Factors affecting Brucella spp. blood cultures positivity in children

Comparative Analysis of Pediatric Brucellosis Cases With and Without Bacteremia

Introduction: Brucellosis, which is among the endemic regions of Turkey, is a common zoonotic disease. The gold standard in diagnosing brucellosis is culture. We aimed to compare demographic characteristics, risk factors, and clinical and laboratory variables between cases with culture positivity and undetected in culture. Materials and Methods: This single-center study was conducted between January 2007 and April 2022. Clinical and laboratory data of patients with brucella growth in blood culture and patients without growth were compared. Results: A total of 150 patients were included in the study. The median age was 10 (1-18 years). Of the patients, 66 (44%) were female and 84 (56%) were male. Forty (26.7%) of the patients were bacteremic and 110 (73.3%) were nonbacteremic. In the bacteremic group, white blood cell count, platelet, and hemoglobin counts were lower, and aspartate aminotransferase (AST) and alanine aminotransferase (ALT) values were higher. In clinical evaluation, fever, hepatomegaly, splenomegaly, and abdominal pain were more common in the bacteremic group. Conclusion: The distinction between bacteremic and nonbacteremic brucellosis can be predicted using laboratory values such as white blood cells, hemoglobin counts, platelet, ALT, and AST, and clinical findings such as fever, abdominal pain, hepatomegaly, and splenomegaly.

Comparison of the Characteristics of Brucella Patients Diagnosed With Blood Culture Positivity and/or Serology

PURPOSE

The aim of this study is to investigate and compare the clinical, laboratory, and treatment response characteristics of patients diagnosed with positive culture or serology. In this way, we wanted to assess the validity of serological diagnosis.

MATERIALS AND METHODS

The study was designed as a retrospective cross-sectional study between January 2010 and 2020. Patients with clinical and laboratory findings of acute/subacute brucellosis, patients with positive serological tests, and patients with growth of Brucella spp. in blood culture were included in the study. The patients were divided into three groups: Group 1 - Wright agglutination test result ≥ 1/160 and Brucella spp. growth in blood culture; Group 2 - Wright agglutination test result ≥ 1/160 and no growth in blood culture; and Group 3 - Brucella spp. growth in blood culture and negative serological test. These three groups were retrospectively evaluated for clinical features, laboratory parameters, areas of involvement, treatment options, and treatment response.

RESULTS

We identified 294 patients diagnosed with brucellosis. Blood cultures were obtained from all patients, and Brucella spp. was detected in 40 patients (13.6%). There were 35 patients in Group 1, 254 patients in Group 2, and five patients in Group 3. When examining patients with symptoms, only fever showed a difference between the groups, which was significantly higher in Group 1. Laboratory investigations of the C-reactive protein (CRP), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) levels of the patients showed significant differences between the groups; these parameters were significantly higher in Group 1.

CONCLUSION

No significant difference was found in terms of treatment response and prognosis between patients with and without blood culture growth who were clinically compatible with acute/subacute brucellosis as diagnosed by serological methods. Therefore, serological tests are reliable methods for the diagnosis of brucellosis in cases where blood culture is inconclusive.

Predicting Factors of Brucella melitensis Bacteremia in Children Admitted with Brucellosis

Objective Brucellosis is the most common zoonotic disease. Isolation of Brucella melitensis in blood culture is accepted as the gold standard for diagnosis. This study aims to determine the predictive factors of B. melitensis bacteremia in pediatric patients followed up with brucellosis.

Methods Two-hundred twenty pediatric brucellosis patients were included in the study. The epidemiological, clinical, and laboratory data were recorded.

Results The patients comprised 63.2% males and 36.8% females with a mean age of 10.45 ±  4.36 years (range, 1–18 years), and 70.5% were younger than 14 years old. B. melitensis was isolated in the blood culture in 33.6% of patients. In the epidemiological history of pediatric patients with bacteremic brucellosis, there was a history of dealing with, owning, or working with livestock. In patients with brucellosis, fever and weight loss, hepatomegaly, and arthritis were more common in patients with bacteremia than in those without bacteremia. Among laboratory findings, leukopenia, low albumin value, and high C-reactive protein were calculated as predictors of Brucella bacteremia in patients with brucellosis.

