Author Profile

Rebecca C. Christofferson

Affiliation: Pathobiological Sciences, Louisiana State University, Baton Rouge, Louisiana, USA

Recent Posts

Utility of a Dengue-Derived Monoclonal Antibody to Enhance Zika Infection In Vitro

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Introduction: Zika virus (ZIKV) has emerged in dengue (DENV) endemic areas, where these two related flaviviruses continue to co-circulate. DENV is a complex of four serotypes and infections can progress to severe disease. It is thought that this is mediated by antibody dependent enhancement (ADE) whereby antibodies from a primary DENV infection are incapable of neutralizing heterologous DENV infections with another serotype. ADE has been demonstrated among other members of the Flavivirus group.

Methods: We utilize an in vitro ADE assay developed for DENV to determine whether ZIKV is enhanced by a commonly available DENV serotype 2-derived monoclonal antibody (4G2).

Results: We show that ZIKV infection in vitro is enhanced in the presence of the 4G2 mAb.

Discussion: Our results demonstrate that ADE between ZIKV and DENV is possible and that the 4G2 antibody is a useful tool for the effects of pre-existing anti-DENV antibodies during ZIKV infections.

Towards an Early Warning System for Forecasting Human West Nile Virus Incidence

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We have identified environmental and demographic variables, available in January, that predict the relative magnitude and spatial distribution of West Nile virus (WNV) for the following summer. The yearly magnitude and spatial distribution for WNV incidence in humans in the United States (US) have varied wildly in the past decade. Mosquito control measures are expensive and having better estimates of the expected relative size of a future WNV outbreak can help in planning for the mitigation efforts and costs. West Nile virus is spread primarily between mosquitoes and birds; humans are an incidental host. Previous efforts have demonstrated a strong correlation between environmental factors and the incidence of WNV. A predictive model for human cases must include both the environmental factors for the mosquito-bird epidemic and an anthropological model for the risk of humans being bitten by a mosquito. Using weather data and demographic data available in January for every county in the US, we use logistic regression analysis to predict the probability that the county will have at least one WNV case the following summer. We validate our approach and the spatial and temporal WNV incidence in the US from 2005 to 2013. The methodology was applied to forecast the 2014 WNV incidence in late January 2014. We find the most significant predictors for a county to have a case of WNV to be the mean minimum temperature in January, the deviation of this minimum temperature from the expected minimum temperature, the total population of the county, publicly available samples of local bird populations, and if the county had a case of WNV the previous year.

Towards an Early Warning System for Forecasting Human West Nile Virus Incidence

·

We have identified environmental and demographic variables, available in January, that predict the relative magnitude and spatial distribution of West Nile virus (WNV) for the following summer. The yearly magnitude and spatial distribution for WNV incidence in humans in the United States (US) have varied wildly in the past decade. Mosquito control measures are expensive and having better estimates of the expected relative size of a future WNV outbreak can help in planning for the mitigation efforts and costs. West Nile virus is spread primarily between mosquitoes and birds; humans are an incidental host. Previous efforts have demonstrated a strong correlation between environmental factors and the incidence of WNV. A predictive model for human cases must include both the environmental factors for the mosquito-bird epidemic and an anthropological model for the risk of humans being bitten by a mosquito. Using weather data and demographic data available in January for every county in the US, we use logistic regression analysis to predict the probability that the county will have at least one WNV case the following summer. We validate our approach and the spatial and temporal WNV incidence in the US from 2005 to 2013. The methodology was applied to forecast the 2014 WNV incidence in late January 2014. We find the most significant predictors for a county to have a case of WNV to be the mean minimum temperature in January, the deviation of this minimum temperature from the expected minimum temperature, the total population of the county, publicly available samples of local bird populations, and if the county had a case of WNV the previous year.