Hygiene Overview

• According to the World Bank, hygiene promotion is the most cost-effective health action to reduce disease.
• As of 2020, 2.3 billion people lacked basic hygiene services (handwashing facility with soap and water), and 1.6 billion people had access to handwashing facilities that lacked water or soap.
• Worldwide, 70% of people used basic hygiene services in 2020.

Hand Hygiene

• Research shows that washing hands with soap and water could reduce deaths from diarrheal disease by up to 50%.
• Researchers estimate that if everyone routinely washed their hands, 1 million deaths a year could be prevented.
• A large percentage of foodborne disease outbreaks are spread by contaminated hands. Handwashing can reduce the risk of foodborne illness and other infections.
• Handwashing can reduce the risk of respiratory illnesses, like colds, in the general population by 16–21%.
• The use of an alcohol-based hand sanitizer in U.S. classrooms reduced absenteeism due to infection by about 20% overall among 16 elementary schools and 6,000 students.
• Handwashing education in the community:
  • Reduces diarrheal illness in people with weakened immune systems by 58%
  • Reduces absenteeism due to gastrointestinal illness in schoolchildren by 29–57%

Face and Body Hygiene

• More than 50% of healthy people have Staphylococcus aureus living in or on their nasal passages, throats, hair, or skin. Within the first 15 minutes of bathing, the average person sheds 6 x 106 colony forming units (CFU) of Staphylococcus aureus. Showering before entering recreational waters (such as pools) prevent the spread of germs by reducing the microbial load.
• The average individual swimmer contributes at least 0.14 grams of fecal material to the water, usually within the first 15 minutes of entering. Showering with soap before swimming helps stop the spread of germs by removing fecal material from the body.
• Trachoma, the leading cause of preventable blindness worldwide, is related to the lack of facial hygiene. An estimated 41 million people suffer from active trachoma, and nearly 10 million people are visually impaired or irreversibly blind as a result of trachoma.
• Inadequate contact lens hygiene, such as failure to properly disinfect lenses, increases the risk of acquiring the eye infection Acanthamoeba keratitis.
• The spread of pinworms can be reduced by proper hygiene, including clipping nails and showering children immediately after they wake in the morning.

Athlete’s foot, or tinea pedis, is an infection of the skin and feet that can be caused by a variety of different fungi. Although tinea pedis can affect any portion of the foot, the infection most often affects the space between the toes. Athlete’s foot is typically characterized by skin fissures or scales that can be red and itchy.

Tinea pedis is spread through contact with infected skin scales or contact with fungi in damp areas (for example, showers, locker rooms, swimming pools). Tinea pedis can be a chronic infection that recurs frequently. Treatment may include topical creams (applied to the surface of the skin) or oral medications.

Body lice, or Pediculus humanus corporis, are parasitic insects that can live and lay eggs on clothing and only move to the skin to feed on human blood. Lice are spread most commonly by close person-to-person contact. Body lice infestation is found worldwide.

Good hygiene can help prevent and control the spread of body lice:

• Bathe regularly and change into properly laundered clothes at least once a week; launder infested clothing at least once a week.
• Machine wash and dry infested clothing and bedding using the hot water (at least 130°F) laundry cycle and the high heat drying cycle. Clothing and items that are not washable can be dry-cleaned OR sealed in a plastic bag and stored for 2 weeks.
• Do not share clothing, beds, bedding, and towels used by an infested person.
• Fumigation or dusting with chemical insecticides sometimes is necessary to control and prevent the spread by body lice of certain diseases (epidemic typhus).

What is chronic diarrhea?

Diarrhea that lasts for more than 2-4 weeks is considered persistent or chronic. In an otherwise healthy person, chronic diarrhea can be a nuisance at best or become a serious health issue. For someone who has a weakened immune system, chronic diarrhea may represent a life-threatening illness.

What causes chronic diarrhea?

Chronic diarrhea has many different causes; these causes can be different for children and adults. Chronic diarrhea sometimes is classified on whether or not it is caused by an infection. The cause of chronic diarrhea sometimes remains unknown.

