The Distribution of Dengue Virus Serotype in Quang Nam Province (Vietnam) during the Outbreak in 2018.

Duong Q Phan,Francesco Inchingolo,Stefania Cantore,Suong T H Nguyen,Tung T Pham,Sergey K Aityan,Ciro Gargiulo Isacco,Gianna Dipalma,Prisco Piscitelli,Alessio Danilo Inchingolo,Andrea Ballini,Sa H Le,Linh D N Nguyen,Scacco Salvatore,Alessandro Miani,Dien T Pham,Thuy Thi Cam Nguyen ,Kieu Cao Diem Nguyen ,Phuong Thu Pham ,Huong Pham ,Duy K Trãn ,Son Bao Pham ,Van Hung Pham

doi:10.3390/ijerph19031285

Abstract

Objectives: Quang Nam province in the Centre of Vietnam has faced an outbreak of dengue hemorrhagic fever (DHF) in 2018. Although DHF is a recurrent disease in this area, no epidemiological and microbiological reports on dengue virus serotypes have been conducted mainly due to lack of facilities for such a kind of advanced surveillance. The aim of this study was to detect different dengue virus serotypes in patients’ blood samples. Design and Methods: Suspected cases living in Quang Nam province (Vietnam) and presenting clinical and hematological signs of dengue hemorrhagic fever were included in the study. The screening was performed, and the results were compared by using two methodologies: RT real-time PCR (RT-rPCR) and the Dengue NS1 rapid test. Results: From December 2018 to February 2019, looking both at RT-rPCR [+] and NS1 [+] methodologies, a total of 488 patients were screened and 336 were positive for dengue virus detection (74 children and 262 adults); 273 of these patients (81.3%) underwent viral serotype identification as follows: 12.82% (35/273) D1 serotype, 17.95% (49/273) D2, 0.37% (1/273) D3, 68.50 (187/283) D4, and 0.37% (1/273) D2+D4 serotypes. The RT-rPCR outcomes showed higher sensitivity during the first three days of infection compared to NS1 (92.3% vs. 89.7%). The NS1 increased sensitivity after the first 3 days whilst the RT-rPCR decreased. Conclusions: Advanced surveillance with dengue virus serotypes identification, if performed routinely, may help to predict and prevent further DHF epidemics based on the exposure of the different serotypes during different periods that lead to the intensification of disease severity as a consequence of antibody-dependent enhancement (ADE).

Highlights

Dengue virus (DENV) is the main cause of dengue hemorrhagic fever (DHF), and it is transmitted by the Aedes aegypti (A. aegypti) mosquito, a typical breed of tropical and subtropical areas
The results of both the reverse transcriptase (RT) real-time PCR (RT-rPCR) and the NS1 tests on 488 participants are resumed in
The sensitivity in the first 3 days of the RT-rPCR assay and NS1 test in the diagnosis of DHF described in this study

Summary

Introduction

Dengue virus (DENV) is the main cause of dengue hemorrhagic fever (DHF), and it is transmitted by the Aedes aegypti (A. aegypti) mosquito, a typical breed of tropical and subtropical areas. DHF is classified as (i) silent DHF without warning signs,. (ii) DHF with warning signs (mucosal bleeding, lethargy, persistent vomiting, fluid accumulation, increasing hematocrit, and decreasing platelets, etc.), and (iii) severe DHF, which is characterized by severe plasma leakage, severe hemorrhagic events, and organ failure. In 2009, the number of infections dramatically increased with the DHF outbreaks in many countries in tropical and subtropical regions, including North and South America, Southern Europe, and especially in Southeast Asian. Countries such as Vietnam [3,5].

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