Failure of short antimicrobial treatments for human brucellosis

The perspective of antibiotic therapeutic challenges of brucellosis in the Middle East and North African (MENA) countries: Current situation and therapeutic management

Brucellosis is among the most prevalent zoonotic infections in Middle Eastern and North African (MENA) countries, critically impacting human and animal health. A comprehensive review of studies on antibiotic susceptibility and therapeutic regimes for brucellosis in ruminants and humans in the MENA region was conducted to evaluate the current therapeutic management in this region. Different scientific databases were searched for peer-reviewed original English articles published from January 1989 to February 2021. Reports from research organizations and health authorities have been taken into consideration. Brucella melitensis and Brucella abortus have been reported from the majority of MENA countries, suggesting a massive prevalence particularly of B. melitensis across these countries. Several sporadic cases of brucellosis relapse, therapeutic failure, and antibiotic resistance of animal and human isolates have been reported from the MENA region. However, several studies proved that brucellae are still in-vitro susceptible to the majority of antibiotic compounds and combinations in current recommended WHO treatment regimens, e.g. levofloxacin, tetracyclines, doxycycline, streptomycin, ciprofloxacin, chloramphenicol, gentamicin, tigecycline, and trimethoprim/sulfamethoxazole. The current review presents an overview on resistance development of brucellae and highlights the current knowledge on effective antibiotics regimens for treating human brucellosis. This article is protected by copyright. All rights reserved.

Boar hunting and brucellosis caused by Brucella suis

Brucellosis remains as a significant public health concern in many areas where the infection persists in domestic hosts (i.e. goats, cattle, and domestic swine) with subsequent risk of transmission to human populations. Brucellosis caused by B. suis remains an important threat to human populations in many countries exposed to domestic and feral swine. In the U.S., swine brucellosis has been under control for many years. Meanwhile, it is a widespread infection among feral swine, particularly in the Southeastern United States; and exposure to infected animals pose a growing threat to humans. We present the case of a 31-year male hunter who six weeks after a knife injury to his hand while field dressing a wild boar, developed a febrile illness associated with hematologic abnormalities and splenic abscesses caused by Brucella suis infection.

A case of acute septic arthritis hip caused by Brucella melitensis in an adolescent child

Brucella is among the most common zoonotic diseases affecting humans. Although musculoskeletal involvement is seen in a large proportion of patients, the disease is often diagnosed late or misdiagnosed due to its subtle nature and rarity, and lack of awareness among clinicians. In this report, a 12-year-old girl was diagnosed with acute septic arthritis of the hip based on clinico-radiological features, and managed with standard treatment, including arthrotomy. However, the child did not respond to the treatment. Based on the histopathology and local endemicity, Brucella was suspected, and confirmed after serological testing. The child subsequently responded to treatment and, at latest follow-up at 1 year, had a full painless range of motion, with no relapse.

Treatment of brucellosis in a young child with trimethoprim/sulfamethoxazole anaphylaxis

Brucellosis is a common zoonotic disease throughout the world. Brucella spp. transmit to humans through contact with fluids of infected animals, especially sheep, cattle, and goats. It is also transmitted by ingestion of fluid-derived products of infected animals, such as unpasteurized milk and cheese. Brucella spp. changes pH level of intracellular environment, so the first treatment approach is to administer antibiotics that have activity in acidic conditions. Anti-brucellosis treatment regimens include doxycycline for children older than eight years old and rifampicin and trimethoprim/sulfamethoxazole (TMP-SMX) combination therapy for children under eight years old, which may be able to act intracellularly under acidic conditions. A TMP-SMX allergy causing anaphylaxis has been reported previously. No alternative anti-brucellosis treatments have been reported in the literature for patients under eight years old with a TMP-SMX allergy. Here, we report a case of a child with brucellosis and a TMP-SMX allergy who was under eight years old at the time of diagnosis and was successfully treated with rifampicin, ciprofloxacin, and gentamicin.

Comparison of two durations of triple-drug therapy in patients with uncomplicated brucellosis: A randomized controlled trial

BACKGROUND

Brucellosis remains the most common zoonotic disease throughout the world and especially in Iran. Several clinical trials have tested different therapeutic regimens for brucellosis, but few have assessed the optimal duration of treatment.

