Institut Pierre Richet / Institut National de Santé Publique, Bouaké, Côte d'Ivoire.
MIVEGEC, University of Montpellier, IRD, CNRS, Montpellier, France.
PLoS Negl Trop Dis. 2021 Dec 13;15(12):e0010004. doi: 10.1371/journal.pntd.0010004. eCollection 2021 Dec.
Culex mosquitoes are vectors for a variety of pathogens of public health concern. New indicators of exposure to Culex bites are needed to evaluate the risk of transmission of associated pathogens and to assess the efficacy of vector control strategies. An alternative to entomological indices is the serological measure of antibodies specific to mosquito salivary antigens. This study investigated whether the human IgG response to both the salivary gland extract and the 30 kDa salivary protein of Culex quinquefasciatus may represent a proxy of human exposure to Culex bites.
METHODOLOGY/PRINCIPAL FINDINGS: A multidisciplinary survey was conducted with children aged 1 to 14 years living in neighborhoods with varying exposure to Culex quinquefasciatus in the city of Bouaké, Côte d'Ivoire. Children living in sites with high exposure to Cx quinquefasciatus had a significantly higher IgG response to both salivary antigens compared with children living in the control site where only very few Culex were recorded. Moreover, children from any Culex-high exposed sites had significantly higher IgG responses only to the salivary gland extract compared with children from the control village, whereas no difference was noted in the anti-30 kDa IgG response. No significant differences were noted in the specific IgG responses between age and gender. Sites and the use of a bed net were associated with the level of IgG response to the salivary gland extract and to the 30 kDa antigen, respectively.
CONCLUSIONS/SIGNIFICANCE: These findings suggest that the IgG response to Culex salivary gland extracts is suitable as proxy of exposure; however, the specificity to the Culex genus needs further investigation. The lower antigenicity of the 30 kDa recombinant protein represents a limitation to its use. The high specificity of this protein to the Culex genus makes it an attractive candidate and other specific antibody responses might be more relevant as a biomarker of exposure. These epidemiological observations may form a starting point for additional work on developing serological biomarkers of Culex exposure.
库蚊是多种公共卫生关注病原体的传播媒介。需要新的暴露于库蚊叮咬的指标来评估相关病原体传播的风险，并评估蚊虫控制策略的效果。替代昆虫学指标的方法是针对蚊子唾液抗原的特异性抗体的血清学测量。本研究调查了人体对库蚊唾液腺提取物和 30kDa 唾液蛋白的 IgG 反应是否可以代表人体接触库蚊叮咬的替代指标。
方法/主要发现：在科特迪瓦布瓦凯市，对居住在不同库蚊暴露地区的 1 至 14 岁儿童进行了一项多学科调查。与居住在控制地点（仅记录到很少的库蚊）的儿童相比，居住在高暴露地点的儿童对两种唾液抗原的 IgG 反应均显著更高。此外，来自任何高暴露于库蚊的地点的儿童仅对唾液腺提取物的 IgG 反应明显高于来自对照村的儿童，而在抗 30kDa IgG 反应中则没有差异。年龄和性别之间的特异性 IgG 反应没有差异。地点和使用蚊帐与 IgG 对唾液腺提取物和 30kDa 抗原的反应水平相关。
结论/意义：这些发现表明，对库蚊唾液腺提取物的 IgG 反应适合作为暴露的替代指标；然而，对库蚊属的特异性需要进一步研究。30kDa 重组蛋白的抗原性较低是其使用的限制。该蛋白对库蚊属的高特异性使其成为一个有吸引力的候选物，其他特异性抗体反应可能更适合作为暴露的生物标志物。这些流行病学观察结果可能为开发库蚊暴露的血清学生物标志物提供进一步研究的起点。
