Exploring the Use of Monoclonal Antibodies and Antiviral Therapies for Early Treatment of COVID-19 Outpatients in a Real-World Setting: A Nationwide Study from England and Italy

BACKGROUND

Real-world data on early treatment of coronavirus disease 2019 (COVID-19) outpatients with newly approved therapies are sparse.

AIM

To explore the pattern of use of monoclonal antibodies (mAbs)/antiviral therapies approved for early COVID-19 treatment in non-hospitalized patients from England and Italy from December 2021 to October 2022.

METHODS

Public national dashboards on weekly mAb/antiviral use and/or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection diagnoses from the Italian Medicines Agency, the Italian National Institute of Health, National Health Service in England and the UK Government were explored. Prevalence of antiviral use in outpatients during the entire study period and every two weeks was calculated, as a whole and by class and compounds. An interrupted time-series (ITS) analysis was carried out to assess the impact of predominant SARS-CoV-2 variants over time on the prevalence of use of mAbs/antivirals in England and Italy.

RESULTS

Overall, 77,469 and 195,604 doses of mAbs/antivirals were respectively administered to a total of 10,630,903 (7.3 per 1000) and 18,168,365 (10.8 per 1000) patients diagnosed with SARS-CoV-2 infection in England and Italy. Prevalence of use every two weeks increased from 0.07% to 3.1% in England and 0.9% to 2.3% in Italy during the study period. Regarding individual compounds, sotrovimab (prevalence of use, 1.6%) and nirmatrelvir/ritonavir (1.6%) in England, and nirmatrelvir/ritonavir (1.7%) and molnupiravir (0.5%) in Italy, reported the highest prevalence during a 2-week period. In the ITS analysis, the transition from Delta to Omicron variant predominance was associated with a significant increase in the use of sotrovimab, molnupiravir, remdesivir and nirmatrelvir/ritonavir in both England and Italy, with a reduction of other marketed mAbs. The extent of the increase was higher in England than in Italy for all these drugs except for nirmatrelvir/ritonavir.

CONCLUSIONS

In this dual nationwide study, the prevalence of use of mAbs/antivirals against SARS-CoV-2 for early outpatients' treatment increased slowly up to 2.0-3.0% of all patients diagnosed with SARS-CoV-2 infection in both England and Italy from December 2021 to October 2022. The trend of individual drug use varied in relation to predominant SARS-CoV-2 variants with some differences across countries. In line with scientific societies' guidelines, nirmatrelvir/ritonavir was the most frequently prescribed antiviral in both countries in the most recent period.

Clinical phenotypes and quality of life to define post-COVID-19 syndrome: a cluster analysis of the multinational, prospective ORCHESTRA cohort

Background

Lack of specific definitions of clinical characteristics, disease severity, and risk and preventive factors of post-COVID-19 syndrome (PCS) severely impacts research and discovery of new preventive and therapeutics drugs.

Methods

This prospective multicenter cohort study was conducted from February 2020 to June 2022 in 5 countries, enrolling SARS-CoV-2 out- and in-patients followed at 3-, 6-, and 12-month from diagnosis, with assessment of clinical and biochemical features, antibody (Ab) response, Variant of Concern (VoC), and physical and mental quality of life (QoL). Outcome of interest was identification of risk and protective factors of PCS by clinical phenotype, setting, severity of disease, treatment, and vaccination status. We used SF-36 questionnaire to assess evolution in QoL index during follow-up and unsupervised machine learning algorithms (principal component analysis, PCA) to explore symptom clusters. Severity of PCS was defined by clinical phenotype and QoL. We also used generalized linear models to analyse the impact of PCS on QoL and associated risk and preventive factors. CT registration number: NCT05097677.

Findings

Among 1796 patients enrolled, 1030 (57%) suffered from at least one symptom at 12-month. PCA identified 4 clinical phenotypes: chronic fatigue-like syndrome (CFs: fatigue, headache and memory loss, 757 patients, 42%), respiratory syndrome (REs: cough and dyspnoea, 502, 23%); chronic pain syndrome (CPs: arthralgia and myalgia, 399, 22%); and neurosensorial syndrome (NSs: alteration in taste and smell, 197, 11%). Determinants of clinical phenotypes were different (all comparisons p < 0.05): being female increased risk of CPs, NSs, and CFs; chronic pulmonary diseases of REs; neurological symptoms at SARS-CoV-2 diagnosis of REs, NSs, and CFs; oxygen therapy of CFs and REs; and gastrointestinal symptoms at SARS-CoV-2 diagnosis of CFs. Early treatment of SARS-CoV-2 infection with monoclonal Ab (all clinical phenotypes), corticosteroids therapy for mild/severe cases (NSs), and SARS-CoV-2 vaccination (CPs) were less likely to be associated to PCS (all comparisons p < 0.05). Highest reduction in QoL was detected in REs and CPs (43.57 and 43.86 vs 57.32 in PCS-negative controls, p < 0.001). Female sex (p < 0.001), gastrointestinal symptoms (p = 0.034) and renal complications (p = 0.002) during the acute infection were likely to increase risk of severe PCS (QoL <50). Vaccination and early treatment with monoclonal Ab reduced the risk of severe PCS (p = 0.01 and p = 0.03, respectively).

Interpretation

Our study provides new evidence suggesting that PCS can be classified by clinical phenotypes with different impact on QoL, underlying possible different pathogenic mechanisms. We identified factors associated to each clinical phenotype and to severe PCS. These results might help in designing pathogenesis studies and in selecting high-risk patients for inclusion in therapeutic and management clinical trials.

Funding

The study received funding from the Horizon 2020 ORCHESTRA project, grant 101016167; from the Netherlands Organisation for Health Research and Development (ZonMw), grant 10430012010023; from Inserm, REACTing (REsearch & ACtion emergING infectious diseases) consortium and the French Ministry of Health, grant PHRC 20-0424.

