Measurement of Recent Exposure to Phlebotomus argentipes, the Vector of Indian Visceral Leishmaniasis, by Using Human Antibody Responses to Sand Fly Saliva

Abstract

Antibody (IgG) responses to the saliva of Phlebotomus argentipes were investigated using serum samples from regions of India endemic and non-endemic for visceral leishmaniasis (VL). By pre-adsorbing the sera against the saliva of the competing human-biting but non-VL vector P. papatasi, we significantly improved the specificity of a P. argentipes saliva enzyme-linked immunosorbent assay. Using this method, we observed a statistically significant correlation between antibodies to P. argenitpes saliva and the average indoor density of female sand flies. Additionally, the method was able to detect recent changes in vector exposure when sera from VL patients were assayed before, during, and after hospitalization and protected from sand fly bites under untreated bed nets. Collectively, these results highlight the utility of antibodies to P. argentipes saliva as an important tool to evaluate VL vector control programs.

Reassessment of Immune Correlates in Human Visceral Leishmaniasis as Defined by Cytokine Release in Whole Blood

“…As the EHCs were all close contacts of individuals with VL, we would expect a relatively high frequency of L. donovani infection (3). We also found that these individuals had significantly elevated serological titers of antibodies against P. argentipes saliva compared to the IGRA-negative EHCs or the NEHCs and were comparable to the individuals with active VL, presumably reflecting their greater exposure to sand fly bites and their greater risk of having been exposed to an infected sand fly (7). This finding lends some support to the argument that the EHCs who were scored positive in this assay represent a population of subclinically exposed, immune individuals.…”

Human Antibody Response to Aedes aegypti Saliva in an Urban Population in Bolivia: A New Biomarker of Exposure to Dengue Vector Bites

“…aegypti saliva because previous studies have demonstrated that the IgG response is a useful biomarker for exposure to mosquito bites. 16,33,34 Further investigations are therefore needed to establish whether the antibody response to saliva is age dependent.…”

Characterization of the Antibody Response to the Saliva of Phlebotomus papatasi in People Living in Endemic Areas of Cutaneous Leishmaniasis

“…In accordance with previous results obtained by Rohousova and others, 15 we found that all positive sera from naturally exposed children reacted strongly with a 30kDa protein, suggesting that this protein is the major immunodominant antigen of P. papatasi saliva in humans. Clements and others 33 recently highlighted the utility of measuring the antibody response to the saliva of Phlebotomus argentipes to assess the exposure among humans living in endemic areas for leishmaniasis and subsequently to evaluate vector control programs. However, these authors showed the possibility of cross-reactive reactions between different species of sand flies.…”