abattoirs, where brucellosis-positive slaughtered cattle and sheep were previously detected, were interviewed and tested with serological assays using the Rose Bengal test (RBT), BrucellaCapt, and IgG-ELISA. A pre-tested questionnaire was administered to consenting respondents to obtain information on risk factors for brucellosis. Of the 103 respondents tested, the distribution of female and male workers was 16 (15.5%) and 87 (84.5%), respectively. The seroprevalence for exposure to brucellosis was 21/103 (20.4%, 95%CI: 13.1-29.5) using a combination of RBT, BrucellaCapt, or IgG-ELISA. For test-specific results, seroprevalences by RBT, BrucellaCapt, and IgG-ELISA were 13/103 (12.6%, 95%CI: 6.9-20.6), 9/103 (8.74%, 95%CI: 4.1-15.9), and 18/103 (17.5%, 95%CI: 10.7-26.2), respectively. Low-throughput abattoirs were identified as associated risks, as 29.3% of workers were seropositive compared with 12.7% of workers in high-throughput abattoirs, which highlights that direct contact at abattoirs poses higher risk to workers than indirect and direct contact outside abattoirs. This study confirms the occurrence of Brucella spp. antibodies among abattoir workers in South Africa, possibly due to occupational exposure to Brucella spp., and highlights the occupational hazard to workers. Furthermore, findings underscore that abattoir facilities can serve as points for active and passive surveillance for indicators of diseases of public health importance. We recommend periodic implementation of brucellosis testing of abattoir workers country-wide to establish baseline data for informing appropriate preventive practices and reducing the potential burden of infection rates among these high-risk workers.

Follow-up outcomes of asymptomatic brucellosis: a systematic review and meta-analysis

Balancing the potentially serious outcomes of asymptomatic brucellosis and "waiting" for treatment in clinical practice is an urgent issue. Therefore, we assessed the follow-up outcomes and epidemiological characteristics of asymptomatic brucellosis in the absence of treatment to provide evidence-based clinical clues. We searched eight databases in which 3610 studies from 1990 to 2021 were related to the follow-up outcomes of asymptomatic brucellosis. Thirteen studies, involving 107 cases, were finally included. Regarding the follow-up outcomes, we examined the presence or absence of symptoms and decreased serum agglutination test (SAT) titre. During the 0.5-18 months follow-up period, the pooled prevalence of appearing symptomatic was 15.4% (95% CI 2.1%-34.3%), cases that remained asymptomatic were 40.3% (95% CI 16.6%-65.8%), and decreased SAT titre was observed in 36.5% (95% CI 11.6%-66.1%). Subgroup analysis indicated that the pooled prevalence of appearing symptomatic with follow-up times of less than 6 months, 6-12 months, and 12-18 months was 11.5%, 26.4%, and 47.6%, respectively. The student subgroup had a higher prevalence of symptoms (46.6%) than the occupational and family populations. In conclusion, asymptomatic brucellosis has a high likelihood of appearing symptomatic and its severity may be underestimated. Active screening of occupational and family populations should be enhanced, and special attention should be paid to high-titre students for early intervention, if necessary. Additionally, future prospective, long-term, and large-sample follow-up studies are essential.

Brucellae as resilient intracellular pathogens: epidemiology, host-pathogen interaction, recent genomics and proteomics approaches, and future perspectives

Brucellosis is considered one of the most hazardous zoonotic diseases all over the world. It causes formidable economic losses in developed and developing countries. Despite the significant attempts to get rid of Brucella pathogens in many parts of the world, the disease continues to spread widely. Recently, many attempts proved to be effective for the prevention and control of highly contagious bovine brucellosis, which could be followed by others to achieve a prosperous future without rampant Brucella pathogens. In this study, the updated view for worldwide Brucella distribution, possible predisposing factors for emerging Brucella pathogens, immune response and different types of Brucella vaccines, genomics and proteomics approaches incorporated recently in the field of brucellosis, and future perspectives for prevention and control of bovine brucellosis have been discussed comprehensively. So, the current study will be used as a guide for researchers in planning their future work, which will pave the way for a new world without these highly contagious pathogens that have been infecting and threatening the health of humans and terrestrial animals.

Case report: A case of brucellosis misdiagnosed as coronavirus disease 2019/influenza in China

Brucellosis is an important zoonosis and a multisystem disease. The signs and symptoms of brucellosis are not specific. In the clinical, brucellosis is often ignored and misdiagnosed. We report a case of brucellosis who was misdiagnosed as coronavirus disease 2019 (COVID-19)/influenza and received delayed treatment during strict COVID-19 control. The neglect of other diseases due to COVID-19 and empirical diagnosis and treatment by medical staff are part of the reasons for misdiagnosis. Otherwise, the normal erythrocyte sedimentation rate (ESR), increased white blood cell count (WBC), and increased neutrophil count (NEUT) of this patient was also a cause of misdiagnosis, which is an important reminder for diagnosis. For patients with the unknown origin of fever and other symptoms related to brucellosis, especially those from endemic areas of brucellosis, brucellosis screening is a priority item, and grassroots doctors should be vigilant and standardize the diagnosis and treatment based on epidemiology history, clinical manifestation, and laboratory tests according to the diagnostic criteria of brucellosis.

Human descending aorta injury caused by brucellosis: A case report

BACKGROUND

Brucellosis is one of the most common zoonotic diseases in the world. Although cardiovascular complications of human brucellosis account for only 3% of morbidity, they are the leading cause of death. Peripheral vascular disease due to brucellosis is rare and under-reported in the literature.

CASE PRESENTATION

Two patients with previous brucellosis, both of whom had been treated with anti-brucellosis, were admitted to vascular surgery for thoracic aortic ulcer and abdominal aortic pseudoaneurysm, respectively, with positive IgG antibody to brucellosis and negative IgM antibody to brucellosis, tube agglutination test, and blood culture. These 2 patients were successfully treated with aortic stent-graft implantation and followed up for 8 and 10 weeks without complications.

CONCLUSIONS

Chronic damage to human blood vessels by brucellosis may not disappear with brucellosis treatment, and peripheral blood vessels should be examined annually in people previously diagnosed with brucellosis. Clinicians in related departments should pay attention to peripheral vascular complications of brucellosis.

Hepatic Manifestations of Systemic Diseases

In addition to being the primary target of infections such as viral hepatitis, the liver may also be affected by systemic disease. These include bacterial, mycotic, and viral infections, as well as autoimmune and infiltrative diseases. These conditions generally manifest as abnormal liver biochemistries, often with a cholestatic profile, and may present with additional signs/symptoms such as jaundice and fever. A high index of suspicion and familiarity with potential causal entities is necessary to guide appropriate testing, diagnosis, and treatment.