Conclusion In regions where brucellosis is endemic, serum agglutination tests may be positive without clinical findings. Brucellosis can mimic many other diseases, so the definitive diagnosis is demonstrated by bacteremia. Blood cultures should be taken in patients with predictive factors suggestive of brucellosis.

Laboratory and clinical predictors of focal involvement and bacteremia in brucellosis

Early diagnosis of organ involvement and bacteremia in brucellosis increases treatment success and may prevent poor clinical outcomes. This study aimed to investigate the predictors of focal involvement and bacteremia in patients with brucellosis. A total of 139 brucellosis patients aged 16 years and older were included in the study. Patients with and without organ involvement and bacteremic and non-bacteremic patients were compared separately. Low back pain, lymphadenomegaly, absence of fever on admission, ESR, AST, and neutrophil-lymphocyte ratio (NLR) were predictors of focal involvement (OR: 2.604; 3.167; 7.224; 1.039; 1.032; 1.738, respectively). The AUC value of ESR was 0.669 (0.573-0.765, p = 0.002) with the cutoff point > 30 mm/h (sensitivity 89.74% and specificity 37.00%) in predicting focal involvement in patients with brucellosis. Myalgia and headache (OR: 2.970; 2692) were defined as clinical predictors of Brucella bacteremia. Focal involvement should be considered in patients with brucellosis in the absence of myalgia and fever, presence of low back pain, and sedimentation > 30 mm/h. Brucella bacteremia should be considered regardless of fever, especially in patients with myalgia and headache in endemic areas.

Bacteremic and Nonbacteremic Brucellosis in Children in Turkey

INTRODUCTION

Human brucellosis is one of the most common zoonotic infections in the world. The definitive diagnosis of brucellosis is based on cultured Brucella organisms from blood or other tissue samples. We aimed to compare bacteremic and nonbacteremic brucellosis patients with demographical, epidemiological, clinical and laboratory features and determine the predictive factors affecting blood culture positivity.

MATERIALS AND METHODS

Children aged 1 month to 18 years who were followed up with the diagnosis of brucellosis between January 2005 and March 2021 were included in this retrospective study. According to the isolation of Brucella melitensis in blood culture, the patients were divided into two groups as bacteremic and nonbacteremic and compared in terms of demographic, clinical and laboratory characteristics.

RESULTS

One hundred eighty-nine (116 male, 61.4%) patients diagnosed with brucellosis were included in the study. There were 76 (40.2%) bacteremic and 113 (59.8%) nonbacteremic patients. Bacteremic patients were younger than nonbacteremic patients. Fever, arthralgia, hepatomegaly and splenomegaly were significantly higher in the culture positive group. High levels of C-reactive protein (CRP), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were found to be significant in the bacteremic group.

CONCLUSION

In our study, history of fever and arthralgia, hepatomegaly and splenomegaly in physical examination and high CRP, ALT and AST levels in the biochemical analysis were important factors determining blood culture positivity.

Epidemiological, Clinical and Laboratory Characteristics of Patients with Brucella Infection in Anhui Province, China

Background

Brucellosis is currently one of the most widespread zoonotic diseases caused by Brucella genus, and the Brucella melitensis is the major pathogen. The number of people infected with Brucella has gradually increased in Anhui Province.

Purpose

To retrospectively evaluate the epidemiological, clinical, and laboratory data of brucellosis patients in Anhui Province.

Patients and Methods

A total of 109 brucellosis patients were admitted to the First Affiliated Hospital of Anhui Medical University from January 2012 to March 2021. Data from all patients were retrieved from the hospital’s electronic medical system. The final results were grouped and compared according to the presence or absence of bacteremic brucellosis and three phases of brucellosis.

Results

The most common symptoms among all 109 brucellosis patients were fever (89.0%), followed by chills (52.3%), arthralgia (48.6%), and weight loss (30.3%), and laboratory results presented with anemia (65.1%), elevate of C-reactive protein (CRP) (91.7%), erythrocyte sedimentation rate (ESR) (86.2%), aspartate aminotransferase (AST) (40.4%), and lactate dehydrogenase (LDH) (43.1%). The percentage of fever (96.1%), arthralgia (58.8%), anorexia (35.3%), leukopenia (31.4%), and the AST (51.0%) were higher in bacteremic than nonbacteremic group. Additionally, the median level of LDH (332.0 mg/L, IQR, 209.0–553.0) was higher in bacteremic than nonbacteremic group. Nevertheless, the albumin (36.0 mg/L, IQR, 33.9–38.2) was lower in the bacteremic group. The percentage of fever (94.9%) and the median LDH level (316.0 U/L (IQR,218.0–517.5)) in the acute phase of brucellosis were higher than the percentage of fever (72.0%) and the median LDH level (209.0 U/L (IQR,162.0–276.0)) in the subacute phase of brucellosis.

