The Pope did not say “contraception”. He said “avoid pregnancy”. Abstinence is one and Natural Family Planning another method. Too quick to yell the contraceptive word.
If a spouse has a contactable sickness such as HIV, one shouldn’t be engaging in sex at all. Zika falls in the same category as it is immoral to pass on a deadly sickness. If one is sick or is a carrier, one should not be making babies.
Condoms and other contraceptives frustrates the procreation act and they are not permitted, regardless of whether any spouse is carrying a disease or not. That is Church teaching. The threat of passing infection and sickness and what not is not a good excuse to commit sin. A million reasons can be conjured to commit other sins as well for “good” reason. Abortion for instance. Use contraceptives, avoid abortion? Now the mantra is use contraceptives, avoid Zika? Many permutations are possible in how to commit sin. Man is innovative when it comes down to looking for loopholes. Jesus said that of the hypocritical scribes and such.