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how vaccines prevent disease |
Why Are Childhood Vaccines So Important? It is always better to prevent a disease than to treat it after it occurs. Diseases that used to be common in this country and around the world, including polio, measles, diphtheria, pertussis (whooping cough), rubella (German measles), mumps, tetanus, rotavirus and Haemophilus influenzae type b (Hib) can now be prevented by vaccination. Thanks to a vaccine, one of the most terrible diseases in history ��� smallpox ��� no longer exists outside the laboratory. Over the years vaccines have prevented countless cases of disease and saved millions of lives. Immunity Protects us From Disease Immunity is the body���s way of preventing disease. Children are born with an immune system composed of cells, glands, organs, and fluids located throughout the body. The immune system recognizes germs that enter the body as "foreign invaders��� (called antigens) and produces proteins called antibodies to fight them. The first time a child is infected with a specific antigen (say measles virus), the immune system produces antibodies designed to fight it. This takes time . . . usually the immune system can���t work fast enough to prevent the antigen from causing disease, so the child still gets sick. However, the immune system ���remembers��� that antigen. If it ever enters the body again, even after many years, the immune system can produce antibodies fast enough to keep it from causing disease a second time. This protection is called immunity. It would be nice if there were a way to give children immunity to a disease without their having to get sick first. In fact there is: Vaccines contain the same antigens (or parts of antigens) that cause diseases. For example, measles vaccine contains measles virus. But the antigens in vaccines are either killed, or weakened to the point that they don���t cause disease. However, they are strong enough to make the immune system produce antibodies that lead to immunity. In other words, a vaccine is a safer substitute for a child���s first exposure to a disease. The child gets protection without having to get sick. Through vaccination, children can develop immunity without suffering from the actual diseases that vaccines prevent. Top of Page More Facts Newborn babies are immune to many diseases because they have antibodies they got from their mothers. However, this immunity goes away during the first year of life. If an unvaccinated child is exposed to a disease germ, the child's body may not be strong enough to fight the disease. Before vaccines, many children died from diseases that vaccines now prevent, such as whooping cough, measles, and polio. Those same germs exist today, but because babies are protected by vaccines, we don���t see these diseases nearly as often. Immunizing individual children also helps to protect the health of our community, especially those people who cannot be immunized (children who are too young to be vaccinated, or those who can���t receive certain vaccines for medical reasons), and the small proportion of people who don���t respond to a particular vaccine. Vaccinepreventable diseases have a costly impact, resulting in doctor's visits, hospitalizations, and premature deaths. Sick children can also cause parents to lose time from work. Related Pages Why Immunize? Vaccines: A Safe Choice Parents Guide to Immunizations For Parents: How Vaccines Prevent Diseases Top of Page Images and logos on this website which are trademarked/copyrighted or used with permission of the trademark/copyright or logo holder are not in the public domain. These images and logos have been licensed for or used with permission in the materials provided on this website. The materials in the form presented on this website may be used without seeking further permission. Any other use of trademarked/copyrighted images or logos requires permission from the trademark/copyright holder...more This graphic notice means that you are leaving an HHS Web site. For more information, please see the Exit Notification and Disclaimer policy. |
Who is at risk for ? ? |