Bioaerosol dispersion and environmental risk simulation: Method and a case study for a biopharmaceutical plant of Gansu province, China

Pathogenic bacteria pose a great threat to global public health from environmental and public health perspectives, especially regarding the impact of the COVID-19 pandemic worldwide. As a result, the increased risk of pathogenic bioaerosol exposure imposes a considerable health burden and raises specific concerns about the layout and location of vaccine manufacturers. This study proposed a grid computing method based on the CALPUFF modelling system and population-based environmental risks to reduce bioaerosol-related potential risks. We previously used the CALPUFF model to quantify the diffusion level, the spatial distribution of emissions, and potential environmental risks of bioaerosol leakage in Gansu province's Zhongmu Lanzhou biopharmaceutical plant from July 24, 2019, to August 20, 2019. By combining it with publicly available test data, the credibility was confirmed. Based on our previous research, the CALPUFF model application combined with the environmental population-based environmental risks in two scenarios: the layout and site selection, was explored by using the leakage accident of Zhongmu Lanzhou biopharmaceutical plant of Gansu province as a case study. Our results showed that the site selection method of scenario 2 coupled with the buffer area was more reasonable than scenario 1, and the final layout site selection point of scenario 2 was grid 157 as the optimal layout point. The simulation results demonstrated agreement with the actual survey. Our findings could assist global bioaerosol manufacturers in developing appropriate layout and site selection strategies to reduce bioaerosol-related potential environmental risks.

Determination of seroprevalence of brucellosis in livestock and high-risk population in Kurdistan, Western Iran

BACKGROUND

Brucellosis is one of the most prevalent zoonotic diseases. Using serological tests are valid and rapid methods that could be used in the detection of the history of getting brucellosis. Considering that Iran is an endemic country for brucellosis, we aimed to investigate the rate of seroprevalence of brucellosis among livestock and human in Kurdistan province.

MATERIAL AND METHOD

Serum sampling was performed from 51 slaughterhouse workers, veterinarians, and husbandry workers, along with 260 livestock (80 cattle, 120 sheep, and 60 goats). Rose Bengal plate test (RBPT), and Enzyme-linked immunosorbent assay (ELISA) were used for livestock and the anti-Brucella IgG antibody was evaluated in human participants.

RESULTS

The seroprevalence (based on ELISA assay) in sheep, goats, and cows was 5.8%, 5%, and 1.2%, respectively. Also, the rate of anti-Brucella IgG was 3.9% among human participants.

DISCUSSION

the current study, provided some valuable information on the seroprevalence of brucellosis in animal and human participants from the west of Iran. Considering the effects of brucellosis on causing reproductive disorders, including abortion, placental retention, andendometritis controlling the infection could have a significant impact on terms of economy.

Outbreak of occupational Brucella infection caused by live attenuated Brucella vaccine in a biological products company in Chongqing, China, 2020

The northern areas of China are traditional endemic regions for brucellosis in both animals and humans, while occasional outbreaks of brucellosis have been observed in neglected southern provinces. On December 16, 2020, Chongqing Center for Disease Control and Prevention (CQCDC) received a report of 15 Brucella seropositive employees in a biological products company. The CQCDC and the local health administrative department launched an investigation that included identification of cases, laboratory testing of samples, and employees' interview to identify the cause of this incident. A case-control study was implemented to compare high-risk factors between cases and serology-negative personals. Human and animal serum samples, and environmental swabs were collected for testing. A total of 61 recessive infectors were found with an infection rate of 43.57% (61/140). Fisher's exact test showed that there were significant differences in Brucella infection rates among different posts classifications (p=0.02), working places (p=0.007), and buildings (p＜0.0001). Case-control study showed that working in vaccine production workshop was independently associated with increased risk of infection (odds ratio (OR): 2.60; 95% confidence interval (CI): 1.31-5.19). The positive detection rate was 88.06% (59/67) for production environment and 16.67% (2/12) for external environment. The investigation indicated that close contact with biological products and aerosol were the potential transmission routes of this outbreak under the condition of insufficient personal protection and disinfection. Our study provides new epidemiological evidence for a more detailed understanding of occupational infections with live attenuated Brucella vaccine.Highlights An Outbreak of occupational Brucella infection was caused by Brucella vaccine.Contacting with biological products and aerosol were potential transmission routes.This is new evidence for the virulent characteristics of attenuated Brucella vaccine.

Seroprevalence of human brucellosis in Morocco and associated risk factors

Background and Aim:

Brucellosis is a prevalent infectious zoonotic disease that affects humans, livestock, and wildlife in many parts of the world. A cross-sectional study was conducted to estimate the seroprevalence and risk factors of brucellosis among farmers and patients attending six health centers in Sidi Kacem province (northwestern Morocco).

Materials and Methods:

Blood samples (3-5 mL) were collected. Among 1283 participants, 351 were males and 932 were females and tested for Brucella antibodies using rose Bengal plate test and immunoglobulin (Ig)M/IgG enzyme-linked immunosorbent assay (ELISA) for confirmation.

Results:

The seroprevalence of brucellosis was 33.20% (426/1283) with a higher risk among males and rural residents. The univariable analysis revealed that contacting cattle, handling abortion products and manure, and consuming undercooked beef and goat meat were all risk factors for brucellosis. Furthermore, raw milk and milk derivatives were risk factors strongly linked to brucellosis.

Conclusion:

Our findings indicate a high prevalence of brucellosis associated with the consumption of raw meat, raw dairy products, milk, and close contact with infected animals. However, there are some limitations to this study, such as we did not use the ELISA test on all sera collected and individuals under the age of 18 were not included in the study. Moreover, building a database on the occurrence of brucellosis and associated epidemiological factors is critical for providing informed advice to policymakers to improve control strategies against this disease in Morocco.

Neurobrucellosis presenting with the features of meningoencephalitis: A case report from Nepal

Introduction and importance

Brucellosis or Malta fever is a zoonotic disease caused by the Brucella species. Patients with neurobrucellosis may present with features of meningoencephalitis. Thus, a high degree of suspicion is required for the diagnosis in the endemic region.

Case presentation

A 13-year old female with a history of exposure to domestic animals presented with the features of meningoencephalitis (intermittent fever with chills and rigor and generalized tonic-clonic seizure).

Clinical findings and investigations

Examination revealed drowsy and lethargic patient with bilateral edema up to mid-shin. Neck rigidity was present. Lab findings include leukocytosis with neutrophilic and erythrocyte sedimentation rate (25 mm/hr). CECT of the brain revealed vasogenic edema. Routine CSF examination was insignificant for common bacterial, viral, fungal or tubercular etiology. CSF ELISA confirmed the presence of Brucella antibody.

