Antibody responses to ectoparasitic arthropods as an indication of exposure history and disease risk
The prevalence of human IgG antibodies able to recognise several different mosquito species salivary extracts was compared in individuals of all ages living at varying altitudes and during varying seasonal mosquito exposures. Antibody prevalence was correlated with altitude and the age of the individual, although seasonal variations of mosquito exposures did not conclusively indicate the ability to distinguish short-term increases in vector exposure. The salivary antigens of Anopheles gambiae were characterised by molecular weight some eliciting stronger more frequent host antibody recognition. Similarly, prevalence of deer IgG antibodies capable of recognising tick Ixodes recinus salivary antigens was compared in animals of all ages and of different geographical location in the UK. Deer antibody prevalence was not correlated with tick exposure or with animal age although there were differences in host responses. The salivary antigens of I. ricinus were also characterised by molecular weight and as with mosquito salivary products some antigens elicited stronger and more frequent deer antibody recognition. Thus, serological markers of host vector exposure may offer an alternative method most certainly in assessing mosquito density exposure of humans and identified I. ricinus antigens may be of use in the development of tick vaccines.