Re-humanisation, Recognising the person behind the patient

Submission content Introduction: At the end of a particularly hectic night shift on the intensive care unit (ICU) I found myself sitting in the relatives' room with the mother and aunt of a young patient, listening to their stories of her hopes and aspirations as she grew up. She had been diagnosed with lymphoma aged 14 and received a bone marrow transplant from her younger sister. Fighting through treatment cycles interposed with school studies, she eventually achieved remission and a portfolio of A-levels. Acceptance into university marked the start of a new era, away from her cancer label, where she studied forensic science and took up netball. Halfway through her first year she relapsed. Main body: When I met this bright, ambitious 20-year-old, none of this history was conveyed. She had been admitted to ICU overnight and rapidly intubated for type-1 respiratory failure. The notes contained a clinical list of her various diagnoses and treatments, with dates but no sense of the context. Rules regarding visitation meant her family were not allowed onto the unit, with next-of-kin updates carried out by designated non-ICU consultants to reduce pressures on ICU staff. No photos or personal items surrounded her bedside, nothing to signify a life outside of hospital. She remained in a medically-induced coma from admission onwards, while various organ systems faltered and failed in turn. Sitting in that relatives' room I had the uncomfortable realisation that I barely saw this girl as a person. Having looked after her for some weeks, I could list the positive microbiology samples and antibiotic choices, the trends in noradrenaline requirements and ventilatory settings. I had recognised the appropriate point in her clinical decline to call the family in before it was too late, without recognising anything about the person they knew and loved. She died hours later, with her mother singing 'Somewhere Over the Rainbow' at her bedside. Poignant as this was, the concept of this patient as more than her unfortunate diagnosis and level of organ failure had not entered my consciousness. Perhaps a coping mechanism, but dehumanisation none-the-less. Conclusion(s): Striking a balance between emotional investment and detachment is of course vital when working in a clinical environment like the ICU, where trauma is commonplace and worst-case-scenarios have a habit of playing out. At the start of my medical career, I assumed I would need to consciously take a step back, that I would struggle to switch off from the emotional aspects of Medicine. However, forgetting the person behind the patient became all too easy during the peaks of Covid-19, where relatives were barred and communication out-sourced. While this level of detachment may be understandable and necessary to an extent, the potential for this attitude to contribute to the already dehumanising experience of ICU patients should not be ignored. I always thought I was more interested in people and their stories than I was in medical science;this experience reminded me of that, and of the richness you lose out on when those stories are forgotten.

Design of a cost-effective diagnosis tool for SARSCov-2 variant detection through a next generation sequencing (NGS) based strategy

Background/Objectives: Current pandemic situation, together with the continuous emergence of new SARS-CoV-2 variants reveal the need to develop a more versatile tool than PCR-based methods that allows both high throughput COVID-19 diagnostic and specific variant detection at reduced cost and fast turnaround times. Thus, with the aim of overcoming current test limitations and providing a strategy with these characteristics arises our novel next generation sequencing based approach. Method(s): The developed strategy works with RNA samples obtained from nasopharyngeal swabs. RNA samples are processed with our custom laboratory protocol and can be sequenced with any Illumina platform to generate results within a 24h timeframe. A tailored bioinformatic pipeline analyzes the data and generates a clinical-level report. Result(s): Clinical validation results have shown that the designed solution, sensitively and specifically identifies negative and positive samples that display a broad range in viral loads and readily identifies the following major SARS-CoV-2 variants of concern (VoC): Alpha, Beta, Gamma, Delta, Lambda and Omicron (BA.1 and BA.2). Conclusion(s): The versatility of our solution allows the capability of identifying the presence of other common respiratory viruses as well as identifying patients at risk through the identification of susceptibility human variants in the host. This, together with the possibility of easily adding new VoC as they emerge, will make VoC monitoring in entire populations feasible, providing a new perspective on the application of NGS methods in the field of clinical microbiology.

