Kissing offers many health benefits but may also transmit a small number of disease-causing bacteria and viruses. Bacteria and viruses in the saliva or blood of one person can be spread to another person by kissing.
Some diseases are more easily spread than others.
Research into passionate kissing has uncovered many valuable health benefits, including:
•Emotional bonding – kissing your partner is a fun, pleasurable and important part of physical intimacy and helps maintain a sense of togetherness and love.
•Stress reduction – kissing your partner, either tenderly or passionately, releases calming brain chemicals (neurotransmitters) that reduce stress levels and soothe the mind.
•Foreplay – deep -kissing your partner can lead to sexual intercourse. Various studies show that sex enhances a person’s physical and mental health. For example, regular sex is protective against stress and depression.
•Metabolic boost – kissing burns kilojoules. The more passionate the kiss, the greater the metabolic boost.
•Healthier mouth – saliva contains substances that fight bacteria, viruses and fungi. Deep kissing increases the flow of saliva, which helps to keep the mouth, teeth and gums healthy.
•Increased immunity – exposure to germs that inhabit your partner’s mouth strengthens your immune system.
How disease is spread
Diseases can be spread from person to person in a number of ways:
•Contact spread – some diseases are spread directly from person to person, for example during kissing, or indirectly when you touch a contaminated surface or object.
•Droplet spread – infected droplets from the nose and throat can usually travel around one metre before they drop onto a surface. Sometimes infected droplets can also linger in the air. Infection occurs when the infected droplet is inhaled or someone comes into contact with a contaminated surface or object.
•Airborne spread – some infected particles from the nose and throat can remain in the air for a long time because of their tiny size. They are called droplet nuclei and can be inhaled directly into the lungs.
Viruses that can be transmitted by kissing
Examples of illnesses caused by viruses that can be transmitted during kissing include:
•Colds – also known as upper respiratory tract infections. Many different viruses can cause the common cold. Colds are thought to be spread by direct contact with the virus. You could catch the cold from airborne droplets or from direct contact with secretions (fluids and mucous) from the infected person’s nose and throat.
•Glandular fever – also known as the kissing disease. Glandular fever is the common term for a viral infection called infectious mononucleosis, caused by the Epstein-Barr virus. The virus is spread through saliva and infection occurs through contact.
•Herpes infection – viruses that are considered part of the herpes family include Epstein-Barr, varicella-zoster (causes chickenpox) and herpes simplex (causes cold sores). Herpes simplex virus can be spread through direct contact with the virus when kissing. Herpes is most easily spread to others when the blisters are forming or have erupted. The virus can be ‘shed’ (spread to others) from the site of blisters even when they have healed. Chickenpox is easily spread from person to person by direct contact, droplets or airborne spread.
•Hepatitis B – kissing may also transmit this virus, although blood has higher levels of this virus than saliva. Infection can occur when infected blood and saliva come into direct contact with someone else’s bloodstream or mucous membranes. (Mucous membranes line various body cavities including the mouth and nose.)
A person is more likely to be infected when kissing if they have open sores in or around the mouth.
•Warts – warts in the mouth can be spread through kissing, especially if there are areas of recent trauma.