Eating primal does tend to reduce illness and infection.
I can sympathise. I always come back from 2-week holidays feeling malnourished due to food intolerances making my diet quite restrictive. Lack of vegetables is always a major issue, especially when travelling in countries where one is advised to avoid salads as they're rinsed in unsafe water. Deciding what to eat is usually a matter of choosing the least of various evils - whichever food will make me less ill.
Take plenty of food with you, e.g. tinned fish and meat. And when you find suitable food, gorge on it!
F 5 ft 3. HW: 196 lbs. Primal SW (May 2011): 182 lbs (42% BF)... W June '12: 160 lbs (29% BF) (UK size 12, US size 8). GW: ~24% BF - have ditched the scales til I fit into a pair of UK size 10 bootcut jeans. Currently aligning towards 'The Perfect Health Diet' having swapped some fat for potatoes.