Chikungunya virus antepartum transmission and abnormal infant outcomes in a cohort of pregnant women in Nigeria.

OBJECTIVES: Chikungunya virus (CHIKV), a reemerging global public health concern, which causes acute febrile illness, rash, and arthralgia and may affect both mothers and infants during pregnancy. Mother-to-child transmission (MTCT) of CHIKV in Africa remains understudied. METHODS: Our cohort study screened 1006 pregnant women with a Zika/dengue/CHIKV rapid test at two clinics in Nigeria between 2019 and 2022. Women who tested positive for the rapid test were followed through their pregnancy and their infants were observed for 6 months, with a subset tested by reverse transcription-polymerase chain reaction (RT-PCR) and neutralization, to investigate seropositivity rates and MTCT of CHIKV. RESULTS: Of the 1006, 119 tested positive for CHIKV immunoglobulin (Ig)M, of which 36 underwent detailed laboratory tests. While none of the IgM reactive samples were RT-PCR positive, 14 symptomatic pregnant women were confirmed by CHIKV neutralization test. Twelve babies were followed with eight normal and four abnormal outcomes, including stillbirth, cleft lip/palate with microcephaly, preterm delivery, polydactyly with sepsis, and jaundice. CHIKV IgM testing identified three possible antepartum transmissions. CONCLUSION: In Nigeria, we found significant CHIKV infection in pregnancy and possible CHIKV antepartum transmission associated with birth abnormalities.

Arbovirus surveillance in pregnant women in north-central Nigeria, 2019-2022.

BACKGROUND: The adverse impact of Zika (ZIKV), dengue (DENV), and chikungunya (CHIKV) virus infection in pregnancy has been recognized in Latin America and Asia but is not well studied in Africa. Although originally discovered in sub-Saharan Africa the non-specific clinical presentation of arbovirus infection may have hampered our detection of adverse clinical outcomes and outbreak. OBJECTIVE: This prospective study of arbovirus infection in pregnant women in north-central Nigeria sought to characterize the prevalence of acute arbovirus infection and determine the impact on pregnancy and infant outcomes. METHODS: In Nigeria, we screened 1006 pregnant women for ZIKV, DENV and CHIKV IgM/IgG by rapid test (2019-2022). Women with acute infection were recruited for prospective study and infants were examined for any abnormalities from delivery through six months. A subset of rapid test-reactive samples were confirmed using virus-specific ELISAs and neutralization assays. RESULTS: The prevalence of acute infection (IgM+) was 3.8 %, 9.9 % and 11.8 % for ZIKV, DENV and CHIKV, respectively; co-infections represented 24.5 % of all infections. The prevalence in asymptomatic women was twice the level of symptomatic infection. We found a significant association between acute maternal ZIKV/DENV/CHIKV infection and any gross abnormal birth outcome (p = 0.014). CONCLUSIONS: Over three rainy seasons, regular acute infection with ZIKV, DENV, and CHIKV was observed with significantly higher rates in pregnant women without symptoms. The potential association arbovirus infection with abnormal birth outcome warrants further prospective study to ascertain the clinical significance of these endemic arboviruses in Africa.

Arbovirus surveillance in pregnant women in north-central Nigeria, 2019-2022.

The adverse impact of Zika (ZIKV), dengue (DENV), and chikungunya (CHIKV) virus infection in pregnancy has been recognized in Latin America and Asia but is not well studied in Africa. In Nigeria, we screened 1006 pregnant women for ZIKV, DENV and CHIKV IgM/IgG by rapid test (2019-2022). Women with acute infection were recruited for prospective study and infants were examined for any abnormalities from delivery through six months. A subset of rapid test-reactive samples were confirmed using virus-specific ELISAs and neutralization assays. Prevalence of acute infection (IgM+) was 3.8%, 9.9% and 11.8% for ZIKV, DENV and CHIKV, respectively; co-infections represented 24.5% of all infections. Prevalence in asymptomatic women was twice the level of symptomatic infection. We found a significant association between acute maternal ZIKV/DENV/CHIKV infection and any gross abnormal birth outcome (p=0.014). Further prospective studies will contribute to our understanding of the clinical significance of these endemic arboviruses in Africa.

Chikungunya virus antepartum transmission and abnormal infant outcomes in Nigeria.

Chikungunya virus (CHIKV) has become a global public health concern since the reemergence of the Indian Ocean lineage and expansion of the Asian genotype. CHIKV infection causes acute febrile illness, rash, and arthralgia and during pregnancy may affect both mothers and infants. The mother-to-child transmission (MTCT) of CHIKV in Africa remains understudied. We screened 1006 pregnant women at two clinics in Nigeria between 2019 and 2022 and investigated the prevalence and MTCT of CHIKV. Of the 1006, 119 tested positive for CHIKV IgM, of which 36 underwent detailed laboratory tests. While none of the IgM reactive samples were RT-PCR positive, 14 symptomatic pregnant women were confirmed by CHIKV neutralization test. Twelve babies were followed with 8 normal and 4 abnormal outcomes, including stillbirth, cleft lip/palate with microcephaly, preterm delivery, polydactyly with sepsis and jaundice. CHIKV IgM testing identified 3 antepartum transmissions, further studies will determine its impact in antepartum infection.

Declining rate of infection with maternal human immunodeficiency virus at delivery units in north-central Nigeria.

HIV testing during labour and delivery provides a critical opportunity for administering appropriate interventions to prevent mother-to-child-transmission (PMTCT). We studied current HIV rates and infection trend among women tested during delivery following scale-up of PMTCT and antiretroviral therapy (ART) programs in Jos, north central Nigeria. Between March 2010 and January 2012, provider-initiated HIV testing and counselling was offered in early labour. Women were recruited from a government tertiary health centre, a faith-based hospital, and a private health centre. Those who previously tested HIV negative during antenatal care (ANC) and those who presented at the labour ward with unknown HIV status were tested. A total of 944 subjects (727 re-tested for HIV infection and 217 with unknown HIV status) were enrolled and tested during labour. The HIV incidence and sero-conversion rates during pregnancy among women who repeated HIV testing at delivery was 1.7 per 100 person-years of observation (pyo) and 0.6% (4/727), respectively, while the rate among those who tested for the first time in labour was 1.8% (4/217). Women who accessed ANC were older and had achieved a higher educational status than those who did not access ANC. A 3- to 5-fold decline in HIV incidence and prevalence rates was detected among women tested at delivery when compared to data from a report in 2004. It is not certain whether the decline in maternal HIV infection is due to the major state-wide scale-up of PMTCT and HIV treatment programs. A broader and purposefully designed evaluation study would be required to verify observed occurrence.