Relying on some government agency to inspect these matebetos may be too much to ask. Just going by how slow the wheels of government turn here in Zambia. If you are looking for a solution that is entirely dependent on you, I have a couple of suggestions. Maybe three.
1. Learn to cook nshima.
2. Date someone who will be willing to cook for you.
3. If somehow the first two listed above are not an option for you, then pack some cloves of garlic when you go to these places. After a meal, eat one clove of garlic. It is a natural antibacterial, antiviral, and antifungal medicine.
And since for you to resort to option #3, means that you haven't had much luck on the dating scene, you will not have to worry about the bad breath garlic will give you. You will not be kissing anyone anyway.
But in case you have to work in close proximity with other people and they complain about your bad breath, try to rinse your mouth with hydrogen peroxide. It's the cheapest, yet, best remedy for bad breath. If you are using 3% hydrogen peroxide, mix it with an equal amount of water. 1% hydrogen peroxide, you can use all by itself. Just make sure you gaggle for about 20 seconds.
Good luck and I hope you will enjoy your nshima next time at the matebeto without a belly ache.