Dengue fever, transmitted by Aedes mosquitoes, is a major public health concern in tropical and subtropical regions. The virus has four serotypes (DENV-1, DENV-2, DENV-3, and DENV-4) that can cause illnesses ranging from mild fever to severe dengue hemorrhagic fever and shock syndrome. The Non-Structural Protein 1 (NS1) antigen, produced by all serotypes during the acute phase, is a key marker for early infection, making it valuable for early-stage diagnostic tests when traditional methods may be ineffective.

Chikungunya virus (CHIKV) is a mosquito-borne alphavirus that causes chikungunya fever, characterized by fever, joint pain, and systemic symptoms. The virus's envelope glycoproteins E1 and E2 are crucial for virus entry and cell fusion, making them important targets for immune response and valuable antigens for diagnostics and research.

Leptospirosis is a zoonotic bacterial infection caused by Leptospira species, affecting humans and animals with symptoms ranging from mild flu-like signs to severe illness like kidney damage and respiratory distress. Key outer membrane lipoproteins, LipL21 and LipL32, are crucial in the pathogenesis and immune response and are highly conserved among pathogenic Leptospira species, making them excellent targets for diagnostic tests.