Chronic Diarrhea caused by an infection may result from:

• Parasites (e.g., Cryptosporidium, Cyclospora, Entamoeba histolytica, Giardia, microsporidia)
• Bacteria (e.g., Aeromonas, Campylobacter, Clostridium difficile, E. coli, Plesiomonas, Salmonella, Shigella)
• Viruses (e.g., norovirus, rotavirus) or
• Unknown causes thought to be infectious (e.g., Brainerd diarrhea)

Chronic Diarrhea not caused by an infection may result from various causes such as:

• Disorders of the pancreas (e.g. chronic pancreatitis, pancreatic enzyme deficiencies, cystic fibrosis)
• Intestinal disorders (e.g. colitis, Crohn’s Disease, irritable bowel syndrome)
• Medications (e.g. antibiotics, laxatives)
• Intolerance to certain foods and food additives (e.g. soy protein, cow’s milk, sorbitol, fructose, olestra)
• Disorders of the thyroid (e.g. hyperthyroidism)
• Previous surgery or radiation of the abdomen or gastrointestinal tract
• Tumors
• Reduced blood flow to the intestine
• Altered immune function (e.g. immunoglobulin deficiencies, AIDS, autoimmune disease)
• Hereditary disorders (e.g. cystic fibrosis, enzyme deficiencies)

How is the cause of chronic diarrhea diagnosed?

Diagnosis of chronic diarrhea can be difficult and requires that your health care provider take a careful health history and perform a physical exam. The types of tests that your health care provider orders will be based on your symptoms and history. Tests may include blood or stool tests. Stool cultures may be used to test for bacteria, parasites or viruses; generally three or more stool samples are collected and examined. Special tests may be required to diagnose some parasites. If these initial tests do not reveal the cause of the diarrhea, additional tests may be done, including radiographs (x-rays) and endoscopy. Endoscopy is a procedure in which a tube is inserted into the mouth or rectum so that the doctor, usually a gastroenterologist, can look at the intestine from the inside.

Who is at risk for serious complications from chronic diarrhea?

The risk of serious complications from chronic diarrhea depends on the cause of the diarrhea and the age and general health of the patient. Chronic diarrhea from some causes can result in serious nutritional disorders and malnutrition. Severely immunocompromised persons, including those with HIV/AIDS and those receiving chemotherapy for cancer or organ transplantation can be at risk for serious chronic diarrhea. Determining the correct cause of chronic diarrhea is necessary in order to select proper treatment and reduce the risk of serious complications.

How is chronic diarrhea treated?

The treatment of chronic diarrhea is determined by its cause. Follow the advice of your health care provider.

• Diarrhea caused by an infection sometimes can be treated with antibiotics or other drugs. However, the correct diagnosis must be made so that the proper medication can be prescribed.
• Diarrhea not caused by an infection can be more difficult to diagnose and therefore treat. Long term medical treatment and nutritional support may be necessary. Surgery may be required to treat some causes of chronic diarrhea.

For diarrhea whose cause has not been determined, the following guidelines may help relieve symptoms. Follow the advice of your health care provider.

• Remain well hydrated and avoid dehydration. Serious health problems can occur if the body does not maintain proper fluid levels. Diarrhea may become worse and hospitalization may be required if dehydration occurs.
• Maintain a well-balanced diet. Doing so may help speed recovery.
• Avoid beverages that contain caffeine, such as tea, coffee, and many soft drinks.
• Avoid alcohol; it can lead to dehydration

How are infections that can cause chronic diarrhea spread?

Infections that can cause chronic diarrhea usually are spread by ingesting food or water or touching objects contaminated with stool. In general, chronic diarrhea not caused by an infection is not spread to other people.

How can infections that cause chronic diarrhea be prevented?

Infections that cause chronic diarrhea usually can be prevented by

• Always drinking clean safe water that has been properly treated,
• Always using proper food handling and preparation techniques,
• Always maintaining good hand hygiene, including always washing hands properly with soap and water before handling food and after using the toilet or changing a diaper.

Dental caries or cavities, more commonly known as tooth decay, are caused by a breakdown of the tooth enamel. This breakdown is the result of bacteria on teeth that breakdown foods and produce acid that destroys tooth enamel and results in tooth decay.

Although dental caries are largely preventable, they remain the most common chronic disease of children aged 6 to 11 years and adolescents aged 12 to 19 years. Tooth decay is four times more common than asthma among adolescents aged 14 to 17 years. Dental caries also affects adults, with 9 out of 10 over the age of 20 having some degree of tooth-root decay.

Water fluoridation, named by CDC as one of the ten great public health achievements of the 20th century, has been a major contributor to the decline of the rate of tooth decay. Studies have shown that water fluoridation can reduce the amount of decay in children’s teeth by 18-40%.

