Zika virus (ZIKV) infection in pregnancy is associated with birth and developmental alterations in infants. In this study, clinical records of 47 infants whose mothers had Zika during pregnancy or clinical manifestations compatible with Zika were reviewed. A description of the infants’ anomalies was established, and a neurodevelopmental assessment was performed on 18 infants, using the Evaluation of Infant Development (EDI for its initialism in Spanish) and DDST-II (Denver Developmental Screening Test II) tests. From his sample, 74.5% of the infants evaluated had major anomalies and 51.9% had minor anomalies. The incidence of major anomalies, related to trimester of pregnancy, was 84.2% for the first trimester, 77.8% for the second trimester, and 37.5% in the third trimester. A similar trend was observed in the frequency of infants without anomalies and was less evident in the incidence of minor anomalies (p = 0.016). Through neurodevelopmental assessments, EDI identified 27.8% of infants as having normal development, while 55.5% of affected infants had developmental delay, and 16.7% were at risk for developmental delay. The DDSST-II showed that 77.7% infants had delay in the gross motor and language area, 88.8% in the fine-adaptative motor area, and 72.2% in the personal–social area. In this work, children of mothers with ZIKV infection during pregnancy may have major or minor anomalies regardless of the trimester of pregnancy in which the infection occurred. The neurodevelopmental assessment shows that ZIKV can cause a developmental delay in infants with the fine-adaptative motor area being the most affected.

The causes of the broad spectrum of severity in COVID-19 are unknown. A protective effect through humoral immunity from previous infections by viruses of the SARS-CoV-2 family could explain a mild form of this disease. This study aimed to address whether the presence of antibodies against human seasonal coronaviruses (HCoVs) could prevent severe manifestations of COVID-19. A cross-sectional study was carried out in 165 participants. The presence of pre-existent antibodies against the seasonal HCoV-OC43, HCoV-HKU1, HCoV-229E, and HCoV-NL63 were detected. From all of the seasonal HCoVs studied, it was only found that being seropositive to HCoV-229E presented an association (p = 0.012) with developing mild clinical symptoms of COVID-19 or being asymptomatic. Multinomial regression analysis showed that being seropositive to HCoV-229E is associated with mild or moderate clinical symptoms for COVID-19. Statistical analysis also showed that being female is associated with being asymptomatic for SARS-CoV-2 infection or developing mild COVID-19. A subgroup analysis taking only seropositive to HCoV-229E revealed that females are more likely to develop asymptomatic SARS-CoV-2 infection (OR = 27.242, 95% CI 2.092–354.706, p = 0.012). Our results suggest that previous infections by HCoV-229E could prevent more serious clinical manifestations of COVID-19, but these are not the only variables that influence this event.

Background/Objectives: Zika disease is caused by the Zika virus (ZIKV) and represents a major public health problem because of the complications in newborn babies from mothers who were infected during pregnancy. It is estimated that 80% of infected pregnant women are asymptomatic, which complicates the identification of infected individuals. In this study, we aimed to detect ZIKV in asymptomatic pregnant women and the effects in the newborns were analyzed. Methods: The presence of ZIKV was evaluated through endpoint reverse transcription–polymerase chain reaction (RT-PCR) in 114 blood samples from pregnant women treated at two hospitals in the state of Veracruz, Mexico. There was a follow-up of the participants until the birth of their newborns. Results: ZIKV RNA was detected in 4.4% (n = 5) of cases. In two positive cases, two consecutive samples were obtained, and one case of persistence of ZIKV in serum after 90 days after delivery was identified. A total of 80% of the positive cases were identified after the third trimester of pregnancy and 20% after the second trimester. Although ZIKV was shown to be a risk factor for low weight and low size at birth and prematurity, after adjustment for other variables, it did not show a significant association. In contrast, preeclampsia/eclampsia was identified as a significant risk factor for low birth weight. Conclusions: The prevalence of ZIKV found in this study suggests a latent circulation of this virus and highlights the importance of epidemiological surveillance in endemic zones. The prolonged viremia that was found suggests the need for more research because of the high impact which can mean the possible dissemination of the virus to the vector.