Predominant secondary dengue infection among Vietnamese adults mostly without warning signs and severe disease

Abstract

Background: The morbidity in dengue fever is dependent on the dengue virus (DENV) serotypes, the patient age, predisposing immunogenic markers and the frequency of primary and secondary infections. This study aims to distinguish acute primary from secondary dengue infections of Vietnamese adults and to assess the association of viremia and anti-dengue immunoglobulin levels with clinical outcomes. Study design: Viral RNA, dengue serotypes and levels of anti-dengue IgM and IgG of hospitalized adult cases were determined in EDTA-plasma samples prospectively collected during three consecutive years of dengue infection in Hanoi. Patients admitted to hospital within 7 days of their 1st reported fever were included. Primary infections were anti-dengue IgG enzyme-linked immunosorbent assay (ELISA) negative on both day of hospital entry (day 0) and day two or three of hospitalization (day 2 or 3) with a positive anti-dengue IgM on either day 0 or day 2 or 3 hospitalization. The secondary infections were anti-dengue IgG ELISA positive on both day 0 and day 2 or 3 with positive anti-dengue IgM ELISA on either day 0 or day 2 or 3. Results: The hospitalized dengue fever cases between October 2016 and March 2019 were predominantly secondary infections (74%, 68% and 77%, respectively) with DENV-1 (60% and 65%) and DENV-2 (22% and 26%) serotypes determined in the latter two years. The viremia in primary infection was significantly higher than that in secondary infection (P < 0.01) and positively correlated with the days of hospital stay. In secondary infections, platelet counts were lower than in primary infections (P = 0.04) and IgG levels in secondary infection negatively correlated with platelet counts (Spearman's r = À0.22, P < 0.01). Conclusions: Our results indicate high rates of secondary infection with DENV1 and DENV2 serotypes. Anti-dengue immunoglobulins negatively correlate with hospital stay and platelet counts with few warning signs or severe disease. Further investigations of specific antibodies in adults which predict auto-inflammatory activity after the recovery from dengue infection are warranted.

Molecular Characterization of Dengue Virus Strains from the 2019–2020 Epidemic in Hanoi, Vietnam

“…A cohort study of hospitalized adult patients in northern Vietnam during 2016–2019 reported that dengue with warning signs in primary infection were found in 33% of patients in the 2017–2018 season and in 17% in the 2018–2019 season. Dengue with warning signs was found more often in secondary infection, at 40% in the 2017–2018 season and at 21% in the 2018–2019 season, while there were few cases of severe dengue [ 21 ]. DENV-1 was reported as the primary serotype responsible for the 2017 epidemic [ 7 , 22 ], whereas DENV-2 was the predominant serotype in the 2019–2020 season.…”

Anti‐Dengue Screening on Several Vietnamese Medicinal Plants: Experimental Evidences and Computational Analyses

“…1 H, 13 C, DEPT, HSQC, HMBC, COSY, NOESY), which were reported in-detail in our preceding publication [25] The composition includes ursolic acid (1), esculentic acid (2), 2-O-trans-p-coumaroylalphitolic acid (3), a mixture of (6S,7Z,9S)-6,9-dihydroxy-7-megastigmen-3-one ( 4) and (À )-boscialin ( 5), astragalin (6), tiliroside ( 7), 2phyten-1-ol ( 8), 4-[3'-(hydroxymethyl)oxiran-2'-yl]-2,6dimethoxyphenol (9) (Figure 4). The chemical constituents are triterpenoids, flavonoids, phenol, and megastimanes, which are known highly active against dengue virus.…”

“…In Vietnam, dengue fever is an annual disease with the serious outbreaks during the rainy season (between August and December), emerged with the presence of all four serotypes DENV‐1, ‐2, ‐3, and ‐4. A study in epidemiology on the hospitalised dengue fever cases in Vietnam between October 2016 and March 2019 indicated that the secondary infection with DENV‐1 and DENV‐2 serotypes are predominant (DENV‐1: 60–65 %; DENV‐2: 22–26 %) [6] . Also, the dengue infections in both areas, the South and the North of Vietnam, register some different characteristics.…”

“…A study in epidemiology on the hospitalised dengue fever cases in Vietnam between October 2016 and March 2019 indicated that the secondary infection with DENV-1 and DENV-2 serotypes are predominant (DENV-1: 60 -65 %; DENV-2: 22 -26 %). [6] Also, the dengue infections in both areas, the South and the North of Vietnam, register some different characteristics. Ngwe Tun et al reported a variety of clinical, virological, and cytokine profiles from children infected with dengue virus in South Vietnam in 2017.…”

Cloning and Expression of a Recombinant NS1 Antigen from a Dengue 3 Serotype Viral Isolate in Escherichia Coli

“…This protein is present in the serum of patients in the early stage of infection [9]. Therefore, NS1 protein has been used as a diagnostic marker of dengue virus infection [10,11]. The NS1 protein has been included in immunological tests such as enzymelinked immunosorbent assay (ELISA) and lateral flow immunoassay test strip (LFA).…”