Viremia and Clinical Presentation in Nicaraguan Patients Infected With Zika Virus, Chikungunya Virus, and Dengue Virus

Abstract

Background: Zika virus (ZIKV), chikungunya virus (CHIKV), and dengue virus (DENV) cocirculate in Nicaragua. In this study, we sought to compare the quantified viremia and clinical presentation of patients infected with 1 or more of these viruses.

Methods: Acute-phase serum samples from 346 patients with a suspected arboviral illness were tested using a multiplex real-time reverse-transcription polymerase chain reaction for ZIKV, CHIKV, and DENV. Viremia was quantitated for each detected virus, and clinical information from request forms submitted with each sample was recorded.

Results: A total of 263 patients tested positive for 1 or more viruses: 192 patients tested positive for a single virus (monoinfections) and 71 patients tested positive for 2 or all 3 viruses (coinfections). Quantifiable viremia was lower in ZIKV infections compared with CHIKV or DENV (mean 4.70 vs 6.42 and 5.84 log₁₀ copies/mL serum, respectively; P < .001 for both comparisons), and for each virus, mean viremia was significantly lower in coinfections than in monoinfections. Compared with patients with CHIKV or DENV, ZIKV patients were more likely to have a rash (P < .001) and less likely to be febrile (P < .05) or require hospitalization (P < .001). Among all patients, hospitalized cases had higher viremia than those who did not require hospitalization (7.1 vs 4.1 log10 copies/mL serum, respectively; P < .001).

Conclusions: ZIKV, CHIKV, and DENV result in similar clinical presentations, and coinfections may be relatively common. Our findings illustrate the need for accurate, multiplex diagnostics for patient care and epidemiologic surveillance.

Keywords: Zika virus; chikungunya virus; coinfection; dengue virus; viremia.

Figure 1.

Levels of viremia in Zika virus (ZIKV), chikungunya virus (CHIKV), and dengue virus (DENV) monoinfections and coinfections. Monoinfections are represented by filled circles (•): ZIKV, red; CHIKV, blue; and DENV, purple. Coinfections are represented by the following: ZIKV-CHIKV (♦), ZIKV-DENV (▾), CHIKV-DENV (▴), and ZIKV-CHIKV-DENV (▪). Viremia for each virus detected in a coinfection is displayed. The limit of quantitation for the multiplex real-time reverse-transcription polymerase chain reaction for the detection and differentiation of ZIKV, CHIKV, and DENV assay is displayed as a dashed gray line (3.6 log₁₀ copies/mL serum). Samples with viral RNA that was detectable but below the limit of quantitation (low positives) are shown below this line; marker positions for these samples do not represent estimated viremia.