Conclusion

Brucellosis has become an important public health issue in Anhui Province. Brucellosis is a disease with diverse clinical manifestations. Our data showed that unexplained fever, arthralgia, and elevated AST and LDH should be considered as a diagnosis of bacteremia brucellosis for early treatment intervention.

Epidemiological and clinical characteristics of bacteremic brucellosis

Objective

To retrospectively investigate the epidemiological features, clinical manifestations and laboratory characteristics of bacteremic brucellosis.

Methods

Brucellosis patients admitted to our clinic from January 2015 to December 2017 were included in the study. Patient electronic medical records were reviewed for epidemiological features, clinical manifestations, and laboratory findings.

Results

A total of 132 brucellosis patients were analyzed (64 cases with bacteremic brucellosis and 68 cases with nonbacteremic brucellosis). The median duration from exposure to onset of symptoms was 6.9 weeks (range: 1 day to 32 weeks) and 21.9 weeks (range: 1–76 weeks) in patients with bacteremic and nonbacteremic brucellosis, respectively. More bacteremic than nonbacteremic patients presented with fever and chills. Arthritis was observed in 34 (25.8%) patients, and was more commonly observed in nonbacteremic patients. Using C-reactive protein (CRP) and procalcitonin (PCT) as serological markers, the areas under the receiving operating characteristic curves were 0.64 [95% confidence interval (CI): 0.54–0.73] and 0.61 (95% CI: 0.51–0.70), respectively, for distinguishing bacteremic from non-bacteremic brucellosis.

Conclusion

Fever and chills were frequently observed in bacteremic brucellosis patients, whereas arthritis was more common in nonbacteremic brucellosis patients. Serum CRP and PCT can be used as potential serological markers for diagnosing bacteremic brucellosis.

The implications of Rose Bengal test seroconversion in the diagnosis of brucellosis in children in an endemic region

BACKGROUND

The Rose Bengal test (RBT) is a commonly used simple serological test for brucellosis. We assessed brucellosis in individuals <18 years for RBT performance; duration of RBT positivity following infection; and potential factors associated with RBT seroconversion timing.

METHODS

The medical files of first hospital admissions of brucellosis, 2005-2014, southern Israel, were retrospectively reviewed.

RESULTS

Overall, RBT was positive in 99% of 416 primary brucellosis admissions. The mean age was 9.8 ± 4.5 years; all patients were of Bedouin ethnicity. Of 273 patients with subsequent RBT testing, RBT remained positive in 169 cases (duration range: 0.1-122 months). Overall, 104 patients had subsequent negative RBT result (duration range: 0.9-127; median: 29.9 months). Comparing fast (<30 months) vs. slow (≥30 months) seroconversion, IgM titres ≥1:640 were more common in fast seroconversion episodes (53% vs. 23%, p = .003). Anaemia was more common in the slow seroconversion group (76% vs. 52%, p = .02). Age, gender, ethnicity, fever, arthralgia, thrombocytopenia, leukopenia, liver enzymes, bacteraemia and adequate treatment rates were similar.

CONCLUSIONS

RBT positivity rate in first hospital visit was high. Fast negative seroconversion was associated with high IgM titres and lower anaemia rates at first presentation. These findings may assist early recognition of long-lasting brucellosis patients in endemic regions.

Factors Associated With Single and Recurrent Bacteremia in Childhood Brucellosis

BACKGROUND

Data regarding risk factors of bacteremic brucellosis, and specifically recurrent bacteremia, are scarce. We assessed patients with childhood brucellosis, differentiating between those having culture-negative, single-bacteremic, and recurrent-bacteremic episodes.