Real world experience of the burden of infection in myeloma

The treatment landscape in myeloma has rapidly changed over the last few years with the advent of an ever increasing number of funded novel therapies. At the same time, the COVID-19 pandemic has caused a paradigm shift in the burden of infection within the community. Clinical trials often exclude older and more comorbid patients and so there is a paucity of data of the effect of infection on patients with myeloma in the 'real world'. We performed a restrospective audit of all patients with myeloma admitted with infection to our level 2b haematology centre over a 3-year period from November 2019 to November 2022. We collected data on patient demographics and characteristics, infection status, microbiology results, length of stay and outcome of admission. During the audit period there were 87 admissions from 52 patients. The median number of admissions per patient was 1 (range 1-6). The median age at admission was 72 (range 41-90). Patients had a median of two major comorbidities (range 0-8). Performance status was <2 in 63% of patients (33/52). In terms of disease characteristics, International Staging Score (ISS) was stage 1 in 12% of patients, stage 2 in 38%, stage 3 in 38% and unavailable in 12%. Revised ISS (R-ISS) was stage 1 in 2% of patients, stage 2 in 44%, stage 3 in 17% and unavailable in 37%. The median line of treatment was 2 (range 0-6). Respiratory tract infection was the most common site of infection in 51% of admissions. Microbiology was negative in over half of infection admissions (50/87). Fifteen per cent (13/87) had a positive COVID-19 PCR. A positive blood culture result was identified in 8% (7/87). The median length of stay was 9 days (range 1-58). The mortality rate of admissions with infection was 17% (15/87). Overall, our real-world results show the continuing burden of infection in myeloma in the era of modern treatment. Despite the omnipresence of the COVID-19 pandemic over the last 2 and a half years, this contributed to only a small number of admissions. Infections happened in patients of all ages and many patients had good performance status, limited comorbidities and intermediate risk disease. The mortality rate of our cohort was surprisingly high at 17%. In summary, infection remains a major complication of myeloma. Given our results we now plan a trial of prophylactic antibiotics for patients on active treatment.

Using Multiple Models to Learn about COVID-19

Furthermore, multiple scientific disciplines, such as immunology, genetics, epidemiology, and microbiology, contribute to our understanding of the pandemic. [...]COVID-19 is a complex socioscientific issue (SSI), meaning that science concepts related to the virus have real-world implications for problems in society (Zeidler 2014). SSI-based teaching and learning creates opportunities for students to grapple with real-world problems relevant to their own lives and that require consideration and evaluation of multiple, sometimes competing, factors associated with the issue. The modeling activities were embedded in a broader unit designed for high school biology classes;descriptions of the full unit and the individual modeling activities can be accessed online at https:// epiclearning.web.unc.edu/covid (Sadler et al. 2021). For this aspect of the work, we chose a Netlogo computer simulation (www.jacobkelter.com/infection-model) that allowed students to identify patterns and make sense of underlying cause-and-effect relationships associated with social distancing-two of the NGSS crosscutting concepts.

COVID-19 monitoring with sparse sampling of sewered and non-sewered wastewater in urban and rural communities.

Equitable SARS-CoV-2 surveillance in low-resource communities lacking centralized sewers is critical as wastewater-based epidemiology (WBE) progresses. However, large-scale studies on SARS-CoV-2 detection in wastewater from low-and middle-income countries is limited because of economic and technical reasons. In this study, wastewater samples were collected twice a month from 186 urban and rural subdistricts in nine provinces of Thailand mostly having decentralized and non-sewered sanitation infrastructure and analyzed for SARS-CoV-2 RNA variants using allele-specific RT-qPCR. Wastewater SARS-CoV-2 RNA concentration was used to estimate the real-time incidence and time-varying effective reproduction number (Re). Results showed an increase in SARS-CoV-2 RNA concentrations in wastewater from urban and rural areas 14-20 days earlier than infected individuals were officially reported. It also showed that community/food markets were "hot spots" for infected people. This approach offers an opportunity for early detection of transmission surges, allowing preparedness and potentially mitigating significant outbreaks at both spatial and temporal scales.

Stool Xpert MTB/RIF as a possible diagnostic alternative to sputum in Africa: a systematic review and meta-analysis.

