Stay safe & healthy
Safety is not an issue in São Tomé and Príncipe, though the roadway traffic is hazardous as in other parts of Africa. Violent crime in public is almost unheard of. However, with an increase in tourism there has been an increase in crime against tourists. Road blocks near Santana have been reported, as well as scams targeting tourists in the main city.
The only dangerous animal in the islands is the black cobra, which can be found in southern and eastern areas of Sao Tome island. Young ones are completely black, adults have yellow-white scales on the front. They are afraid of humans and will normally slither away when you approach. Be alert when hiking and very careful of where you stick your hands. Anti-venom is available at local hospitals. If bitten you need to seek immediate help, preferably within 30-120 minutes. Deaths are rare, though.
Malaria was once extremely common on the islands, but an eradication program initiated by the Taiwanese government in 2005 has effectively stamped out malaria in populated areas (deaths have dropped from over 1000/year to just a handful). However, visitors should still continue taking precautions against mosquito bites (which can transmit other severe illnesses) such as the use of insect repellants and bed netting. Furthermore, the rate of malaria infections in nearby, mainland countries is high and there is the potential for isolated outbreaks from infected people/animals arriving from those countries. If you are also visiting the mainland on your journey, keep in mind the length of time before/after visiting malarial regions that you need to take your anti-malaria medication (which can be several weeks).
The rate of HIV/AIDS in STP is between 1-2%, which is relatively low compared with nearby countries. There is a very strong stigma against those infected on the islands and few have ever come out with their diagnosis and in many cases health workers have to deliver medications to their homes in secret because patients are unwilling to be seen in public collecting these medications. Even with the low risk, you should always use protection, such as condoms.
Water must be boiled before drinking, or purchased and consumed from bottles.