Measles: Make Sure Your Child Is Protected with MMR Vaccine Measles starts with a fever. Soon after, it causes a cough, runny nose, and red eyes. Then a rash of tiny, red spots breaks out. Measles can be serious for young children. Learn about protecting your child from measles with MMR vaccine. Protect your child at every age. Click on your child's age group for vaccine information. View or print agespecific vaccine information [252 KB, 27 pages] Records & Requirements Recording immunizations Finding immunization records Interpreting abbreviations on records Immunization requirements for child care and schools Making the Vaccine Decision How vaccines prevent diseases Vaccine side effects/risks Vaccine ingredients Ensuring vaccine safety Vaccines and your child���s immune system Learn More About Preteen and Teen Vaccines The Vaccines For Children program has helped prevent diseases and save lives���big time! [enlarged view] Watch The Immunization Baby Book Learn what vaccines your child needs, when they are needed, and why it is so important to follow the CDC���s recommended immunization schedule as you flip through this video baby book (4:04 mins) on CDCTV or on YouTube. Who & When (Immunization Schedules) Birth through 6 Years Schedule [2 pages] Create a schedule for your child 7 through 18 Years Schedule [2 pages] 19 Years and Older Schedule [2 pages] Learn more about how CDC sets the immunization schedule for your family Knowing the childhood vaccination rates in your community is important. More Diseases and the Vaccines that Prevent Them Learn more about the 16 diseases that can be prevented with vaccines, as well as the benefits and risks of vaccination. Learn More About... Adoption and Vaccines Pregnancy Help Paying for Vaccines Evaluating Information on the Web |
How to prevent ? |
Vaccines and Preventable Diseases On this Page Vaccine Shortages & Delays Potential New Vaccines Vaccines: The Basics FAQ about Vaccines & Diseases they Prevent VACCINEPREVENTABLE DISEASES OR, find it by Vaccine Anthrax Cervical Cancer Diphtheria Hepatitis A Hepatitis B Haemophilus influenzae type b (Hib) Human Papillomavirus (HPV) H1N1 Flu (Swine Flu) Influenza (Seasonal Flu) Japanese Encephalitis (JE) Measles Meningococcal Mumps Pertussis (Whooping Cough) Pneumococcal Poliomyelitis (Polio) Rabies Rotavirus Rubella (German Measles) Shingles (Herpes Zoster) Smallpox Tetanus (Lockjaw) Tuberculosis Typhoid Fever Varicella (Chickenpox) Yellow Fever At a Glance Vaccinepreventable disease levels are at or near record lows. Even though most infants and toddlers have received all recommended vaccines by age 2, many underimmunized children remain, leaving the potential for outbreaks of disease. Many adolescents and adults are underimmunized as well, missing opportunities to protect themselves against diseases such as Hepatitis B, influenza, and pneumococcal disease. CDC works closely with public health agencies and private partners to improve and sustain immunization coverage and to monitor the safety of vaccines so that this public health success story can be maintained and expanded in the century to come. Vaccine Shortages & Delays The latest national information about vaccine supplies and guidance for healthcare providers who are facing vaccine shortages or delays Chart of shortages & delays Potential New Vaccines Resources for finding information on potential vaccines, research and development status, licensure status, etc. New Vaccine Surveillance Network Program evaluates impact of new vaccines and vaccine policies through a network of 6 US sites Status of Licensure and Recs for New Vaccines American Academy of Pediatrics (AAP) Potential New Vaccines Immunization Action Coalition (IAC) Vaccines: The Basics Without vaccines, epidemics of many preventable diseases could return, resulting in increased ��� and unnecessary ��� illness, disability, and death. All about vaccines How vaccines prevent disease List of all vaccinepreventable diseases List of all vaccines used in United States Photos of vaccinepreventable diseases and/or people affected by them View all... FAQ about Vaccines & Diseases they Prevent What are the ingredients in vaccines? What vaccines do adults need? What vaccines do children need? What vaccines are used in the United States? What diseases do vaccines prevent? View all... Related Pages Basics and Common Questions Who Should NOT Get These Vaccines? Unprotected Stories Top of Page Images and logos on this website which are trademarked/copyrighted or used with permission of the trademark/copyright or logo holder are not in the public domain. These images and logos have been licensed for or used with permission in the materials provided on this website. The materials in the form presented on this website may be used without seeking further permission. Any other use of trademarked/copyrighted images or logos requires permission from the trademark/copyright holder...more This graphic notice means that you are leaving an HHS Web site. For more information, please see the Exit Notification and Disclaimer policy. |
what diseases are vaccine preventable |
