These are the Health-Related Reasons for Visa Denial in Thailand. Having a visa denial in Thailand can be difficult if it is based on a health related matter. Normally they will tell you why the visa has been denied and you can then appeal from there. You are going to need an experienced immigration lawyer to appeal this for you as it will become very complicated for which time and money cannot be wasted on any errors. This will be from the US visa medical examination in Thailand.
Health-Related Reasons for Visa Denial
Circumstances do change and you should have a specialist to look at your options wherein you might have to start the legal process again. Mental illness and other medical illnesses do change and 
you would have to provide proof of these changes. Not having all your vaccinations will be the most common issue and you can change this once you have proof of the required vaccines.
Your fiancée or wife will either need to find these which can be difficult but there would be a check for the most common vaccinations such as mumps, measles, polio, rubella as well as tetanus. Note however that there will be a check for HIC/AIDS as well as measles and Hepatitis.
Hepatitis B affects a number of people in Thailand. Estimates in Thailand for Hepatitis B is between 5 and 9% in the urban centers while more prevalent in the rural areas as between 6 and 12 % of the population. Again depending on the reason for the denial you will need to speak to a lawyer in Thailand and it consequences. If you did not know then you might have to have yourself tested as well for any illnesses that you did not know about.
Vaccinations in Thailand
Measles in Thailand is another issue and vaccinations for this in Southern Thailand tends to be lower. This is mainly due to religious reasons and there was an anti-vaccination push for many years. You will need to find the measles vaccination certificate for your wife or fiancée if you are going to apply for a US visa from Thailand. All settlement visas to the US will need all of these when applying for a visa from Thailand. Measles outbreaks do occur and they tend to be 10 times higher in the South of Thailand.
The last outbreak in Thailand was 4 in 100,000 in Central Bangkok compared to 55 in 100,000 people in the Southern Provinces. Thailand has been Polio free, however, those close to the borders might have an issue due to mutations. You will need to check where you Thai wife was born and you might need a vaccination certificate. These requirements do change so you will need to ensure that you are properly informed. You will need to check with your wife about these issues.
Speak to a lawyer about these concerns as they do become complicated and a visa denial is a costly process. With Hepatitis B in Central Thailand, Measles in Southern Thailand and Polio on the borders you should make sure that all the vaccination certificates are all in order. The health-related reasons for visa denial in Thailand is explained.