METHODS

We performed a randomized controlled trial to compare a triple-drug regimen of doxycycline plus rifampicin for 6 weeks and streptomycin for the first 7 days with doxycycline plus rifampicin for 8 weeks and streptomycin for 7 days in patients with uncomplicated brucellosis in Arak, Iran. The primary outcome measure for the treatment groups was the relapse rate measured at 1, 3, 6, 12, and 24 months after cessation of therapy.

RESULTS

Eligible patients were randomized to one of the 2 groups with 72 per arm. We found no significant difference in the relapse rate for the 8-week treatment group compared to the 6-week group (9.7% vs 13.9%). There were no significant differences between the 6-week and 8-week groups regarding the relapse rate, period between clinical presentation and beginning of treatment, and time of relapse. Symptom resolution was achieved in all cases at a median 9.5 days and no cases experienced continuing symptoms after treatment.

CONCLUSIONS

Our trial found no significant difference between 6-week and 8-week regimens of doxycycline and rifampicin plus streptomycin for the first 7 days. Further comparative studies with a large sample size should be implemented to achieve a consistent therapeutic regimen for uncomplicated brucellosis, to help identify those who may benefit from longer treatment, and to minimize adverse effects and unnecessary continuation of treatment.

Antibiotics for treating human brucellosis

BACKGROUND

Brucellosis is the most common zoonotic infection in the world. Several antibiotics, separately or in combination, have been tried for treatment of human brucellosis. The inconsistencies between different treatment regimens warrants the need for a systematic review to inform clinical practice and future research.

OBJECTIVES

To evaluate the effects of various antibiotic regimens, monotherapy or in combination with other antibiotics, for treating human brucellosis.

SEARCH METHODS

We searched the Cochrane Infectious Diseases Group Specialized Register, Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, and LILACS until May 2012. We browsed the abstract books of several international infectious diseases conferences. We also checked the reference lists of all studies identified

SELECTION CRITERIA

We included the randomized controlled trials on the pharmaceutical interventions in treatment of acute, chronic, non-complicated, and complicated human brucellosis. The outcomes of interest were relapse, persistence of symptoms at the end of treatment, and adverse drug effects.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the studies for inclusion, risk of bias, and extracted relevant data using pre-designed extraction forms. The findings of homogenous studies were pooled using fixed-effect meta-analysis.

MAIN RESULTS

In total we included 25 studies comparing various antibiotic regimens. Methods of allocation and concealment were inadequately described in half the studies, and only three were blinded. In comparisons of doxycycline plus rifampicin versus doxycycline plus streptomycin we found eight studies with 694 participants. For treatment failure, the doxycycline plus rifampicin regimen was less effective (risk ratio (RR) 1.91, 95% confidence interval (CI) 1.07 to 3.42, seven studies, 567 participants), relapse (RR 2.39, 95% CI 1.17 to 4.86), and minor adverse drug reactions (RR 1.38, 95% CI 0.99 to 1.92). In comparisons of doxycycline plus rifampicin against quinolone (ciprofloxacin or ofloxacin) plus rifampicin we found five studies of 336 participants. The pooled analysis did not demonstrate any significant difference between two regimens in terms of relapse and symptom persistence, but showed a non-significant higher risk of minor adverse reactions in doxycycline plus rifampicin (RR 1.80, 95% CI 0.78 to 4.18). Other comparisons were reported in a few heterogenous studies, and the pooled analyses, where applied, did not show any significant difference.

AUTHORS' CONCLUSIONS

Doxycycline (six weeks) plus streptomycin (two or three weeks) regimen is more effective regimen than doxycycline plus rifampicin (six weeks) regimen. Since it needs daily intramuscular (IM) injection, access to care and cost are important factors in deciding between two choices. Quinolone plus rifampicin (six weeks) regimen is slightly better tolerated than doxycycline plus rifampicin, and low quality evidence did not show any difference in overall effectiveness.

Systematic review and meta-analysis of randomized clinical trials in the treatment of human brucellosis

Background

Brucellosis is a persistent health problem in many developing countries throughout the world, and the search for simple and effective treatment continues to be of great importance.

