Communicable Diseases

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Indiana State Department of Health Quick Facts

Communicable Diseases Reference Guide for School Personnel


  • Signs and Symptoms
    • Fever and weakness;
    • Red, itchy rash.

    Chickenpox, also known as varicella, occurs primarily in children, although adults who are not immune can contract it. It is quite contagious and is spread by breathing in infected respiratory droplets or coming into contact with the rash where it has ruptured. In persons who have had chickenpox, the virus can cause shingles later in life.

    The Diagnosis. The best known symptom of chickenpox is the itchy, red rash that breaks out on the face, scalp, chest, back and, to a lesser extent, arms and legs. The rash usually appears about 2 weeks after exposure to the virus and begins as superficial spots.

    The spots quickly fill with a clear fluid, rupture, and turn crusty. These then slough off in a week or two. The rash continues to break out for the first 1 to 5 days, so spots at various stages of development may be present at the same time. Fever and malaise, mild in children and more severe in adults, also develop.

    How Serious Is Chickenpox? In children, chickenpox is a mild disease, but in adults it is more serious. In adults, pneumonia may develop, which can lead to death, although this is rare. In persons with suppressed immune systems, the disease is very serious.

    If a pregnant woman contracts chickenpox during the first or second trimester, there is a small risk that her child will be born with a congenital malformation.

    Chickenpox seldom lasts for more than 2 weeks, from the appearance of the first rash to the disappearance of the last one. Infection of the ruptured rash by bacteria may cause scarring.


Signs and Symptoms

  • Redness in the eyes;
  • Gritty feeling in the eye;
  • Itching of the eye;
  • Discharge in the eye that forms a crust during the night;
  • Blurred vision and sensitivity to light.

Conjunctivitis (commonly known as pinkeye), is an inflammation of the transparent membrane (the conjunctiva) that lines the eyelids and the eyeball up to the margin of the cornea. Conjunctivitis can be caused by a bacterial or viral infection, by an allergic reaction, or, in newborns, by an incompletely opened tear duct.

Both viral and bacterial conjunctivitis are common among children and are extremely infectious. Conjunctivitis can spread through a whole classroom of children in a matter of a few days.

The Diagnosis. All forms of conjunctivitis share certain symptoms. The white of the eye becomes red or pink, and the eye feels gritty when you blink. The eye also produces a yellowish discharge that forms a crust during the night. This sticky crust can seal the eyes shut and you may have to pry the lids gently apart or to soak off the crusts.

Viral conjunctivitis usually produces a small amount of watery discharge, whereas bacterial conjunctivitis often produces a good deal of thicker matter.

How Serious Is Conjunctivitis? The inflammation of conjunctivitis makes it an irritating condition, but it is usually harmless to sight. However, because it can be highly contagious, it must be diagnosed and treated early.

Fifth Disease

Parvovirus B19, erythema infectiosum

Incubation Period: 4-20 days, generally 7 days.

Signs and Symptoms: Marked redness of cheeks ("slapped-face" appearance) that is often followed in 1-4 days by a red, lace-like rash on the trunk and body. The rash might appear to change or reappear for 1-3 weeks with exposure to sunlight or increases in the environmental temperature, although not all infected persons have a rash. Child may have a slight fever or feel unwell.

It is estimated that about 50% of adults have had previous infection and are immune. In adults the rash is often absent, but arthritis lasting for days to months may occur. In 25% of infected adults, the person is asymptomatic (without any symptoms). Immunodeficient persons with infection may experience chronic anemia.

Methods of Transmission: Primarily from direct contact, droplet or airborne spread of respiratory secretions. Rarely by transfusion of blood or blood products. Vertically, from mother to fetus.

Communicable Period: The exact period is unknown, but children are thought to be most infectious before the rash breaks out; the disease is not communicable after the rash appears. Persons with aplastic crisis (absence of normal cell development) are communicable up to one week after the onset of symptoms. Immunosuppressed patients may be infectious for months to years.

Control: EXCLUDE the child with fever who feels ill. Otherwise, exclusion is not generally practical. Proper handwashing and disposal of tissues can help to lessen transmission.

Other Information: Some pregnant women have miscarried after becoming infected with parvovirus B19. However, the risk for this occurring is relatively low. Pregnant women who subsequently find that they have been in contact with children during the incubation period (4-20 days before signs or symptoms) may want to follow up with their physicians to discuss the option of serological testing to determine their immune status.