Host immunological responses facilitate development of SARS-CoV-2 mutations in patients receiving monoclonal antibody treatments

BackgroundThe role of host immunity in emergence of evasive SARS-CoV-2 Spike mutations under therapeutic monoclonal antibody (mAb) pressure remains to be explored.MethodsIn a prospective, observational, monocentric ORCHESTRA cohort study, conducted between March 2021 and November 2022, mild-to-moderately ill COVID-19 patients (n = 204) receiving bamlanivimab, bamlanivimab/etesevimab, casirivimab/imdevimab, or sotrovimab were longitudinally studied over 28 days for viral loads, de novo Spike mutations, mAb kinetics, seroneutralization against infecting variants of concern, and T cell immunity. Additionally, a machine learning-based circulating immune-related biomarker (CIB) profile predictive of evasive Spike mutations was constructed and confirmed in an independent data set (n = 19) that included patients receiving sotrovimab or tixagevimab/cilgavimab.ResultsPatients treated with various mAbs developed evasive Spike mutations with remarkable speed and high specificity to the targeted mAb-binding sites. Immunocompromised patients receiving mAb therapy not only continued to display significantly higher viral loads, but also showed higher likelihood of developing de novo Spike mutations. Development of escape mutants also strongly correlated with neutralizing capacity of the therapeutic mAbs and T cell immunity, suggesting immune pressure as an important driver of escape mutations. Lastly, we showed that an antiinflammatory and healing-promoting host milieu facilitates Spike mutations, where 4 CIBs identified patients at high risk of developing escape mutations against therapeutic mAbs with high accuracy.ConclusionsOur data demonstrate that host-driven immune and nonimmune responses are essential for development of mutant SARS-CoV-2. These data also support point-of-care decision making in reducing the risk of mAb treatment failure and improving mitigation strategies for possible dissemination of escape SARS-CoV-2 mutants.FundingThe ORCHESTRA project/European Union's Horizon 2020 research and innovation program.

Diagnostic Accuracy of a Rapid SARS-CoV-2 Antigen Test Among People Experiencing Homelessness: A Prospective Cohort and Implementation Study

INTRODUCTION

Detection strategies in vulnerable populations such as people experiencing homelessness (PEH) need to be explored to promptly recognize severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreaks. This study investigated the diagnostic accuracy of a rapid SARS-CoV-2 Ag test in PEH during two pandemic waves compared with gold standard real-time multiplex reverse transcription polymerase chain reaction (rtRT-PCR).

METHODS

All PEH ≥ 18 years requesting residence at the available shelters in Verona, Italy, across two cold-weather emergency periods (November 2020-May 2021 and December 2021-April 2022) were prospectively screened for SARS-CoV-2 infection by means of a naso-pharyingeal swab. A lateral flow immunochromatographic assay (Biocredit^® COVID-19 Ag) was used as antigen-detecting rapid diagnostic test (Ag-RDT). The rtRT-PCR was performed with Allplex™ SARS-CoV-2 assay kit (Seegene). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated as measures for diagnostic accuracy.

RESULTS

Overall, 503 participants were enrolled during the two intervention periods for a total of 732 paired swabs collected: 541 swabs in the first period and 191 in the second. No significant differences in demographic and infection-related characteristics were observed in tested subjects in the study periods, except for the rate of previous infection (0.8% versus 8%; p < 0.001) and vaccination (6% versus 73%; p < 0.001). The prevalence of SARS-CoV-2 in the cohort was 8% (58/732 swabs positive with rtRT-PCR). Seventeen swabs were collected from symptomatic patients (7%). Among them, the concordance between rtRT-PCR and Ag-RDT was 100%, 7 (41.2%) positive and 10 negative pairs. The overall sensitivity of Ag-RDT was 63.8% (95% CI 60.3-67.3) and specificity was 99.8% (95% CI 99.6-100). PPV and NPV were 97.5% and 96.8%, respectively. Sensitivity and specificity did not change substantially across the two periods (65.1% and 99.8% in 2020-2021 vs. 60% and 100% in 2021-2022).

CONCLUSIONS

A periodic Ag-RDT-based screening approach for PEH at point of care could guide preventive measures, including prompt isolation, without referral to hospital-based laboratories for molecular test confirmation in case of positive detection even in individuals asymptomatic for COVID-19. This could help reduce the risk of outbreaks in shelter facilities.

Exploratory data on the clinical efficacy of monoclonal antibodies against SARS-CoV-2 Omicron variant of concern

Background:

Recent in-vitro data have shown that the activity of monoclonal antibodies (mAbs) targeting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) varies according to the variant of concern (VOC). No studies have compared the clinical efficacy of different mAbs against Omicron VOC.

Methods:

The MANTICO trial is a non-inferiority randomised controlled trial comparing the clinical efficacy of early treatments with bamlanivimab/etesevimab, casirivimab/imdevimab, and sotrovimab in outpatients aged 50 or older with mild-to-moderate SARS-CoV-2 infection. As the patient enrolment was interrupted for possible futility after the onset of the Omicron wave, the analysis was performed according to the SARS-CoV-2 VOC. The primary outcome was coronavirus disease 2019 (COVID-19) progression (hospitalisation, need of supplemental oxygen therapy, or death through day 14). Secondary outcomes included the time to symptom resolution, assessed using the product-limit method. Kaplan-Meier estimator and Cox proportional hazard model were used to assess the association with predictors. Log rank test was used to compare survival functions.

Results:

Overall, 319 patients were included. Among 141 patients infected with Delta, no COVID-19 progression was recorded, and the time to symptom resolution did not differ significantly between treatment groups (Log-rank Chi-square 0.22, p 0.90). Among 170 patients infected with Omicron (80.6% BA.1 and 19.4% BA.1.1), two COVID-19 progressions were recorded, both in the bamlanivimab/etesevimab group, and the median time to symptom resolution was 5 days shorter in the sotrovimab group compared with the bamlanivimab/etesevimab and casirivimab/imdevimab groups (HR 0.53 and HR 0.45, 95% CI 0.36–0.77 and 95% CI 0.30–0.67, p<0.01).

Conclusions:

Our data suggest that, among adult outpatients with mild-to-moderate SARS-CoV-2 infection due to Omicron BA.1 and BA.1.1, early treatment with sotrovimab reduces the time to recovery compared with casirivimab/imdevimab and bamlanivimab/etesevimab. In the same population, early treatment with casirivimab/imdevimab may maintain a role in preventing COVID-19 progression. The generalisability of trial results is substantially limited by the early discontinuation of the trial and firm conclusions cannot be drawn.

Funding:

This trial was funded by the Italian Medicines Agency (Agenzia Italiana del Farmaco, AIFA). The VOC identification was funded by the ORCHESTRA (Connecting European Cohorts to Increase Common and Effective Response to SARS-CoV-2 Pandemic) project, which has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement number 101016167.

Clinical trial number:

NCT05205759.

