Clinical Features and Laboratory Findings of Travelers Returning to South Australia with Dengue Virus Infection

Abstract

Reported cases of dengue are rising in South Australia (SA) in travellers returning from dengue-endemic regions. We have undertaken a retrospective analysis to identify the clinical and laboratory characteristics of patients returning to SA with suspected dengue virus (DENV) infection. From 488 requests, 49 (10%) were defined by serology as acute dengue, with the majority of patients (75%) testing as non-structural protein 1 (NS1) and/or IgM positive. Dengue was most commonly acquired in Indonesia (42.9%) with clinical features of fever (95%), headache (41%) and myalgia/arthralgia (56%). The presence of rash (36%) and laboratory findings of neutropenia, leukopenia, thrombocytopenia, but not elevated C-reactive protein, were distinct from findings in DENV-seronegative patients. Available dengue seropositive samples were analysed by RT-PCR, with 14/32 (43.8%) positive by a serotype non-specific DENV assay, but 28/32 positive (87.5%) when also assessed by serotype-specific RT-PCR. Serotype analysis revealed the predominance of DENV-1 and DENV-2 and the presence of DENV-3, but not DENV-4 or Zika virus (ZIKV). Thus, dengue in returned travellers in SA presents in a manner consistent with World Health Organization (WHO) definitions, with symptoms, travel history and laboratory results useful in prioritising the likelihood of dengue. This definition will assist the future management in DENV-non-endemic regions, such as SA.

Changes in complement alternative pathway components, factor B and factor H during dengue virus infection in the AG129 mouse

“…benign headache, afebrile, C-reactive protein [CRP]<8 mg l −1 with normal full blood examination results), (, DENV negative, healthy); (ii) DENV-seronegative who demonstrated a clinically relevant infectious diagnosis (e.g. Salmonella enterica infection), or laboratory result such as elevated white-cell count or CRP, (, DENV negative, ill); and (iii) DENV-seropositive and clinically diagnosed with dengue fever, representing a cohort of adults with primary dengue infection and a febrile illness, as described previously (, DENV positive, dengue) [36]. FB was significantly elevated in the DENV seronegative, ill group, relative to the DENV-seronegative, healthy controls or the DENV-seropositive group, ().…”

“…The DENV-seropositive group was stratified further based on DENV NS1/IgM/IgG serology and the presence of circulating viral RNA: 22/29 samples were DENV RT-PCR positive with the exceptions as indicated () and the majority of infections presented as RT-PCR, NS1 and/or IgM positive and thus in the early stages of infection. Most infections were DENV-1 and -2 with one DENV-3 case [36]. Although numbers in some groups were small, no significant difference or trend was observed in FB or FH levels in any DENV-seropositive group ().…”

“…5b) and the majority of infections presented as RT-PCR, NS1 and/or IgM positive and thus in the early stages of infection. Most infections were DENV-1 and -2 with one DENV-3 case [36]. Although numbers in some groups were small, no significant difference or trend was observed in FB or FH levels in any DENV-seropositive group (Fig.…”

“…These samples were collected over a 13 month period between 1 January 2014 and 31 January 2015 and sera was obtained from archival material stored at −20 °C. Serological analysis of DENV IgM/IgG/NS1 was performed by Dengue Duo assay (SD BIOLINE) and reverse transcription (RT)-PCR and serotype identified by PCR, as described [36]. The current study includes 10 DENV-seronegative and 29 DENV-seropositive patients from the total cohort encompassing DENV-1, -2 and -3 serotypes [36].…”

“…Human serum samples from DENV-seropositive and seronegative healthy patients form part of a retrospective descriptive study [36]. These samples were collected over a 13 month period between 1 January 2014 and 31 January 2015 and sera was obtained from archival material stored at −20 °C.…”