Introduction: Worldwide, COVID-19 pandemic lead to a large fall in the number of newly reported TB cases. In sub-Saharan Africa, microbiological diagnosis of TB is generally based on smear microscopy and Xpert MTB/RIF on sputum samples, but good quality sputum samples are often difficult to obtain, leading clinicians to rely on more invasive procedures for diagnosis. Aim of this study was to investigate pooled sensitivity and specificity of Xpert MTB/RIF on stool samples compared to respiratory microbiological reference standards in African countries. Methods: Four investigators independently searched PubMed, SCOPUS, and Web of Science until 12th October 2022, then screened titles and abstracts of all potentially eligible articles. The authors applied the eligibility criteria, considered the full texts. All the studies reported the data regarding true positive (TP), true negative (TN), false positive (FP) and false negative (FN). Risk of bias and applicability concerns were assessed with the Quadas-2 tool. Results: overall, among 130 papers initially screened, we evaluated 47 works, finally including 13 papers for a total of 2,352 participants, mainly children. The mean percentage of females was 49.6%, whilst the mean percentage of patients reporting HIV was 27.7%. Pooled sensitivity for Xpert MTB/RIF assay for detecting pulmonary tuberculosis was 68.2% (95%CI: 61.1-74.7%) even if characterized by a high heterogeneity (I2=53.7%). Specificity was almost 100% (99%, 95%CI: 97-100%; I2 = 45.7%). When divided for reference standard, in the six studies using sputum and nasogastric aspirate the accuracy was optimal (AUC = 0.99, SE = 0.02), whilst in the studies using only sputum for tuberculosis detection the AUC was 0.85 (with a SE = 0.16). The most common source of bias was exclusion of enrolled patients in the analysis. Conclusions: Our study confirms that, in Africa, stool Xpert MTB/RIF may be a useful rule-in test for children above and below 5 years of age under evaluation for pulmonary tuberculosis. Sensitivity increased substantially when using both sputum and nasogastric aspirate as reference samples.

Evaluation of BioFire® FilmArray® Pneumonia Panel in Bronchoalveolar Lavage Samples From Immunocompromised Patients With Suspected Pneumonia.

Objectives Immunocompromised patients, specifically those with solid organ transplants or cancer on chemotherapy, are at particularly high risk of severe pneumonia and opportunistic infections. In select patients, bronchoalveolar lavage (BAL) is performed to provide high-quality samples for analysis. We compare BioFire® FilmArray® Pneumonia Panel (BioFire Diagnostics, Salt Lake City, Utah, United States), a multiplex polymerase chain reaction (PCR) assay, with standard of care diagnostics in BAL samples from immunocompromised patients to identify opportunities for this test to affect clinical decision making. Methods Patients hospitalized with pneumonia based on clinical and radiographic findings who underwent evaluation with bronchoscopy between May 2019 to January 2020 were reviewed. Among those patients undergoing bronchoscopy, those who were immunocompromised were selected for inclusion in the study. BAL specimens submitted to the microbiology laboratory were chosen based on as part of the internal validation of the panel in comparison with sputum culture at our hospitals. We compared the outcomes of the multiplex PCR assay with traditional culture methods and evaluated the role of PCR assay in de-escalating antimicrobial therapy. Results Twenty-four patients were identified for testing with the multiplex PCR assay. Of the 24 patients, 16 were immunocompromised, all with solid or hematological malignancy or a history of organ transplant. Seventeen individual BAL samples from the 16 patients were reviewed. BAL culture results and the multiplex PCR assay were in agreement in 13 samples (76.5%). In four cases, the multiplex PCR assay identified a possible causative pathogen not detected by standard workup. The median time to de-escalation of antimicrobials was three days (interquartile range (IQR) 2-4) from the day of collection of the BAL samples. Conclusions Studies have established the additive role of multiplex PCR testing in addition to traditional diagnostic tools like sputum culture in diagnosing the etiology of pneumonia. Limited data exist specifically looking at immunocompromised patients, in whom a timely and accurate diagnosis is particularly important. There is a potential benefit for performing multiplex PCR assays as an additive diagnostic tool in BAL samples for these patients.

Protocol for studying co-infection between SARS-CoV-2 and Staphylococcus aureus in vitro.

Bacterial co-infection is one of the most common complications of SARS CoV-2 infection. Here, we present a protocol for the in vitro study of co-infection between SARS CoV-2 and Staphylococcus aureus. We describe steps for quantifying viral and bacterial replication kinetics in the same sample, with the optional extraction of host RNA and proteins. This protocol is applicable to many viral and bacterial strains and can be performed in different cell types. For complete details on the use and execution of this protocol, please refer to Goncheva et al.1.

Comprehensive bronchoalveolar lavage characterization in COVID-19 associated acute respiratory distress syndrome patients: a prospective cohort study.

