| Country | Major infectious diseases |
| China | degree of risk: intermediate food or waterborne diseases: bacterial diarrhea, hepatitis A, and typhoid fever vectorborne diseases: Japanese encephalitis and dengue fever soil contact disease: hantaviral hemorrhagic fever with renal syndrome (HFRS) 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) |
| Christmas Island | void |
| Clipperton Island | void |
| Cocos (Keeling) Islands | void |
| Colombia | degree of risk: high food or waterborne diseases: bacterial diarrhea vectorborne diseases: dengue fever, malaria, and yellow fever water contact disease: leptospirosis (2009) |
| Comoros | void |
| Congo, Democratic Republic of the | degree of risk: very high food or waterborne diseases: bacterial and protozoal diarrhea, hepatitis A, and typhoid fever vectorborne diseases: malaria, plague, and African trypanosomiasis (sleeping sickness) water contact disease: schistosomiasis animal contact disease: rabies (2009) |
| Congo, Republic of the | degree of risk: very high food or waterborne diseases: bacterial and protozoal diarrhea, hepatitis A, and typhoid fever vectorborne disease: malaria and African trypanosomiasis (sleeping sickness) animal contact disease: rabies water contact disease: schistosomiasis (2009) |
| Cook Islands | void |
| Coral Sea Islands | void |
| Costa Rica | degree of risk: intermediate food or waterborne diseases: bacterial diarrhea vectorborne diseases: dengue fever (2009) |
| Cote d'Ivoire | degree of risk: very high food or waterborne diseases: bacterial diarrhea, hepatitis A, and typhoid fever vectorborne diseases: malaria and yellow fever water contact: schistosomiasis 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) |