Conclusion

When patients present with undulant fever, lethargy, seizure, or other features of meningitis/encephalitis, the diagnosis of neurobrucellosis must be considered after common pathological causes are ruled out.

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Brucellosis or Malta fever is a zoonotic disease caused by the Brucella species.

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Patients with Neurobrucellosis may present with features of meningoencephalitis.

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A high degree of suspicion is required for the diagnosis in the endemic region.

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Patients with undulant fever, seizure, or other features of meningoencephalitis should be tested for Neurobrucellosis.

The Genome Sequence of Brucella abortus vaccine strain A19 provides insights on its virulence attenuation compared to Brucella abortus strain 9-941

BACKGROUND

Brucellosis is a widespread disease that affects animals and humans. The live attenuated Brucella abortus A19 strain is used for vaccination against brucellosis in China. In addition, the main mechanisms supporting the residual toxicity of A19 have not been elucidated. Here, we performed a comprehensive comparative analysis of the genome-wide sequence of A19 against the whole genome sequences of the published virulent reference strain 9-941. The primary objective of this study was to identify candidate virulence genes by systematically comparing the genomic sequences between the two genomes.

RESULTS

This analysis revealed two deletion regions in the A19 genome, in which all included large fragments of 63 bp, and one of their gene function is related to ABC transporter permease protein. In addition, we have identified minor mutations in important virulence-related genes that can be used to determine the underlying mechanisms of virulence attenuation. The function of its virulence gene covers LysR family transcriptional regulator, outer membrane, MFS transporter and oxidoreductase etc. At the same time, a PCR differential diagnosis method was constructed, which can distinguish A19, S19 and most other commonly used Brucella viruent strains and vaccine strains.

CONCLUSION

The data may help to provide resources for further detailed analysis of mechanisms for other Brucella vaccines. It laid the foundation for further distinguishing between vaccine immunity and virulent strains infection.

Generation and Selection of Specific Aptamers Targeting Brucella Species through an Enhanced Cell-SELEX Methodology

Brucellae are Gram-negative, aerobic, non-motile coccobacilli causing brucellosis in man and animals. The disease is one of the most significant yet neglected global zoonoses. Especially in developing countries, brucellosis is causing public health problems and economic losses to private animal owners and national revenues. Composed of oligonucleotides, aptamers are chemical analogues of antibodies that are promising components for developing aptamer-based rapid, sensitive, and specific tests to identify the Brucella group of bacteria. For this purpose, aptamers were generated and selected by an enhanced protocol of cell systematic evolution of ligands by exponential enrichment (cell-SELEX). This enhanced cell-SELEX procedure involved the combination of both conventional and toggle cell-SELEX to boost the specificity and binding affinity to whole Brucella cells. This procedure, combined with high-throughput sequencing of the resulting aptamer pools, comprehensive bioinformatics analysis, and wet lab validation assays, led to the selection of a highly sensitive and specific aptamer for those Brucella species known to circulate in Egypt. The isolated candidate aptamer showed dissociation constant (K_D) values of 43.5 ± 11, 61.5 ± 8, and 56 ± 10.8 nM for B. melitensis, B. abortus, and B. suis, respectively. This is the first development of a Brucella-specific aptamer using an enhanced combination of conventional and toggle cell-SELEX to the authors’ best knowledge.

Brucellar Knee Arthritis with Knee Joint Tuberculosis: A Case Report and Review of the Literature

Brucella and Mycobacterium tuberculosis (MTB) primarily affect the spine and only rarely the knee joint in osteoarticular disease in adults. We present an unusual instance of brucellar knee arthritis combined with knee joint tuberculosis. A 59-year-old man was initially diagnosed with brucellar knee arthritis in the orthopedics department of our hospital, while two weeks of standardized treatment did not improve the joint discomfort and inflammation indexes. Subsequent evaluation of serum tuberculosis interferon-gamma release assays (TB-IGRAs) and the effectiveness of empirical anti-tuberculosis therapy confirmed the mixed infection of tuberculosis. This case report demonstrates that clinical signs and imaging for brucellar knee arthritis and knee joint tuberculosis are similar. Patients with both disorders are more likely to be misdiagnosed or have their diagnosis delayed; clinicians should be aware of this uncommon combination of mixed infections.

Human Brucellosis in Greece, 2005-2020: A Persistent Public Health Problem

Brucellosis remains an important zoonosis in various parts of the world. In Greece, brucellosis is endemic in sheep and goats. Since 1998, animal control measures include vaccination of sheep and goats older than 3 months of age in the mainland (vaccination zone) and slaughtering of infected livestock on the islands (eradication zone). We retrieved data from the mandatory notification system for 2005-2020 to describe the epidemiology in humans and assess current public health measures. Overall, 1786 notifications and an additional 111 cases related to an outbreak in 2008 (eradication zone) were recorded. The mean annual notification rate was 0.9/100,000 population (standard deviation [SD]: 0.35). A substantial mean annual decline in notification rate was reported in 2019 and 2020. A statistically significant decreasing trend of brucellosis notification rate was observed over the whole 16-year period (p < 0.001). The mean annual notification rate was significantly higher in the vaccination zone (1.2/100,000) (SD: 036) compared with the eradication zone (0.2/100,000) (SD: 0.14) (p < 0.001). Seventy percent of cases was male (n = 1175) and the highest mean notification rate was recorded in the 45-64 age group (1.3/100,000). The majority of cases (71%) reported animal contact and almost half of the cases (49%) were stockbreeders by occupation. Consumption of unpasteurized dairy products, mainly of their own production, was reported by 57% of cases; for 115 (6.5%) cases, animal exposure or consumption of unpasteurized dairy products were not recorded. Despite animal control measures, brucellosis remains endemic in Greece with cases in the vaccination zone, as well as the eradication zone. We recommend re-evaluation and strengthening of animal control programs and training of people working in stock breeding regarding disease transmission in co-operation with local farmers' associations.

Survival benefit from paediatric transplantation in brucellosis-infected patients listed for heart transplantation

This article reported two cases of brucellosis in children on the waiting list for a cardiac transplant who have been referred with the diagnosis of Fever of Unknown Origin. The serology was positive and patients were treated with cardiac transplantation in the 6th week. They had no recurrence or rejection. Therefore, brucellosis should be considered in patients on the waiting list for cardiac transplants.

