Good luck on your trip. I’ll advice you to do your research on what infectious diseases are endemic in the regions that you will be visiting (www.cdc.gov/travel is a good please to start). Also, check with your doctor for immunizations required when traveling abroad, such as, Hepatitis A and B. If you are traveling in areas where mosquitoes and ticks are present, try to always use an insect repellent with DEET of at least 30% and use appropriate clothing. Be vigilant on waterborne diseases and try to avoid swimming in fresh, unchlorinated water. As for traveler’s diarrhea, which is probably the most common one, try to start taking probiotics at least 2-3 weeks before the trip and stay on them for 3-4 weeks after returning.
Hope this helps and safe travels!
Diseases which are transmitted by mosquitos such as malaria, or ticks, such as Africa tick bite fever,.. and a few more such as hemorrhagic fever and West Nile and Yellow fever
Diseases that are food and water-borne: Hepatitis A, typhoid, paratyphoid, amebiasis, cholera, dysenteria.
Airborne diseases -such as Tuberculosis- particularly in certain areas of South Africa
Sexually-transmitted disease such as HIV-AIDS
Diseases transmitted from animals such as rabies, plague (Anthrax)
Soil- and -water associated such as schistosomiasis, leptospirosis
The risk depends on where you go, what you do and how long you stay in a particular area
Some travelers may need Hep B, Malaria, and Rabies.
Some countries require Yellow Fever vaccine.