List of VaccinePreventable Diseases The following links will lead you to the main page that describes both the disease and the vaccine(s). Vaccines are available for all of the following vaccinepreventable diseases (unless otherwise noted): Anthrax Cervical Cancer (Human Papillomavirus) Diphtheria Hepatitis A Hepatitis B Haemophilus influenzae type b (Hib) Human Papillomavirus (HPV) Influenza (Flu) Japanese encephalitis (JE) Measles Meningococcal Mumps Pertussis Pneumococcal Polio Rabies Rotavirus Rubella Shingles (Herpes Zoster) Smallpox Tetanus Typhoid Tuberculosis (TB) Varicella (Chickenpox) Yellow Fever Related Pages For Parents: What You Need to Know List of Vaccines Used in U.S. Photos of diseases Top of Page Images and logos on this website which are trademarked/copyrighted or used with permission of the trademark/copyright or logo holder are not in the public domain. These images and logos have been licensed for or used with permission in the materials provided on this website. The materials in the form presented on this website may be used without seeking further permission. Any other use of trademarked/copyrighted images or logos requires permission from the trademark/copyright holder...more This graphic notice means that you are leaving an HHS Web site. For more information, please see the Exit Notification and Disclaimer policy. |
what is yersiniosis for Yersinia ? |
Yersiniosis is an infectious disease caused by a bacterium of the genus Yersinia. In the United States, most human illness is caused by one species, Y. enterocolitica. Infection with Y. enterocolitica can cause a variety of symptoms depending on the age of the person infected. Infection with Y. enterocolitica occurs most often in young children. Common symptoms in children are fever, abdominal pain, and diarrhea, which is often bloody. Symptoms typically develop 4 to 7 days after exposure and may last 1 to 3 weeks or longer. In older children and adults, rightsided abdominal pain and fever may be the predominant symptoms, and may be confused with appendicitis. In a small proportion of cases, complications such as skin rash, joint pains, or spread of bacteria to the bloodstream can occur. |
how common is infection with y. enterocolitica for Yersinia ? |
Y. enterocolitica is a relatively infrequent cause of diarrhea and abdominal pain. Based on data from the Foodborne Diseases Active Surveillance Network (FoodNet), which measures the burden and sources of specific diseases over time, approximately one cultureconfirmed Y. enterocolitica infection per 100,000 persons occurs each year. Children are infected more often than adults, and the infection is more common in the winter. |
how can y. enterocolitica infections be diagnosed for Yersinia ? |
Y. enterocolitica infections are generally diagnosed by detecting the organism in the stools. Many laboratories do not routinely test for Y. enterocolitica,so it is important to notify laboratory personnel when infection with this bacterium is suspected so that special tests can be done. The organism can also be recovered from other sites, including the throat, lymph nodes, joint fluid, urine, bile, and blood. |
how can y. enterocolitica infections be treated for Yersinia ? |
Uncomplicated cases of diarrhea due to Y. enterocolitica usually resolve on their own without antibiotic treatment. However, in more severe or complicated infections, antibiotics such as aminoglycosides, doxycycline, trimethoprimsulfamethoxazole, or fluoroquinolones may be useful. |
what are public health agencies doing to prevent or control yersiniosis for Yersinia ? |
The Centers for Disease Control and Prevention (CDC) monitors the frequency of Y. enterocolitica infections through the foodborne disease active surveillance network (FoodNet). In addition, CDC conducts investigations of outbreaks of yersiniosis to control them and to learn more about how to prevent these infections. CDC has collaborated in an educational campaign to increase public awareness about prevention of Y. enterocolitica infections. The U.S. Food and Drug Administration inspects imported foods and milk pasteurization plants and promotes better food preparation techniques in restaurants and food processing plants. The U.S. Department of Agriculture monitors the health of food animals and is responsible for the quality of slaughtered and processed meat. The U.S. Environmental Protection Agency regulates and monitors the safety of our drinking water supplies. |
What is (are) Parasites - Zoonotic Hookworm ? |
There are many different species of hookworms, some are human parasites and some are animal parasites. People can be infected by larvae of animal hookworms, usually dog and cat hookworms. The most common result of animal hookworm infection is a skin condition called cutaneous larva migrans. |
Who is at risk for Parasites - Zoonotic Hookworm? ? |