Clinical efficacy of different monoclonal antibody regimens among non-hospitalised patients with mild to moderate COVID-19 at high risk for disease progression: a prospective cohort study

This study aimed to compare the clinical progression of COVID-19 in high-risk outpatients treated with the monoclonal antibodies (mAb) bamlanivimab, bamlanivimab-etesevimab and casirivimab-imdevimab. This is an observational, multi-centre, prospective study conducted from 18 March to 15 July 2021 in eight Italian tertiary-care hospitals including mild-to-moderate COVID-19 outpatients receiving bamlanivimab (700 mg), bamlanivimab-etesevimab (700–1400 mg) or casirivimab-imdevimab (1200–1200 mg). All patients were at high risk of COVID-19 progression according to Italian Medicines Agency definitions. In a patient subgroup, SARS-CoV-2 variant and anti-SARS-CoV-2 serology were analysed at baseline. Factors associated with 28-day all-cause hospitalisation were identified using multivariable multilevel logistic regression (MMLR) and summarised with adjusted odds ratio (aOR) and 95% confidence interval (CI). A total of 635 outpatients received mAb: 161 (25.4%) bamlanivimab, 396 (62.4%) bamlanivimab-etesevimab and 78 (12.2%) casirivimab-imdevimab. Ninety-five (15%) patients received full or partial SARS-CoV-2 vaccination. The B.1.1.7 (Alpha) variant was detected in 99% of patients. Baseline serology showed no significant differences among the three mAb regimen groups. Twenty-eight-day all-cause hospitalisation was 11.3%, with a significantly higher proportion (p 0.001) in the bamlanivimab group (18.6%), compared to the bamlanivimab-etesevimab (10.1%) and casirivimab-imdevimab (2.6%) groups. On MMLR, aORs for 28-day all-cause hospitalisation were significantly lower in patients receiving bamlanivimab-etesevimab (aOR 0.51, 95% CI 0.30–0.88 p 0.015) and casirivimab-imdevimab (aOR 0.14, 95% CI 0.03–0.61, p 0.009) compared to those receiving bamlanivimab. No patients with a history of vaccination were hospitalised. The study suggests differences in clinical outcomes among the first available mAb regimens for treating high-risk COVID-19 outpatients. Randomised trials are needed to compare efficacy of mAb combination regimens in high-risk populations and according to circulating variants.

Assessment of SARS-CoV-2 IgG and IgM antibody detection with a lateral flow immunoassay test

The dramatic impact of SARS-CoV-2 infection on the worldwide public health has elicited the rapid assessment of molecular and serological diagnostic methods. Notwithstanding the diagnosis of SARS-CoV-2 infection is based on molecular biology approaches including multiplex or singleplex real time RT-PCR, there is a real need for affordable and rapid serological methods to support diagnostics, and surveillance of infection spreading. In this study, we performed a diagnostic accuracy analysis of COVID-19 IgG/IgM rapid test cassette lateral flow immunoassay test (LFIA) assay. To do so, we analyzed different cohorts of blood samples obtained from 151 SARS-CoV-2 RT-PCR assay positive patients (group 1) and 51 SARS-CoV-2 RT-PCR assay negative patients (group 2) in terms of sensitivity, specificity, PPV, NPV and likelihood ratios. In addition, we challenged LFIA with plasma from 99 patients stored during 2015–2017 period. Our results showed that this LFIA detected SARS-CoV-2 IgM and/or IgG in 103 out of 151 (68.21%) samples of group 1, whereas no IgM and/or IgG detection was displayed both in the group 2 and in pre-pandemic samples. Interestingly, IgM and/or IgG positivity was detected in 86 out of 94 (91.49%) group 1 samples collected after 10 days from symptoms onset whereas only 17 out of 57 of group 1 samples obtained before day 10 were positive to SARS-CoV-2 specific antibodies. We also compared the performance of this LFIA test with respect to other four different LFIA assays in 40 serum samples from multiplex RT-PCR positive individuals. Within the limits of the study size, the results demonstrated that COVID-19 IgG/IgM rapid test cassette LFIA assay displayed valid performance in IgM and IgG detection when compared with the other four LFIA assays.

Hence, this approach might be considered as an alternative point-of-care procedure for SARS-CoV-2 serological investigation.

Diagnostic accuracy of point-of-care tests in acute community-acquired lower respiratory tract infections. A systematic review and meta-analysis

BACKGROUND

Point-of-care tests could be essential in differentiating bacterial and viral acute community-acquired lower respiratory tract infections and driving antibiotic stewardship in the community.

OBJECTIVES

To assess diagnostic test accuracy of point-of-care tests in community settings for acute community-acquired lower respiratory tract infections.

DATA SOURCES

Multiple databases (MEDLINE, EMBASE, Web of Science, Cochrane Library, Open Gray) from inception to 31 May 2021, without language restrictions.

STUDY ELIGIBILITY CRITERIA

Diagnostic test accuracy studies involving patients at primary care, outpatient clinic, emergency department and long-term care facilities with a clinical suspicion of acute community-acquired lower respiratory tract infections. The comparator was any test used as a comparison to the index test. In order not to limit the study inclusion, the comparator was not defined a priori.

ASSESSMENT OF RISK OF BIAS

Four investigators independently extracted data, rated risk of bias, and assessed the quality using QUADAS-2.

METHODS OF DATA SYNTHESIS

The measures of diagnostic test accuracy were calculated with 95% CI.

RESULTS

A total of 421 studies addressed at least one point-of-care test. The diagnostic performance of molecular tests was higher compared with that of rapid diagnostic tests for all the pathogens studied. The accuracy of stand-alone signs and symptoms or biomarkers was poor. Lung ultrasound showed high sensitivity and specificity (90% for both) for the diagnosis of bacterial pneumonia. Rapid antigen-based diagnostic tests for influenza, respiratory syncytial virus, human metapneumovirus, and Streptococcus pneumoniae had sub-optimal sensitivity (range 49%-84%) but high specificity (>80%).

DISCUSSION

Physical examination and host biomarkers are not sufficiently reliable as stand-alone tests to differentiate between bacterial and viral pneumonia. Lung ultrasound shows higher accuracy than chest X-ray for bacterial pneumonia at emergency department. Rapid antigen-based diagnostic tests cannot be considered fully reliable because of high false-negative rates. Overall, molecular tests for all the pathogens considered were found to be the most accurate.

