The major innate immune pathways in Asian longhorned ticks, Haemaphysalis longicornis, include Toll, IMD, and JAK/STAT. In the field, H. longicornis can be infected with various pathogens including Severe Fever with Thrombocytopenia Syndrome Virus (SFTS virus), Rickettsia, Babesia and Anaplasma species. One approach to identify whether ticks are infected with pathogens is by examining the expression levels of immune response genes. To evaluate whether upregulation of immune genes from H. longicornis can serve as an indicator for pathogen infection in ticks, we first designed primer sets for Dorsal, STAT, and Relish from the H. longicornis genome. We then conducted quantitative reverse transcription PCR(qRT-PCR) on cDNA of field-collected H. longicornis and identified individuals with high expression levels in immune response genes. Subsequently, we performed digital PCR assays to determine whether selected ticks were infected with SFTS virus. Using this approach, we evaluated correlation between pathogen infection and upregulation of immune response genes in ticks. Although more experiments are needed to draw conclusions, this study suggests immune response gene-based screening methods for pathogen infected ticks from the field.