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.

Clinical and Laboratory Characteristics of Dengue-Orienti Tsutsugamushi Co-Infection From a Tertiary Care Center in South India

“… 13 In our study patients with co-infection had hypoalbuminemia, but none of them fulfilled the criteria for severe scrub typhus. Similar to findings of the present study, elevated transaminases (AST > ALT), bilirubin and alkaline phosphatase were also noted in the study by Ahmed et al and a case of dengue – scrub co-infection reported by Iqbal et al 4 , 5 …”

“…Duration of fever, mean age of presentation and male to female ratio in our study were similar to the study by Ahmed et al 4 Abdominal pain was a common clinical manifestation in the above study, whereas headache was the common clinical feature apart from fever in our study. Patients with co-infection had symptoms indistinguishable from isolated dengue fever.…”

“… 3 However, only one study from North India and a case report from this institute has been reported, on dengue-scrub typhus co-infection to the best of our knowledge. 4 , 5 Clinical and laboratory features of both the diseases have been extensively studied and described separately. We describe the clinical and laboratory features of patients diagnosed with this rare combination of infections and compare with those of patients with isolated dengue fever and isolated scrub typhus.…”

Concurrent Coinfections in Tropics: A Hospital-Based Observational Study from Himachal Pradesh, India

“…Malaria, dengue, and chikungunya are the most common coinfections reported from India [17]. Scrub typhus, malaria, dengue fever, and leptospirosis coinfections have been reported from Himachal Pradesh, Uttarakhand, central India, Puducherry, and also from other parts of India [2,[18][19][20][21][22]. The prevalence of coinfections among patients with AUF was 1.39% in this study.…”

“…Little is known about the clinical significance of coinfections as compared to monoinfections. Conflicting reports about the severity of illness have been observed in different studies [18,25,26]. We could not draw any conclusion on the clinical significance of concurrent coinfections in our study, as monoinfections were not studied as controls.…”