Methods and Findings

A search was conducted in MEDLINE and in the Cochrane Central Register of Controlled Trials (CENTRAL). Clinical trials published from 1985 to present that assess different antimicrobial regimens in cases of documented acute uncomplicated human brucellosis were included. The primary outcomes were relapse, therapeutic failure, combined variable of relapse and therapeutic failure, and adverse effect rates. A meta-analysis with a fixed effect model was performed and odds ratio with 95% confidence intervals were calculated. A random effect model was used when significant heterogeneity between studies was verified.

Comparison of combined doxycycline and rifampicin with a combination of doxycycline and streptomycin favors the latter regimen (OR = 3.17; CI95% = 2.05–4.91). There were no significant differences between combined doxycycline-streptomycin and combined doxycycline-gentamicin (OR = 1.89; CI95% = 0.81–4.39). Treatment with rifampicin and quinolones was similar to combined doxycycline-rifampicin (OR = 1.23; CI95% = 0.63–2.40). Only one study assessed triple therapy with aminoglycoside-doxycycline-rifampicin and only included patients with uncomplicated brucellosis. Thus this approach cannot be considered the therapy of choice until further studies have been performed. Combined doxycycline/co-trimoxazole or doxycycline monotherapy could represent a cost-effective alternative in certain patient groups, and further studies are needed in the future.

Conclusions

Although the preferred treatment in uncomplicated human brucellosis is doxycycline-aminoglycoside combination, other treatments based on oral regimens or monotherapy should not be rejected until they are better studied. Triple therapy should not be considered the current treatment of choice.

Epidemiological and clinical features of Brucella arthritis in 24 children

BACKGROUND AND OBJECTIVES

Brucellosis is considered the leading zoonotic disease of the Middle East. The disease has a wide spectrum of clinical manifestations and can result in complications with severe morbidity. The aim of this study was to evaluate the frequency, distribution and characteristics of arthritis in Iranian children with brucellosis.

DESIGN AND SETTING

A retrospective descriptive study conducted in a referral children center in Tehran from 1997 to 2005.

PATIENTS AND METHODS

Arthritis in children with brucellosis who were admitted to a specialized hospital was detected by clinical signs of the involved joint(s) and characteristics of joint fluid aspiration. Socio-demographic information was recorded.

RESULTS

Of 96 patients diagnosed with brucellosis, 24 (25%) had Brucella arthritis 14 (58.3%) males and 10 (41.7%) females. Most common manifestations were fever in 21 patients (87.5%) and fatigue in 18 patients (75%). Monoarthritis was recorded in 15 patients (62.5%) of the cases with involvement of the knee in 8 (45%) and hip in 5 (29%), the ankle in 2 (8%) patients while 9 (37.5%) patients suffered from polyarthritis. None of the patients had axial joints involvement. Seventy-five percent of the subjects (18 patients) were from urban areas and 66.7% (16 patients) had consumed un-pasteurized cheese. Recurrence was not seen in any of the 24 patients who received a combination of co-trimoxazole for 6 weeks and gentamicin for 5 days.

CONCLUSION

Childhood brucellosis is a challenging disease in Iran that has serious complications like arthritis. Therefore all physicians who work in endemic areas should be familiar with this disease and consider the possibility of brucellosis in all children who present with arthritis and arthralgia.

Comparison of the efficacy of gentamicin for 5 days plus doxycycline for 8 weeks versus streptomycin for 2 weeks plus doxycycline for 45 days in the treatment of human brucellosis: a randomized clinical trial

OBJECTIVES

To compare the efficacy of gentamicin for 5 days plus doxycycline for 8 weeks with streptomycin for 2 weeks plus doxycycline for 45 days in the treatment of human brucellosis.

METHODS

In each arm of the study, 82 patients older than 10 years randomly received 5 mg/kg gentamicin once daily for 5 days plus 100 mg of doxycycline twice daily for 8 weeks or 1 g of streptomycin intramuscularly for 2 weeks plus the same dose of doxycycline for 45 days. Therapeutic failure and relapse in these two treatment groups were compared. This study was registered in the Iranian Registry of Clinical Trials (www.irct.ir) with registration number ID: IRCT138708191441N1.