COVID-19-related acute respiratory distress syndrome (CARDS) is associated with high mortality rates. We still have limited knowledge of the complex alterations developing in the lung microenvironment. The goal of the present study was to comprehensively analyze the cellular components, inflammatory signature, and respiratory pathogens in bronchoalveolar lavage (BAL) of CARDS patients (16) in comparison to those of other invasively mechanically ventilated patients (24). In CARDS patients, BAL analysis revealed: SARS-CoV-2 infection frequently associated with other respiratory pathogens, significantly higher neutrophil granulocyte percentage, remarkably low interferon-gamma expression, and high levels of interleukins (IL)-1ß and IL-9. The most important predictive variables for worse outcomes were age, IL-18 expression, and BAL neutrophilia. To the best of our knowledge, this is the first study that was able to identify, through a comprehensive analysis of BAL, several aspects relevant to the complex pathophysiology of CARDS.

Promoting Science Literacy and Awareness across the Globe: the Role of Scientists as Science Ambassadors

Science literacy has many personal and societal benefits that allows for better informed decision-making. Although the importance of science literacy is recognized globally, there are many challenges associated with its promotion. Scientists are more frequently engaging with nonscientific audiences through public outreach activities and with increasing support from institutions and professional societies. This is especially true regarding microbiologists and other related professionals since the start of the global 2019 coronavirus disease pandemic heightened the need to convey novel and rapidly evolving scientific information to lay audiences. The means by which professionals engage with these audiences affect the efficacy of the relay of scientific information. One method of engagement is the "ambassador approach," which aims to establish dialogue among different groups of people and scientists. In this perspective article, we discuss this approach, highlighting activities for the promotion of science literacy organized by the American Society for Microbiology Ambassador Program and similar programs of other scientific societies. We discuss the benefits and challenges of implementing an ambassador approach, propose potential improvements that could be made to existing programs promoting science literacy, and ultimately advocate for increased implementation of science ambassador programs.

Structural changes in the SARS-CoV-2 spike E406W mutant escaping a clinical monoclonal antibody cocktail.

Continued evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is eroding antibody responses elicited by prior vaccination and infection. The SARS-CoV-2 receptor-binding domain (RBD) E406W mutation abrogates neutralization mediated by the REGEN-COV therapeutic monoclonal antibody (mAb) COVID-19 cocktail and the AZD1061 (COV2-2130) mAb. Here, we show that this mutation remodels the receptor-binding site allosterically, thereby altering the epitopes recognized by these three mAbs and vaccine-elicited neutralizing antibodies while remaining functional. Our results demonstrate the spectacular structural and functional plasticity of the SARS-CoV-2 RBD, which is continuously evolving in emerging SARS-CoV-2 variants, including currently circulating strains that are accumulating mutations in the antigenic sites remodeled by the E406W substitution.

Screening Strategies in Different Resource Settings

Health care-associated infections/ Hospital-acquired infections (HAIs) have a significant impact on patients' morbidity and mortality. The risk of HAIs in resource-limited settings (RLS) has been reported 2-20 times higher than that in developed countries. Moreover, multi-drug- resistant organisms (MDROs) have emerged and spread throughout the world. In addition, increases in HAIs were observed during the COVID-19 pandemic throughout the world.Thus, screening strategies/surveillance of MDROs were recommended as a core component of infection prevention and control (IPC) measures for the effective HAIs prevention. We review and summarize current critical knowledge on screening strategies in different resource settings, especially on guidelines for the prevention and control of carbapenem- resistant Enterobacteriaceae (CRE), Acinetobacter baumannii (CRAB), and Pseudomonas aeruginosa (CRPsA) in health care facilities. The guidelines (especially WHO) were strongly recommended for surveillance of CRE-CRAB-CRPsA infections and surveillance cultures of asymptomatic CRE colonization. There were conditional recommended on surveillance cultures of the environment for CRE-CRAB-CRPsA colonization/contamination. The surveillance cultures (stool samples or rectal swabs) allowed the early introduction of IPC measures to prevent transmission to other patients and the hospital environment. Given the clinical importance of CRE-CRAB-CRPsA infections, regular ongoing active surveillance of infections were required in all microbiology laboratory settings. In addition, surveillance cultures for asymptomatic CRE colonization should also be performed, guided by local epidemiology and risk assessment. The surveillance cultures of asymptomatic CRE colonization should be considered for patients with previous CRE colonization and patients with a history of recent hospitalization in endemic CRE settings or contacted CRE colonized/ infected patients. In contrast, the evidence available on surveillance cultures for CRAB and CRPsA colonization in asymptomatic patients was not sufficiently relevant for the recommendation. Nowadays, the CRE surveillance strategies have been implemented in various methods from traditional culture- based methods to molecular assays. The limitation of microbiology laboratory capacity for MDROs in RLS was concerning. However, the surveillance data would help with appropriate IPC measure implementation and outbreak investigations. Thus, the proper screening strategies and strengthening microbiology laboratory capacity, especially in RLS are challenge for improving IPC measures and patient outcomes.Copyright © 2023

