In 2004, singer Paula Abdul battled a staph infection on her thumb after getting a manicure at a Los Angeles nail salon. The infection reportedly took about a year to heal, with the former judge saying that the pain was so excruciating that even her hair touching her thumb caused her to scream.

Yu adds that it is also possible to develop hepatitis or even HIV through a manicure or pedicure, although the chances of this happening are slim.

A study by researchers in Brazil published in October 2014 in , described a case of a 22-year-old woman who had seemingly contracted HIV-1 from having shared manicure instruments with a cousin who was later found to be HIV-positive. The subject had no apparent risk factors for acquiring HIV, but genetic analysis of the viruses from both patients showed that they shared a common viral ancestor, suggesting that the virus was likely transmitted through the manicure tools.

As the nail service industry can be hard to regulate - even someone with minimal knowledge and training can buy a set of tools and call herself a nail technician - it is important to look out for yourself when visiting a nail salon.

First off, Yu advises you to pay attention to the hygiene practices of the technicians when you are at the nail salon. If they merely clean their manicure tools with an antiseptic solution, it's a red flag.

Good salons sterilise their equipment with autoclaves, special machines that use high-pressure, high-temperature steam to kill bacteria. Yu says that as long as the autoclaves are used correctly, they are highly effective against pathogens.

In addition to using a UV steriliser, Stephanie Millington, owner of Cupcake Nails in Tsim Sha Tsui, Kowloon, takes the extra step of wiping her tools down with rubbing alcohol before and after use, and cleaning them with a hospital-grade disinfectant between clients. At the end of the day, she also soaks the tools in rubbing alcohol.

Patty Lo, director of Nail Parlor in Central, ensures that all her customers receive new buffers and nail files, and, if they are getting a pedicure, toe separators as well. All metal instruments are sanitised in front of customers before being used. After the manicure or pedicure, they are sterilised in the salon's autoclave.

Yu adds that clean and autoclaved metal instruments should be opened in front of you. Towels can also harbour bacteria, so make sure that the technician uses only clean and freshly laundered towels or paper towels on you.

She should also use disposable gloves during the service, and if she uses disposable tools, such as pumice stones, nail brushes, cuticle sticks, and nail files - which are often shared between customers - all the better. In fact, you should always ask for a brand-new set to be used on you.

Pumice stones, which are used to smooth rough skin, are porous, making them the ideal breeding ground for bacteria. It's one mani-pedi tool you should never share.

If you want to be extra careful, bring your own tools and nail polish to the salon. Most nail technicians would not mind if you do. "I am more than happy to serve clients who wish to use their own manicure kit and nail polish," says Lo.

Just remember to thoroughly clean and disinfect all the instruments before and after use.

You should also consider the overall cleanliness of the nail salon. For example, is the floor clean and dry? Does the bin look like it gets emptied regularly? Are the tools neatly organised or strewn all over the place?

The footbaths, basins and step stools, too, should be clean. A study, published in October 2011 in , found that poorly sanitised footbaths in a number of North Carolina nail salons was the likely cause behind an outbreak of infection.

A similar outbreak - 143 cases - was reported among persons who visited nail salons in California in 2004. Mycobacteria can cause weeping lesions and painful ulcers, and it can be very difficult to treat.

At her salon, Millington says she uses pedicure bowls instead of piped tubs, as they are easier to clean. She drains the bowls after every use before scrubbing them with disinfectant, rinsing them and then leaving them to air-dry.

If your footbath looks dirty or you suspect that it has not been washed, demand that it be cleaned in front of you. It doesn't take long to scrub and dry and you will have peace of mind knowing that your feet are not sitting in a bacteria-laden pool.

Remember to also observe your nail technician while she is attending to you. If she is busy chatting to the other technicians and not completely focused on you, she may forget to clean her instruments or neglect to replace a dirty towel, or worse, accidentally cut you, leaving you vulnerable to infection.

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As a paying customer, you deserve good service, so speak up if you feel that your nail technician has fallen short in this area. Also watch that she washes her hands between customers.

Yu advises to avoid invasive or dangerous procedures, such as blading, which gets rid of the dry, dead skin on the soles of the feet, and cuticle cutting.

The cuticles are there to protect your nails' growth matrix - that part of the nail where growth starts. If the skin breaks, you risk getting an infection. A cuticle infection can also hamper the growth of your nails.

The best way to neaten cuticles is to soften them and push them back with a cuticle stick. If your nail technician is over-enthusiastic or aggressive with this step in your manicure or pedicure, tell her to go easy.

Finally, it is best to avoid getting a manicure or pedicure if you have an open cut or wound on your hands or feet. As many of the instruments in nail salons are reused, this will only increase your chances of picking up an infection.

Likewise, if you have a nail or skin infection, the sensible thing to do would be to wait until it has completely cleared before getting a manicure or pedicure. A responsible nail technician would also turn away any customer who appears to have a skin or nail infection.

Lo says that she always politely tells such customers to come back after their infection has cleared up.

"These infections tend to be contagious and we have to protect our nail technicians and other customers," she says.