What are the Class A communicable diseases?

Class A notifiable infectious diseases as defined by Chinese law include plague and cholera. Both are highly contagious and extremely dangerous infectious diseases that require strict prevention and control measures to prevent transmission. If symptoms such as high fever, chills, severe diarrhea, or vomiting occur, it is recommended to immediately report to local disease control agencies or medical institutions.

Plague is caused by the bacterium *Yersinia pestis* and is primarily transmitted through flea bites from infected rodents, respiratory droplets, and direct contact. Clinical manifestations include high fever, swollen and painful lymph nodes, and bleeding tendencies. Pneumonic plague is highly contagious and progresses rapidly; without prompt treatment, it has a high fatality rate.

Cholera is caused by infection with *Vibrio cholerae* and spreads through contaminated water and food. Typical symptoms include severe, painless diarrhea and vomiting, with stool resembling rice-water. Within a short time, this can lead to severe dehydration, electrolyte imbalance, and even shock or death.

In daily life, attention should be paid to food and drinking water hygiene—avoid drinking untreated water and consuming unclean food, wash hands frequently, and develop good hygiene habits. Avoid contact with rodents and their secretions. When traveling to endemic areas, take proper protective measures and actively learn about prevention and control knowledge to enhance self-protection.