Malaria advice for Indonesia is strongly regional. Papua, also called Irian Jaya, is treated as a higher-risk area where antimalarial tablets are usually recommended after assessment. Bali, Lombok, Java and Sumatra are generally lower risk, while Jakarta is not considered a malaria risk area. That does not make mosquito precautions optional. Dengue occurs in Indonesia, and the mosquitoes that spread it often bite in the daytime in towns and built-up areas. Zika risk is also recognised, which matters particularly if you are pregnant, travelling with a pregnant partner, or planning pregnancy soon after travel. Chikungunya is another daytime mosquito-borne infection to be aware of. Japanese encephalitis occurs countrywide, with risk linked especially to rural stays, rice-growing areas, pig farming areas, longer trips and repeated travel. Hepatitis A is commonly recommended for previously unvaccinated travellers because it spreads through contaminated food and water. Typhoid is also commonly considered, especially for longer stays, lower-budget travel, rural areas and visiting friends or relatives. Make sure tetanus-containing vaccines are up to date. Hepatitis B may be relevant for longer stays, new sexual partners, medical or dental treatment, contact sports, tattoos or work involving blood exposure. Rabies is present in domestic animals, and children are often at higher risk because they may approach animals or not report a scratch. Schistosomiasis is also reported in Indonesia, so avoid swimming or wading in untreated freshwater. Higher-altitude plans, such as Mount Rinjani or Mount Semeru, need gradual ascent and realistic fitness planning.