Oral linezolid compared with benzathine penicillin G for treatment of early syphilis in adults (Trep-AB Study) in Spain: a prospective, open-label, non-inferiority, randomised controlled trial.

BACKGROUND: Management of syphilis, a sexually transmitted infection (STI) with increasing incidence, is challenged by drug shortages, scarcity of randomised trial data, an absence of non-penicillin alternatives for pregnant women with penicillin allergy (other than desensitisation), extended parenteral administration for neurosyphilis and congenital syphilis, and macrolide resistance. Linezolid was shown to be active against Treponema pallidum, the causative agent of syphilis, in vitro and in the rabbit model. We aimed to assess the efficacy of linezolid for treating early syphilis in adults compared with the standard of care benzathine penicillin G (BPG). METHODS: We did a multicentre, open-label, non-inferiority, randomised controlled trial to assess the efficacy of linezolid for treating early syphilis compared with BPG. We recruited participants with serological or molecular confirmation of syphilis (either primary, secondary, or early latent) at one STI unit in a public hospital and two STI community clinics in Catalonia (Spain). Participants were randomly allocated in a 1:1 ratio using a computer-generated block randomisation list with six participants per block, to receive either oral linezolid (600 mg once per day for 5 days) or intramuscular BPG (single dose of 2·4 million international units) and were assessed for signs and symptoms (once per week until week 6 and at week 12, week 24, and week 48) and reagin titres of non-treponemal antibodies (week 12, week 24, and week 48). The primary endpoint was treatment response, assessed using a composite endpoint that included clinical response, serological response, and absence of relapse. Clinical response was assessed at 2 weeks for primary syphilis and at 6 weeks for secondary syphilis following treatment initiation. Serological cure was defined as a four-fold decline in rapid plasma reagin titre or seroreversion at any of the 12-week, 24-week, or 48-week timepoints. The absence of relapse was defined as the presence of different molecular sequence types of T pallidum in recurrent syphilis. Non-inferiority was shown if the lower limit of the two-sided 95% CI for the difference in rates of treatment response was higher than -10%. The primary analysis was done in the per-protocol population. The trial is registered at ClinicalTrials.gov (NCT05069974) and was stopped for futility after interim analysis. FINDINGS: Between Oct 20, 2021, and Sept 15, 2022, 62 patients were assessed for eligibility, and 59 were randomly assigned to linezolid (n=29) or BPG (n=30). In the per-protocol population, after 48 weeks' follow-up, 19 (70%) of 27 participants (95% CI 49·8 to 86·2) in the linezolid group had responded to treatment and 28 (100%) of 28 participants (87·7 to 100·0) in the BPG group (treatment difference -29·6, 95% CI -50·5 to -8·8), which did not meet the non-inferiority criterion. The number of drug-related adverse events (all mild or moderate) was similar in both treatment groups (five [17%] of 29, 95% CI 5·8 to 35·8 in the linezolid group vs five [17%] of 30, 5·6 to 34·7, in the BPG group). No serious adverse events were reported during follow-up. INTERPRETATION: The efficacy of linezolid at a daily dose of 600 mg for 5 days did not meet the non-inferiority criteria compared with BPG and, as a result, this treatment regimen should not be used to treat patients with early syphilis. FUNDING: European Research Council and Fondo de Investigaciones Sanitarias.

Performance characteristics of five antigen-detecting rapid diagnostic test (Ag-RDT) for SARS-CoV-2 asymptomatic infection: a head-to-head benchmark comparison.

BACKGROUND: Mass testing for early identification and isolation of infectious COVID-19 individuals is efficacious for reducing disease spread. Antigen-detecting rapid diagnostic tests (Ag-RDT) may be suitable for testing strategies; however, benchmark comparisons are scarce. METHODS: We used 286 nasopharyngeal specimens from unexposed asymptomatic individuals collected between December 2020 and January 2021 to assess five Ag-RDTs marketed by Abbott, Siemens, Roche Diagnostics, Lepu Medical, and Surescreen. RESULTS: For the overall sample, the performance parameters of Ag-RDTs were as follows: Abbott assay, sensitivity 38.6% (95%CI 29.1-48.8) and specificity 99.5% (97-100%); Siemens, sensitivity 51.5% (41.3-61.6) and specificity 98.4% (95.3-99.6); Roche, sensitivity 43.6% (33.7-53.8) and specificity 96.2% (92.4-98.5); Lepu, sensitivity 45.5% (35.6-55.8) and specificity 89.2% (83.8-93.3%); Surescreen, sensitivity 28.8% (20.2-38.6) and specificity 97.8% (94.5-99.4%). For specimens with cycle threshold (Ct) <30 in RT-qPCR, all Ag-RDT achieved a sensitivity ≥70%. The modelled negative- and positive-predictive value for 1% prevalence were >99% and <50%, respectively. CONCLUSIONS: When screening unexposed asymptomatic individuals, two Ag-RDTs achieved sensitivity ≥80% for specimens with Ct<30 and specificity ≥96%. The estimated negative predictive value suggests the suitability of Ag-RDTs for mass screenings of SARS-CoV-2 infection in the general population.

Transmission of COVID-19 in 282 clusters in Catalonia, Spain: a cohort study.

