Brucellosis in the UK: a risk to laboratory workers? Recommendations for prevention and management of laboratory exposure

Efficacy of antibiotic prophylaxis to preventing brucellosis in accidental exposure: A systematic review

BACKGROUND

Antibiotic prophylaxis to prevent brucellosis after accidental exposure to Brucella is an important topic in public health. This study aimed to systematically review the efficacy of antibiotic prophylaxis following accidental exposure to Brucella in preventing human brucellosis disease.

METHODS

The study protocol was registered in PROSPERO (CRD42023456812). The outcomes included the incidence of brucellosis disease, adverse events rate, and antibiotic prophylaxis adherence. A comprehensive literature search, conducted until 20 November, 2023, involved Medline, Embase, Cochrane Library, and LILACS databases. Descriptive analysis and meta-analysis using R software were performed, risk of bias was assessed using JBI Critical appraisal tools, and certainty of evidence was assessed using the GRADE tool.

RESULTS

Among 3102 initially identified records, eight studies involving 97 individuals accidentally exposed, all focused on high-risk accidental exposure to Brucella in laboratory settings, were included in the review. All studies reported the prophylactic treatment comprising doxycycline at a dosage of 100 mg twice daily, combined with rifampicin at 600 mg, both administered over 21 days. Prophylaxis adherence was reported in 86% of cases, and incidence of brucellosis post-treatment was 0.01. Adverse events, mainly gastrointestinal, occurred in 26% of cases. Critical appraisal revealed limitations in reporting demographics and clinical information. The certainty of evidence was rated as 'very low,' emphasising the need for caution in interpreting the observed outcomes due to study design constraints and the absence of comparative groups.

CONCLUSIONS

PEP is an alternative practice reported in the literature, used in accidents with high-risk exposure to Brucella. The currently available evidence of the efficacy of antibiotic prophylaxis is insufficient to support a recommendation for or against the widespread use of antibiotic prophylaxis, so caution is needed in interpreting results due to the very low certainty of evidence, primarily stemming from case series and lack of comparative groups.

An accidental laboratory exposure to Brucella melitensis: the prospective post-exposure management and a detailed investigation into the nature of the exposure

Our aim was to prospectively manage 22 Brucella-exposed individuals and identify the lapses in laboratory practices that lead to the exposure. The exposed individuals were risk-stratified, assessed for post-exposure prophylaxis (PEP), counselled to self-monitor symptoms and followed-up with three serology tests. Staff laboratory practices were recorded. Ten out of 13 high-risk individuals received PEP within 48 h of exposure. Compliance with PEP and serology monitoring was 90 and 96 %, respectively. No brucellosis cases were documented. A single handler manipulated the Brucella isolate on the open bench. Movement of the isolate was tracked in detail, highlighting various points of laboratory non-conformance. Early PEP intervention is effective in preventing acquired brucellosis. Our pragmatic post-exposure management achieved high PEP and serology compliance. We experience first-hand how regular staff engagement motivated PEP adherence and interval blood sampling attendance. The enforcement of practical strategies and safety practices was also implemented without compromising our laboratory processing times.

Imported brucellosis: A case series and literature review

BACKGROUND

Brucellosis is one of the main neglected zoonotic diseases. Several factors may contribute to the epidemiology of brucellosis. Imported cases, mainly in travellers but also in recently arrived immigrants, and cases associated with imported products, appear to be infrequently reported.

METHODS

Cases of brucellosis diagnosed at a referral unit for imported diseases in Europe were described and a review of the literature on imported cases and cases associated with contaminated imported products was performed.

RESULTS

Most imported cases were associated with traditional risk factors such as travel/consumption of unpasteurized dairy products in endemic countries. Cases associated with importation of food products or infected animals also occurred. Although a lower disease incidence of brucellosis has been reported in developed countries, a higher incidence may still occur in specific populations, as illustrated by cases in Hispanic patients in the USA and in Turkish immigrants in Germany. Imported brucellosis appears to present with similar protean manifestations and both classical and infrequent modes of acquisition are described, leading on occasions to mis-diagnoses and diagnostic delays.

