JEV Model: Japanese Encephalitis Vector-Host Simulator
What is the JEV model? The Japanese Encephalitis Virus (JEV) transmission model is a deterministic compartmental system mapping viral cycling between Culex mosquito vectors and amplifying hosts (swine and ardeid wading birds), with incidental spillover to dead-end human hosts. Explore the temperature-dependent reproduction number ($R_0$), extrinsic incubation periods, and intervention strategies in real time.
Japanese Encephalitis Virus (JEV) is maintained in an enzootic cycle between night-biting Culex mosquitoes (chiefly Culex tritaeniorhynchus breeding in flooded rice fields) and amplifying vertebrate hosts. Pigs exhibit prolonged, high-titer viremia (> $10^5 \text{ PFU/mL}$) without severe clinical mortality, transmitting back to vectors. Ardeid wading birds (egrets and herons) act as maintenance reservoirs.
Vector parameters are thermodynamic: ambient temperature dictates both the extrinsic incubation period ($\text{EIP} = 1/\sigma_v$) and biting frequency ($a$). Warmer temperatures between 24°C and 30°C dramatically accelerate viral replication within the mosquito salivary glands, shortening EIP from 14 days to 4 days, resulting in steep exponential jumps in $R_0$. Above 33°C, mosquito survival drops sharply.
Humans and equines are accidental dead-end hosts. When an infectious mosquito bites a human, viral titers remain insufficient ($< 10^3 \text{ PFU/mL}$) to infect naive mosquitoes that subsequently feed. While ~99% of human infections are subclinical, ~1% develop acute encephalitis with 20â30% case fatality and 30â50% permanent neurological sequelae.