Selected Livestock-Associated Zoonoses as a Growing Challenge for Public Health

The aim of this paper is to review the most significant livestock-associated zoonoses. Human and animal health are intimately connected. This idea has been known for more than a century but now it has gained special importance because of the increasing threat from zoonoses. Zoonosis is defined as any infection naturally transmissible from vertebrate animals to humans. As the frequency and prevalence of zoonotic diseases increase worldwide, they become a real threat to public health. In addition, many of the newly discovered diseases have a zoonotic origin. Due to globalization and urbanization, some of these diseases have already spread all over the world, caused by the international flow of goods, people, and animals. However, special attention should be paid to farm animals since, apart from the direct contact, humans consume their products, such as meat, eggs, and milk. Therefore, zoonoses such as salmonellosis, campylobacteriosis, tuberculosis, swine and avian influenza, Q fever, brucellosis, STEC infections, and listeriosis are crucial for both veterinary and human medicine. Consequently, in the suspicion of any zoonoses outbreak, the medical and veterinary services should closely cooperate to protect the public health.

Neurobrucellosis: Brief Review

BACKGROUND

Brucella are small, nonmotile, intracellular, and aerobic gram-negative bacteria. Of the 10 species that currently form the genus Brucella, 5 were shown to be pathogenic in humans.

REVIEW SUMMARY

The epidemiology, clinical manifestations, diagnosis and imaging, and treatment of neurobrucellosis will be reviewed.Brucellosis's transmission to humans occurs by direct contact with contaminated animals. Older patients are at increased risk of nervous system involvement in brucellosis. Brucella spp. can lead to central nervous system involvement through direct damage via invasion of neural tissue or indirect damage caused by endotoxins or immune inflammatory reactions elicited by the presence of the bacteria in the body. Patients can have general nonspecific symptoms in addition to neurological and psychiatric symptoms. There are 4 diagnostic criteria for the diagnosis of neurobrucellosis, which include signs and symptoms suggestive of neurobrucellosis, a positive finding of Brucella spp. in the cerebrospinal fluid (CSF), and/or a positive titer of antibodies targeting brucella in the CSF, lymphocytosis with high protein levels and low glucose levels in CSF, and imaging findings (either cranial magnetic resonance imaging or computed tomography) peculiar to neurobrucellosis. For the treatment, a combined therapy is favored over monotherapy for the eradication of Brucella. Moreover, a multirouted therapy has been associated with increased treatment efficacy. The prognosis of neurobrucellosis is dependent on patients' clinical presentation: brucellar meningitis is associated with a good prognosis, whereas diffuse central nervous system involvement is associated with the development of long-term sequelae.

CONCLUSIONS

Neurobrucellosis affects patients globally and in endemic areas. Neurologists should familiarize themselves with its clinical presentation, diagnosis, and treatment to provide optimal care for their patients.

Evaluation of Putative Toxin-antitoxins Systems in Clinical Brucella melitensis in Iran

BACKGROUND

Toxin-antitoxin systems (TAs) are two-component elements, which are extensive in the bacterial genome and have a regulatory role in many cellular activities including, growth arrest, survival, biofilm formation, and bacterial persistence.

OBJECTIVE

TAs have not well studied in Brucella spp.

METHODS

We evaluated the presence of different toxin-antitoxin systems, including relE- rhhlike, Fic- Phd, Cog- Rhh, and cogT- cogAT in 40 clinical Brucella melitensis isolates using PCRbased sequencing assay.

RESULTS

Our results showed the high presence of relE-rhh-like, Fic-Phd, Cog-rhh, and cogTcogAT s TAs genes in B. melitensis isolates that were 96.25%, 92.5%, 96.25%, and 95%, respectively.

CONCLUSION

A high presence of TAs genes in clinical B. melitensis isolates revealed that the TA system could be an antibacterial target in B. melitensis but more investigation is necessitated to elucidate the exact roles of these genes.

Evidence for human-to-human transmission of hantavirus: a systematic review

Background

Hantavirus is known to be transmitted from rodents to humans. However, some reports from Argentina and Chile have claimed that the hantavirus strain Andes virus (ANDV) can cause human-to-human transmission of the disease. The aim of this systematic review was to assess the evidence for human-to-human transmission of hantavirus.

Methods

We searched PubMed (inception to 28 February 2021), Cochrane Central, Embase, LILACS and SciELO (inception to 3 July 2020), and other sources. We included studies that assessed whether interpersonal contact with a person with laboratory-confirmed hantavirus infection led to human-to-human transmission. Two reviewers conducted screening, selection, data extraction, and risk of bias assessment.

Results

Twenty-two studies met the inclusion criteria. Meta-analysis was not possible due to heterogeneity. With the exception of 1 prospective cohort study of ANDV in Chile with serious risk of bias, evidence from comparative studies (strongest level of evidence available) does not support human-to-human transmission of hantavirus infection. Noncomparative studies with a critical risk of bias suggest that human-to-human transmission of ANDV may be possible.

Conclusions

The balance of the evidence does not support the claim of human-to-human transmission of ANDV. Well-designed cohort and case-control studies that control for co-exposure to rodents are needed to inform public health recommendations.

The one hundred year journey of the genus Brucella (Meyer and Shaw 1920)

The genus Brucella, described by Meyer and Shaw in 1920, comprises bacterial pathogens of veterinary and public health relevance. For 36 years, the genus came to include three species that caused brucellosis in livestock and humans. In the second half of the 20th century, bacteriologists discovered five new species and several 'atypical' strains in domestic animals and wildlife. In 1990, the Brucella species were recognized as part of the Class Alphaproteobacteria, clustering with pathogens and endosymbionts of animals and plants such as Bartonella, Agrobacterium and Ochrobactrum; all bacteria that live in close association with eukaryotic cells. Comparisons with Alphaproteobacteria contributed to identify virulence factors and to establish evolutionary relationships. Brucella members have two circular chromosomes, are devoid of plasmids, and display close genetic relatedness. A proposal, asserting that all brucellae belong to a single species with several subspecies debated for over 70 years, was ultimately rejected in 2006 by the subcommittee of taxonomy, based on scientific, practical, and biosafety considerations. Following this, the nomenclature of having multiples Brucella species prevailed and defined according to their molecular characteristics, host preference, and virulence. The 100-year history of the genus corresponds to the chronicle of scientific efforts and the struggle for understanding brucellosis.