CONCLUSIONS

Importation of Brucella spp. especially into non-endemic areas, or areas which have achieved recent control of both animal and human brucellosis, may have public health repercussions and timely recognition is essential.

A Case-Study of Implementation of Improved Strategies for Prevention of Laboratory-acquired Brucellosis

Background

In 2012, the Alaska Section of Epidemiology investigated personnel potentially exposed to a Brucella suis isolate as it transited through three laboratories.

Methods

We summarize the first implementation of the United States Centers for Disease Control and Prevention 2013 revised recommendations for monitoring such exposures: (1) risk classification; (2) antimicrobial postexposure prophylaxis; (3) serologic monitoring; and (4) symptom surveillance.

Results

Over 30 people were assessed for exposure and subsequently monitored for development of illness. No cases of laboratory-associated brucellosis occurred. Changes were made to gaps in laboratory biosafety practices that had been identified in the investigation.

Conclusion

Achieving full compliance for the precise schedule of serologic monitoring was challenging and resource intensive for the laboratory performing testing. More refined exposure assessments could inform decision making for follow-up to maximize likelihood of detecting persons at risk while not overtaxing resources.

Biologically hazardous agents at work and efforts to protect workers' health: a review of recent reports

Because information on biological agents in the workplace is lacking, biological hazard analyses at the workplace to securely recognize the harmful factors with biological basis are desperately needed. This review concentrates on literatures published after 2010 that attempted to detect biological hazards to humans, especially workers, and the efforts to protect them against these factors. It is important to improve the current understanding of the health hazards caused by biological factors at the workplace. In addition, this review briefly describes these factors and provides some examples of their adverse health effects. It also reviews risk assessments, protection with personal protective equipment, prevention with training of workers, regulations, as well as vaccinations.

Laboratory exposure to Brucella melitensis in Denmark: a prospective study

Brucella species are a frequent cause of laboratory-acquired infections. This report describes the handling of a laboratory exposure of 17 laboratory staff members exposed to Brucella melitensis in a large microbiology laboratory in a brucella-non-endemic area. We followed the US Centers for Disease Control and Prevention guidelines, but, of 14 staff members classified as high-risk exposure, none accepted post-exposure prophylaxis. However, in a period of 6 months of follow-up, none of the exposed laboratory workers developed brucellosis and all obtained sera were negative for antibrucella antibodies. We therefore question the value of routine serological follow-up.

Laboratory-acquired brucellosis in Turkey

BACKGROUND

Laboratory healthcare workers (HCWs) are at risk of laboratory-acquired brucellosis (LAB).

AIM

To describe the risk factors of LAB among HCWs.

METHODS

A multicentre survey study was conducted by face-to-face interview in 38 hospitals from 17 provinces of Turkey. A structured survey was administered to the HCWs, working in infectious diseases clinics and microbiology departments, who were at risk of brucella infection.

FINDINGS

The survey response rate was 100%. Of the 667 laboratory workers, 38 (5.8%) had a history of LAB. In multivariate analysis, factors independently associated with an increased risk of LAB included working with the brucella bacteria (odds ratio: 5.12; 95% confidence interval: 2.28-11.52; P < 0.001) and male gender (2.14; 1.02-4.45; P = 0.042). Using a biosafety cabinet level 2 (0.13; 0.03-0.60; P = 0.009), full adherence to glove use (0.27; 0.11-0.65; P = 0.004) and longer duration of professional life (0.86; 0.80-0.92; P < 0.001) were found to be protective.

CONCLUSIONS

Working with the brucella bacteria, being male, a lack of compliance with personal protective equipment and biosafety cabinets were the independent risk factors for the development of LAB in our series. Increased adherence to personal protective equipment and use of biosafety cabinets should be priority targets to prevent LAB.