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

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.

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.

A Review of Laboratory-Acquired Infections in the Asia-Pacific: Understanding Risk and the Need for Improved Biosafety for Veterinary and Zoonotic Diseases

A rapid review was performed to determine (1) the number and causes of reported laboratory-acquired infections (LAI) in the Asia-Pacific region; (2) their significance and threat to the community; (3) the primary risk factors associated with LAIs; (4) the consequences in the event of a LAI or pathogen escape; and (5) to make general recommendations regarding biosafety practices for diagnosis and research in the Asia-Pacific region. A search for LAI and zoonoses in the Asia-Pacific region using online search engines revealed a relatively low number of reports. Only 27 LAI reports were published between 1982 and 2016. The most common pathogens associated with LAIs were dengue virus, Arthroderma spp., Brucella spp., Mycobacterium spp., Rickettsia spp., and Shigella spp. Seventy-eight percent (21 out of 27 LAI reports) occurred in high-income countries (i.e., Australia, Japan, South Korea, Singapore, and Taiwan) where laboratories were likely to comply with international biosafety standards. Two upper-middle income countries (China (2), and Malaysia (2)) and one lower-middle income country (India (2)) reported LAI incidents. The majority of the reports (fifty-two percent (14/27)) of LAIs occurred in research laboratories. Five LAI reports were from clinical or diagnostic laboratories that are considered at the frontier for zoonotic disease detection. Governments and laboratories in the Asia-Pacific region should be encouraged to report LAI cases as it provides a useful tool to monitor unintended release of zoonotic pathogens and to further improve laboratory biosafety. Non-reporting of LAI events could pose a risk of disease transmission from infected laboratory staff to communities and the environment. The international community has an important and continuing role to play in supporting laboratories in the Asia-Pacific region to ensure that they maintain the safe working environment for the staff and their families, and the wider community.