RESULTS

The clinical manifestations in these two groups were similar. Therapeutic failure was seen in two (2.4%) patients in the gentamicin/doxycycline group and in four (4.9%) patients in the streptomycin/doxycycline group [relative risk (RR) = 0.5, 95% confidence interval (CI) 0.09-2.66, P = 0.68]. Relapse was seen in two (2.4%) cases in the gentamicin/doxycycline group and in five (6.1%) cases in the streptomycin/doxycycline group (RR = 0.4, 95% CI 0.08-2, P = 0.44). The efficacy with the gentamicin/doxycycline regimen was 95.12% and that with the streptomycin/doxycycline regimen was 89% (RR = 1.07, 95% CI 0.98-1.17, P = 0.25). Cox regression analyses showed no differences among the two treatment groups for patients who had relapse or therapeutic failure and those who had not regarding baseline covariates such as sex, duration of disease before diagnosis, positive blood culture and focal disease.

CONCLUSIONS

The results show that the efficacy of gentamicin for 5 days plus doxycycline for 8 weeks is not superior to that of streptomycin for 2 weeks plus doxycycline for 45 days.

Therapeutic options for human brucellosis

Worldwide, human brucellosis is the most common zoonotic disease and it has gained increasing interest because of the potential use of Brucella as a biological weapon. Monotherapy for brucellosis is associated with a high relapse rate and dual therapy in different combinations is more efficacious. The combination regimen of intramuscular streptomycin with an oral tetracycline resulted in fewer relapses than the doxycycline-rifampin combination in meta-analysis and prospective studies, although the use of doxycycline and rifampin is a reasonable choice in certain conditions. Longer duration and triple antimicrobial therapy appear to improve outcome and prevent relapses, especially in patients with focal disease. Recently, the use of gentamicin-loaded microparticles and the use of new antibiotics, such as tigecycline, may hold future promise. In addition, there are a few studies of the enhanced effect of immune response stimulators, such as levimasole and IFN-2, in the treatment of brucellosis. The development of an effective subcellular Brucella vaccine would be an important step forward to curtail the disease. However, currently and for the near future, only the control of animal disease is possible using vaccine strategies.

Efficacy of cotrimoxazole and rifampin for 6 or 8 weeks of therapy in childhood brucellosis

From March 1998 to September 2001, 64 children and from October 2001 to December 2004, 66 children < or = 15 years with brucellosis in Babol, Iran, were treated with cotrimoxazole and rifampin for 6 or 8 weeks, respectively. Cure rate for 6 weeks was 89.1% and for 8 weeks it was 95.5%. Six weeks of therapy with cotrimoxazole plus rifampin is sufficient for treatment of childhood brucellosis.

Efficacy of gentamicin plus doxycycline versus streptomycin plus doxycycline in the treatment of brucellosis in humans

BACKGROUND

In the treatment of human brucellosis, antibiotic regimens containing an aminoglycoside are reportedly associated with fewer relapses.

METHODS

This prospective, randomized study employed doxycycline (100 mg administered orally twice daily for 45 days) in combination with either streptomycin (1 g administered intramuscularly daily for 14 days; the DS regimen) or gentamicin (5 mg/kg per day administered intramuscularly for 7 days; the DG regimen). Efficacy of treatment was determined by rates of failure or relapse with a follow-up period of 1 year.

RESULTS

Ninety-seven patients with a mean age (+/- standard deviation [SD]) of 33.74+/-15.47 years and 94 patients with the a mean age (+/-SD) of 36.2+/-14.14 years were treated with regimens DG and DS, respectively (P = .277). The clinical manifestations in both groups of patients were similar with the exception of sweating, which was more common in the DG group (P = .04). Three (3.2%) of the patients in the DS group and 3 (3.1%) of patients in the DG group experienced relapse (difference, 0.1%; 95% confidence interval [CI], -4% to 5%; P = 1.0). Overall, 7 (7.4%) of the patients in the DS group and 5 (5.2%) of the patients in the DG group experienced failure of therapy or relapse (difference, 2.2%; 95% CI, -4.5% to 8.9%; P = .563). The actuarial probability for relapse at 12 months after completion of therapy was 4.3% in the DS group and 2.1% in the DG group (difference, 2.2%; 95% CI, -2.8% to 7.2%).

