I’ve never been so the information is just stuff I found while doing a search. I always think it’s funny how people say, Oh, I found this on the internet so it must be true! So you can decide! ;O)
http://www.pngtourism.org.pg/practical-information/visiting-png/#Health%20Regulations
http://wwwnc.cdc.gov/travel/destinations/papua-new-guinea.aspx
Also, I don’t know if/when you’re going but here’s a Contact Us page that you can use to send a quick email: http://www.pngtourism.org.pg/contact-us/contact-form/
Good Luck!
Becky