Is it permissible to manipulate the result of a Hepatitis C virus test (by bribery) in order to work in countries that prohibit carriers of this virus, knowing that there are personal justifications for doing so?

If the state has a legitimate purpose in preventing infected individuals from entering its territory, then it is not permissible for you to lie or resort to deception to gain entry. The sin is compounded by paying a bribe. Since your financial situation is comfortable and you are engaged in religious Dawah, we advise you to stay. You can change innovations (Bid'ah) with gentleness and leniency.