Although 32 of 44 countries where yellow fever occurs endemically do have vaccination programmes, in many of these countries, less than 50% of their population is vaccinated. Vector control
Control of the yellow fever mosquito A. aegypti is of major importance, especially because the same mosquito can also transmit dengue fever and chikungunya disease. A. aegypti breeds preferentially in water, for example, in installations by inhabitants of areas with precarious drinking water supplies, or in domestic refuse, especially tires, cans, and plastic bottles. These conditions are common in urban areas in developing countries.Two main strategies are employed to reduce A. aegypti populations. One approach is to kill the developing larvae. Measures are taken to reduce the water accumulations in which the larvae develop. Larvicides are used, along with larvae-eating fish and copepods, which reduce the number of larvae. For many years, copepods of the genus Mesocyclops have been used in Vietnam for preventing dengue fever. This eradicated the mosquito vector in several areas. Similar efforts may prove effective against yellow fever. Pyriproxyfen is recommended as a chemical larvicide, mainly because it is safe for humans and effective in small doses.The second strategy is to reduce populations of the adult yellow fever mosquito. Lethal ovitraps can reduce Aedes populations, using lesser amounts of pesticide because it targets the pest directly. Curtains and lids of water tanks can be sprayed with insecticides, but application inside houses is not recommended by the WHO. Insecticide-treated mosquito nets are effective, just as they are against the Anopheles mosquito that carries malaria.
Some of these drugs also induce the enzyme UGT1A1 and thus reduce blood plasma concentrations of cabotegravir, further compromising the effectiveness of this combination therapy.It is also contraindicated in combination with proton pump inhibitors because the increased gastric pH causes decreased rilpivirine absorption from the gut, with similar consequences as with CYP3A4 inducers. Adverse effects
The most common side effects of the injectable formulation are reactions at the injection site (in up to 84% of patients) such as pain and swelling, as well as headache (up to 12%) and fever or feeling hot (in 10%). Less common (under 10%) are depressive disorders, insomnia, and rashes. The most common side effects of the tablets are also depressive disorders (4.1%), headache (3.5%), insomnia (3.5%) and rashes (2.3%). All of these side effects occurred under combination therapies of rilpivirine with one or more other drugs against HIV. QT prolongation of the heart rhythm has been observed at very high doses, but is not clinically relevant at standard doses of the drug. Pharmacology
Mechanism of action
Rilpivirine is a non-nucleoside reverse transcriptase inhibitor (NNRTI). Pharmacokinetics
When taken by mouth, rilpivirine reaches highest levels in the blood plasma after about four to five hours. Taking the drug without food lowers its plasma levels by 40% as compared to taking it with food, which is considered to be clinically relevant. Therefore, patients are advised to take the medication together with a meal.