Serological Markers of Viral Infections (Rubella Virus, Human Cytomegalovirus and Arboviruses) among Symptomatic Pregnant Women in Rural and Urban Areas of Mwanza, Tanzania.

Najma Awadh,Margareth Ollomi,Majigo Mtebe,Karim Hassan,Fridolin Mujuni,Helmut Nyawale,Lucas Matemba,Stephen E Mshana,Elieza Chibwe,Mariam M Mirambo

doi:10.3390/tropicalmed6040186

Abstract

Viral infections have been associated with poor pregnancy outcomes. We investigated the magnitude of rubella virus (RV), dengue virus (DENV), Zika virus (ZIKV) and human cytomegalovirus (HCMV) among symptomatic pregnant women in rural and urban areas of Mwanza. A cross-sectional study was conducted between July 2017 and April 2018 in Mwanza. A rapid immunochromatographic test was done to detect ZIKV IgM and IgG as well as DENV IgM and IgG antibodies. A multiplex_RT-PCR was also done to detect the viral RNA genome. Enzyme immunoassays were done to detect RV and HCMV. Out of 171 participants, 1 (0.6%) was found to be seropositive for ZIKV_IgM antibodies, while 5 (2.9%) were ZIKV_IgG seropositive. DENV seropositivity was 9 (5.3%) and 3 (1.8%) for IgM and IgG, respectively, with all being PCR negative. Two participants (1.2%) were RV_IgM seropositive. 100% were HCMV_IgG seropositive and none was HCMV_IgM seropositive. Among 70 women with high HCMV_IgG titters, 10 (14.3%) had a low avidity index, indicating recent infections. Residing in rural areas (p = 0.044) and advanced age (p = 0.024) independently predicted ZIKV/DENV seropositivity. A substantial proportion of pregnant women had markers for viral infections. There is a need for introducing routine screening and monitoring pregnancy outcomes of positive cases to establish the relationship of these viruses and adverse pregnancy outcomes in endemic areas.

Highlights

Seropositivity of specific Zika virus (ZIKV) IgG and IgM antibodies were found to be 2.92% and 0.6%, respectively, while none of them was positive for ZIKV and dengue virus (DENV) by PCR
This observation is comparable to the study done in Brazil that showed ZIKV IgG seropositivity of 0.55% among blood donors with negative PCR results [34]
The seropositivity of ZIKV IgG in the current study was slightly higher than that of Brazil among blood donors; the possible explanation could be differences in the study population, whereby the current study focused on pregnant women with signs and symptoms consistent with ZIKV infection

Summary

Introduction

Overwhelming evidence suggests that perinatal viral infections are common in resource-constrained countries and significantly contribute to the adverse pregnancy outcomes [4,5,6,7,8]. Rubella virus (RV), human cytomegalovirus (HCMV), dengue virus (DENV) and Zika virus (ZIKV) are endemic in the tropical regions and have been fairly studied in different populations in the study setting, with IgG seroprevalence of RV and HCMV of more than 90% being reported among general pregnant women [9,10,11,12,13,14]. In a study involving 8 districts, the seroprevalence of CHIKV, DENV and ZIKV were 28%, 16.1% and 6.8%, respectively. Despite being endemic in these countries little has been documented regarding the magnitude and outcomes associated with these infections during pregnancy

Methods

Results

Conclusion