Humanitarian Health Action

FAQs: Japan tsunami concerns

21 March 2011

Is there a risk of communicable diseases following the tsunami?

The risk of an outbreak of a communicable disease is associated with the size, health status and living conditions of the population displaced by the tsunami. Crowding, inadequate water and sanitation, poor access to health services and sudden population displacement increase the risk of communicable disease transmission. Japan has achieved very high levels of immunization coverage for many years, decreasing the risk of communicable diseases common in other disaster settings such as measles, diphtheria, pertussis, tetanus and polio.

Although the overall risk of communicable disease outbreaks is lower than often perceived, the risk of transmission of certain endemic and epidemic-prone diseases can increase following natural disasters.

  • Diarrhoeal diseases can occur when the drinking water is contaminated, and the risk is higher in developing than developed countries following a natural disaster.
  • Hepatitis A and E are transmitted by faecal-oral route, in association with lack of access to safe water and sanitation.
  • Leptospirosis can spread through exposure of the skin and mucous membranes to water or mud contaminated with the urine of infected rats and some animals.
  • Acute respiratory infections are a major cause of illness and death among displaced populations. Lack of access to medical services and antibiotics can further increase the risk of death from acute respiratory infection.
  • Scabies is a contagious disease of the skin, and the parasite is usually transmitted by skin-to-skin contact or through sexual contact with someone else who is infected with it. The infection spreads more easily in crowded and unsanitary conditions.