An Evaluation of Dried Blood Spots and Oral Swabs as Alternative Specimens for the Diagnosis of Dengue and Screening for Past Dengue Virus Exposure

Abstract

Non-invasive specimens for dengue diagnosis may be preferable where venous blood is difficult to collect and/or process, such as community-based or remote settings or when sampling from young children. We evaluated the performance of oral swabs and dried blood spots (DBS), compared with plasma, in diagnosing acute dengue and screening for past dengue virus (DENV) exposure. DENV-specific immunoglobulin (Ig) M, IgG, and NS1 antigen were detected both in oral swabs and DBS from acute patients. Oral swabs were less sensitive (IgM: 68.7%, IgG: 91.9%, NS1: 64.7%), but retained good specificity (100%, 92.3%, 95.8%, respectively) compared with plasma. DBS displayed high sensitivity (IgM: 100%, IgG: 96%, NS1: 100%) and specificity (IgM: 75%, IgG: 93%). DENV RNA was amplified from DBS (sensitivity 95.6%) but not from oral swabs. DENV-IgG (indicative of past flavivirus exposure) were detected with moderate sensitivity (61.1%) but poor specificity (50%) in oral swabs from healthy volunteers. Dried blood spots allow sensitive and specific diagnosis of acute dengue by serological, molecular, and antigen detection methods. Oral swabs may be an adequate alternative where blood cannot be collected.

High prevalence of clinically unsuspected dengue disease among children in Ribeirao Preto city, Brazil

“…This study showed that non-invasive samples like saliva and urine could be used in surveillance to monitor DENV circulation in children, especially the first one that showed a similar sensitivity to blood samples after the third day of onset. In agreement with our findings, several other studies have also showed that saliva and urine can be used for dengue diagnosis by detecting anti-DENV specific antibody, DENV-NS1 protein, and DENV-RNA [Balmaseda et al, 2003;Chakravarti et al, 2007;Mizuno et al, 2007;V azquez et al, 2007;Chuansumrit et al, 2011;Anders et al, 2012;Hirayama et al, 2012;Korhonen et al, 2014]. The presence of virus in saliva and urine might represent a true viral replication in the salivary gland and kidney, since no correlation with the viral load in blood samples was observed.…”

Isolation of infective Zika virus from urine and saliva of patients in Brazil

“…Although saliva functions as a protective barrier for virus entry, some studies have shown that a disruption in oral mucosa or periodontal disease can facilitate virus entry [44]. Since previous studies detected Flaviviruses as Dengue [45, 46] and Zika [30] virus in saliva, and our study have demonstrated possible infectious ability of Zika viral particles in saliva, a potential person-to-person Zika virus infection through this specimen, using a disrupted oral mucosa or periodontal pockets as virus entry, should be considered and investigated.…”

Burden of Dengue Infection and Disease in a Pediatric Cohort in Urban Sri Lanka

“…A recent report validated the use of dried blood spots for dengue serologic analysis. 27 We performed dengue IgM capture enzyme-linked immunosorbent assay (ELISA) as described, 28 except that monoclonal antibody (MAb) 4G2 against flavivirus, followed by enzyme-conjugated goat anti-mouse IgG to detect captured DENV antigen. In brief, 96-well plates were coated (overnight at 4 C) with 100 μL/well (1 ng/μL) of goat anti-human IgM (Sigma, St. Louis, MO) at a concentration of 0.1 mol/L in carbonate buffer, pH 9.6.…”