Diagnosis of Infectious Diseases

Introduction. The public health laboratory system in the United States (USA) is extensive and focuses on the health of the nation’s population by providing testing for the identification and spread mitigation of public health concerns. Testing for communicable diseases, antimicrobial resistance, per- and polyfluoroalkyl substances, and much more is performed on human, animal and environmental specimens by federal, state and local level public health laboratories.

Gap Statement. Unique challenges exist for public health laboratory professionals, and individuals in this field are commonly appointed to leadership positions without any formal leadership or management training.

Aim. The authors aim to identify potential challenges for public health laboratory leaders and suggest how leaders may successfully navigate them. Additionally, this article aims to expand awareness of federally funded public health laboratory leadership programmes in the United States and when they may be applicable for prospective or current leaders.

Methodology. The authors reviewed publications and presentations to determine successful and unsuccessful leadership attributes in a public health laboratory context. They assessed federally funded leadership programmes in the USA via publications and publicly available information and interviewed select individuals who participated in or assisted in the development of these programmes.

Results. Six common challenges for public health laboratory leaders were identified and potential solutions are suggested. The Centers for Disease Control and Prevention (CDC) and the Association of Public Health Laboratories (APHL) provide four unique laboratory leadership training programmes for laboratorians interested in or currently employed within public health laboratories.

Conclusion. While the content of the federally funded programmes is different, they all aim to provide current and future public health laboratory leaders with the skills that they need to effectively guide and support laboratory staff through the critical and intense situations that public health laboratories commonly face.

Introduction. Strongyloides stercoralis, the human threadworm, is a parasitic nematode with global distribution, estimated to infect over 600 million people. Chronic infection is often asymptomatic, but hyperinfection and dissemination syndromes can occur in the immunosuppressed with high case fatality rates. Whilst strongyloidiasis is endemic in Fiji, its prevalence in Fijian migrant groups in the UK is unknown.

Gap Statement. No previous studies have been conducted on the prevalence of Strongyloides and other gastrointestinal parasites (GIPs) in Fijian migrants to the UK.

Aim. We conducted a cross-sectional study of the prevalence of GIPs in a Fijian migrant population.

Methodology. Participants completed a questionnaire on residence, travel and clinical symptoms and were asked to provide a serum sample for S. stercoralis IgG ELISA, venous blood samples for eosinophil count and a faecal sample for charcoal culture, multiplex real-time PCR (rtPCR) and microscopy after formalin-ethyl acetate concentration. Sequencing was performed on pooled Strongyloides larvae for nuclear 18S rRNA hyper-variable regions (HVRs) I and IV.

Results. A total of 250 participants (94% male) with median (range) age 37 (20–51) years entered the study, 15 (1–24) years since leaving Fiji. S. stercoralis IgG ELISA was positive in 87/248 (35.1 %) and 14/74 (18.9 %) had a GIP detected in faeces. This included 7/74 (9.5 %) with Strongyloides and 5/74 (6.8 %) with hookworms. Dermatological symptoms were more common in those with Strongyloides, and eosinophilia (>0.5×109 cells per litre) was present in 55.6% of those with positive S. stercoralis IgG. rtPCR was the most sensitive faecal diagnostic test for Strongyloides and hookworms in faeces. Sequences of nuclear 18S rRNA for HVRs I and IV confirmed the presence of S. stercoralis.

Conclusion. This first cross-sectional study in Fijian migrants found a high rate of chronic infection with GIPs, particularly S. stercoralis. Faecal microscopy was insensitive compared to charcoal culture, rtPCR or serology, demonstrating the importance of specialist parasitological tests when investigating people with a suspected chronic infection. Our study highlights an overlooked burden of strongyloidiasis in the UK and has implications for screening and treatment programmes in Fiji and for migrants from Fiji.

Introduction. Laboratory participation in external quality assessment (EQA) programmes including proficiency testing (PT) is a requirement of clinical laboratory conformance to ISO 15189:2022 Medical laboratories – Requirements for quality and competence. PT is one EQA method whereby laboratories are sent blinded samples for characterization by routine laboratory diagnostic methods. Importantly, PT enables a laboratory’s performance to be evaluated in comparison to the standard reference methods and to the performance of other peer laboratories using similar diagnostic methods.

Gap statement. The desired outcome of participating in PT is to help laboratories identify possible sources of error in each step of the total testing process and particularly in their test methods during the analytical phase.

Aim. This cross-sectional study investigated the impact of using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) compared to conventional phenotypic biochemical testing on laboratory performance in a clinical bacteriology PT scheme.

Methodology. During a 6-year period from 2017-2022, the Canadian Microbiology Proficiency Testing implemented 112 PT challenges comprising 22 different sample types and included 61 different bacterial species. This was translated into 5883 graded test events for analysis. Multiple logistic regression techniques were employed to explore the association between the test method employed and laboratory performance. The sample type and aerobic classification of challenge organisms were included as confounding variables.

Results. Laboratories using MALDI-TOF MS performed significantly better in characterizing microorganisms than laboratories using phenotypic biochemical testing alone [odds ratio OR = 5.68, confidence interval (CI): 3.92, 8.22] regardless of the sample type and aerobic classification. Notably, our analysis identified a significant association between anaerobic organisms and laboratory performance (OR: 0.24, CI: 0.17–0.35), suggesting that culturing and identifying fastidious organisms remains a significant obstacle for many clinical microbiology laboratories.

Conclusions. Although no method is infallible and its performance will depend on the validation and quality assurance procedures, this finding may help the management in the decision for implementing MALDI-TOF MS in the microbiology laboratory. This study highlights the important role PT providers play in the objective assessment of laboratory performance and how it can provide evidence for quality improvement.

Introduction. Antimicrobial resistance (AMR) is recognized as an important global health risk, associated with increased mortality, morbidity and healthcare costs. Antimicrobial stewardship (AMS) involves a coherent set of processes that promote the rational use of antimicrobials.

Gap statement. An AMS programme should be adapted and developed according to the available resources of a facility. This requires an analysis of the core AMS elements that are already in place and the resources available.

Aim. This study aimed to assess the readiness of a tertiary healthcare facility and staff towards implementing an antimicrobial stewardship programme (ASP).

Methodology. This study focused on two aspects during an AMS pre-implementation phase. A situational or strengths, weaknesses, opportunities, and threats analysis was conducted based on (1) a questionnaire on attitudes and perceptions of pharmacists, clinicians and nurses towards AMR and AMS and (2) a situational analysis on the readiness of the facility.

Results. The questionnaire, which was available for completion between September 2021 and December 2021, was sent to a total of 3100 healthcare professionals (HCPs). Thirty-two (1.0 %) HCPs comprising 2 pharmacists, 16 clinicians and 14 nurses completed the questionnaire. Of the total participants, 31 (96.9 %) viewed AMR as a problem in South African hospitals and 29 (90.6 %) perceived AMR as a problem at their facility. The majority (n = 29, 90.6 %) of the participants were familiar with the term AMS, and 26 (81.3 %) participants agreed to willingly participate in any initiatives involving antimicrobial use at the facility. The situational analysis depicted existing strengths in terms of AMS structures such as the formation of an AMS committee and information and technology systems at the HCP’s disposal. Weaknesses included the limited number of AMS activities being carried out and poor participation from HCPs within the AMS team.

Conclusion. A pre-implementation phase in the building of an ASP can greatly assist in finding gaps for improvement, which can then be addressed in the implementation phase. Furthermore, the pre-implementation phase provides a baseline to measure improvements once the implementation phase has been instituted.