Zika Virus Immunoglobulin G Seroprevalence among Young Adults Living with HIV or without HIV in Thailand from 1997 to 2017

Zika virus (ZIKV) epidemiological data in Thailand are limited. We assessed ZIKV IgG seroprevalence among young adults during 1997–2017 and determined factors associated with ZIKV IgG seropositivity. This retrospective laboratory study included randomly selected subjects aged 18–25 years participating in large clinical studies conducted in Thailand during 1997–2017. Stored plasma samples were analyzed for ZIKV IgG using an ELISA test (Anti-Zika Virus IgG, EUROIMMUN, Lübeck, Germany). Sociodemographic, clinical and laboratory data were used in univariable and multivariable analyses to identify factors associated with ZIKV IgG positivity. Of the 1648 subjects included, 1259 were pregnant women, 844 were living with HIV and 111 were living with HBV. ZIKV IgG seroprevalence was similar among the HIV-infected and -uninfected pregnant women (22.8% vs. 25.8%, p-value = 0.335) and was overall stable among the pregnant women, with a 25.2% prevalence. Factors independently associated with ZIKV IgG positivity included an age of 23–25 years as compared to 18–20 years, an HIV RNA load below 3.88 log10 copies/mL and birth in regions outside northern Thailand. Our study shows that a large proportion of the population in Thailand probably remains susceptible to ZIKV infection, which could be the ground for future outbreaks. Continued surveillance of ZIKV spread in Thailand is needed to inform public health policies

Characteristics of pregnant women and ARTs for perinatal HIV prevention according to study.

<p>^a sdNVP either in the woman at onset of labor, in the infant or in both</p><p>^b only in women who did not receive LPV/r</p><p>Characteristics of pregnant women and ARTs for perinatal HIV prevention according to study.</p

Transmission probabilities according to zidovudine duration, viral load at baseline/delivery, and nevirapine intake.

<p>A. Probability of <i>in-utero</i> HIV transmission as a function of zidovudine duration; B. Probability of <i>in-utero</i> HIV transmission as a function of viral load at baseline. The lines denote the median, 5^th and 95^thpercentiles of the model predictions. The open circles stand for the observed mean proportion of transmission, the solid vertical segments denote the corresponding 95% confidence intervals (numbers at top of each segment stand for the number of women in each time interval or VL interval). C. Probability of <i>intra-partum</i> HIV mother-to-child transmission as a function of viral load at delivery without single dose nevirapine; D. Probability of <i>intra-partum</i> HIV mother-to-child transmission as a function of viral load at delivery with single dose nevirapine.</p

Diagnostic plots for viral load time-course model.

<p>Top: 2a and 2b: Observed versus model predicted viral load values (expressed as log₁₀ copies) of the population and individual predictions respectively. Solid black circles, measure values; grey symbols, simulation of below the limit of quantification data. Line, identity line. Bottom: Visual predictive check plots. (2c) Women receiving only zidovudine (ZDV); (2d) women receiving zidovudine plus lopinavir/ritonavir (ZDV+LPV/r).The lines denote the median, 5^th and 95^th percentiles for the observed data. The grey areas stand for the 95% confidence intervals of the median, 5^th and 95^th model prediction percentiles.</p

The univariate and multivariable analyses of the HIV <i>in-utero</i> model using data from 3,707 HIV-1-infected mothers enrolled in the PHPT-1, PHPT-2, and PHPT-5 studies.

<p>^a RSE%, relative standard error (standard error of estimate / estimate*100)</p><p>^b Bayesian Information Criterion</p><p>^c Random effect of individuals: <i>η</i>~<i>N</i>(0,0.527²)</p><p>The univariate and multivariable analyses of the HIV <i>in-utero</i> model using data from 3,707 HIV-1-infected mothers enrolled in the PHPT-1, PHPT-2, and PHPT-5 studies.</p

The univariate and multivariable analyses of the HIV intra-partum transmission model using data from 3,707 HIV-1-infected mothers enrolled in the PHPT-1, PHPT-2, and PHPT-5 studies.

<p>^aRSE%, relative standard error (standard error of estimate / estimate*100)</p><p>^b Bayesian Information Criterion</p><p>^c Random effect of individuals: <i>η</i>~<i>N</i>(0,0.73²)</p><p>The univariate and multivariable analyses of the HIV intra-partum transmission model using data from 3,707 HIV-1-infected mothers enrolled in the PHPT-1, PHPT-2, and PHPT-5 studies.</p

Population parameter estimates of HIV time-course model for 3,759 HIV-1-infected mothers enrolled in the PHPT-1, PHPT-2, and PHPT-5 studies.

<p>^a SE, standard error of estimate</p><p>^b RSE%, relative standard error (standard error of estimate / estimate*100)</p><p>^c<i>σ</i>_<i>VL</i>, residual (square roots of variances)</p><p>Population parameter estimates of HIV time-course model for 3,759 HIV-1-infected mothers enrolled in the PHPT-1, PHPT-2, and PHPT-5 studies.</p