Overexpression of ASMT likely enhances the resistance of transgenic sheep to brucellosis by influencing immune-related signaling pathways and gut microbiota

Melatonin is a pleiotropic molecule with a variety of biological functions, which include its immunoregulatory action in mammals. Brucellosis is a worldwide endemic zoonotic disease caused by the Brucella, which not only causes huge economic losses for the livestock industry but also impacts human health. To target this problem, in current study, two marker-free transgenic sheep overexpressing melatonin synthetic enzyme ASMT (acetylserotonin O-methyltransferase) gene were generated and these melatonin enrich transgenic sheep were challenged by Brucella infection. The results showed that the serum melatonin concentration was significantly higher in transgenic sheep than that of wild type (726.92 ± 70.6074 vs 263.10 ± 34.60 pg/mL, P < .05). Brucella challenge test showed that two thirds (4/6) of the wild-type sheep had brucellosis, while none of the transgenic sheep were infected. Whole-blood RNA-seq results showed that differential expression genes (DEGs) were significantly enriched in natural killer cell-mediated cytotoxicity, phagosome, antigen processing, and presentation signaling pathways in overexpression sheep. The DEGs of toll-like receptors (TLRs) and NOD-like receptors (NLRs) families were verified by qPCR and it showed that TLR1, TLR2, TLR7, CD14, NAIP, and CXCL8 expression levels in overexpression sheep were significantly higher and NLRP1, NLRP3, and TNF expression levels were significantly lower than those of wild type. The rectal feces were subjected to 16S rDNA amplicon sequencing, and the microbial functional analysis showed that the transgenic sheep had significantly lower abundance of microbial genes related to infectious diseases compared to the wild type, indicating overexpression animals are likely more resistant to infectious diseases than wild type. Furthermore, exogenous melatonin treatment relieved brucellosis inflammation by upregulating anti-inflammatory cytokines IL-4 and downregulating pro-inflammatory IL-2, IL-6, and IFN-γ. Our preliminary results provide an informative reference for the study of the relationship between melatonin and brucellosis.

Abnormal liver findings as the first manifestation in a patient with brucellosis : Case report

In January 2019, a 30-year-old woman admitted to our inpatient department presented with undulating fever, pain in several joints, and significantly elevated liver enzymes and lactate dehydrogenase. After extended examination, infection with Brucella melitensis with liver, musculoskeletal, and pulmonary involvement was diagnosed and treated. Diagnosis was based on clinical examination, laboratory findings including seroconversion as a proof of immune response, magnetic resonance imaging, three-phase bone scintigraphy, and F‑18 FDG-PET (F-18 Flourdeoxyglucose positron emission tomography) illustrating the bone involvement and its normalization upon treatment. After treatment the patient showed a remarkable improvement of clinical symptoms within a short period. The patient remained symptom free and polymerase chain reaction (PCR) testing for brucellosis was negative, even at the follow-up examination 12 months after the end of the antibiotic therapy. The family members were also examined due to the similar travel history, and by this, brucellosis was also diagnosed in her husband but not in her children.

Bovine brucellosis - a comprehensive review

Brucellosis is a zoonotic disease of great animal welfare and economic implications worldwide known since ancient times. The emergence of brucellosis in new areas as well as transmission of brucellosis from wild and domestic animals is of great significance in terms of new epidemiological dimensions. Brucellosis poses a major public health threat by the consumption of non-pasteurized milk and milk products produced by unhygienic dairy farms in endemic areas. Regular and meticulous surveillance is essentially required to determine the true picture of brucellosis especially in areas with continuous high prevalence. Additionally, international migration of humans, animals and trade of animal products has created a challenge for disease spread and diagnosis in non-endemic areas. Isolation and identification remain the gold standard test, which requires expertise. The advancement in diagnostic strategies coupled with screening of newly introduced animals is warranted to control the disease. Of note, the diagnostic value of miRNAs for appropriate detection of B. abortus infection has been shown. The most widely used vaccine strains to protect against Brucella infection and related abortions in cattle are strain 19 and RB51. Moreover, it is very important to note that no vaccine, which is highly protective, safe and effective is available either for bovines or human beings. Research results encourage the use of bacteriophage lysates in treatment of bovine brucellosis. One Health approach can aid in control of this disease, both in animals and man.

Isolation of Brucella melitensis biovar 1 from human milk confirms breastfeeding as a possible route for infant infection

Brucellosis during pregnancy is associated with major concerns for mothers but, it is still not clear whether the infection could be transmitted through breastfeeding to newborns. This study aimed at evaluating the shedding of Brucella melitensis through human milk. We describe phenotypic and genotypic characterization of Brucella isolate from human milk. The characterized isolate by Bruce-ladder PCR, AMOS PCR and biotyping confirmed the presence of Brucella melitensis biovar 1 from human milk. However, the breastfeeding of newborn baby induced no serious abnormality, although occasional weakness, loss of appetite and vomiting were reported by the parents. All Brucella serological tests including RBT, SAT and 2 ME test were also positive for the baby and her mother, although the blood culture was negative for the baby. Evaluation of the blood DNA from mother and her baby also confirm the presence of Brucella melitensis in the blood samples. Therefore, the isolation of B. melitensis biovar 1 from human milk as well as presence of Brucella melitensis in the blood samples confirms breastfeeding as a possible route for infant infection.

Molecular characteristics of Brucella melitensis isolates from humans in Qinghai Province, China

BACKGROUND

The prevalence of human brucellosis in Qinghai Province of China has been increasing rapidly, with confirmed cases distributed across 31 counties. However, the epidemiology of brucellosis transmission has not been fully elucidated. To characterize the infecting strains isolated from humans, multiple-locus variable-number tandem repeats analysis (MLVA) and whole-genome single-nucleotide polymorphism (SNP)-based approaches were employed.

METHODS

Strains were isolated from two males blood cultures that were confirmed Brucella melitensis positive following biotyping and MLVA. Genomic DNA was extracted from these two strains, and whole-genome sequencing was performed. Next, SNP-based phylogenetic analysis was performed to compare the two strains to 94 B. melitensis strains (complete genome and draft genome) retrieved from online databases.

RESULTS

The two Brucella isolates were identified as B. melitensis biovar 3 (QH2019001 and QH2019005) following conventional biotyping and were found to have differences in their variable number tandem repeats (VNTRs) using MLVA-16. Phylogenetic examination assigned the 96 strains to five genotype groups, with QH2019001 and QH2019005 assigned to the same group, but different subgroups. Moreover, the QH2019005 strain was assigned to a new subgenotype, IIj, within genotype II. These findings were then combined to determine the geographic origin of the two Brucella strains.

CONCLUSIONS

Utilizing a whole-genome SNP-based approach enabled differences between the two B. melitensis strains to be more clearly resolved, and facilitated the elucidation of their different evolutionary histories. This approach also revealed that QH2019005 is a member of a new subgenotype (IIj) with an ancient origin in the eastern Mediterranean Sea.

Brucellosis in transplant recipients: A systematic review

BACKGROUND

Brucellosis is a bacterial disease caused by Brucella species. The purpose of this study was to evaluate brucellosis in all types of transplant patients.