Assessment of COVID-19 progression on day 5 from symptoms onset

BACKGROUND

A major limitation of current predictive prognostic models in patients with COVID-19 is the heterogeneity of population in terms of disease stage and duration. This study aims at identifying a panel of clinical and laboratory parameters that at day-5 of symptoms onset could predict disease progression in hospitalized patients with COVID-19.

METHODS

Prospective cohort study on hospitalized adult patients with COVID-19. Patient-level epidemiological, clinical, and laboratory data were collected at fixed time-points: day 5, 10, and 15 from symptoms onset. COVID-19 progression was defined as in-hospital death and/or transfer to ICU and/or respiratory failure (PaO2/FiO2 ratio < 200) within day-11 of symptoms onset. Multivariate regression was performed to identify predictors of COVID-19 progression. A model assessed at day-5 of symptoms onset including male sex, age > 65 years, dyspnoea, cardiovascular disease, and at least three abnormal laboratory parameters among CRP (> 80 U/L), ALT (> 40 U/L), NLR (> 4.5), LDH (> 250 U/L), and CK (> 80 U/L) was proposed. Discrimination power was assessed by computing area under the receiver operating characteristic (AUC) values.

RESULTS

A total of 235 patients with COVID-19 were prospectively included in a 3-month period. The majority of patients were male (148, 63%) and the mean age was 71 (SD 15.9). One hundred and ninety patients (81%) suffered from at least one underlying illness, most frequently cardiovascular disease (47%), neurological/psychiatric disorders (35%), and diabetes (21%). Among them 88 (37%) experienced COVID-19 progression. The proposed model showed an AUC of 0.73 (95% CI 0.66-0.81) for predicting disease progression by day-11.

CONCLUSION

An easy-to-use panel of laboratory/clinical parameters computed at day-5 of symptoms onset predicts, with fair discrimination ability, COVID-19 progression. Assessment of these features at day-5 of symptoms onset could facilitate clinicians' decision making. The model can also play a role as a tool to increase homogeneity of population in clinical trials on COVID-19 treatment in hospitalized patients.

Deciphering the state of immune silence in fatal COVID-19 patients

Since the beginning of the SARS-CoV-2 pandemic, COVID-19 appeared as a unique disease with unconventional tissue and systemic immune features. Here we show a COVID-19 immune signature associated with severity by integrating single-cell RNA-seq analysis from blood samples and broncho-alveolar lavage fluids with clinical, immunological and functional ex vivo data. This signature is characterized by lung accumulation of naïve lymphoid cells associated with a systemic expansion and activation of myeloid cells. Myeloid-driven immune suppression is a hallmark of COVID-19 evolution, highlighting arginase-1 expression with immune regulatory features of monocytes. Monocyte-dependent and neutrophil-dependent immune suppression loss is associated with fatal clinical outcome in severe patients. Additionally, our analysis shows a lung CXCR6⁺ effector memory T cell subset is associated with better prognosis in patients with severe COVID-19. In summary, COVID-19-induced myeloid dysregulation and lymphoid impairment establish a condition of 'immune silence' in patients with critical COVID-19.

Deciphering the state of immune silence in fatal COVID-19 patients

Since the beginning of the SARS-CoV-2 pandemic, COVID-19 appeared as a unique disease with unconventional tissue and systemic immune features. Here we show a COVID-19 immune signature associated with severity by integrating single-cell RNA-seq analysis from blood samples and broncho-alveolar lavage fluids with clinical, immunological and functional ex vivo data. This signature is characterized by lung accumulation of naïve lymphoid cells associated with a systemic expansion and activation of myeloid cells. Myeloid-driven immune suppression is a hallmark of COVID-19 evolution, highlighting arginase-1 expression with immune regulatory features of monocytes. Monocyte-dependent and neutrophil-dependent immune suppression loss is associated with fatal clinical outcome in severe patients. Additionally, our analysis shows a lung CXCR6+ effector memory T cell subset is associated with better prognosis in patients with severe COVID-19. In summary, COVID-19-induced myeloid dysregulation and lymphoid impairment establish a condition of 'immune silence' in patients with critical COVID-19.

Nucleic acid amplification tests on respiratory samples for the diagnosis of coronavirus infections: a systematic review and meta-analysis

BACKGROUND

Management and control of coronavirus disease 2019 (COVID-19) relies on reliable diagnostic testing.

OBJECTIVES

To evaluate the diagnostic test accuracy (DTA) of nucleic acid amplification tests (NAATs) for the diagnosis of coronavirus infections.

DATA SOURCES

PubMed, Web of Science, the Cochrane Library, Embase, Open Grey and conference proceeding until May 2019. PubMed and medRxiv were updated for COVID-19 on 31st August 2020.

STUDY ELIGIBILITY

Studies were eligible if they reported on agreement rates between different NAATs using clinical samples.

PARTICIPANTS

Symptomatic patients with suspected upper or lower respiratory tract coronavirus infection.

METHODS

The new NAAT was defined as the index test and the existing NAAT as reference standard. Data were extracted independently in duplicate. Risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Confidence regions (CRs) surrounding summary sensitivity/specificity pooled by bivariate meta-analysis are reported. Heterogeneity was assessed using meta-regression.

RESULTS

Fifty-one studies were included, 22 of which included 10 181 persons before COVID-19 and 29 including 8742 persons diagnosed with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The overall summary sensitivity was 89.1% (95%CR 84.0-92.7%) and specificity 98.9% (95%CR 98.0-99.4%). Nearly all the studies evaluated different PCRs as both index and reference standards. Real-time RT PCR assays resulted in significantly higher sensitivity than other tests. Reference standards at high risk of bias possibly exaggerated specificity. The pooled sensitivity and specificity of studies evaluating SARS-COV-2 were 90.4% (95%CR 83.7-94.5%) and 98.1% (95%CR 95.9-99.2), respectively. SARS-COV-2 studies using samples from the lower respiratory tract, real-time RT-PCR, and tests targeting the N or S gene or more than one gene showed higher sensitivity, and assays based on reverse transcriptase loop-mediated isothermal amplification (RT-LAMP), especially when targeting only the RNA-dependent RNA polymerase (RdRp) gene, showed significantly lower sensitivity compared to other studies.

CONCLUSIONS

Pooling all studies to date shows that on average 10% of patients with coronavirus infections might be missed with PCR tests. Variables affecting sensitivity and specificity can be used for test selection and development.

