Major infectious diseases: degree of risk: very high ... food or waterborne diseases: bacterial and protozoal diarrhea, hepatitis A, and typhoid fever ... vectorborne diseases: dengue fever and malaria ... water contact disease: leptospirosis ... animal contact disease: rabies ... note: highly pathogenic H5N1 avian influenza has been identified in this country; it poses a negligible risk with extremely rare cases possible among US citizens who have close contact with birds (2009) ... Definition: This entry lists major infectious diseases likely to be encountered in countries where the risk of such diseases is assessed to be very high as compared to the United States. These infectious diseases represent risks to US government personnel traveling to the specified country for a period of less than three years. The degree of risk is assessed by considering the foreign nature of these infectious diseases, their severity, and the probability of being affected by the diseases present. The diseases listed do not necessarily represent the total disease burden experienced by the local population.