METHODS

All the cases of brucellosis in transplant patients with no time and language limitations were searched and retrieved on May 20, 2020, using the following search keywords: (Brucella OR Brucellosis) AND (Transplant OR Transplantation) through the following medical databases: Web of Sciences, Google Scholar, Scopus, PubMed, and regional databases, for example, SID. All clinical features, including the time of transmission (before, during, and after transplantation), treatment protocols and medications, and patients' outcomes were investigated.

RESULTS

A total of 14 cases reported in 14 studies (out of 777 studies) were retrieved. Kidney (50%), liver (28.5%), and hematopoietic stem cell transplantation (14.2%) were the most reported types of transplantation. The presentation of brucellosis in 42.8% of the patients occurred in the early post-transplantation period, whereas 57.1% of the cases presented with late onset disease.

CONCLUSION

Brucellosis in transplant recipients seems to be uncommon even in the endemic regions. However, rare cases could be transmitted through bone marrow transplantation and transfusion. Precise screening and meticulous supervision during and after transplantation might lead to a reduction in the frequency of brucellosis.

Brucella melitensis-Induced Transaminitis

Brucellosis is infrequently reported in the United States and is mostly an occupational hazard among workers engaged in livestock raising and processing. It is a systemic infectious disease and can involve the liver in varying ways, ranging from benign subclinical increases in serum aminotransferase levels to ominous chronic suppurative disease. It is endemic in many countries, primarily those of the Mediterranean region. It is usually treated with antibiotics. We present a case of a 37-year-old female who developed Brucella melitensis-induced transaminitis, which improved with proper diagnosis and management.

Uncovering the Hidden Credentials of Brucella Virulence

Bacteria in the genus Brucella are important human and veterinary pathogens. The abortion and infertility they cause in food animals produce economic hardships in areas where the disease has not been controlled, and human brucellosis is one of the world's most common zoonoses. Brucella strains have also been isolated from wildlife, but we know much less about the pathobiology and epidemiology of these infections than we do about brucellosis in domestic animals. The brucellae maintain predominantly an intracellular lifestyle in their mammalian hosts, and their ability to subvert the host immune response and survive and replicate in macrophages and placental trophoblasts underlies their success as pathogens. We are just beginning to understand how these bacteria evolved from a progenitor alphaproteobacterium with an environmental niche and diverged to become highly host-adapted and host-specific pathogens. Two important virulence determinants played critical roles in this evolution: (i) a type IV secretion system that secretes effector molecules into the host cell cytoplasm that direct the intracellular trafficking of the brucellae and modulate host immune responses and (ii) a lipopolysaccharide moiety which poorly stimulates host inflammatory responses. This review highlights what we presently know about how these and other virulence determinants contribute to Brucella pathogenesis. Gaining a better understanding of how the brucellae produce disease will provide us with information that can be used to design better strategies for preventing brucellosis in animals and for preventing and treating this disease in humans.

Brucella: Reservoirs and Niches in Animals and Humans

Brucella is an intracellular bacterium that causes abortion, reproduction failure in livestock and leads to a debilitating flu-like illness with serious chronic complications if untreated in humans. As a successful intracellular pathogen, Brucella has developed strategies to avoid recognition by the immune system of the host and promote its survival and replication. In vivo, Brucellae reside mostly within phagocytes and other cells including trophoblasts, where they establish a preferred replicative niche inside the endoplasmic reticulum. This process is central as it gives Brucella the ability to maintain replicating-surviving cycles for long periods of time, even at low bacterial numbers, in its cellular niches. In this review, we propose that Brucella takes advantage of the environment provided by the cellular niches in which it resides to generate reservoirs and disseminate to other organs. We will discuss how the favored cellular niches for Brucella infection in the host give rise to anatomical reservoirs that may lead to chronic infections or persistence in asymptomatic subjects, and which may be considered as a threat for further contamination. A special emphasis will be put on bone marrow, lymph nodes, reproductive and for the first time adipose tissues, as well as wildlife reservoirs.

One health approach to tackle brucellosis: a systematic review

Background

Brucellosis is the most significant and common bacterial zoonosis and is recognized as a re-emerging and neglected disease. Tackling zoonosis is very important for the health and the economy. One Health is an approach characterized by the integration of human and animal health, plants, and ecosystems and encourages joining local, national, and global multidisciplinary efforts to achieve optimal levels of health and collaboration among different disciplines to address complex health problems.

Objectives

The present study aimed to review published scientific literature related to the use of the One Health approach to tackle human brucellosis.

Methods

Web of Science (WoS), PubMed, Scopus, The Cochrane Library, and Embase databases were searched from inception until 30 January 2020. The reference lists of all relevant papers were hand-searched. Two authors extracted data from published studies independently. The Joanna Briggs Institute tool was used to assess the quality of studies.

Results

Of 2297 studies, 10 studies were deemed eligible, which were conducted between 2013 and 2019. Studies were performed in Uganda, Malta, Serbia, Greece, Mongolia, Azerbaijan, Israel, India, Ethiopia, and the USA. All studies suggested that brucellosis is still a major public health problem and that the most important aspect of the One Health approach is the interdependence of humans, ecosystems, and animals .Some studies have focused on livestock vaccination as the most effective way to prevent disease, and others have focused on the biology of Brucella infection and its transmission patterns. Some studies have pointed to the effectiveness of the One Health approach in all the phases of disease management as well as to its role in reducing health costs.

Conclusion

The success of the approach depends on the willingness of the decision-makers to implement the necessary policies. Due to the heterogeneity of current practices, and organizations involved in One Health approach-based programs, it will be incomplete without proper planning. To better implement the approach, strategies should be appraised and disseminated by experts and relevant stakeholders.

Leishmaniasis Diagnosis via Metagenomic Next-Generation Sequencing

Leishmaniasis is a vector-borne disease caused by Leishmania. Although the incidence of leishmaniasis in China is currently low, it has not been completely eradicated. In 2019, visceral leishmaniasis was diagnosed in three patients using bone marrow microscopic examination and metagenomic next-generation sequencing (mNGS). The bone marrow mNGS results from the three patients indicated that 99.9, 99.6, and 30.3% of non-human reads matched the Leishmania genome, and plasma mNGS results from one of the patients revealed that 46.2% of non-human reads matched the Leishmania genome. In the second patient's plasma, no Leishmania sequences were detected by plasma mNGS, and the third patient's plasma was unavailable. The pathogen in all three patients was identified as Leishmania infantum. Leishmania amastigotes were observed by microscopic examination of bone marrow smears in all three patients, but were not found in peripheral blood smears. This indicates that the sensitivity of mNGS is higher than that of smear microscopy and that mNGS can be used to identify Leishmania at the species level. All three patients were elderly male farmers, two from Shanxi and one from Beijing. All three patients had splenomegaly and pancytopenia. Originally, these patients were misdiagnosed and treated for extended periods in other hospitals. Diagnoses of visceral leishmaniasis took place 6, 2, and 2 months after the onset of symptoms in the three patients. In conclusion, this study confirms that bone marrow mNGS can be used to quickly and accurately confirm a diagnosis in patients with suspected leishmaniasis.

