If a tobacco company deliberately witholds information from the public about safety, they're hauled in front of a grand jury. When the Catholics do it in Africa, they're just "expressing their faith".
Properly speaking, this is a poor analogy -- tobacco companies actively sell products which can be and are harmful to the consumer's health; deliberately withholding that information is unethical, because the products can cause addiction or death on the part of the consumer. The Roman Catholic Church disseminates its religious beliefs; withholding information about Catholic beliefs will not cause addiction or death on the part of practising Catholics due to Roman Catholicism.
It is the opinion of the Roman Catholic Church that the use of contraceptives is contrary to the purpose of sexual intercourse (CCC 2370), and for that reason, the Church opposes the use of contraceptives.
To be sure, engaging in sexual activity without the use of contraceptives (particularly condoms) increases the risk of contraction of venereal diseases, some of which can result in death, with acquired immune deficiency syndrom being the most prominent example.
If a person, out of desire to obey the Church's teaching on contraceptives, engages in sexual activity without using contraceptives, and contracts a venereal disease, it is a tragedy. No person should ever be so unfortunate to contract such a disease, whether by sexual contact or any other. However, it is not fair to the Church to immediately conclude that it is wholly responsible for the fact -- because the chances are high that the person who obeyed the one part of the Church's teaching did not obey another part --
sc., the Church's teaching on abstinence.
Make no mistake -- it is entirely possible that the Church's activities in Africa have exacerbated the AIDS crisis in that continent. If that is the case, it is indeed a tragedy, and we weep for those who have suffered. It is wholly possible that the Church leaders have erred -- they have done so in the past, some times spectacularly so. If you would really like examples, they are not difficult to find.
Nevertheless, it is only fair to point out that if a person were to obey all the Church's teachings on sexuality, the odds of contracting a venereal or sexually-transmitted disease are extremely small. Certainly, one may disagree with the Church's teachings -- and that does not make one a bad person. There is no legitimate obligation to practise any religion -- in fact, it is the opinion of the Church that no person or institution has the right to force one to act against one's convictions, or to prevent one from acting in accordance to one's convictions within due limits (CCC 2106--7).
No one forces people to obey Church doctrine; if any one actually coerces another to obey Church doctrine, he or she is actually violating Church doctrine. Individuals are free to make their own choices, including whether or not they will obey Catholic teachings, including but not limited to those on contraceptives and on abstinence.
Publius