Dog and cat hookworms are found throughout the world, especially in warmer climates. In the United States, zoonotic hookworms are found everywhere but more commonly along the East Coast than the West Coast. Worldwide, zoonotic hookworms are found in tropical and subtropical regions where the parasite is better able to survive because of environmental conditions. However, there is one type of dog and cat hookworm that is more commonly found in cooler climates. The global burden of zoonotic hookworm in dogs and cats is not known; also, the amount of disease in people caused by these parasites is also unknown. Cutaneous larva migrans (CLM) is most often reported by returning travelers to tropical regions who have had soil and/or sand exposures in places where dogs and cats are likely to have hookworms. However, CLM is likely causing significant problems for the people who live in less developed parts of the world, even though the disease is not reported regularly. In less developed areas of the world, dogs and cats are often freeranging and have high rates of infection with hookworm which leads to widespread contamination of sand and soil. In a survey of a rural population in Brazil, the prevalence of CLM during the rainy season was 14.9% among children less than 5 years old and 0.7% among adults aged 20 years and older. |
How to diagnose Parasites - Zoonotic Hookworm ? |
Cutaneous larva migrans (CLM) is a clinical diagnosis based on the presence of the characteristic signs and symptoms, and exposure history to zoonotic hookworm. For example, the diagnosis can be made based on finding red, raised tracks in the skin that are very itchy. This is usually found on the feet or lower part of the legs on persons who have recently traveled to tropical areas and spent time at the beach. There is no blood test for zoonotic hookworm infection. Persons who think they have CLM should consult their health care provider for accurate diagnosis. |
What are the treatments for Parasites - Zoonotic Hookworm ? |
The zoonotic hookworm larvae that cause cutaneous larva migrans (CLM) usually do not survive more than 5 ��� 6 weeks in the human host. In most patients with CLM, the signs and symptoms resolve without medical treatment. However, treatment may help control symptoms and help prevent secondary bacterial infections. Antiparasitic treatments may be prescribed by your health care provider. More on: Resources For Health Professionals: Treatment |
How to prevent Parasites - Zoonotic Hookworm ? |
Wearing shoes and taking other protective measures to avoid skin contact with sand or soil will prevent infection with zoonotic hookworms. Travelers to tropical and subtropical climates, especially where beach exposures are likely, should be advised to wear shoes and use protective mats or other coverings to prevent direct skin contact with sand or soil. Routine veterinary care of dogs and cats, including regular deworming, will reduce environmental contamination with zoonotic hookworm eggs and larvae. Prompt disposal of animal feces prevents eggs from hatching and contaminating soil which makes it important for control of this parasitic infection. |
Who is at risk for Chapare Hemorrhagic Fever (CHHF)? ? |
Like all arenaviruses, Chapare virus has a rodent host as its reservoir. Humans can contract CHHF through contact with an infected rodent. Contact can be direct or through inhalation of aerosolized Chapare virus from the urine or feces of infected rodents. Although arenaviruses have been isolated from insects, neither they nor any other intermediary host appear to spread CHHF. Persontoperson transmission of arenaviruses through aerosolization, although possible, is rare. From the only observed cluster of cases of CHHF, there was no evidence of persontoperson transmission. Transmission, if it can occur with CHHF, is most likely the result of direct contact with an infected person. |
What are the symptoms of Chapare Hemorrhagic Fever (CHHF) ? |
The symptoms of CHHF, as reported in the only described patient, resemble those of other South American hemorrhagic fevers, such as Argentine HF or Bolivian HF. The incubation period is unknown, but for Argentine hemorrhagic fever (AHF) is 6 to 16 days. The CHHF clinical course included: fever headache articulation and muscle pain vomiting These symptoms were followed by deterioration with multiple hemorrhagic signs. The only described CHHF patient died 14 days after onset of symptoms. Since Arenaviruses may enter the fetus through infection of the mother, and anecdotal evidence suggests that infected pregnant women may suffer miscarriages, it is reasonable to assume that both infection of the fetus and miscarriage may be associated with CHHF infection in the mother. |
