East Asia
Travel To East Asia
* China * Hong Kong SAR * Japan * Macau SAR * Mongolia * North Korea * South Korea * Taiwan
Risk of infection is highly variable in the region. Access to clean water and good sanitary facilities are limited in many rural areas, especially in China and Mongolia. Respiratory infections (aetiology often undefined) are common in travellers to the region. Chronic and latent infections in immigrants (and long-term residents) include tuberculosis, complications from chronic hepatitis B (and also hepatitis C) infection, schistosomiasis, paragonimiasis, and strongyloidiasis.
Vector-borne infections: Malaria is found in focal areas of China and North and South Korea. Japanese encephalitis (JE) is found in wide areas of China and Japan and focally in Korea. Transmission of malaria and JE is seasonal in many areas. Reported infections in travellers are rare. Other vector-borne infections include dengue, which has caused outbreaks in mainland China, Hong Kong, and Taiwan; spotted fever caused by R. sibirica (China, Mongolia); murine typhus; Oriental spotted fever caused by R. japonica (Japan); rickettsialpox (Korea); scrub typhus (especially in China, Korea, and Japan); tick-borne encephalitis (in forested regions northeastern China and in South Korea); visceral and cutaneous leishmaniasis (in rural China); lymphatic filariasis (in focal coastal areas of China and South Korea); and Crimean-Congo haemorrhagic fever* (in western China).
Food- and water-borne infections: Risk of diarrhoea is highly variable within the region. Diarrhoea in travellers may be caused by bacteria, viruses, and parasites. Risk of hepatitis A is high in some areas (excluding Japan), especially in rural areas of China and Mongolia. Outbreaks of hepatitis E have been reported in China. Cases of cholera were reported from China in 2002-2003. Sporadic cases of anisakiasis are reported from Korea and Japan. Brucellosis is found, especially in sheep-raising regions of China and Mongolia. Paragonimiasis is endemic in China and still occurs in Korea. Clonorchiasis is found in local populations in China, Japan, Korea, and Taiwan, but risk to usual traveller is low.
Airborne and person-to-person transmission: The estimated annual incidence of tuberculosis per 100,000 population is 100-300 in China, Mongolia, and North Korea and 50-100 in Japan and South Korea. High rates of multiple drug-resistant tuberculosis are found in parts of China (about 10% in new patients). Outbreaks of SARS occurred in mainland China, Hong Kong, and Taiwan in 2003. Measles remains endemic in the region, and infection has occurred in adopted children from China and in travellers to the region. In tropical areas, influenza may occur during all months of the year.
Sexually transmitted and blood-borne infections: The prevalence of HIV in adults is low (0.1%-1%) in most of the region, but a much higher prevalence is found in focal areas in southern China. Hepatitis B is highly endemic among adults in region, excluding Japan. Prevalence of chronic infection exceeds 8% in many areas. Prevalence of hepatitis C is 10% or higher in Mongolia; 2.5%-9.9% in mainland China and Taiwan, and 1%-2.4% in the rest of the region. A high prevalence of HTLV-I is found focally in the southern islands of Japan.
Zoonotic infections: Rabies is widespread in China (not Hong Kong) and Mongolia. Avian influenza has been transmitted to humans in Hong Kong and China. To date, the virus has caused high mortality in humans but has not been readily transmissible from person to person. Highly pathogenic H5N1 has also been found in bird populations in Japan, and South Korea. Cases of human plague* are reported most years from China and Mongolia. Hantaviruses causing haemorrhagic fever with renal syndrome are a major health threat in China and the Republic of Korea, primarily affecting residents of rural areas in late fall and early winter. Risk to the usual traveller is low. Anthrax* is enzootic in China and Mongolia, and sporadic infection is reported in the rest of the region. Tularemia* occurs in China and Japan and is found especially in northern parts of region. Echinococcosis* is endemic in rural areas of China and Mongolia.
Schistosomiasis (S. japonicum) is present in focal areas in China, especially in the Yangtze River basin. Leptospirosis* is a risk, especially in tropical areas of China and South Korea. Cutaneous larva migrans is common in warm coastal areas. Cases of histoplasmosis have been reported.
Other risks for travellers include injury from motor vehicle accidents and venomous snake bites. Screening of blood before transfusion is inadequate in many hospitals in the region.
