Can I gain immunity against traveler's disease?

Question

I need to visit Nepal every 2 years (at least). I was there 2 years ago and got very sick in the second week, basically stomach flu, probably salmonella or e.coli or both.

I was there about a month ago and became sick again in a similar fashion, although it seemed very slightly less dramatic, no high fever this time etc.

Can I expect to gain immunity against e.coli at least or maybe even salmonella? Can I expect to get a stronger stomach, which is not so easily upset? Do frequent travelers to Asia or Africa, who tend to experience these type of problems tend to experience them less the more they travel?

I have asked a similar question on The Great Outdoors and was advised to ask on Health as well.

Answer 1

A short summary of a report by Prof. DDr. Martin Haditsch seems to come to the conclusion that a permanent immunity of travelers against "traveler's disease" can not be gained.

Traveler's diarrhea is usually caused by a toxin-producing gut germ, namely ETEC (enterotoxic / enterotoxigenic E. coli), the resulting immunity requires a recurrent contact, which is only guaranteed in the local population. As a result, travelers can repeatedly fall ill during repeated visits.

Actions that can be taken are mentioned as:

In addition to the well-known "Peel it, boil it, cook it - or forget it!", a strengthening of the defense barriers is possible through several measures:

• high-percentage alcoholic drinks (WITHOUT ice cubes!)
• bitter tinctures or bitter teas stimulate the gastric acid secretion (important unspecific line of defense)
• In addition, cholera (Dukoral®) oral vaccination as a specific measure may be due to one of the vaccine antigens used (B-subunit of the cholera toxin; deceptively similar to the heat-labile ETEC toxin - produced by up to 75% of the strains detected) considerable cross-immunity (for 3 to 7 months) and thus lead to a significant protection against ETEC.

Regarding the mentioned salmonella:

Salmonellosis does not leave an effective immunity against re-infection from Die Salmonellose hinterlässt keine wirksame Immunität gegen eine erneute Infektion