In addition to fluoridated water, good oral hygiene can help prevent tooth decay:

• Brush twice a day with a fluoride toothpaste
• Clean between your teeth daily with floss or interdental cleaner
• Eat nutritious and balanced meals and limit snacking
• Visit your dentist regularly for professional cleanings and oral examination
• Check with your dentist about use of supplemental fluoride, which strengthens your teeth, and about use of dental sealants (a plastic protective coating) applied to the chewing surfaces of the back teeth to protect them from decay

Head lice, or Pediculus humanus capitis, are parasitic insects that can be found on the head and neck and survive by feeding on human blood. Lice are spread most commonly by close person-to-person contact.

Getting head lice is not related to cleanliness of the person or his environment; however, good hygiene is still important to help prevent and control the spread of head lice:

• Avoid head-to-head (hair-to-hair) contact during play and other activities at home, school, and elsewhere (sports activities, playground, slumber parties, camp).
• Never share clothing such as hats, scarves, coats, sports uniforms, hair ribbons, or barrettes.
• Never share combs, brushes, or towels. Disinfest combs and brushes used by an infested person by soaking them in hot water (at least 130°F) for 5-10 minutes.
• Never lie on beds, couches, pillows, carpets, or stuffed animals that have recently been in contact with an infested person.
• Machine wash and dry clothing, bed linens, and other items that an infested person wore or used during the 2 days before treatment using the hot water (130°F) laundry cycle and the high heat drying cycle. Clothing and items that are not washable can be dry-cleaned OR sealed in a plastic bag and stored for 2 weeks.
• Vacuum the floor and furniture, particularly where the infested person sat or lay. However, spending much time and money on housecleaning activities is not necessary to avoid reinfestation by lice or nits that may have fallen off the head or crawled onto furniture or clothing.
• Do not use fumigant sprays or fogs; they are not necessary to control head lice and can be toxic if inhaled or absorbed through the skin.

Hot Tub Rash, or Pseudomonas dermatitis, is an infection of the skin. Hot Tub Rash infections are often caused by the germ Pseudomonas aeruginosa. This germ is common in the environment (water, soil) and is microscopic so that it can’t be seen with the naked eye. Hot Tub Rash is spread by direct skin contact with contaminated water and usually occurs within a few days of swimming in poorly maintained hot tubs or spas. It can also be spread by swimming in a contaminated pool or lake.

Symptoms of Hot Tub Rash include itchy skin that may progress to a bumpy red rash that may become tender. It is also characterized by pus-filled blisters usually found surrounding hair follicles. Because a swimsuit can keep contaminated water in longer contact with the skin, the rash may be worse under a person’s swimsuit.

Most rashes clear up in a few days without medical treatment. However, if your rash persists, consult your healthcare provider.

Good pool maintenance and personal hygiene are important to prevent Hot Tub Rash:

• Ask the pool manager about the disinfectant and pH testing program at your hot tub or pool.
• Ensure frequent testing, control of disinfectant (usually chlorine or bromine) levels, and pH control.
• Remove swimsuits and shower after swimming.
• Clean swimsuits after swimming.

Lymphatic filariasis (LF) is a mosquito-borne parasitic disease caused by microscopic, thread-like worms. Globally, 120 million people in 80 countries are affected by LF, and the disease is the second leading cause of permanent and long-term disability worldwide. Adult worms cause permanent damage to the human lymphatic system that results in swelling of the limbs and breasts (lymphedema) and scrotum (hydrocele), or swollen limbs with severely thickened, hard, rough and fissured skin (elephantiasis). Affected people frequently are unable to work because of their disability, and this harms their families and their communities.

Lymphatic filariasis can be eliminated. To achieve that goal, the Global Alliance to Eliminate Lymphatic Filariasis was established and set a target elimination date of 2020. Elimination will be achieved primarily through regular mass drug administration in affected communities. In most countries, a single dose of two drugs (albendazole and diethyl-carbamazine or albendazole and ivermectin) is administered annually to the entire population in an at-risk area. In order to interrupt the spread of LF and eliminate the disease, coverage must reach a minimum of 80% of the population for an estimated duration of 6-7 years.

Symptoms of lymphatic filariasis such as lymphedema (swelling) and accompanying secondary infections, occurring when germs enter the body through entry lesions (such as cracks in the skin and between the toes), can be managed by practicing basic principles of care such as simple hygiene, exercise, and treatment of wounds. Patients can be taught simple hygiene techniques for washing the affected body parts daily with soap and room temperature water, and keeping the nails and spaces between toes clean. When practiced regularly in conjunction with daily exercise of the affected limb and treatment of wounds, these hygiene measures have been shown to reduce the frequency of acute attacks.