METHODS

The medical files of pediatric brucellosis patients, from 2005 through 2014, were reviewed retrospectively. Univariate and multivariate analyses were performed to compare demographic and clinical characteristics of culture-negative, single-bacteremic, and recurrent-bacteremic (≥30 days between positive cultures) episodes.

RESULTS

Of all 436 brucellosis cases, 22% were culture-negative, 72% were single-bacteremic, and 6% were recurrent-bacteremic. In a univariate analysis, single-bacteremic episodes were associated with fever (90% vs 65% and 40% in culture-negative and recurrent bacteremia, respectively) and elevated glutamic oxaloacetic transaminase (GOT) levels. Recurrent-bacteremic episodes were associated with anemia (26% vs 14% and 9% in single bacteremia and culture negative, respectively), elevated GOT, low immunoglobulin M (IgM) titers (56% vs 89% and 99%, respectively), and lower levels of adequate treatment (74% vs 94% and 86%, respectively). In multivariate analyses, single bacteremia was associated with fever (odds ratio [OR], 3.595, compared with culture negative), while recurrent bacteremia was inversely associated with IgM titers ≥1:160 (OR, 0.022 and 0.226 compared with culture negative and single bacteremia, respectively) and fever (OR, 0.108 compared with single bacteremia).

CONCLUSIONS

Brucellosis episodes are commonly complicated with bacteremia. Single-bacteremic episodes were associated with high-grade fever and elevated liver enzymes, possibly indicating high bacterial virulence. Recurrent-bacteremic episodes were associated with poor treatment at initial diagnosis, along with low rates of fever, low IgM titers, and high anemia rates, possibly indicating impaired host response. Physicians should consider treatment modifications for suspected recurrent-bacteremic brucellosis, including monitoring treatment adherence, and possibly administering prolonged treatment.

Investigation of the Sensitivity and Specificity of Laboratory Tests Used in Differential Diagnosis of Childhood Brucellosis

Objectives 

Childhood brucellosis is a common public health problem in developing countries. The diagnosis of brucellosis based on nonspecific symptoms is an ongoing problem for physicians, especially in endemic areas. In this study, it is aimed to discuss the efficacy of frequently used test methods in the differential diagnosis of brucellosis.

Methods

The records of 332 patients admitted to pediatric clinic on suspicion of brucellosis were retrospectively analyzed. Patients with brucellosis were included in the positive group (n = 262) and those without brucellosis were included in the negative group (n = 70).

Results

 As a result of biochemical analysis of the cases, median alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), erythrocyte sedimentation rate (ESR), and C reactive protein (CRP) values were significantly higher in the positive group than that in the negative group (p<0.05). There was no significant difference between median white blood cell, neutrophil, lymphocyte, neutrophil to lymphocyte ratio, hemoglobin, and platelet values between groups (p>0.05). Receiver operating curves were plotted to compare predictive values of CRP (area under curve (AUC): 0.635, p= 0.001), ESR(AUC:0.701, p<0.001), AST(AUC: 0.595, p=0.015), ALT(AUC:0.604, p=0.007), and GGT(AUC:0.593, p=0.016) in 332 patients with suspected brucellosis.

Conclusions

Increased levels of AST, ALT, GGT, CRP, and ESR may have a complementary role in the differential diagnosis of childhood brucellosis. However, all of these markers should be evaluated with clinical findings due to their low specificity and sensitivity. 

Laboratory Diagnosis of Human Brucellosis

The clinical presentation of brucellosis in humans is variable and unspecific, and thus, laboratory corroboration of the diagnosis is essential for the patient's proper treatment. The diagnosis of brucellar infections can be made by culture, serological tests, and nucleic acid amplification assays. Modern automated blood culture systems enable detection of acute cases of brucellosis within the routine 5- to 7-day incubation protocol employed in clinical microbiology laboratories, although a longer incubation and performance of blind subcultures may be needed for protracted cases. Serological tests, though they lack specificity and provide results that may be difficult to interpret in individuals repeatedly exposed to Brucella organisms, nevertheless remain a diagnostic cornerstone in resource-poor countries. Nucleic acid amplification assays combine exquisite sensitivity, specificity, and safety and enable rapid diagnosis of the disease. However, long-term persistence of positive molecular test results in patients that have apparently fully recovered is common and has unclear clinical significance and therapeutic implications. Therefore, as long as there are no sufficiently validated commercial tests or studies that demonstrate an adequate interlaboratory reproducibility of the different homemade PCR assays, cultures and serological methods will remain the primary tools for the diagnosis and posttherapeutic follow-up of human brucellosis.

