One Measles Patient Can Infect Up to 18 People

The Health Ministry reported through week 8 of 2026, there were 10,453 suspected measles cases with 8,372 confirmed cases and 6 deaths. Additionally, there were 45 measles outbreak events across 29 districts and cities.

Responding to this development, Dr Aisyah Amanda Hanif, lecturer at the IPB Faculty of Medicine, stated that the surge in measles cases can serve as an indicator of declining community immunity (herd immunity). “The increase in measles cases often indicates that population immunity is declining. Measles is a highly contagious disease. One infected person can transmit this virus to 12 to 18 susceptible people in their surroundings,” she stated in a written statement on Tuesday (10 March 2026).

Based on research, approximately 90 percent of people without immunity to measles virus have the potential to become infected if exposed. For this reason, immunisation coverage rates are critical in preventing the spread of this disease.

According to Aisyah, herd immunity will be achieved when more than 94 percent of the population has immunity to measles, either through vaccination or previous infection. Meanwhile, the measles immunisation coverage target set by the Health Ministry is a minimum of 95 percent.

“If immunisation coverage declines, the number of susceptible individuals will increase. When the virus enters a community with many people who lack immunity, outbreaks can occur more easily,” she explained.

Dr Aisyah stated that measles cannot be regarded as a mild disease or merely a skin rash. The measles virus spreads through the air (airborne) and generally enters the body through the respiratory tract.