Causes of fever in returning travelers: a European multicenter prospective cohort study.

BACKGROUND: Etiological diagnosis of febrile illnesses in returning travelers is a great challenge, particularly when presenting with no focal symptoms [acute undifferentiated febrile illnesses (AUFI)], but is crucial to guide clinical decisions and public health policies. In this study, we describe the frequencies and predictors of the main causes of fever in travelers. METHODS: Prospective European multicenter cohort study of febrile international travelers (November 2017-November 2019). A predefined diagnostic algorithm was used ensuring a systematic evaluation of all participants. After ruling out malaria, PCRs and serologies for dengue, chikungunya and Zika viruses were performed in all patients presenting with AUFI ≤ 14 days after return. Clinical suspicion guided further microbiological investigations. RESULTS: Among 765 enrolled participants, 310/765 (40.5%) had a clear source of infection (mainly traveler's diarrhea or respiratory infections), and 455/765 (59.5%) were categorized as AUFI. AUFI presented longer duration of fever (p < 0.001), higher hospitalization (p < 0.001) and ICU admission rates (p < 0.001). Among travelers with AUFI, 132/455 (29.0%) had viral infections, including 108 arboviruses, 96/455 (21.1%) malaria and 82/455 (18.0%) bacterial infections. The majority of arboviral cases (80/108, 74.1%) was diagnosed between May and November. Dengue was the most frequent arbovirosis (92/108, 85.2%). After 1 month of follow-up, 136/455 (29.9%) patients with AUFI remained undiagnosed using standard diagnostic methods. No relevant differences in laboratory presentation were observed between undiagnosed and bacterial AUFI. CONCLUSIONS: Over 40% of returning travelers with AUFI were diagnosed with malaria or dengue, infections that can be easily diagnosed by rapid diagnostic tests. Arboviruses were the most common cause of AUFI (above malaria) and most cases were diagnosed during Aedes spp. high season. This is particularly relevant for those areas at risk of introduction of these pathogens. Empirical antibiotic regimens including doxycycline or azithromycin should be considered in patients with AUFI, after ruling out malaria and arboviruses.

Pre-exposure prophylaxis with hydroxychloroquine for COVID-19: a double-blind, placebo-controlled randomized clinical trial.

BACKGROUND: Pre-exposure prophylaxis (PrEP) is a promising strategy to break COVID-19 transmission. Although hydroxychloroquine was evaluated for treatment and post-exposure prophylaxis, it is not evaluated for COVID-19 PrEP yet. The aim of this study was to evaluate the efficacy and safety of PrEP with hydroxychloroquine against placebo in healthcare workers at high risk of SARS-CoV-2 infection during an epidemic period. METHODS: We conducted a double-blind placebo-controlled randomized clinical trial in three hospitals in Barcelona, Spain. From 350 adult healthcare workers screened, we included 269 participants with no active or past SARS-CoV-2 infection (determined by a negative nasopharyngeal SARS-CoV-2 PCR and a negative serology against SARS-CoV-2). Participants allocated in the intervention arm (PrEP) received 400 mg of hydroxychloroquine daily for the first four consecutive days and subsequently, 400 mg weekly during the study period. Participants in the control group followed the same treatment schedule with placebo tablets. RESULTS: 52.8% (142/269) of participants were in the hydroxychloroquine arm and 47.2% (127/269) in the placebo arm. Given the national epidemic incidence decay, only one participant in each group was diagnosed with COVID-19. The trial was stopped due to futility and our study design was deemed underpowered to evaluate any benefit regarding PrEP efficacy. Both groups showed a similar proportion of participants experiencing at least one adverse event (AE) (p=0.548). No serious AEs were reported. Almost all AEs (96.4%, 106/110) were mild. Only mild gastrointestinal symptoms were significantly higher in the hydroxychloroquine arm compared to the placebo arm (27.4% (39/142) vs 15.7% (20/127), p=0.041). CONCLUSIONS: Although the efficacy of PrEP with hydroxychloroquine for preventing COVID-19 could not be evaluated, our study showed that PrEP with hydroxychloroquine at low doses is safe. TRIAL REGISTRATION: ClinicalTrials.gov NCT04331834 . Registered on April 2, 2020.

Incidence of human granulocytic anaplasmosis in returning travellers with fever.

BACKGROUND: Although tick-borne pathogens have been reported as an important cause of imported fever, the incidence of Anaplasma phagocytophilum, the causative agent of human granulocytic anaplasmosis (HGA), in travellers is unknown. METHODS: We conducted a prospective cohort study to investigate the aetiologies of fever in returning travellers (November 2017-July 2019). Polymerase chain reaction for msp2 gene amplification and indirect immunofluorescence assay for A. phagocitophilum were performed in all returning travellers with undifferentiated non-malarial fever. RESULTS: Among 141 travellers included, 8 patients were diagnosed with probable or confirmed HGA. The overall incidence rate of HGA was 19.9 cases/1000 person-week of travel. The main destination of travel was Asia, accounting for 62.5% patients with HGA. Co-infections were found in 37.5% of patients with HGA. CONCLUSIONS: Diagnosis of HGA and empirical treatment with doxycycline should be considered in travellers with fever.