Although women who work primarily with children are at increased risk of infection, a routine policy to exclude pregnant women from the workplace when parvovirus B19 is occurring is not recommended. Occupational settings are not the only place where transmission may occur. Prevention methods to avoid infection include proper handwashing, teaching children to cover their mouth when coughing, and disposal of tissues for respiratory secretions.

German Measles

Signs and Symptoms

  • Rash;
  • Mild fever

German measles (rubella) is only moderately infectious. It is transmitted by inhalation of droplets of moisture that are carrying the virus. The incubation period is 2 to 3 weeks, and the affected person is contagious for 1 week before the rash appears.

The Diagnosis. The symptoms of the disease usually are mild and sometimes are hardly noticed. they may include mild fever, enlarged lymph nodes, and a fine, pink rash that appears on the face, the trunk, and then the arms and legs. The rash usually disappears in 2 to 3 days, lasting no more than 1 day on each part of the body. In many cases, the rash does not even occur. Your physician may take a blood sample to check for antibodies to the virus.

How Serious Is Rubella? In itself, rubella is a mild infection. Once you have had the disease, you usually are permanently immune. However, if a woman is pregnant when she contracts rubella, the consequences for her unborn child may be severe. The child may have any one of various problems including growth retardation, cataracts, rashes, deafness, congenital heart defects, and organ defects. the highest risk to the infant is during the first trimester, but exposure during the second trimester is also dangerous.

Head Lice

Signs and Symptoms

  • Intense itching;
  • Lice on the scalp and clothing;
  • Nits on hair shafts.

Getting head lice is not as bad as you may think. It is not a sign of uncleanliness, or poor health habits. It is not limited to the poor, or to certain racial or ethnic groups. Head lice can occur at any age, and to either sex. It doesn't just affect "other people"...it could happen to you or your family. So it's wise to learn how to recognize head lice infestation, how to treat it, and how to prevent it from coming back.

What are head lice? These tiny insects live in human hair. They hatch from small eggs, called nits, which are attached to the base of individual hairs. The eggs hatch in about 10 days, with the new lice reaching maturity in about two weeks. The female louse can live for 20 to 30 days, and can lay as many as six eggs a day. Since lice multiply fast, they should be treated promptly.

How does someone get head lice? Head lice can be transmitted in a number of ways besides direct physical contact. Borrowing a comb or brush from a person who has lice will do it. So can borrowing hats, ribbons, scarves or other head coverings. Sharing towels or pillowcases can also spread head lice. Even a stray hair that has nits can transmit head lice.

What signs should I look for? Persistent itching of the head and back of the neck can indicate head lice. You should also look for infected scratch marks or a rash on the scalp. Most important of all, look for nits attached to individual hairs. These can be seen with the naked eye, but you can probably identify them more easily with the aid of a magnifying glass under strong illumination.

Sometimes, small white specks in the hair such as dandruff or droplets of hair spray can be confused with nits. Try removing the specks from the hair shaft. Dandruff or hair spray will come off easily – nits are very difficult to remove. Check with a health professional if you are not sure whether head lice are present.

Treating head lice: the sooner, the better. Once head lice are found, the problem should be taken care of promptly in order to prevent it from spreading to others. Fortunately, the head does not need to be shaved in order to bring the problem under control. Several effective over-the-counter preparations are available at pharmacies to treat head lice. Ask the pharmacist and read the labels for instructions.

Your house should be "treated", too. Even after all lice are removed from the hair and scalp, the danger of reinfestation may still exist because lice can survive in the environment for up to four days. Also, nits can lie dormant for several weeks, then hatch to reinfest members of your family. All articles that may harbor lice or nits, such as clothes, towels and bed linens, should be washed in hot water and detergent and machine dried, or dry-cleaned. Disinfect combs and brushes by soaking them in a bleach solution and washing them in hot, soapy water; inspect for signs of lice or nits. For items that cannot be washed or dry-cleaned, vacuum as much as possible, especially upholstery, carpets, mattresses and other areas of the house or car where lice and their eggs may have been deposited. Wrap vacuum bag and contents in plastic bag and discard.

Should other family members or roommates be checked for head lice? Yes. If one member of a residence has head lice, all members should be inspected periodically for two weeks. If lice or nits are found, they should be treated promptly.

How can I help prevent head lice in the future? You should avoid borrowing personal items – combs, brushes, hats, towels or clothing – from each other or from friends. It is best for everyone to use only his or her own personal articles, both at home and while away.


Signs and Symptoms

  • Fever;
  • Cough, sneezing, swollen eyelids;
  • Sore throat;
  • Tiny white spots on the lining of the cheek;
  • Rash.