Who is at risk for Chapare Hemorrhagic Fever (CHHF)? ? |
CHHF occurs in the Cochabamba region of Bolivia. Field workers Field workers are at greatest risk because of increased human contact with the reservoir rodent population. Sexual partners of field workers may be at greater risk as well. Laboratory infections have been frequently described with Arenaviruses and Chapare virus can certainly be transmitted to laboratory workers during manipulation of the virus especially during experimental infections of rodents. |
How to diagnose Chapare Hemorrhagic Fever (CHHF) ? |
CHHF virus has been successfully isolated from both blood and serum during the acute febrile phase of illness. Although not undertaken at the time of the initial cluster, virus can certainly be isolated from tissue obtained postmortem if available. A subsequent complete genomic analysis of Chapare virus facilitated the development of specific molecular detection (RTPCR) assays. Serologic diagnosis of CHHF can be made by indirect immunofluorescent assay and ELISA. However, individuals from endemic areas who show fever, dizziness, and myalgia, accompanied by laboratory findings of low white blood cell and platelet counts and excess protein in the urine, should be suspected of having one of the South American hemorrhagic fever viruses. Clinical specimens should be tested using specific assays. |
What are the treatments for Chapare Hemorrhagic Fever (CHHF) ? |
Supportive therapy is important in CHHF. This includes: maintenance of hydration management of shock sedation pain relief usual precautions for patients with bleeding disorders transfusions (when necessary) Use of convalescent plasma therapy for treatment of AHF reduces mortality significantly and anecdotal evidence shows that the antiviral drug ribavirin may also hold promise for treating AHF. Ribavirin has also been considered for preventing development of disease in people exposed to other arenaviruses. Recovery The precise mortality of CHHF is unknown and the only described case was fatal. Patients who have suffered from other arenaviruses may continue to excrete virus in urine or semen for weeks after recovery. For this reason, these fluids should be monitored for infectivity, since convalescent patients have the potential to infect others (particularly sexual partners) via these fluids. |
How to prevent Chapare Hemorrhagic Fever (CHHF) ? |
Although rodent control would be desirable, it will not be a successful strategy for preventing Chapare hemorrhagic fever cases caused by exposures outdoors. As for other hemorrhagic fevers, full barrier nursing procedures should be implemented during management of suspected or confirmed CHHF cases. |
What is (are) Parasites - Trichuriasis (also known as Whipworm Infection) ? |
Whipworm (Trichuris trichiura) is an intestinal parasite of humans. The larvae and adult worms live in the intestine of humans and can cause intestinal disease. The name is derived from the worm���s distinctive whiplike shape. |
Who is at risk for Parasites - Trichuriasis (also known as Whipworm Infection)? ? |
Whipworm is a soiltransmitted helminth (STH) and is the third most common roundworm of humans. Whipworm causes an infection called trichuriasis and often occurs in areas where human feces is used as fertilizer or where defecation onto soil happens. The worms are spread from person to person by fecaloral transmission or through fecescontaminated food. Geographic DistributionWorldwide, infection occurs more frequently in areas with tropical weather and poor sanitation practices, and among children. In 2002, the estimated number of persons infected with whipworm was 1 billion. Trichuriasis also occurs in the southern United States. |
How to diagnose Parasites - Trichuriasis (also known as Whipworm Infection) ? |
The standard method for diagnosing the presence of whipworm is by microscopically identifying whipworm eggs in a stool sample. Because eggs may be difficult to find in light infections, a concentration procedure is recommended. |
What are the treatments for Parasites - Trichuriasis (also known as Whipworm Infection) ? |
Anthelminthic medications (drugs that rid the body of parasitic worms), such as albendazole and mebendazole, are the drugs of choice for treatment. Infections are generally treated for 3 days. The recommended medications are effective. Health care providers may decide to repeat a stool exam after treatment. Iron supplements may also be prescribed if the infected person suffers from anemia. More on: Resources for Health Professionals: Treatment |
How to prevent Parasites - Trichuriasis (also known as Whipworm Infection) ? |