Multi-Criteria Decision Analysis to prioritize hospital admission of patients affected by COVID-19 in low-resource settings with hospital-bed shortage

Objective

To use Multi-Criteria Decision Analysis (MCDA) to determine weights for eleven criteria in order to prioritize COVID-19 non-critical patients for admission to hospital in healthcare settings with limited resources.

Methods

The MCDA was applied in two main steps: specification of criteria for prioritizing COVID-19 patients (and levels within each criterion); and determination of weights for the criteria based on experts’ knowledge and experience in managing COVID-19 patients, via an online survey. Criteria were selected based on available COVID-19 evidence with a focus on low- and middle-income countries (LMICs).

Results

The most important criteria (mean weights, summing to 100%) are: PaO₂ (16.3%); peripheral O₂ saturation (15.9%); chest X-ray (14.1%); Modified Early Warning Score-MEWS (11.4%); respiratory rate (9.5%); comorbidities (6.5%); living with vulnerable people (6.4%); body mass index (5.6%); duration of symptoms before hospital evaluation (5.4%); CRP (5.1%); and age (3.8%).

Conclusions

At the beginning of a new pandemic, when evidence for disease predictors is limited or unavailable and effective national contingency plans are difficult to establish, the MCDA prioritization model could play a pivotal role in improving the response of health systems.

Implementing a combined infection prevention and control with antimicrobial stewardship joint program to prevent caesarean section surgical site infections and antimicrobial resistance: a Tanzanian tertiary hospital experience

Background

Surgical site infections are a leading cause of morbidity and mortality after caesarean section, especially in Low and Middle Income Countries. We hypothesized that a combined infection prevention and control with antimicrobial stewardship joint program would decrease the rate of post- caesarean section surgical site infections at the Obstetrics & Gynaecology Department of a Tanzanian tertiary hospital.

Methods

The intervention included: 1. formal and on-job trainings on infection prevention and control; 2. evidence-based education on antimicrobial resistance and good antimicrobial prescribing practice. A second survey was performed to determine the impact of the intervention. The primary outcome of the study was post-caesarean section surgical site infections prevalence and secondary outcome the determinant factors of surgical site infections before/after the intervention and overall. The microbiological characteristics and patterns of antimicrobial resistance were ascertained.

Results

Total 464 and 573 women were surveyed before and after the intervention, respectively. After the intervention, the antibiotic prophylaxis was administered to a significantly higher number of patients (98% vs 2%, p < 0.001), caesarean sections were performed by more qualified operators (40% vs 28%, p = 0.001), with higher rates of Pfannenstiel skin incisions (29% vs 18%, p < 0.001) and of absorbable continuous intradermic sutures (30% vs 19%, p < 0.001). The total number of post-caesarean section surgical site infections was 225 (48%) in the pre-intervention and 95 (17%) in the post intervention group (p < 0.001). A low prevalence of gram-positive isolates and of methicillin-resistant Staphylococus aureus was detected in the post-intervention survey.

Conclusions

Further researches are needed to better understand the potential of a hospital-based multidisciplinary approach to surgical site infections and antimicrobial resistance prevention in resource-constrained settings.

A retrospective evaluation of bites at risk of rabies transmission across 7 years: The need to improve surveillance and reporting systems for rabies elimination

The vast majority of rabies deaths occur in developing countries and rural areas. Due to the absence of surveillance and the lack of reliable information, many endemic countries are not able to assess their rabies burden and implement appropriate solutions. This study reports the incidence of animal bites considered at risk of rabies transmission, along with rates and determinants of the adherence to post-exposure prophylaxis (PEP) between 2008 and 2014 in Dodoma Region, Tanzania. A retrospective analysis of rabid animal bites considered at risk of rabies transmission at Dodoma Regional Referral Hospital (DRRH) during 2008-2014 was conducted. Data were collected from the registers of patients presenting to the hospital because of a potential rabies exposure. The patients were assessed by a trained health worker and each bite was considered as "at risk of rabies" based on the victim's description of the event. Overall, 10,771 patients coming from Dodoma Region attended DRRH because of a bite from a suspected rabid animal, giving a mean incidence of 74 bites at risk of rabies transmission per 100,000 persons per year. Overall, only 46.0% of people exposed received a complete course of PEP and 61.6% attended the clinic within 48 hours after the bite. Multivariate analysis shows that people age >15 years, residence in rural areas and occurrence during the rainy season were independently associated to delayed access to care. Male gender, age below 15 years. and bites occurring during the dry season were associated with completion of PEP. In this area with a high rate of at-risk bites, several factors-mainly related to health care access and to the affordability and delivery of rabies vaccines-still need to be addressed in order to reduce gender and social inequalities in rabies prevention and control. Further efforts are required to establish an efficient rabies surveillance system in Dodoma Region.

Reliability and validity of using telephone calls for post-discharge surveillance of surgical site infection following caesarean section at a tertiary hospital in Tanzania

Background

Surgical site infection (SSI) is a common post-operative complication causing significant morbidity and mortality. Many SSI occur after discharge from hospital. Post-discharge SSI surveillance in low and middle income countries needs to be improved.

Methodology

We conducted an observational cohort study in Dodoma, Tanzania to examine the sensitivity and specificity of telephone calls to detect SSI after discharge from hospital in comparison to a gold standard of clinician review. Women undergoing caesarean section were enrolled and followed up for 30 days. Women providing a telephone number were interviewed using a structured questionnaire at approximately days 5, 12 and 28 post-surgery. Women were then invited for out-patient review by a clinician blinded to the findings of telephone interview.

Results

A total of 374 women were enrolled and an overall SSI rate of 12% (n = 45) was observed. Three hundred and sixteen (84%) women provided a telephone number, of which 202 had at least one telephone interview followed by a clinical review within 48 h, generating a total of 484 paired observations. From the clinical reviews, 25 SSI were diagnosed, of which telephone interview had correctly identified 18 infections; telephone calls did not incorrectly identify SSI in any patients. The overall sensitivity and specificity of telephone interviews as compared to clinician evaluation was 72 and 100%, respectively.

Conclusion

The use of telephone interview as a diagnostic tool for post-discharge surveillance of SSI had moderate sensitivity and high specificity in Tanzania. Telephone-based detection may be a useful method for SSI surveillance in low-income settings with high penetration of mobile telephones.

