ChoLab brings real-time cholera detection to the frontlines of public health. Using a portable, low-cost device and a smartphone, it identifies contaminated water in just 20 minutes, removing the need for traditional laboratory facilities. Community health workers can respond immediately and upload test results to create a grassroots surveillance network. Public health agencies gain early warning of outbreaks, shifting response from reactive to proactive. Designed with local input, ChoLab empowers communities and supports stronger water safety and disease prevention