The best way to prevent whipworm infection is to always: Avoid ingesting soil that may be contaminated with human feces, including where human fecal matter ("night soil") or wastewater is used to fertilize crops. Wash your hands with soap and warm water before handling food. Teach children the importance of washing hands to prevent infection. Wash, peel, or cook all raw vegetables and fruits before eating, particularly those that have been grown in soil that has been fertilized with manure. More on: Handwashing Transmission of infection to others can be prevented by Not defecating outdoors. Effective sewage disposal systems. |
What is (are) Parasites - Trichinellosis (also known as Trichinosis) ? |
Trichinellosis, also called trichinosis, is caused by eating raw or undercooked meat of animals infected with the larvae of a species of worm called Trichinella. Infection occurs commonly in certain wild carnivorous (meateating) animals such as bear or cougar, or omnivorous (meat and planteating) animals such as domestic pigs or wild boar. |
Who is at risk for Parasites - Trichinellosis (also known as Trichinosis)? ? |
People acquire trichinellosis by consuming raw or undercooked meat infected with the Trichinella parasite, particularly wild game meat or pork. Even tasting very small amounts of undercooked meat during preparation or cooking puts you at risk for infection. Outbreaks occur in settings where multiple people consume the same Trichinellainfected meat.Worldwide, an estimated 10,000 cases of trichinellosis occur every year. Several different species of Trichinella can cause human disease; the most common species is Trichinella spiralis, which has a global distribution and is the species most commonly found in pigs. Other Trichinella species are less commonly reported as the cause of human disease and may be found in different parts of the world, usually infecting wild animals.In the United States, trichinellosis cases are reported to CDC much less commonly now than in the past (Figure 1). During the late 1940s, when the U.S. Public Health Service began counting cases of trichinellosis, 400 cases in the United States were recorded each year on average. During 20082010, 20 cases were reported to CDC each year on average. The overall number of cases reported has decreased because of improved pigraising practices in the pork industry, commercial and home freezing of pork, and public awareness of the danger of eating raw or undercooked meat products. The number of cases associated with raw or undercooked wild game meats has remained relatively constant over time (Figure 2). Over the past 40 years, few cases of trichinellosis have been reported in the United States, and the risk of trichinellosis from commercially raised and properly prepared pork is very low. However, eating undercooked wild game, particularly bear meat, puts one at risk for acquiring this disease. |
How to diagnose Parasites - Trichinellosis (also known as Trichinosis) ? |
A diagnosis of trichinellosis is made in patients whose signs and symptoms are compatible with trichinellosis, have a positive laboratory test for Trichinella, and who can recall eating raw or undercooked pork or wild game meat. Laboratory diagnosis of Trichinella infection is most often made by a Trichinella antibody test. In some cases a muscle biopsy may be performed. More on: Resources for Health Professionals: Diagnosis |
What are the treatments for Parasites - Trichinellosis (also known as Trichinosis) ? |
Safe and effective prescription drugs are available to treat both Trichinella infection and the symptoms that occur as a result of infection. Treatment should begin as soon as possible; a doctor will make the decision to treat based upon symptoms, exposure to raw or undercooked meat, and laboratory test results. More on: Resources For Health Professionals: Treatment |
How to prevent Parasites - Trichinellosis (also known as Trichinosis) ? |
Wash your hands with warm water and soap after handling raw meat. Curing (salting), drying, smoking, or microwaving meat alone does not consistently kill infective worms; homemade jerky and sausage were the cause of many cases of trichinellosis reported to CDC in recent years. Freeze pork less than 6 inches thick for 20 days at 5��F (15��C) to kill any worms. Freezing wild game meats, unlike freezing pork products, may not effectively kill all worms because some worm species that infect wild game animals are freezeresistant. Clean meat grinders thoroughly after each use. To help prevent Trichinella infection in animal populations, do not allow pigs or wild animals to eat uncooked meat, scraps, or carcasses of any animals, including rats, which may be infected with Trichinella. |
What is (are) Parasites - Hookworm ? |