Pinworms, or Enterobius vermicularis, are small, thin, white roundworms (about the length of a staple) that sometimes live in the colon and rectum of humans. While an infected person sleeps, female pinworms leave the intestine through the anus and deposit their eggs on the surrounding skin. Pinworm infection is the most common worm infection in the United States.

Good hygiene is important to prevent and control pinworms:

• Because itching and scratching of the anal area is common in pinworm infection, strict observance of good hand hygiene is the most effective means of preventing pinworm infection. This includes:
  • Appropriate handwashing (particularly before eating or handling food, after using the toilet, and after changing a diaper)
  • Keeping fingernails clean and short
  • Avoiding fingernail-biting
  • Avoiding scratching the skin in the perianal area
• Daily morning bathing removes a large proportion of eggs; showering may be preferred to avoid possible contamination of bath water. Careful handling and frequent changing of underclothing, night clothes, towels, and bedding can help reduce infection, reinfection, and environmental contamination with pinworm eggs. These items should be laundered in hot water, especially after each treatment of the infected person.
• Control can be difficult in child care centers and schools because the rate of reinfection is high. In institutions, effective prevention and control methods include:
  • Appropriate hand hygiene (the most effective method of prevention)
  • Mass and simultaneous treatment, repeated in 2 weeks
  • Trimming and scrubbing the fingernails and bathing after treatment to help prevent reinfection and spread of pinworms

Pubic lice, or Pthirus pubis, are parasitic insects that can be found attached to hair in the pubic area but sometimes are found on coarse hair elsewhere on the body (for example, eyebrows, eyelashes, beard, mustache, chest, armpits, etc.). Pubic lice survive by feeding on human blood and are usually spread through sexual contact.

Good hygiene and other behaviors can help prevent and control the spread of pubic lice:

• Inform all sexual contacts of the infested person that they should be examined for pubic lice. Treat all those who are infested.
• Avoid sexual contact between the infested person(s) and their sexual partner(s) until all have been examined, treated as necessary, and reevaluated to rule out persistent infestation.
• Machine wash and dry clothing worn and bedding used by the infested person in the hot water (at least 130°F) laundry cycle and the high heat drying cycle. Clothing and items that are not washable can be dry-cleaned OR sealed in a plastic bag and stored for 2 weeks.
• Do not share clothing, bedding, and towels used by an infested person.
• Do not use fumigant sprays or fogs; they are not necessary to control pubic (“crab”) lice and can be toxic if inhaled or absorbed through the skin.

Human scabies is caused by an infestation of the skin by the human itch mite (Sarcoptes scabiei var. hominis). The microscopic scabies mite burrows into the upper layer of the skin where it lives and lays its eggs. The most common symptoms of scabies are intense itching and a pimple-like skin rash. The scabies mite usually is spread by direct, prolonged, skin-to-skin contact with a person who has scabies.Scabies occurs worldwide and affects people of all races and social classes. Scabies can spread rapidly under crowded conditions where close body contact is frequent. Institutions such as nursing homes, extended-care facilities, and prisons are often sites of scabies outbreaks.

Images: Sarcoptes scabiei mites in a skin scraping, stained with lactophenol cotton-blue. (Credit: DPDx)

Swimmer’s ear is a common problem that can cause pain and discomfort for children and swimmers of all ages. In the United States, swimmer’s ear results in an estimated 2.4 million health care visits every year and nearly half a billion dollars in health care costs. Below are answers to the most common questions regarding swimmer’s ear and healthy swimming.

What are the symptoms of swimmer's ear?

Symptoms of swimmer’s ear usually appear within a few days of swimming and include:

• Itchiness inside the ear.
• Redness and swelling of the ear.
• Pain when the infected ear is tugged or when pressure is placed on the ear.
• Pus draining from the infected ear.

Although all age groups are affected by swimmer’s ear, it is more common in children and can be extremely painful.

How is swimmer's ear spread at recreational water venues?

Swimmer’s ear can occur when water stays in the ear canal for long periods of time, providing the perfect environment for germs to grow and infect the skin. Germs found in pools and at other recreational water venues are one of the most common causes of swimmer’s ear.

Swimmer’s ear cannot be spread from one person to another.

If you think you have swimmer’s ear, consult your healthcare provider. Swimmer’s ear can be treated with antibiotic ear drops.

