The insect Head lice _Pediculus humanus How are head lice spread

Document Sample
The insect Head lice _Pediculus humanus How are head lice spread Powered By Docstoc
					Head lice are tiny blood-sucking insects     lice can be spread by sharing objects        with these cases (parents, brothers and
that live on the human head. Infestations    such as hair combs, brushes, hats,           sisters, playmates). It is important to do
of head lice are common in children and      scarves, earphones, and pillows. Head        both of these at the same time so that no
often spread in schools. Efforts to          lice do not fly or jump; they only crawl.    unrecognized cases remain untreated.
control head lice can cause frustration      The environment is NOT an important          When further spread occurs, people
for both parents and school officials.       source of infection. Thus, disinfection of   often think that the lice are resistant to
Repeated treatments can become               furniture, such as chairs and sofas, is      treatment. However, what often occurs is
expensive.       A better understanding of   not necessary. Treating your                 “ping-pong transmission” from
head lice infestation helps to control the   surroundings or environment is not           unrecognized cases. Resistance to
problem.                                     helpful to control head lice. Head lice      treatment does happen, but should be
                                             infestation is not a sign of uncleanliness   considered only after other reasons for
                                             and is not controlled by baths or regular    failure of control have been ruled out.
The insect                                   shampoo. All socioeconomic groups are        Some of the pediculicides (treatments)
Head lice (Pediculus humanus                                                              can be bought only with a doctor’s
capitis) only infest humans. They do not     Head lice do not carry any diseases, but     prescription, while others can be bought
infest dogs or cats, and pet lice do not     constant scratching may lead to scalp        without a prescription. Most over-the-
infest humans. The adults are less than      infection.                                   counter products contain pyrethrin
inch long and are grayish-white wingless                                                  (Rid®, XXX®, A-200 Pyranate®), a
insects with three pairs of legs. Like                                                    natural insecticide. These and Lindane
mosquitos, they bite to obtain blood         Recognizing head lice                        (Kwell®), a prescription drug, kill adult
meals and can cause scalp itching. Adult     Itching is the most common symptom.          lice but do not kill all the nits. Therefore,
lice live for about three to four weeks.     Suspect head lice when a person              a second treatment is needed about 7-
Adult lice and their eggs are found          scratches his or her hair frequently. In     10 days after the first treatment, to kill
among the hair, especially behind the        mild cases, there may be no symptoms.        the lice born from surviving nits. Nix®, a
ears and on the back of the neck.            Recognition of head lice requires careful    synthetic permethrin, has the advantage
                                             scalp examination of all persons in          of attaching to the hair and remaining
The eggs, called nits, are cemented to                                                    active for about two weeks, killing newly
the base of the hair shaft. Nits hatch       contact with someone who has head
                                             lice. It is important to receive training    hatched nits. However, because its
after about one week, usually before                                                      activity is not 100%, treating again may
they are inch from the scalp. It is very     from a school or health department
                                             nurse before checking for head lice.         be necessary. Other drugs, including
rare to find living unhatched nits beyond                                                 some taken by mouth, may become
inch from the scalp. Therefore, although     A common sign of head lice is a red or       licensed in the future for the treatment of
most schools have a ‘no nit’ policy, the     irritated scalp, especially around the       head lice.
living nits, those close to the scalp, are   ears or back of the neck. Adult head lice
really the only ones of concern.             may be difficult to locate. Therefore,       Treatment with agents that smother
However, parents need to follow the          checking for nits is the most reliable way   head lice are also effective. These
head lice policies of the school where       to find infestations.                        consist of application of petroleum jelly
their children are enrolled.                                                              (Vaseline®), mineral or olive oil, or even
                                                                                          mayonnaise. The person’s head should
Head lice die quickly when away from                                                      be covered with a shower cap overnight.
their human host.                            Treatment and other control
                                                                                          If dealing with a young child, treatment
                                             measures                                     can be perfomed during the day using a
                                             The best strategy to control head lice is    shower cap.
How are head lice spread?                    to combine a) treatment of recognized        Do not use products for controlling
Head lice are spread mostly by direct        cases with b) detection and treatment of     animal fleas and ticks on children. This
head-to-head contact. Less commonly,         infestation among persons in contact         can be very harmful. Do not over treat
beyond instructions on the product being      Need More Information?
used or beyond the directions of your
doctor. Overexposure to chemicals is not
healthy.                                      Contact your local Health Department

Following a treatment, nits can be                             or the
removed using a special fine-toothed
comb. Metal combs may give better
results. Several solutions may help                       NC Department of
loosen the nits from the hairs (vinegar                   Environment and
diluted in half with water, or hair                       Natural Resources
conditioner). After the first and second      Division of Environmental Health
treatments on days 1 and 7, daily use of      Public Health Pest Management Section
ordinary shampoos followed by use of a        919-733-6407
conditioner or cream rinse and wet
combing for 14 days also are                                   or the
Head-to-head contact between children                          NC Department of Health
should be discouraged during outbreaks,                        and Human Services
and children should be made aware of                           Division of Public Health
this. Sharing of personal items (combs,                        Communicable Disease
brushes) that may spread lice should be                          Control Branch
avoided, and outerwear (hats, coats,                           919-733-3419
scarves) should be stored separately for
each child.
Bedding, hats, scarves, and other
clothing of persons being treated should
be machine-washed in hot water and
machine-dried using the hot cycle.
Combs and brushes should be washed
with a pediculicide solution or soaked in
very hot water (about 130 degrees F for
5 minutes) to kill lice and eggs. Clothes
which cannot be washed can be
disinfected by dry cleaning. Items that
may be contaminated also can be
sealed in a plastic bag for 10-14 days to
kill the lice. Remember that lice soon die

after leaving a human head. Simple                          State of North Carolina
                                               Department of Environment and Natural Resources
vacuuming of carpets and furniture will
provide further control. Lice do not infest        Department of Health and Human Services

rooms and, as stated above,                    A. Dennis McBride, MD, MPH, State Health Director
environmental chemical decontamination
is not needed.                                The N.C. Department of Health and Human Services does not
                                              discriminate on the basis of race, color, national origin, sex,
If you have more questions, contact your      religion, age or disability in employment or the provision of
                                              services. (ERC 89) 6G-8/99
local health department.

Shared By: