It's nothing to worry about unless you're under the age of 5 and your immune system is still developing, or you're sick and/or elderly with a compromised immune system.
About Salmonella:
According to the numbers from the CDC, if you're hospitalized with a case of Salmonella poisoning, you have barely less than a 1% chance of it being lethal. But, that's only accounting for the 42,000 cases that require medical attention. According to their estimates of cases that go unreported. There are about 1,218,000 cases of Salmonella poisoning each year. That makes a whopping 3% of cases that require treatment from a doctor.
But it's not like you can't prevent Salmonella poisoning.
So basically, if you've gotten Salmonella poisoning from your pet, it means you've ingested their feces. If the idea of eating your pet's feces sounds absolutely appalling to you, then congratulations, you've taken the biggest step into avoiding getting Salmonella poisoning from your pet.
Salmonella and reptiles:
With terrestrial (and arboreal) reptiles, like most snakes and lizards, it's pretty easy to avoid getting Salmonella poisoning from. Simply ensure that they live in a sanitary environment by inspecting their cage daily for feces that need to be removed. This should be easy, as you should enjoy looking at your pet at least once a day.
When you notice feces in their enclosure, simply dispose of it in a sanitary fashion. You can grab it with gloves or paper towels if you're comfortable doing something like that, or you can purchase reptile scoops (which look like cat litter scoops but smaller). The faster you can dispose of the feces the better, as it will keep the bacteria from spreading from the feces into the bedding of the enclosure. I will also throw away a handful of the substrate surrounding the feces as an extra measure to keeping it clean.
You can also purchase terrarium cleaning agents to help you keep your pet's enclosure minty fresh.
With aquatic reptiles, like turtles, you will have a higher risk of coming into contact with the Salmonella bacteria because the animals will defecate in the water, which will then spread the bacteria throughout the water in the tank.
What this means is that you will have to wash your hands every time you come into contact with the water in their tank. Regular water changes, and a good filter on the tank, will help keep the water clean and reduce any bacteria growth. Both are important for the health of the reptile anyways.
*Note: This also applies to the water in fish aquariums, and there's an interesting article that suggests that 60% of Salmonella poisoning cases might come from contact with water in fish tanks.*
Conclusion:
As long as you take care of your reptile, and keep its enclosure clean, the chance of you getting Salmonella poisoning from it is extremely low. Salmonella poisoning isn't even something healthy adults should worry about as the vast majority of people who become ill only notice minor effects for a few days, attributing it to other factors like food poisoning.
Because Salmonella poisoning comes from ingesting the bacteria, it's easy to prevent infection by washing your hands regularly, whether it's after you handle your reptile, or before you eat, and by sanitizing areas where you prepare food.
Salmonella poisoning is only a real concern for people with immune systems that are still developing (children under 5), and people with compromised immune systems (the sick and the elderly), so it would probably be best for them not to handle reptiles.
The reason why Salmonella poisoning is so over-hyped with reptiles, is from misunderstanding that not all reptiles are the same. Aquatic reptiles pose a higher risk because of their feces spreading the bacteria in the water, but terrestrial reptiles pose no more risk than other terrestrial pets. Likewise, aquatic reptiles will pose the same risk as other aquatic pets, which also defecate in their water, such as fish.
Anecdotal Data:
Personally, I don't allow any of my pets onto the kitchen table or counters where I would be preparing food. This includes my cats who could also be considered carriers of the bacteria. But if I let my bearded dragon outside his terrarium, I don't bother cleaning everything he touches, just whatever he defecates on (if he does).
I not only own reptiles and fish, but have worked in a pet store and spent several hours a day having my hands in both fish and reptile tanks without ever contracting Salmonella poisoning.