First Case of Brucella Pneumonia in a Lung Transplant Patient: Case Report and Review of the Literature

Brucella is one of the most common zoonotic diseases worldwide. It is endemic in the Mediterranean basin. Brucella pneumonia is a rare complication of brucellosis that can present with a variety of clinical and radiological manifestations. It was described only once previously in the setting of solid organ transplant.

A 32-year-old female from Saudi Arabia with cystic fibrosis and bronchiectasis presented five weeks after a bilateral lung transplant with fever and cough. Investigation showed high inflammatory markers in addition to a pulmonary infiltrate in the chest imaging. All microbiological workups were negative including bronchoalveolar lavage cultures. Brucella serology was positive and she was started on anti-Brucella therapy which resulted in complete resolution of her symptoms and radiological changes. This case demonstrates an unusual presentation of Brucellosis. It highlights the importance of epidemiology in evaluating post-transplant infections. We reviewed and summarized the literature on brucellosis post solid organ transplant and the various treatment regimens for Brucella pneumonia.

This is the first case report of Brucella pneumonia in a lung transplant patient. Brucella is a rare complication post solid organ transplant but it has a good prognosis.

Shedding of Brucella melitensis happens through milk macrophages in the murine model of infection

Although shedding of zoonotic brucellae in milk has been demonstrated in natural hosts, these data are still missing for the standard murine infection model. We therefore analysed shedding kinetics and the niche of B. melitensis in murine milk. Pregnant Balb/cByJ mice were intraperitoneally infected with 10⁵ CFU of the 16 M reference strain, a 16 M mCherry mutant or a human isolate. Milk was collected over the course of lactation, and subjected to culture and immunofluorescence assays. Bacteria were also quantified in spleen and mammary glands of maternal mice and in spleen of the litter. The shedding of the three strains did not differ significantly (p = 0.301), ranging from log₁₀ 1.5 to 4.04 CFU/ml. A total of 73% of the mice excreted B. melitensis into the milk with peak values at mid-lactation; up to 30 bacteria/cell were found in macrophages and neutrophils. While the bacterial counts in the spleen of lactating females confirmed a well-established infection, only 50% of the pups harboured brucellae in their spleen, including the spleen of an uninfected pup fed by an infected foster mother. In conclusion, the murine model of infection may contribute to a better understanding of the zoonotic transmission of brucellosis.

Optimization of Precontrol Methods and Analysis of a Dynamic Model for Brucellosis: Model Development and Validation

BACKGROUND

Brucella is a gram-negative, nonmotile bacterium without a capsule. The infection scope of Brucella is wide. The major source of infection is mammals such as cattle, sheep, goats, pigs, and dogs. Currently, human beings do not transmit Brucella to each other. When humans eat Brucella-contaminated food or contact animals or animal secretions and excretions infected with Brucella, they may develop brucellosis. Although brucellosis does not originate in humans, its diagnosis and cure are very difficult; thus, it has a huge impact on humans. Even with the rapid development of medical science, brucellosis is still a major problem for Chinese people. Currently, the number of patients with brucellosis in China is 100,000 per year. In addition, due to the ongoing improvement in the living standards of Chinese people, the demand for meat products has gradually increased, and increased meat transactions have greatly promoted the spread of brucellosis. Therefore, many researchers are concerned with investigating the transmission of Brucella as well as the diagnosis and treatment of brucellosis. Mathematical models have become an important tool for the study of infectious diseases. Mathematical models can reflect the spread of infectious diseases and be used to study the effect of different inhibition methods on infectious diseases. The effect of control measures to obtain effective suppression can provide theoretical support for the suppression of infectious diseases. Therefore, it is the objective of this study to build a suitable mathematical model for brucellosis infection.

OBJECTIVE

We aimed to study the optimized precontrol methods of brucellosis using a dynamic threshold-based microcomputer model and to provide critical theoretical support for the prevention and control of brucellosis.

METHODS

By studying the transmission characteristics of Brucella and building a Brucella transmission model, the precontrol methods were designed and presented to the key populations (Brucella-susceptible populations). We investigated the utilization of protective tools by the key populations before and after precontrol methods.

RESULTS

An improvement in the amount of glove-wearing was evident and significant (P<.001), increasing from 51.01% before the precontrol methods to 66.22% after the precontrol methods, an increase of 15.21%. However, the amount of hat-wearing did not improve significantly (P=.95). Hat-wearing among the key populations increased from 57.3% before the precontrol methods to 58.6% after the precontrol methods, an increase of 1.3%.

CONCLUSIONS

By demonstrating the optimized precontrol methods for a brucellosis model built on a dynamic threshold-based microcomputer model, this study provides theoretical support for the suppression of Brucella and the improved usage of protective measures by key populations.

Different Clinical Manifestations of Human Brucellosis in Pregnant Women: A Systematic Scoping Review of 521 Cases from 10 Countries

Introduction

This systematic scoping review aims to assess the frequency and severity of clinical manifestations of pregnant women with brucellosis.

Methods

Three literature databases, PubMed, Web of Science and China National Knowledge Infrastructure (CNKI), and two search engines (Google and Yahoo) were adopted to identify the relevant articles that published until 31 December 2019. Two investigators independently screened the publications and extracted the data; the case reports and case series which described at least two symptoms or clinical manifestations of pregnant women with brucellosis were included.

Results

A total of 27 articles describing the information of 521 pregnant women with brucellosis were included. Serum agglutination test was the most common laboratory test in the diagnosis of brucellosis. A total of 36 clinical manifestations were extracted from the included articles, and the most common clinical manifestations were fever (400, 76.8%), joint pain/swelling/arthralgia (389, 74.7%), sweats (382, 73.3%), fatigue/asthenia/weakness (262, 50.3%) and back pain (189, 36.3%). Among the 32 included individual cases that with available obstetric outcome information, 10 (31.3%) suffered preterm delivery, 12 (37.5%) had an abortion and 3 (9.8%) had intrauterine fetal death.

Conclusion

Brucellosis is popular and threatening for pregnant women. Regarding the localized body system complications, osteoarticular system was mostly involved, the obstetrics outcomes were severe among pregnant women with brucellosis. The detailed clinical and epidemiological characteristics in this scoping review may add a better and more complete understanding of the disease for both physicians and policy-makers, and provide evidence for timely diagnosis, adequate therapy and better prevention.