BACKGROUND: Scarce data are available on what variables affect the risk of transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the development of symptomatic COVID-19, and, particularly, the relationship with viral load. We aimed to analyse data from linked index cases of COVID-19 and their contacts to explore factors associated with transmission of SARS-CoV-2. METHODS: In this cohort study, patients were recruited as part of a randomised controlled trial done between March 17 and April 28, 2020, that aimed to assess if hydroxychloroquine reduced transmission of SARS-CoV-2. Patients with COVID-19 and their contacts were identified by use of the electronic registry of the Epidemiological Surveillance Emergency Service of Catalonia (Spain). Patients with COVID-19 included in our analysis were aged 18 years or older, not hospitalised, had quantitative PCR results available at baseline, had mild symptom onset within 5 days before enrolment, and had no reported symptoms of SARS-CoV-2 infections in their accommodation or workplace within the 14 days before enrolment. Contacts included were adults with a recent history of exposure and absence of COVID-19-like symptoms within the 7 days preceding enrolment. Viral load of contacts, measured by quantitative PCR from a nasopharyngeal swab, was assessed at enrolment, at day 14, and whenever the participant reported COVID-19-like symptoms. We assessed risk of transmission and developing symptomatic disease and incubation dynamics using regression analysis. We assessed the relationship of viral load and characteristics of cases (age, sex, number of days from reported symptom onset, and presence or absence of fever, cough, dyspnoea, rhinitis, and anosmia) and associations between risk of transmission and characteristics of the index case and contacts. FINDINGS: We identified 314 patients with COVID-19, with 282 (90%) having at least one contact (753 contacts in total), resulting in 282 clusters. 90 (32%) of 282 clusters had at least one transmission event. The secondary attack rate was 17% (125 of 753 contacts), with a variation from 12% when the index case had a viral load lower than 1 × 106 copies per mL to 24% when the index case had a viral load of 1 × 1010 copies per mL or higher (adjusted odds ratio per log10 increase in viral load 1·3, 95% CI 1·1-1·5). Increased risk of transmission was also associated with household contact (3·0, 1·59-5·65) and age of the contact (per year: 1·02, 1·01-1·04). 449 contacts had a positive PCR result at baseline. 28 (6%) of 449 contacts had symptoms at the first visit. Of 421 contacts who were asymptomatic at the first visit, 181 (43%) developed symptomatic COVID-19, with a variation from approximately 38% in contacts with an initial viral load lower than 1 × 107 copies per mL to greater than 66% for those with an initial viral load of 1 × 1010 copies per mL or higher (hazard ratio per log10 increase in viral load 1·12, 95% CI 1·05-1·20; p=0·0006). Time to onset of symptomatic disease decreased from a median of 7 days (IQR 5-10) for individuals with an initial viral load lower than 1 × 107 copies per mL to 6 days (4-8) for those with an initial viral load between 1 × 107 and 1 × 109 copies per mL, and 5 days (3-8) for those with an initial viral load higher than 1 × 109 copies per mL. INTERPRETATION: In our study, the viral load of index cases was a leading driver of SARS-CoV-2 transmission. The risk of symptomatic COVID-19 was strongly associated with the viral load of contacts at baseline and shortened the incubation time of COVID-19 in a dose-dependent manner. FUNDING: YoMeCorono, Generalitat de Catalunya. TRANSLATIONS: For the Catalan translation of the abstract see Supplementary Materials section.

Hydroxychloroquine for Early Treatment of Adults With Mild Coronavirus Disease 2019: A Randomized, Controlled Trial.

BACKGROUND: No effective treatments for coronavirus disease 2019 (COVID-19) exist. We aimed to determine whether early treatment with hydroxychloroquine (HCQ) would be efficacious for outpatients with COVID-19. METHODS: Multicenter open-label, randomized, controlled trial conducted in Catalonia, Spain, between 17 March and 26 May 2020. Patients recently diagnosed with <5-day of symptom onset were assigned to receive HCQ (800 mg on day 1 followed by 400 mg once daily for 6 days) or usual care. Outcomes were reduction of viral load in nasopharyngeal swabs up to 7 days after treatment start, disease progression up to 28 days, and time to complete resolution of symptoms. Adverse events were assessed up to 28 days. RESULTS: A total of 293 patients were eligible for intention-to-treat analysis: 157 in the control arm and 136 in the intervention arm. The mean age was 41.6 years (SD, 12.6), mean viral load at baseline was 7.90 log10 copies/mL (SD, 1.82), and median time from symptom onset to randomization was 3 days. No differences were found in the mean reduction of viral load at day 3 (-1.41 vs -1.41 log10 copies/mL in the control and intervention arm, respectively) or at day 7 (-3.37 vs -3.44). Treatment did not reduce risk of hospitalization (7.1% control vs 5.9% intervention) nor shorten the time to complete resolution of symptoms (12 days, control vs 10 days, intervention). No relevant adverse events were reported. CONCLUSIONS: In patients with mild COVID-19, no benefit was observed with HCQ beyond the usual care.

Yaws, Haemophilus ducreyi, and Other Bacterial Causes of Cutaneous Ulcer Disease in the South Pacific Islands.

Cutaneous ulcers in the tropics are a painful and debilitating condition that anchors people into poverty. In rural regions of the South Pacific, infectious cutaneous ulcers are caused mainly by bacteria, including Treponema pallidum pertenue (yaws), Haemophilus ducreyi, and polymicrobial ulcers. For this group of infections the term cutaneous ulcer disease (CUD) is proposed. Some infections can cause malformations on the bone that have a permanent impact on lives in endemic communities. Better characterization of CUD may help design diagnostic tools and more effective antimicrobial therapies. This review updates the knowledge of CUD and discusses optimized terminology and syndromic management.