ABSTRACT
Zika and Dengue viruses present considerable immunological cross-reactivity, resulting in a troublesome serodiagnosis due to occurrence of false positive results. Due to Brazil's wide variety of circulating flaviviruses we aimed to access the use of in house serological tests adapted by National Reference Laboratory for Arboviruses in Brazil and evaluate commercial tests available. We evaluated in house IgM ELISAs for the individual detection of anti-ZIKV, -DENV, and -YFV IgM, against a panel of samples positive for dengue, zika, yellow fever, Rocio, Ilheus, Saint Louis encephalitis, West Nile and chikungunya. We also evaluated two commercial kits for dengue and zika IgM detection recommended by the Brazilian Ministry of Health in 2015. The sensitivity and specificity for the in house ZIKV IgM ELISA was 60.0 % and 88.6 % and for the in house DENV IgM ELISA was 100 % and 82.2 %, respectively. The in house YFV IgM ELISA presented 100 % for both sensitivity and specificity. The Novagnost Zika Virus IgM test presented a sensitivity of 47.3 % and specificity of 85.3 % and the Serion ELISA classic Dengue Virus IgM, 92.8 % and 58.9 %, respectively. Overall, both in house ELISAs for ZIKV and DENV adapted and evaluated here, presented better performances than the commercial kits tested.
Subject(s)
Dengue Virus , Dengue , Flavivirus , Zika Virus Infection , Zika Virus , Antibodies, Viral , Dengue/diagnosis , Enzyme-Linked Immunosorbent Assay , Humans , Immunoglobulin M , Laboratories , Sensitivity and Specificity , Zika Virus Infection/diagnosisABSTRACT
OBJECTIVE: To establish the risk of microcephaly in neonates born to women infected with ZIKV during pregnancy. METHODS: A cohort of laboratory-confirmed ZIKV cases of congenital infections (109 mothers infected during pregnancy and 101 newborns) among 308 suspect cases was followed in Belem, Pará, Brazil, from October 2015 to December 2017. RESULTS: A microcephaly risk of 1.98% (95% CI 0.54-6.93%) was found, or 2 cases among the 101 neonates infected with ZIKV during pregnancy. 72% of the pregnant women had ZIKV infection confirmed by RT-qPCR during gestation. CONCLUSIONS: Results showed a low incidence of ZIKV-associated birth defects, stillbirth, and miscarriage, which contrasts with previous studies in other Brazilian regions. Previous exposure to yellow fever vaccine and/or multiserotype DENV infection could be implicated in the protection from ZIKV congenital infection.
OBJETIVO: Establecer el riesgo de microcefalia en los recién nacidos de mujeres infectadas con ZIKV durante el embarazo. MÉTODOS: Se siguió a una cohorte de casos con infección congénita por ZIKV confirmada por laboratorio (109 madres infectadas durante el embarazo, 101 recién nacidos) conformada a partir de 308 casos sospechosos en Belem, Pará, Brasil, de octubre de 2015 a diciembre de 2017. RESULTADOS: Se encontró un riesgo de microcefalia de 1,98% (IC95% 0,54-6,93%), o 2 casos entre los 101 neonatos infectados con ZIKV durante el embarazo. En el 72% de las mujeres embarazadas se confirmó mediante RT-qPCR la infección por ZIKV durante la gestación. CONCLUSIONES: Los resultados mostraron una baja incidencia de malformaciones congénitas, mortinatos y abortos asociados al ZIKV, lo que contrasta con estudios anteriores de otras regiones de Brasil. La exposición previa a la vacuna contra la fiebre amarilla o la infección previa por varios serotipos de virus del dengue podrían estar implicados en la protección contra la infección congénita por ZIKV.