Pre-exposure prophylaxis with hydroxychloroquine for high-risk healthcare workers during the COVID-19 pandemic: A structured summary of a study protocol for a multicentre, double-blind randomized controlled trial.

OBJECTIVES: The aim of this study is to assess the efficacy of the use of pre-exposure prophylaxis (PrEP) with hydroxychloroquine against placebo in healthcare workers with high risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in reducing their risk of coronavirus disease 2019 (COVID-19) disease during an epidemic period. As secondary objectives, we would like to: i) assess the efficacy of the use of PrEP with hydroxychloroquine against placebo in healthcare workers with high risk of SARS-CoV-2 infection in reducing their risk of exposure to SARS-CoV-2 (defined by seroconversion) during an epidemic period, ii) evaluate the safety of PrEP with hydroxychloroquine in adults, iii) describe the incidence of SARS-CoV-2 infection among healthcare workers at high risk of SARS-CoV-2 infection, iv) identify clinical, analytical and microbiological predictors of COVID-19 among healthcare workers at high risk of SARS-CoV-2 infection, v) set up a repository of serum samples obtained from healthcare workers at high risk of SARS-CoV-2 infection for future research on blood markers to predict SARS-CoV-2 infection. TRIAL DESIGN: Multicentre double-blind parallel design (ratio 1:1) randomized controlled clinical trial. PARTICIPANTS: Approximately 440 healthcare workers of four Spanish hospitals (Hospital Clínic of Barcelona, Hospital de la Santa Creu i Sant Pau of Barcelona, Hospital Plató of Barcelona, Hospital General de Granollers, Barcelona) will be recruited. Participants are considered to be at high-risk of SARS-CoV-2 infection due to their frequent contact with suspected and confirmed cases of COVID-19. For eligibility, healthcare workers with 18 years old or older working at least 3 days a week in a hospital with both negative SARS-CoV-2 polymerase chain reaction (PCR) assays and serological COVID-19 rapid diagnostic tests (RDT) are invited to participate. Participants with any of the following conditions are excluded: pregnancy, breastfeeding, ongoing antiviral, antiretroviral or corticosteroids treatment, chloroquine or hydroxychloroquine uptake the last month or any contraindication to hydroxychloroquine treatment. INTERVENTION AND COMPARATOR: Eligible participants will be allocated to one of the two study groups: Intervention group (PrEP): participants will receive the standard of care and will take 400mg of hydroxychloroquine (2 tablets of 200 mg per Dolquine® tablet) daily the first four consecutive days, followed by 400 mg weekly for a period of 6 months. CONTROL GROUP: participants will receive placebo tablets with identical physical appearance to hydroxychloroquine 200 mg (Dolquine®) tablets following the same treatment schedule of the intervention group. Both groups will be encouraged to use the personal protection equipment (PPE) for COVID-19 prevention according to current hospital guidelines. MAIN OUTCOMES: The primary endpoint will be the number of confirmed cases of a COVID-19 (defined by a positive PCR for SARS-CoV-2 or symptoms compatible with COVID-19 with seroconversion) in the PrEP group compared to the placebo group at any time during the 6 months of the follow-up in healthcare workers with negative SARS-CoV-2 PCR and serology at day 0. As secondary endpoints, we will obtain: i) the SARS-CoV-2 seroconversion in the PrEP group compared to placebo during the 6 months of follow-up in healthcare workers with negative serology at day 0; ii) the occurrence of any adverse event related with hydroxychloroquine treatment; iii) the incidence of SARS-CoV-2 infection and COVID-19 among healthcare workers in the non-PrEP group, among the total of healthcare workers included in the non-PrEP group during the study period; iv) the risk ratio for the different clinical, analytical and microbiological conditions to develop COVID-19; v) a repository of serum samples obtained from healthcare workers confirmed COVID-19 cases for future research on blood markers to predict SARS-CoV-2 infection. RANDOMISATION: Participants meeting all eligibility requirements will be allocated to one of the two study arms (PrEP with hydroxychloroquine or non-PrEP control group) in a 1:1 ratio using simple randomisation with computer generated random numbers. BLINDING (MASKING): Participants, doctors and nurses caring for participants, and investigators assessing the outcomes will be blinded to group assignment. NUMBERS TO BE RANDOMISED (SAMPLE SIZE): Each intervention group will have 220 participants, giving a total of 440 participants. TRIAL STATUS: The current protocol version is 1.5, 2nd of June 2020. Two hundred and seventy-fiveparticipants were recruited and completed first month follow-up until date. The estimated sample size could not be reached yet due to the declining national epidemic curve. Thus, 275 is the total number of participants included until date. The study has been suspended (26th of June) until new epidemic curve occurs. TRIAL REGISTRATION: This trial was registered on April 2nd 2020 at clinicaltrials.gov with the number NCT04331834. FULL PROTOCOL: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.