title: A comparative hospital-based observational study of mono- and co-infections of malaria, dengue virus and scrub typhus causing acute undifferentiated fever.
abstract: Positive serology for dengue and/or scrub typhus infection with/without positive malarial smear (designated as mixed or co-infection) is being increasingly observed during epidemics of acute undifferentiated febrile illnesses (AUFIs). We planned to study the clinical and biochemical spectrum of co-infections with Plasmodium sp., dengue virus and scrub typhus and compare these with mono-infection by the same organisms. During the period from December 2012 to December 2013, all cases presenting with AUFIs to a single medical unit of a referral centre in Garhwal region of the north Indian state of Uttarakhand were retrospectively selected and categorised aetiologically as co-infections, malaria, dengue or scrub typhus. The groups thus created were compared in terms of demographic, clinical, biochemical and outcome parameters. The co-infection group (n = 49) was associated with milder clinical manifestations, fewer, milder and non-progressive organ dysfunction, and lesser need for intensive care, mechanical ventilation and dialysis as compared to mono-infections. When co-infections were sub-grouped and compared with the relevant mono-infections, there were differences in certain haematological and biochemical parameters; however, this difference did not translate into differential outcomes. Scrub typhus mono-infection was associated with severe disease in terms of both morbidity and mortality. Malaria, dengue and scrub typhus should be routinely tested in all patients with AUFIs. Co-infections, whether true or due to serological cross-reactivity, appear to be a separate entity so far as presentation and morbidity is concerned. Further insight is needed into the mechanism and identification of the protective infection.
authors: Department of Medicine, Himalayan Institute of Medical Sciences, SRH University, Swami Ram Nagar, Jolly Grant, Dehradun, Uttarakhand, 248106, India. sohadia@hotmail.com.
authors: S
authors: S
authors: Ahmad
authors: Department of Medicine, Himalayan Institute of Medical Sciences, SRH University, Swami Ram Nagar, Jolly Grant, Dehradun, Uttarakhand, 248106, India.
authors: M
authors: M
authors: Dhar
authors: Department of Microbiology, Himalayan Institute of Medical Sciences, Dehradun, India.
authors: G
authors: G
authors: Mittal
authors: Department of Pediatrics, Himalayan Institute of Medical Sciences, Dehradun, India.
authors: N K
authors: NK
authors: Bhat
authors: Department of Pathology, Himalayan Institute of Medical Sciences, Dehradun, India.
authors: N
authors: N
authors: Shirazi
authors: Department of Medicine, Himalayan Institute of Medical Sciences, SRH University, Swami Ram Nagar, Jolly Grant, Dehradun, Uttarakhand, 248106, India.
authors: V
authors: V
authors: Kalra
authors: Department of Community Medicine, Himalayan Institute of Medical Sciences, Dehradun, India.
authors: H C
authors: HC
authors: Sati
authors: Department of Pathology, Himalayan Institute of Medical Sciences, Dehradun, India.
authors: V
authors: V
authors: Gupta
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D060085:Coinfection / Q000453:epidemiology*; D003715:Dengue / Q000150:complications / Q000453:epidemiology* / Q000473:pathology; D005260:Female; D005335:Fever of Unknown Origin / Q000453:epidemiology* / Q000209:etiology; D006761:Hospitals; D006801:Humans; D007194:India / Q000453:epidemiology; D008288:Malaria / Q000150:complications / Q000453:epidemiology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012612:Scrub Typhus / Q000150:complications / Q000453:epidemiology* / Q000473:pathology; D055815:Young Adult