Microbiology and Bioterrorism

It's been 2 decades since the posting of the anthrax letters in the United States in 2001. This event marked a pivotal point in our history. It highlighted the vulnerability of modern society to acts of bioterrorism and set countries on a course to develop capabilities to pre-empt, prevent, react to, investigate, and recover from acts of bioterrorism. The current COVID-19 pandemic is a stark reminder of the enormity of the impact that the release of a biological agent, natural or otherwise, can have on an immunological naïve society. The purpose of this article is to describe how microbiology is applied in the investigation of bioterrorism, highlighting the modern advances in technology, particularly the DNA technologies, which have assisted this discipline as a forensic practice. © 2023 Elsevier Ltd. All rights reserved.

Virtual Journey and Virtual Bio-Labs: Two Novel Strategies Implemented in the Pandemic to Boost Dynamic Learning in the Microbiology Laboratory

During the first months of 2020, the world was surprised by the emergence of the COVID-19 pandemic. Educational institutions were partially or fully closed. Social distancing and restrictive movement policies significantly disturbed traditional educational practices. In Mexico, Tecnologico de Monterrey faced one of the most sudden changes in its history, teaching all its courses 100% digitally. Its teachers had to search for alternative tools that would allow students to take practical classes, for example, laboratory, preserving the experience of being in a specialized laboratory even from home. This research evaluated two innovative tools designed and implemented for the Microbiology Laboratory subject. The first one is the Virtual BioLabs (VBL) application for using and managing specialized laboratory equipment. The second is Virtual Journey (VJ), a 360-degree interactive video to explain a foodborne bacterial infection [1]. We used qualitative and quantitative evaluation instruments to measure the impact of these tools during the pandemic. Results showed that the mean grade from pandemic groups using VBL was 93.5 vs. SS.5 obtained from those who did not use the app. Additionally, the grade average from pandemic groups before watching the VJ video was 63.5 vs. 93.5 after watching it. These results indicate that these strategies improved student performance, reflected in the increase in their averages. Finally, in the satisfaction survey, the students commented that using VBL and Virtual Journey made them feel more immersed in the laboratory, even at home. They enjoyed and liked both technical strategies. However, 93% of the students agreed that, although the virtual tools have excellent potential, their preference for face-To-face learning in practical laboratory subjects remains indisputable. © 2023 IEEE.

Omicron BQ.1.1 and XBB.1 unprecedentedly escape broadly neutralizing antibodies elicited by prototype vaccination.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron subvariants have seriously attacked the antibody barrier established by natural infection and/or vaccination, especially the recently emerged BQ.1.1 and XBB.1. However, crucial mechanisms underlying the virus escape and the broad neutralization remain elusive. Here, we present a panoramic analysis of broadly neutralizing activity and binding epitopes of 75 monoclonal antibodies isolated from prototype inactivated vaccinees. Nearly all neutralizing antibodies (nAbs) partly or totally lose their neutralization against BQ.1.1 and XBB.1. We report a broad nAb, VacBB-551, that effectively neutralizes all tested subvariants including BA.2.75, BQ.1.1, and XBB.1. We determine the cryoelectron microscopy (cryo-EM) structure of VacBB-551 complexed with the BA.2 spike and perform detailed functional verification to reveal the molecular basis of N460K and F486V/S mutations mediating the partial escape of BA.2.75, BQ.1.1, and XBB.1 from the neutralization of VacBB-551. Overall, BQ.1.1 and XBB.1 raised the alarm over SARS-CoV-2 evolution with unprecedented antibody evasion from broad nAbs elicited by prototype vaccination.

Cohort profile: a longitudinal study of HIV infection in the central nervous system with focus on cerebrospinal fluid - the Gothenburg HIV CSF Study Cohort.