Measles, also known as rubeola, is a common childhood illness, although adults also are susceptible. The virus that causes the disorder is transmitted by inhalation of infecting droplets such as from a sneeze. Measles are most contagious before the rash appears, making it difficult to avoid the disease; until the rash disappears you still can pass it on to others. Once you have had measles, you are permanently immune and will not contract the disease again.

The Diagnosis. Measles begins as a fever, often as high as 104 degrees F to 105 degrees F, with a persistent cough sneezing, and sore throat. After about 4 days, a red blotchy rash appears on the face and behind the ears. The rash spreads to the chest and back and, finally, to the arms and legs. By the time it reaches the arms and legs, it has begun to fade from the face.

The symptoms usually appear 10 to 14 days after exposure to the virus. The diagnosis ordinarily is made on the basis of the characteristic rash and the small white spots on the inside lining of the cheek.

How Serious Is Measles? Normally, the infection lasts for 10 days to 2 weeks, and the person recovers completely. In a small number of cases, pneumonia may develop early in the course of the illness, or complications may arise immediately after appearance of the rash. Encephalitis, which causes vomiting, convulsions, coma, and brain disorders, or a bacterial infection may develop.


Signs and Symptoms

  • Swollen, painful salivary glands;
  • Fever;
  • Weakness and fatigue;
  • Possibly, inflammation of the pancreas, testes, ovaries, or brain.

Mumps is a childhood disease, but it can occur in adults. Its clinical name is epidemic parotitis. Mumps is caused by a virus and is spread by inhalation of infected droplets. The affected person becomes contagious 1 day before the symptoms appear, is most contagious for another 3 days, and then becomes less contagious as the swelling goes down.

The Diagnosis. The symptoms of mumps usually appear 2 to 3 weeks after the virus infection begins. The primary, and best known, symptom is swollen, painful salivary glands, causing the cheeks to puff out. In small children, fever is usually slight. If the affected person experiences headaches and becomes lethargic, inflammation of the brain and its lining may be present. Pain in the upper abdomen, nausea, and vomiting may indicate inflammation of the pancreas; lower abdominal pain in women may mean inflammation of the ovaries. This is often difficult to diagnose.

In about a quarter of the men who contract mumps, inflammation of the testicles develops. Your physician can confirm this diagnosis.

How Serious Is Mumps? Mumps make you quite uncomfortable but it usually is not a serious disease and rarely lasts more than 2 weeks. In some cases, however, encephalitis may develop, which is a serious complication of mumps and can lead to neurological symptoms and, rarely, death. Orchitis is uncomfortable and occasionally causes sterility.


Signs and Symptoms

  • Itching at night;
  • Thin, pencil-like lines on your skin.

In scabies, tiny mites, almost impossible to see without a magnifying glass, cause severe itching. Usually the itching is worse at night. Found worldwide among all groups of people and at all ages, they often infest an entire family. Scabies is highly contagious and is spread by close physical contact and, less often, by sharing clothing or bed sheets with an infested person. Canine scabies can be transmitted from dogs to humans.

The Diagnosis. Scabies prefer to burrow into certain areas of the skin, such as between your fingers, in your armpits, around your waist, along the insides of your wrists, on the back of your elbows, on your ankles and soles of the feet. They form a characteristic burrow that looks like a thin, irregular pencil mark.

Your physician will look for such a burrow and will remove the mite located at the end of one to confirm the diagnosis. Although not serious, scabies is very annoying.

Strep and Scarlet Fever

Incubation Period: 1-3 days, rarely longer.

Signs and Symptoms:

  • Strep Throat: Fever, sore and red throat, pus spots on the back of the throat, tender and swollen lymph nodes in the neck.
  • Scarlet Fever: Includes all symptoms that occur with strep throat, as well as strawberry tongue and rash on the skin and inside the mouth. High fever, nausea and vomiting may occur. The rash on the skin is normally easily felt but not seen. The tongue is usually white before the appearance of the strawberry tongue.

Methods of Transmission: Direct or intimate contact with an infected person or carrier. Rarely, by contaminated objects or hands. Outbreaks of strep throat may follow ingestion of contaminated foods, such as milk, egg salad or deviled eggs.

Minimum Control Measures: Communicable Period: With antibiotic treatment, communicability is eliminated within 24 hours. Variable for untreated cases. Can spread through mild, unrecognized cases.

Other Information: Medical attention is essential. Untreated children may develop severe complications, including rheumatic fever and glomerulonephritis (kidney disease).