Poxvirus and Rabies Branch, Division of High-Consequence Pathogens and Pathology (DHCPP), National Center for Emerging and Zoonotic Infectious Diseases (NCEZID), US Centers for Disease Control and Prevention, Atlanta, GA, USA.
Int J Health Geogr. 2017 Aug 7;16(1):28. doi: 10.1186/s12942-017-0100-1.
Emerging and understudied pathogens often lack information that most commonly used analytical tools require, such as negative controls or baseline data; thus, new analytical strategies are needed to analyze transmission patterns and drivers of disease emergence. Zoonotic infections with Vaccinia virus (VACV) were first reported in Brazil in 1999, VACV is an emerging zoonotic Orthopoxvirus, which primarily infects dairy cattle and farmers in close contact with infected cows. Prospective studies of emerging pathogens could provide critical data that would inform public health planning and response to outbreaks. By using the location of 87-recorded outbreaks and publicly available bioclimatic data, we demonstrate one such approach. Using an ecological niche model (ENM) algorithm, we identify the environmental conditions under which VACV outbreaks have occurred, and determine additional locations in two affected countries that may be susceptible to transmission. Further, we show how suitability for the virus responds to different levels of various environmental factors and highlight the most important factors in determining its transmission.
A literature review was performed and the geospatial coordinates of 87 molecularly confirmed VACV outbreaks in Brazil were identified. An ENM was generated using MaxENT software by combining principal component analysis results of 19 bioclim spatial layers, and 25 randomly selected subsets of the original list of 87 outbreaks.
The final ENM predicted all areas where Brazilian outbreaks occurred, one out of five of the Colombian outbreak regions and identified new regions within Brazil that are suitable for transmission based on bioclimatic factors. Further, the most important factors in determining transmission suitability are precipitation of the wettest quarter, annual precipitation, mean temperature of the coldest quarter and mean diurnal range.
The analyses here provide a means by which to study patterns of an emerging infectious disease and identify regions that are potentially suitable for its transmission, in spite of the paucity of high-quality critical data. Policy and methods for the control of infectious diseases often use a reactionary model, addressing diseases only after significant impact on human health has ensued. The methodology used in the present work allows the identification of areas where disease is likely to appear, which could be used for directed intervention.
新兴且研究不足的病原体通常缺乏最常用分析工具所需的信息，例如阴性对照或基线数据；因此，需要新的分析策略来分析疾病爆发的传播模式和驱动因素。1999 年，巴西首次报告了天花病毒（VACV）的人畜共患感染，VACV 是一种新兴的人畜共患正痘病毒，主要感染奶牛和与受感染奶牛密切接触的农民。对新兴病原体的前瞻性研究可以提供关键数据，为公共卫生规划和疫情应对提供信息。通过使用 87 次记录爆发的位置和公开可用的生物气候数据，我们展示了这样一种方法。我们使用生态位模型（ENM）算法来确定 VACV 爆发发生的环境条件，并确定在两个受影响国家中可能容易传播的其他地点。此外，我们展示了病毒的适宜性如何对不同水平的各种环境因素做出响应，并强调了决定其传播的最重要因素。
进行了文献综述，并确定了巴西 87 例分子确诊的 VACV 爆发的地理空间坐标。通过结合 19 个生物气候空间层的主成分分析结果以及原始 87 个爆发列表中 25 个随机选择的子集，使用 MaxENT 软件生成了一个 ENM。
最终的 ENM 预测了巴西所有爆发地区，以及哥伦比亚五个爆发地区中的一个，还确定了基于生物气候因素在巴西内部适合传播的新地区。此外，决定传播适宜性的最重要因素是最湿润季度的降水量、年降水量、最寒冷季度的平均温度和平均昼夜温差。
尽管高质量关键数据不足，但这里的分析提供了一种研究新兴传染病模式并确定潜在传播区域的方法。传染病控制的政策和方法通常采用反应性模型，仅在对人类健康产生重大影响后才解决疾病问题。本工作中使用的方法可以识别疾病可能出现的区域，从而可以进行有针对性的干预。
