title: Bacterial coinfections in dengue virus disease: what we know and what is still obscure about an emerging concern.
abstract: OBJECTIVE
  Dengue virus is the most frequent arthropod-borne viral infection worldwide. Simultaneously to the growth of its incidence, cases of bacterial coinfection in dengue have been increasingly reported. The clinical course of dual infections may worsen for reciprocal interactions and delays in the diagnosis, so that clinicians should be aware of this eventuality. Therefore, we reviewed literature to provide an overview of the epidemiological, clinical, and physiopathological issues related to bacterial coinfections and bacteremia in dengue.
  
  
  METHODS
  Clinical studies and case reports regarding bacteremia and bacterial coinfections in dengue and the interactions between the pathogens published on PubMed were reviewed.
  
  
  RESULTS
  We found 26 case reports, only 3 studies on concurrent bacteremia and 12 studies reporting data on bacterial coinfections in dengue. According to the three available studies, the 0.18-7 % of dengue infections are accompanied by concurrent bacteremia, while the 14.3-44.4 % of dengue-related deaths seem associated to bacterial coinfections. Comorbidities, advanced age, and more severe dengue manifestations could be risk factors for dual infections. A longer duration of fever and alterations in laboratory parameters such as procalcitonin, hyponatremia, leukocyte count, and renal function tests can raise the suspicion.
  
  
  CONCLUSIONS
  Despite the real burden and consequences of this emerging concern is still not computable accurately due to the lack of a significant number of studies on large cohorts, clinicians need a greater awareness about it to early recognize warning signs, to properly use available diagnostic tools and to readily start antibiotic treatment able to prevent worsening in mortality and morbidity.
authors.affiliation: Department of Medical Sciences, Universitary Clinic of Infectious and Tropical Diseases, Amedeo di Savoia Hospital, University of Torino, Corso Svizzera 164, 10149, Torino, Italy. mattia.trunfio@edu.unito.it.
authors.forename: Mattia
authors.identifier: http://orcid.org/0000-0001-8663-719X
authors.initials: M
authors.lastname: Trunfio
authors.affiliation: Department of Health Sciences, Universitary Clinic of Infectious and Tropical Diseases, San Paolo Hospital, University of Milano, Via A. di Rudinì 8, 20142, Milan, Italy.
authors.forename: Alessia
authors.initials: A
authors.lastname: Savoldi
authors.affiliation: Department of Health Sciences, Universitary Clinic of Infectious and Tropical Diseases, San Paolo Hospital, University of Milano, Via A. di Rudinì 8, 20142, Milan, Italy.
authors.forename: Ottavia
authors.initials: O
authors.lastname: Viganò
authors.affiliation: Department of Health Sciences, Universitary Clinic of Infectious and Tropical Diseases, San Paolo Hospital, University of Milano, Via A. di Rudinì 8, 20142, Milan, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: d'Arminio Monforte
mesh_terms: D000293:Adolescent; D000328:Adult; D016470:Bacteremia / Q000150:complications*; D060085:Coinfection / Q000150:complications*; D003715:Dengue / Q000150:complications*; D005260:Female; D006801:Humans; D008297:Male; D055815:Young Adult
keywords: Bacteremia; Bacteria; Coinfection; Dengue; Innate immunity; Pathogenesis