A measles outbreak that began in March in Okinawa has grown to near 150 cases across the country, according to the Japanese National Institute of Infectious Diseases (NIID). As of May 16, 149 cases have been confirmed, including the 99 in Okinawa.
In addition to Okinawa, health officials have reported 23 cases in Aichi, 17 in Fukuoka and at least two in Tokyo.
Health authorities say the number of cases could increase due to the spring vacation period in late April and early May, when large numbers of people travel around the country.
Measles is a highly infectious viral illness that can be very unpleasant and sometimes lead to serious complications. The measles virus is contained in the millions of tiny droplets that come out of the nose and mouth when an infected person coughs or sneezes.
The initial symptoms of measles develop around 10 days after you’re infected.
These can include:
- cold-like symptoms, such as a runny nose, sneezing, and a cough
- sore, red eyes that may be sensitive to light
- a high temperature (fever), which may reach around 40C (104F)
- small greyish-white spots on the inside of the cheeks
A few days later, a red-brown blotchy rash will appear. This usually starts on the head or upper neck, before spreading outwards to the rest of the body.
Measles can be unpleasant, but will usually pass in about 7 to 10 days without causing any further problems.
Once you’ve had measles, your body builds up resistance (immunity) to the virus and it’s highly unlikely you’ll get it again.
However, measles can lead to serious and potentially life-threatening complications in some people. These include infections of the lungs (pneumonia) and brain (encephalitis).