Hematologic Manifestations of Brucellosis in Children

BACKGROUND

Brucellosis is a common zoonosis in the Bedouin population of southern Israel. Limited data exist for the rate and risk factors of hematologic complication of brucellosis in children. We assessed anemia, leukopenia, thrombocytopenia and pancytopenia in childhood brucellosis in southern Israel.

METHODS

Our medical center is the sole hospital in southern Israel. All medical files of brucellosis, 2005-2014, identified through positive blood cultures or International Classification of Diseases 9th revision coding with positive serology, were reviewed retrospectively.

RESULTS

Overall, 511 brucellosis episodes were identified; 42% (N = 214) with ≥1 cytopenia, including 13% (N = 68) anemia, 28% (N = 144) leukopenia, 14% (N = 74) thrombocytopenia and 2% (N = 9) pancytopenia. Overall, 99.8% of episodes were in Bedouin children and 70% in males. In 79% of episodes, blood culture was positive for Brucella melitensis. Acute infections comprised 84% of all episodes. In univariate analysis, older age (10.49 ± 4.81 vs. 9.25 ± 4.89 years), fever (92% vs. 78%), positive blood culture (84% vs. 75%) and IgM ≥1:640 levels (50% vs. 39%) were associated with cytopenia. In contrast, arthralgia was associated with noncytopenic episodes. In multivariate analyses, older age (odds ratio = 1.063) and fever (odds ratio = 3.127) were associated with cytopenia.

CONCLUSIONS

Brucellosis is commonly presented with cytopenia, especially in bacteremic episodes with fever. However, pancytopenia is uncommon and its finding should alert the physician to look for other possible etiologies.

Epidemiological, diagnostic, clinical, and therapeutic aspects of Brucella bacteremia in children in southern Israel: a 7-year retrospective study (2005-2011)

BACKGROUND

Data on the various aspects of brucellosis in children living in southern Israel are missing.

OBJECTIVES

Our aim was to study the epidemiological, microbiological, diagnostic, clinical, therapeutic and outcome features of brucellosis in children <19 years of age in southern Israel during 2005-2011.

PATIENTS AND METHODS

The study population included all patients hospitalized with a diagnosis of brucellosis, established according to a clinical presentation compatible with brucellosis+presence of Brucella bacteremia (BB).

RESULTS

A total of 128 (50.8%) of 252 patients admitted with a diagnosis of brucellosis had BB (all with Brucella melitensis). All patients were of Muslim Bedouin ethnicity. The mean incidence of BB in southern Israel was 16 cases/100,000 Bedouin, with no significant changes during the study period. Overall duration of symptoms before diagnosis was 10.1±10.9 days. Fever at diagnosis was recorded in <20% of the patients. The most frequent symptoms were arthralgia (61.7%), weakness (32.8%), gastrointestinal disturbances (27.3%), myalgia (25%), and headache (18.8%). The main clinical findings included monoarthritis (36.7%), hepatosplenomegaly (25%), lymphadenopathy (17.2%), heart murmur (11.7%), and skin rash (9.4%), respectively. Anemia, leukopenia, thrombocytopenia, and pancytopenia were reported in 17.6%, 29.6%, 12.8%, and 2.3% of the patients, respectively. Twenty-nine (30.5%) patients with BB had serum agglutinin titers ≤1/160 (13, 13.7%%, had titers <1/160). Twenty-seven (93%) of the 29 patients aged 0-4 years were treated with gentamicin and trimethoprim-sulfamethoxazole; a total of 77 (60.2%) patients received gentamicin and doxycycline.

CONCLUSIONS

Childhood brucellosis remains an important public health problem in southern Israel. BB was diagnosed in >50% of the children with brucellosis, and B. melitensis was identified in all cases. Arthralgia, weakness, and gastrointestinal complaints were the most common symptoms, and monoarthritis, hepatosplenomegaly, and lymphadenopathy were the most common clinical findings. A considerable number of patients with BB had undetectable/low serum agglutinin titers, suggesting insufficient reliability on serology alone in diagnosis of brucellosis.