Risk factors for acute human brucellosis in Ijara, north-eastern Kenya

Brucellosis is an important zoonotic disease globally, with particularly high burdens in pastoral settings. While the zoonotic transmission routes for Brucella spp. are well known, the relative importance of animal contact, food-handling and consumption practices can vary. Understanding the local epidemiology of human brucellosis is important for directing veterinary and public health interventions, as well as for informing clinical diagnostic decision making. We conducted a cross-sectional study in Ijara District Hospital, north-eastern Kenya. A total of 386 individuals seeking care and reporting symptoms of febrile illness were recruited in 2011. Samples were tested for the presence of Brucella spp. using a real-time PCR (RT-PCR) and results compared to those from the test for brucellosis used at Ijara District Hospital, the febrile Brucella plate agglutination test (FBAT). A questionnaire was administered to all participants and risk factors for brucellosis identified using logistic regression with an information theoretic (IT) approach and least absolute shrinkage and selection (LASSO). Sixty individuals were RT-PCR positive, resulting in a prevalence of probable brucellosis of 15.4% (95% CI 12.0-19.5). The IT and LASSO approaches both identified consuming purchased milk as strongly associated with elevated risk and boiling milk before consumption strongly associated with reduced risk. There was no evidence that livestock keepers were at different risk of brucellosis than non-livestock keepers. The FBAT had poor diagnostic performance when compared to RT-PCR, with an estimated sensitivity of 36.6% (95% CI 24.6-50.1) and specificity of 69.3% (95% CI 64.0-74.3). Brucellosis is an important cause of febrile illness in north-eastern Kenya. Promotion of pasteurisation of milk in the marketing chain and health messages encouraging the boiling of raw milk before consumption could be expected to lead to large reductions in the incidence of brucellosis in Ijara. This study supports the growing evidence that the FBAT performs very poorly in the diagnosis of brucellosis.

Susceptibility of Avian Species to Brucella Infection: A Hypothesis-Driven Study

Brucellosis is a highly contagious bacterial disease affecting a wide range of animals, as well as humans. The existence of the clinically diagnosed brucellosis in avian species is controversially discussed. In the current study, we set to summarize the current knowledge on the presence of brucellae in avian species. Anti-Brucella antibodies were monitored in different avian species using classical diagnostic tools. Experimental infection of chicken embryos induced the disease and resulted in the development of specific lesions. Few empirical studies have been performed in adult poultry. However, the isolation of brucellae from naturally-infected chickens has not been possible yet.

High index of suspicion for brucellosis in a highly cosmopolitan city in southern China

Background

Brucellosis is one of the most widespread zoonosis in the world. In China, 90% of human brucellosis occurs in six northern agricultural provinces. However, there is a recent increase in the trend of human brucellosis in southern provinces with limited cases reported in the literature. Our study aims to describe the clinical features and epidemiology of brucellosis in a tertiary hospital in southern China.

Methods

A retrospective case series of brucellosis was conducted between January 1, 2014 and October 31. 2018. Cases were identified based on positive Brucella serology by tube agglutination test, or positive culture from clinical specimen identified by Vitek 2 and MALDL-TOF MS. Clinical details of brucellosis including patients’ occupation, risk factors, and complications were analyzed. Clinical characteristics between patients from Guangdong and other provinces were also compared.

Results

A total of 13 cases of laboratory-confirmed brucellosis were identified. 7 (53.8%) of the patients were male, 6 (46.2%) were female, with age ranging from 29 to 73 years old (median age: 51 years). 5 patients (38.5%) were from Guangdong province, while the remaining patients (61.5%) were from other provinces. The commonest risk factors of acquisition were consumption of undercooked meat and goat placenta. Patients from Guangdong province were found to be more likely to have prior placenta consumption. The commonest clinical presentations were fever, osteoarticular pain, urinary symptoms, splenomegaly, and lymphadenopathy. Spondylodiscitis/ peripheral joint arthritis (5 patients, 38.5%) was the most prevalent complication, while extra-osteoarticular complications including abdominal aortitis, hepatosplenic abscess, chest wall abscess, and epididymo-orchitis were observed in 4 other patients. Furthermore, it was demonstrated that MALDI-TOF MS is reliable in Brucella identification after additional of reference spectra with standard Brucella strain.

Conclusions

Brucellosis, previously thought to be only found in northern China, is now increasingly seen in highly cosmopolitan part of southern China. MALDI-TOF MS in hospitals in China should include reference spectra with standard Brucella strain to aid bacterial identification in routine clinical practice. In addition to tuberculosis, typhoid fever and typhus, brucellosis should be considered in patients with fever of unknown origin in this locality.

Breastfeeding and the Risk of Infant Illness in Asia: A Review

Infancy remains the most vulnerable period of human life for death, illness, and establishing a lifetime trajectory of growth and health. It is estimated that there are 5.3 million deaths under five years of age worldwide and approximately 800,000 lives could be saved by improving breastfeeding rates and duration. In Asia, an estimated 300,000-350,000 child deaths could be prevented with optimal breastfeeding and the majority would be under 12 months of age. We present a systematic review of studies of infection and breastfeeding in infants in Asia and further review interactions of selected infectious diseases and breastfeeding. Initially, 2459 records of possible interest were identified, 153 full text papers were reviewed in detail, and 13 papers describing diarrhoeal disease and/or acute respiratory tract infection were selected for inclusion in the review. Additional papers were selected to discuss specific diseases and their relationship to breastfeeding. The review found that a variety of methods were used with differing definitions of breastfeeding and diseases. Overall, breastfeeding when compared to the use of infant formula, is associated with significantly lower rates of diarrhoeal disease and lower respiratory tract infection, with a reduction of 50% or more to be expected, especially in infants under six months of age. The relationship between breastfeeding and specific diseases including measles and HTLV1 were reviewed. Breastfeeding reduces some disease rates, but there remain a few conditions where breastfeeding may be contra-indicated.

Research Progress on Brucellosis

Brucellosis is a debilitating febrile illness caused by an intracellular Brucella. The disease is distributed in humans and animals widely, especially in developing countries. Ten species are included in the genus Brucella nowadays; four species of them are pathogenic to humans, which make brucellosis a zoonosis with more than 500,000 new cases reported annually. For human brucellosis, the most pathogenic species is B. melitensis followed by B. suis, while B. abortus is the mildest type of brucellosis. The infection mechanism of Brucella is complicated and mostly relies on its virulence factors. The therapy of the disease contains vaccination and antibiotic. However, there are some defects in currently available vaccines such as the lower protective level and safety. Thus, safe and efficient vaccines for brucellosis are still awaited. The dual therapy of antibacterial is effective in the treatment of brucellosis if a rapid and exact detection method is found.