Clinical, Virologic, and Epidemiologic Characteristics of Dengue Outbreak, Dar es Salaam, Tanzania, 2014

We investigated a dengue outbreak in Dar es Salaam, Tanzania, in 2014, that was caused by dengue virus (DENV) serotype 2. DENV infection was present in 101 (20.9%) of 483 patients. Patient age and location of residence were associated with infection. Seven (4.0%) of 176 patients were co-infected with malaria and DENV.

Functional status and failed rotator cuff repair predict outcomes after arthroscopic-assisted latissimus dorsi transfer for irreparable massive rotator cuff tears

BACKGROUND

Arthroscopic-assisted latissimus dorsi tendon transfer (LDTT) has been recently introduced for treatment of irreparable, posterosuperior massive rotator cuff tears. We sought to evaluate the functional outcomes of this technique and to check for possible outcome predictors.

METHODS

The study reviewed 86 patients (aged 59.8 ± 5.9 years) who underwent an arthroscopic-assisted latissimus dorsi tendon transfer after 36.4 ± 9 months of follow-up. Of these, 14 patients (16.3%) sustained an irreparable massive rotator cuff tear after a failed arthroscopic rotator cuff repair. The Constant and Murley score (CMS) was used to assess patients' functionality preoperatively and at follow-up.

RESULTS

As a group, the CMS improved with surgery from 35.5 ± 6.1 to 69.5 ± 12.3 (P < .001). A lower preoperative CMS and a previous failed rotator cuff repair resulted in lower postoperative range of motion (P = .044 and P = .007, respectively) and CMS (P = .042 and P = .018, respectively). A previous rotator cuff repair resulted in lower satisfaction with surgery (P = .009). Gender and age did not affect the clinical outcomes.

CONCLUSIONS

Our results support the effectiveness of arthroscopic-assisted LDTT in the treatment of patients with an irreparable, posterosuperior massive rotator cuff tears in pain relief, functional recovery, and postoperative satisfaction. Patients with lower preoperative CMS and a history of failed rotator cuff repair have a greater likelihood of having a lower clinical result. However, the favorable values of summary postoperative scores do not exclude these patients as candidates for arthroscopic-assisted LDTT.

The Risk of Dengue Virus Transmission in Dar es Salaam, Tanzania during an Epidemic Period of 2014

Background

In 2010, 2012, 2013 and 2014 dengue outbreaks have been reported in Dar es Salaam, Tanzania. However, there is no comprehensive data on the risk of transmission of dengue in the country. The objective of this study was to assess the risk of transmission of dengue in Dar es Salaam during the 2014 epidemic.

Methodology/Principal Findings

This cross-sectional study was conducted in Dar es Salaam, Tanzania during the dengue outbreak of 2014. The study involved Ilala, Kinondoni and Temeke districts. Adult mosquitoes were collected using carbon dioxide-propane powered Mosquito Magnet Liberty Plus traps. In each household compound, water-holding containers were examined for mosquito larvae and pupae. Dengue virus infection of mosquitoes was determined using real-time reverse transcription polymerase chain reaction (qRT-PCR). Partial amplification and sequencing of dengue virus genome in infected mosquitoes was performed. A total of 1,000 adult mosquitoes were collected. Over half (59.9%) of the adult mosquitoes were collected in Kinondoni. Aedes aegypti accounted for 17.2% of the mosquitoes of which 90.6% were from Kinondoni. Of a total of 796 houses inspected, 38.3% had water-holding containers in their premises. Kinondoni had the largest proportion of water-holding containers (57.7%), followed by Temeke (31.4%) and Ilala (23.4%). The most common breeding containers for the Aedes mosquitoes were discarded plastic containers and tires. High Aedes infestation indices were observed for all districts and sites, with a house index of 18.1% in Ilala, 25.5% in Temeke and 35.3% in Kinondoni. The respective container indices were 77.4%, 65.2% and 80.2%. Of the reared larvae and pupae, 5,250 adult mosquitoes emerged, of which 61.9% were Ae. aegypti. Overall, 27 (8.18) of the 330 pools of Ae. aegypti were positive for dengue virus. On average, the overall maximum likelihood estimate (MLE) indicates pooled infection rate of 8.49 per 1,000 mosquitoes (95%CI = 5.72–12.16). There was no significant difference in pooled infection rates between the districts. Dengue viruses in the tested mosquitoes clustered into serotype 2 cosmopolitan genotype.

Conclusions/Significance

Ae. aegypti is the main vector of dengue in Dar es Salaam and breeds mainly in medium size plastic containers and tires. The Aedes house indices were high, indicating that the three districts were at high risk of dengue transmission. The 2014 dengue outbreak was caused by Dengue virus serotype 2. The high mosquito larval and pupal indices in the area require intensification of vector surveillance along with source reduction and health education.

Until 2010, little was known about Dengue in Tanzania. Since then, four outbreaks have been reported in Dar es Salaam City. This study was therefore carried out to assess the risk of transmission of dengue in Dar es Salaam during an outbreak in 2014. In this study adult mosquitoes were collected using carbon dioxide-propane powered traps. In addition, household compounds were visited and all water-holding containers examined for presence of mosquito larvae and pupae. Mosquito virus infection was determined using real-time reverse transcription polymerase chain reaction (qRT-PCR). Of the total of 1,000 adult mosquitoes collected, Aedes aegypti accounted for 17.2%. A total of 796 houses were inspected and 38.3% had water-holding containers in their premises. The most common breeding containers for the Aedes mosquitoes were discarded plastic containers and tires. High Aedes infestation indices were observed for all districts and sites, with a house and container indices ranging from 18.1–25.5% and 65.2–80.2%, respectively. The Breteaux indices were 30.6, 20.8 and 25.3 in Ilala, Kinondoni and Temeke, respectively. An overall 8.18% of mosquito pools were infected with dengue virus serotype 2. The overall maximum likelihood estimate of pooled infection rate of 8.49 per 1,000 mosquitoes was observed. This information is useful for the design of appropriate vector surveillance and control strategies in the City of Dar es Salaam.

Efavirenz-based antiretroviral therapy versus nevirapine-including regimens for prevention of mother-to-child transmission of HIV option B plus in resource-limited settings: is there anything missing?

In 2013, an estimated 1.5 million HIV-positive pregnant women gave birth, with 240,000 children worldwide acquiring HIV. More than 90% of new pediatric infections occurred in Sub-Saharan Africa. The latest WHO guidelines recommended efavirenz (EFV)-based antiretroviral therapy as the first-line regimen for prevention of mother-to-child transmission of HIV (PMTCT). On the other hand, some data suggest that nevirapine (NVP), a well-known antiretroviral, could still play a relevant role in PMTCT, especially in resource-limited settings (RLSs) where the fertility rate is dramatically high compared to developed countries. Given the lack of an unanimous consensus and definitive opinions, this paper goes through the reasons for WHO decisions and aims at refreshing the debate about NVP and EFV pros and cons for PMTCT in RLSs.