PURPOSE: In order to enable long-term follow-up of the natural course of HIV infection in the central nervous system, a longitudinal cohort study with repeated cerebrospinal fluid (CSF) analyses at intervals over time was initiated in 1985. When antiretrovirals against HIV were introduced in the late 1980s, short-term and long-term effects of various antiretroviral treatment (ART) regimens were added to the study. PARTICIPANTS: All adult people living with HIV (PLWH) who were diagnosed at or referred to the Department of Infectious Diseases, Sahlgrenska University Hospital, Gothenburg, Sweden were asked to participate in the Gothenburg HIV CSF Study Cohort. PLWH with neurological symptoms or other clinical symptoms of HIV, as well as those with no symptoms of HIV infection, were included. Most participants were asymptomatic, which distinguishes this cohort from most other international HIV CSF studies. In addition, HIV-negative controls were recruited. These included people on HIV pre-exposure prophylaxis who served as lifestyle-matched controls to HIV-infected men who have sex with men. Since lumbar puncture (LP) is an invasive procedure, some PLHW only consented to participate in one examination. Furthermore, at the beginning of the study, several participants were lost to follow-up having died from AIDS. Of 662 PLWH where an initial LP was done, 415 agreed to continue with follow-up. Among the 415, 56 only gave permission to be followed with LP for less than 1 year, mainly to analyse the short-term effect of ART. The remaining 359 PLWH were followed up with repeated LP for periods ranging from >1 to 30 years. This group was defined as the 'longitudinal cohort'. So far, on 7 April 2022, 2650 LP and samplings of paired CSF/blood had been performed, providing a unique biobank. FINDINGS TO DATE: A general finding during the 37-year study period was that HIV infection in the central nervous system, as mirrored by CSF findings, appears early in the infectious course of the disease and progresses slowly in the vast majority of untreated PLWH. Combination ART has been highly effective in reducing CSF viral counts, inflammation and markers of neural damage. Minor CSF signs of long-term sequels or residual inflammatory activity and CSF escape (viral CSF blips) have been observed during follow-up. The future course of these changes and their clinical impact require further studies. FUTURE PLANS: PLWH today have a life expectancy close to that of non-infected people. Therefore, our cohort provides a unique opportunity to study the long-term effects of HIV infection in the central nervous system and the impact of ART and is an ongoing study.

Preparing for the next pandemic: lessons learnt from the implementation of point-of-care SARS-CoV-2 testing in an emergency department.

Point-of-care testing (POCT) provides rapid, accurate results that facilitate diagnosis and patient management. POCT for infectious agents allows timely infection prevention and control interventions and informs decisions around safe patient placement. However, POCT implementation requires careful governance as they are primarily operated by staff with limited prior education on laboratory quality control and assurance processes. Here, we describe our experience implementing SARS-CoV-2 POCT in the emergency department of a large tertiary referral hospital during the COVID-19 pandemic. We describe collaborative governance between pathology and clinical specialities, quality assurance, testing (volume and positivity rates), impact on patient flow and focus on lessons learnt during implementation that should be incorporated into revised pandemic preparedness planning.

Vaccine Preventable Disease Seroprevalence in a Nationwide Assessment of Timor-Leste (VASINA-TL): study protocol for a population-representative cross-sectional serosurvey.

INTRODUCTION: Historic disruption in health infrastructure combined with data from a recent vaccine coverage survey suggests there are likely significant immunity gaps to vaccine preventable diseases and high risk of outbreaks in Timor-Leste. Community-based serological surveillance is an important tool to augment understanding of population-level immunity achieved through vaccine coverage and/or derived from prior infection. METHODS AND ANALYSIS: This national population-representative serosurvey will take a three-stage cluster sample and aims to include 5600 individuals above 1 year of age. Serum samples will be collected by phlebotomy and analysed for measles IgG, rubella IgG, SARS-CoV-2 antispike protein IgG, hepatitis B surface antibody and hepatitis B core antigen using commercially available chemiluminescent immunoassays or ELISA. In addition to crude prevalence estimates and to account for differences in Timor-Leste's age structure, stratified age-standardised prevalence estimates will be calculated, using Asia in 2013 as the standard population. Additionally, this survey will derive a national asset of serum and dried blood spot samples which can be used for further investigation of infectious disease seroepidemiology and/or validation of existing and novel serological assays for infectious diseases. ETHICS AND DISSEMINATION: Ethical approval has been obtained from the Research Ethics and Technical Committee of the Instituto Nacional da Saúde, Timor-Leste and the Human Research Ethics Committee of the Northern Territory Department of Health and Menzies School of Health Research, Australia. Co-designing this study with Timor-Leste's Ministry-of-Health and other relevant partner organisations will allow immediate translation of findings into public health policy, which may include changes to routine immunisation service delivery and/or plans for supplementary immunisation activities.