Is there a difference between a childhood middle ear infection and swimmer's ear?

Yes. Swimmer’s ear is not the same as the common childhood middle ear infection. If you can wiggle the outer ear without pain or discomfort then your ear condition is probably not swimmer’s ear.

How do I protect myself and my family?

To reduce the risk of swimmer’s ear:

DO keep your ears as dry as possible.

• Use a bathing cap, ear plugs, or custom-fitted swim molds when swimming.

DO dry your ears thoroughly after swimming or showering.

• Use a towel to dry your ears well.
• Tilt your head to hold each ear facing down to allow water to escape the ear canal.
• Pull your earlobe in different directions while your ear is faced down to help water drain out.
• If you still have water left in your ears, consider using a hair dryer to move air within the ear canal.
  • Put the dryer on the lowest heat and speed/fan setting.
  • Hold the dryer several inches from your ear.

DON’T put objects in your ear canal (including cotton-tip swabs, pencils, paperclips, or fingers).

DON’T try to remove ear wax. Ear wax helps protect your ear canal from infection.

• If you think that your ear canal is blocked by ear wax, consult your healthcare provider.

CONSULT your healthcare provider about using ear drops after swimming.

• Drops should not be used by people with ear tubes, damaged ear drums, outer ear infections, or ear drainage (pus or liquid coming from the ear).

CONSULT your healthcare provider if you have ear pain, discomfort, or drainage from your ears.

ASK your pool/hot tub operator if disinfectant and pH levels are checked at least twice per day—hot tubs and pools with proper disinfectant and pH levels are less likely to spread germs.

USE pool test strips to check the pool or hot tub yourself for adequate disinfectant (chlorine or bromine) levels.

Trachoma causes more vision loss and blindness than any other infection in the world. This disease is caused by Chlamydia trachomatis bacteria. Other variants or strains of these bacteria can cause a sexually transmitted infection (chlamydia) and disease in lymph nodes.  

Trachoma is easily spread through direct personal contact such as from fingers, through shared towels and clothes, and through flies that have been in contact with the eyes or nose of an infected person. When left untreated, repeated Chlamydia trachomatis infections in the eye can cause severe scarring on the inside of the eyelid. This can cause the eyelashes to scratch the cornea (trichiasis). In addition to causing pain, trichiasis permanently damages the cornea and can lead to irreversible blindness.

Chlamydia trachomatis infections spread in areas that lack access to safely managed drinking water and sanitation systems. Trachoma affects the most resource-limited communities in the world. Globally, almost 1.9 million people have vision loss because of trachoma, and it causes 1.4% of all blindness worldwide. In 2021, 136 million people lived in trachoma-endemic areas and were at risk of trachoma blindness.

The SAFE Strategy

To support the elimination of trachoma, the World Health Organization (WHO) established a public health strategy known as SAFE:

• Surgery to treat the advanced, blinding stage of the disease (trichiasis)
• Antibiotics to treat active infection
• Facial cleanliness
• Environmental improvements, specifically increasing access to water and sanitation.

The SAFE strategy combines surgery to correct trichiasis (S), antibiotics to clear infection (A), and prevention measures to keep the disease from spreading (F, & E).

Surgery to correct trichiasis (“S” in the SAFE strategy). Surgery relieves the pain of lashes rubbing against the eye. It also stops the lashes from scratching the cornea, which stops blindness from progressing.

Antibiotics (A). Pfizer donates the antibiotic Zithromax™ to trachoma programs, and the International Trachoma Initiative manages distribution. Antibiotics are given annually to entire districts affected by trachoma. These mass drug administration programs continue until trachoma levels drop below levels recommended by WHO.

Facial cleanliness (F). Since trachoma is spread through close personal contact, it typically infects children and their caretakers. Children are more likely to touch their eyes and have unclean faces that attract eye-seeking flies, so they are especially vulnerable to infection. Women are blinded by trachoma 4 times as often as men. This is likely due to their close contact with infected children and their increased frequency of getting infected. Good hygiene practices such as washing hands with soap, and washing faces with water to remove discharge from eyes and nose help reduce the spread of trachoma.

Environmental improvement (E). Improvements in community and household sanitation, such as access to household latrines, help control fly populations and breeding grounds. By increasing access to safely managed water and sanitation, communities can support good hygiene practices and long-term elimination of the disease. Affected communities can also help control trachoma by separating animal living quarters from human living space. They can also handle food and drinking water safely.