IgG against dengue virus in healthy blood donors, Zanzibar, Tanzania

We conducted a seroprevalence survey among 500 healthy adult donors at Zanzibar National Blood Transfusion Services. Dengue virus IgG seroprevalence was 50.6% and independently associated with age and urban residence. These data will aid in building a surveillance, preparedness, and response plan for dengue virus infections in the Zanzibar Archipelago.

HIV-1 drug resistance in recently HIV-infected pregnant mother's naïve to antiretroviral therapy in Dodoma urban, Tanzania

Background

HIV resistance affects virological response to therapy and efficacy of prophylaxis in mother-to-child-transmission. The study aims to assess the prevalence of HIV primary resistance in pregnant women naïve to antiretrovirals.

Methods

Cross sectional baseline analysis of a cohort of HIV + pregnant women (HPW) enrolled in the study entitled Antiretroviral Management of Antenatal and Natal HIV Infection (AMANI, peace in Kiswahili language). The AMANI study began in May 2010 in Dodoma, Tanzania. In this observational cohort, antiretroviral treatment was provided to all women from the 28^th week of gestation until the end of the breastfeeding period. Baseline CD4 cell count, viral load and HIV drug-resistance genotype were collected.

Results

Drug-resistance analysis was performed on 97 naïve infected-mothers. The prevalence of all primary drug resistance and primary non-nucleoside reverse-transcriptase inhibitors resistance was 11.9% and 7.5%, respectively. K103S was found in two women with no M184V detection. HIV-1 subtype A was the most commonly identified, with a high prevalence of subtype A1, followed by C, D, C/D recombinant, A/C recombinant and A/D recombinant. HIV drug- resistance mutations were detected in A1 and C subtypes.

Conclusion

Our study reports an 11.9% prevalence rate of primary drug resistance in naïve HIV-infected pregnant women from a remote area of Tanzania. Considering that the non-nucleoside reverse-transcriptase inhibitors are part of the first-line antiretroviral regimen in Tanzania and all of Africa, resistance surveys should be prioritized in settings where antiretroviral therapy programs are scaled up.

Strengthening tuberculosis diagnosis in a low-resource setting: experience learned in Dodoma, Tanzania

INTRODUCTION

Diagnosing tuberculosis in low-resource settings mostly relies on sputum smear microscopy. Improvement through capacity building is a priority. This project aimed to strengthen tuberculosis diagnosis at an intermediate level laboratory.

METHODOLOGY

The Italian National Institute for Infectious Diseases and the Italian Development Cooperation closely collaborated with regional and national institutions and reference laboratories to provide laboratory setup, equipment and reagents, personnel training, and the implementation of culture and quality assessment programs at Dodoma Regional Hospital, Dodoma, Tanzania.

RESULTS

Microscopy sensitivity was increased, personnel were trained, and culture techniques and quality assessment programs were introduced.

CONCLUSIONS

Implementing tuberculosis diagnosis in resource-constrained settings is feasible and represents a basis for further strengthening.

Determination of P-glycoprotein surface expression and functional ability after in vitro treatment with darunavir or raltegravir in lymphocytes of healthy donors

It has been shown that P-glycoprotein (P-gp) can greatly affect the cell uptake of antiretroviral drugs, thus hampering their access to HIV-1 replication sites. Lymphocytes are important sites of replication of HIV and target of other drugs, modification on these cells of P-gp could have an effect on pharmacokinetic of antiretrovirals and drug substrates. Blood samples from 16 healthy volunteers were used to determine the expression of P-gp on total, T and T helper lymphocytes after exposure to darunavir, a second generation protease inhibitor, and raltegravir, the first approved integrase inhibitor. Moreover, the effect of the drugs on P-gp functional activity was also studied by the rhodamine-123 efflux test. Darunavir, but not raltegravir, exposure caused a moderate, dose-dependent increment in P-gp expression in total, T and T helper lymphocytes, as demonstrated by the relative frequency of P-gp+ cells and by the amount of P-gp molecules present on cell surface. Functionally, incubation with darunavir led to a marked inhibition of P-gp activity measured by the efflux of rhodamine-123 similar to that observed by verapamil, a specific P-gp inhibitor. Raltegravir was not able to modify the efflux of rhodamine-123 level. Data show that darunavir, unlike raltegravir, may modify the expression and functionality of P-gp on human lymphocytes, thus leading to potential changes in intracellular concentrations of darunavir in patients treated with other drugs substrate of P-gp and vice versa. Our study highlights the need for studies on drug interactions via the P-gp modulation mechanism, especially with the current multi-drug regimens.

Left thigh phlegmon caused by Nocardia farcinica identified by 16S rRNA sequencing in a patient with leprosy: a case report

BACKGROUND

In recent years, Nocardia farcinica has been reported to be an increasingly frequent cause of localized and disseminated infections in the immunocompromised patient. However, recent literature is limited. We report a case of left thigh phlegmon caused by N. farcinica that occurred in a patient with leprosy undergoing treatment with prednisone for leprosy reaction.

CASE PRESENTATION

We describe the case of left thigh phlegmon caused by Nocardia farcinica in a 54-year-old Italian man affected by multi-bacillary leprosy. The patient had worked in South America for 11 years. Seven months after his return to Italy, he was diagnosed with leprosy and started multi-drug antibiotic therapy plus thalidomide and steroids. Then, during therapy with rifampicin monthly, minocycline 100 mg daily, moxifloxacin 400 mg daily, and prednisone (the latter to treat type 2 leprosy reaction), the patient complained of high fever associated with erythema, swelling, and pain in the left thigh. Therefore, he was admitted to our hospital with the clinical suspicion of cellulitis. Ultrasound examination and Magnetic Resonance Imaging showed left thigh phlegmon. He was treated with drainage and antibiotic therapy (meropenem and vancomycin replaced by daptomycin). The responsible organism, Nocardia farcinica, was identified by 16S rRNA sequencing in the purulent fluid taken out by aspiration. The patient continued treatment with intravenous trimethoprim/sulfamethoxazole and imipenem followed by oral trimethoprim/sulfamethoxazole and moxifloxacin. A whole-body computed tomography did not reveal dissemination to other organs like the lung or brain.The patient was discharged after complete remission. Oral therapy with trimethoprim/sulfamethoxazole, moxifloxacin, rifampicin monthly, clofazimine and thalidomide was prescribed to be taken at home. One month after discharge from the hospital the patient is in good clinical condition with complete resolution of the phlegmon.