CONCLUSIONS

The combination of oral doxycycline for 45 days plus intramuscular gentamicin for 7 days is equally as effective as traditional therapy using doxycycline for 45 days plus streptomycin for 14 days.

Laboratory exposures to brucellae and implications for bioterrorism

Brucellae are class 3 organisms and potential agents of bioterrorism. Because of effective public health measures, brucellosis has become a rare disease in industrialized countries, and clinical microbiology laboratories are frequently unfamiliar with the genus. A low index of suspicion by physicians or failure to notify the laboratory, equivocal Gram-stain results, misidentification of the organism by commercial systems, unsafe laboratory practices, and laboratory accidents have been responsible for numerous cases of exposure to the organism and laboratory-acquired disease in recent years. Discovery of a laboratory exposure to brucellae should prompt an exhaustive investigation of the event and its circumstances, definition of the population at risk, enforcement of safe laboratory practices, and antimicrobial drug prophylaxis for exposed persons. Inadvertent exposures to brucellae in the clinical laboratory indicate a widespread lack of preparedness to cope with eventual biologic threats involving use of the organism.

A randomized, double-blind study to assess the optimal duration of doxycycline treatment for human brucellosis

BACKGROUND

Human brucellosis is usually treated with a combination of tetracyclines and aminoglycosides. However, the optimal duration of therapy has not been clearly determined.

METHODS

We conducted a prospective, double-blind, randomized, multicenter study comparing treatment with doxycycline (100 mg po b.i.d.) for 30 days (30-day group) with the same dosage of doxycycline for 45 days (45-day group) in patients with brucellosis without endocarditis, spondylitis, or neurobrucellosis. All patients were treated with gentamicin (240 mg im once daily) for the first 7 days. Therapeutic outcome was evaluated by measuring relapse rates and drug safety.

RESULTS

Seventy-three patients were included in each group. During the first 45 days after treatment, the percentage of patients with relapse was significantly higher in the 30-day group than in the 45-day group (12.3% vs. 1.37%; relative risk, 9.00; 95% confidence interval [CI], 1.17-69.2; P=.017). Between day 45 after treatment and 12 months after treatment, no further significant differences were found in relapse rates between groups (9.38% in the 30-day group vs. 11.11% in the 45-day group; relative risk, 0.84; 95% CI, 0.31-2.30; P=.78). Overall, relapses occurred in 15 (20.55%) of 73 patients in the 30-day group and in 9 (12.33%) of 73 patients in the 45-day group (relative risk, 1.67; 95% CI, 0.78-3.56; P=.264). Compliance and adverse effects were comparable in the 2 groups.

CONCLUSIONS

Doxycycline treatment for 45 days significantly decreased early relapse rates among adults with brucellosis without increasing adverse effects.

Clinical features, complications and treatment outcome of childhood brucellosis in central Greece

OBJECTIVES

To examine the epidemiology, clinical and hematological characteristics, complications and treatment outcome of childhood brucellosis in central Greece.

METHODS

Retrospective record review of all patients 0-14 years of age with brucellosis admitted during a 16-year period between 1984 and 1999.

RESULTS

A total of 39 cases (23 males, median age 132 months) were recorded in which the diagnosis was confirmed by a positive culture (n=30) or detection of IgM antibodies with ELISA (n=9). About 38% of these patients came from families of farmers or shepherds who owned a few domestic animals or small herds of goats or sheep and another 43% had consumed dairy products bought from shepherds. In 41% of the cases another family member developed symptomatic infection. Most of the patients presented with fever (61%) and musculoskeletal symptoms (69%). Splenomegaly was recorded in 38% and hepatomegaly in 28% of the cases. Anemia (39%) and monocytosis (31%) were the most common hematological manifestations, followed by lymphopenia (18%). Unusual complications were detected in two patients who developed thrombocytopenic purpura and acute facial nerve palsy, respectively, but recovered without long-term sequelae. None of the 22 patients who received a combination of two or three antibiotics for > or =6 weeks and had adequate follow-up had a relapse.

CONCLUSION

Childhood brucellosis remains an important public health problem in central Greece. It usually occurs in families that raise small ruminants and the development of symptomatic infection in more than one family member is common. It may cause serious complications in children and treatment with at least two antibiotics for not less than six weeks appears to be effective.