CONCLUSION

N. farcinica is a rare infectious agent that mainly affects immunocompromised patients. Presentation of phlegmon only without disseminated infection is unusual, even in these kinds of patients. In any case, a higher index of suspicion is needed, as diagnosis can easily be missed due to the absence of characteristic symptoms and the several difficulties usually encountered in identifying the pathogen.

Treatment of Recurrent Hepatocellular Carcinoma with Sorafenib in a HIV/HCV Co-Infected patient in HAART: A Case Report

Background

Liver disease is the second cause of death among HIV patients receiving highly active antiretroviral therapy (HAART) in Europe. HIV patients have a high prevalence of chronic HBV (6–10%) and HCV (33%) co-infection, and accelerated progression of viral hepatitis. Furthermore, the long duration of both HIV and HCV diseases in the HAART era increases the risk of hepatocellular carcinoma.

Findings

We report the case of a 49 year -old HIV/HCV co-infected male patient who developed hepatocellular carcinoma. The patient underwent a partial hepatectomy, and a few months later was treated with transcatheter arterial chemoembolisation due to hepatocarcinoma recurrence. Two months later, advanced hepatocellular carcinoma was diagnosed and sorafenib therapy was initiated. The patient achieved partial response of the main lesions, complete regression of the smallest lesions and did not experience clinical progression during the 20-month follow-up period. During therapy with sorafenib, the patient was treated with HAART with good viral and immunological responses. We used the therapeutic drug monitoring to assess antiretroviral concentrations during co-administration of sorafenib. Fosamprenavir C_trough was found under the minimum level recommended by international guidelines. No grade 3 or 4 toxicities were observed. At month 20 of treatment, new liver lesions with portal vein thrombosis were diagnosed. After 28 months of sorafenib therapy, the patient deceased for severe liver insufficiency.

Conclusions

Sorafenib monotherapy demonstrated a marked delay in HCC disease progression in an HIV/HCV co-infected patient. Fosamprenavir C_trough was found under the minimum level recommended by international guidelines, suggesting a possible interaction.

Haemolytic anaemia in an HIV-infected patient with severe falciparum malaria after treatment with oral artemether-lumefantrine

Intravenous (i.v.) artesunate is now the recommended first-line treatment of severe falciparum malaria in adults and children by WHO guidelines. Nevertheless, several cases of haemolytic anaemia due to i.v. artesunate treatment have been reported. This paper describes the case of an HIV-infected patient with severe falciparum malaria who was diagnosed with haemolytic anaemia after treatment with oral artemether-lumefantrine.

The patient presented with fever, headache, and arthromyalgia after returning from Central African Republic where he had been working. The blood examination revealed acute renal failure, thrombocytopaenia and hypoxia. Blood for malaria parasites indicated hyperparasitaemia (6%) and Plasmodium falciparum infection was confirmed by nested-PCR. Severe malaria according to the laboratory WHO criteria was diagnosed. A treatment with quinine and doxycycline for the first 12 hours was initially administered, followed by arthemeter/lumefantrine (Riamet^®) for a further three days. At day 10, a diagnosis of severe haemolytic anaemia was made (Hb 6.9 g/dl, LDH 2071 U/l). Hereditary and autoimmune disorders and other infections were excluded through bone marrow aspiration, total body TC scan and a wide panel of molecular and serologic assays. The patient was treated by transfusion of six units of packed blood red cell. He was discharged after complete remission at day 25. At present, the patient is in a good clinical condition and there is no evidence of haemolytic anaemia recurrence.

This is the first report of haemolytic anaemia probably associated with oral artemether/lumefantrine. Further research is warranted to better define the adverse events occurring during combination therapy with artemisinin derivatives.

Total hip replacement infected with Mycobacterium tuberculosis complicated by Addison disease and psoas muscle abscess: a case report

Introduction

Prosthetic joint infection due to Mycobacterium tuberculosis is occasionally encountered in clinical practice. To the best of our knowledge, this is the first report of a prosthetic joint infection due to Mycobacterium tuberculosis complicated by psoas abscesses and secondary Addison disease.

Case presentation

A 67-year-old immunocompetent Caucasian woman underwent total left hip arthroplasty because of osteoarthritis. After 18 months, she underwent arthroplasty revision for a possible prosthetic infection. Periprosthetic tissue specimens for bacteria were negative, and empirical antibiotic therapy was unsuccessful. She was then admitted to our department because of complications arising 22 months after arthroplasty. A physical examination revealed a sinus tract overlying her left hip and skin and mucosal pigmentation. Her levels of C-reactive protein, basal cortisol, adrenocorticotropic hormone, and sodium were out of normal range. Results of the tuberculin skin test and QuantiFERON-TB Gold test were positive. Computed tomography revealed a periprosthetic abscess and the inclusion of the left psoas muscle. Results of microbiological tests were negative, but polymerase chain reaction of a specimen taken from the hip fistula was positive for Mycobacterium tuberculosis. Our patient's condition was diagnosed as prosthetic joint infection and muscle psoas abscess due to Mycobacterium tuberculosis and secondary Addison disease. She underwent standard treatment with rifampicin, ethambutol, isoniazid, and pyrazinamide associated with hydrocortisone and fludrocortisone. At 15 months from the beginning of therapy, she was in good clinical condition and free of symptoms.

Conclusions

Prosthetic joint infection with Mycobacterium tuberculosis is uncommon. A differential diagnosis of tuberculosis should be considered when dealing with prosthetic joint infection, especially when repeated smears and histology examination from infected joints are negative. Clinical outcomes of prosthetic joint infection by Mycobacterium tuberculosis are unpredictable, especially given the limited literature in this field and the uncertainty of whether medical treatment alone can eradicate the infection without prosthesis removal. Furthermore, this case report raises interesting issues such as the necessity of a follow-up evaluation after treatment based on clinical conditions, the utility of a more standardized length of treatment for periprosthetic tuberculous infection, and the importance of a high diffusion capacity of anti-mycobacterial agents in order to eradicate the infection.