Hookworm is an intestinal parasite of humans. The larvae and adult worms live in the small intestine can cause intestinal disease. The two main species of hookworm infecting humans are Ancylostoma duodenale and Necator americanus. |
Who is at risk for Parasites - Hookworm? ? |
Hookworm is a soiltransmitted helminth (STH) and is one of the most common roundworm of humans. Infection is caused by the nematode parasites Necator americanus and Ancylostoma duodenale. Hookworm infections often occur in areas where human feces are used as fertilizer or where defecation onto soil happens. Geographic Distribution The geographic distributions of the hookworm species that are intestinal parasites in human, Ancylostoma duodenale and Necator americanus, are worldwide in areas with warm, moist climates and are widely overlapping. Necator americanus was widespread in the Southeastern United States until the early 20th century. |
How to diagnose Parasites - Hookworm ? |
The standard method for diagnosing the presence of hookworm is by identifying hookworm eggs in a stool sample using a microscope. Because eggs may be difficult to find in light infections, a concentration procedure is recommended. |
What are the treatments for Parasites - Hookworm ? |
Anthelminthic medications (drugs that rid the body of parasitic worms), such as albendazole and mebendazole, are the drugs of choice for treatment of hookworm infections. Infections are generally treated for 13 days. The recommended medications are effective and appear to have few side effects. Iron supplements may also be prescribed if the infected person has anemia. More on: Resources for Health Professionals: Treatment |
How to prevent Parasites - Hookworm ? |
The best way to avoid hookworm infection is not to walk barefoot in areas where hookworm is common and where there may be human fecal contamination of the soil. Also, avoid other skin contact with such soil and avoid ingesting it. Infection can also be prevented by not defecating outdoors and by effective sewage disposal systems. |
What is (are) Parasites - African Trypanosomiasis (also known as Sleeping Sickness) ? |
Frequently Asked Queestions (FAQs) |
Who is at risk for Parasites - African Trypanosomiasis (also known as Sleeping Sickness)? ? |
There are two subspecies of the parasite Trypanosoma brucei that cause disease in humans. The clinical features of the infection depend on the subspecies involved. The two subspecies are found in different regions of Africa. At present, there is no overlap in their geographic distribution. T. b. rhodesiense (East African sleeping sickness) is found in focal areas of eastern and southeastern Africa. Each year a few hundred cases are reported to the World Health Organization. Over 95% of the cases of human infection occur in Tanzania, Uganda, Malawi, and Zambia. Animals are the primary reservoir of infection. Cattle have been implicated in the spread of the disease to new areas and in local outbreaks. A wild animal reservoir is thought to be responsible for sporadic transmission to hunters and visitors to game parks. Infection of international travelers is rare, but it occasionally occurs. In the U.S., one case per year, on average, is diagnosed. Most cases of sleeping sickness imported into the U.S. have been in travelers who were on safari in East Africa. T. b. gambiense (West African sleeping sickness) is found predominantly in central Africa and in limited areas of West Africa. Most of the sleeping sickness in Africa is caused by this form of the parasite. Epidemics of sleeping sickness have been a significant public health problem in the past, but the disease is reasonably wellcontrolled at present, with 7,00010,000 cases reported annually in recent years. Over 95% of the cases of human infection are found in Democratic Republic of Congo, Angola, Sudan, Central African Republic, Chad, and northern Uganda. Humans are the important reservoir of infection, although the parasite can sometimes be found in domestic animals (e.g., pigs, dogs, goats). Imported infection in the U.S. is extremely rare, and most cases have occurred in African nationals who have immigrated rather than in returning U.S. travelers. Both forms of sleeping sickness are transmitted by the bite of the tsetse fly (Glossina species). Tsetse flies inhabit rural areas, living in the woodlands and thickets that dot the East African savannah. In central and West Africa, they live in the forests and vegetation along streams. Tsetse flies bite during daylight hours. Both male and female flies can transmit the infection, but even in areas where the disease is endemic, only a very small percentage of flies are infected. Although the vast majority of infections are transmitted by the tsetse fly, other modes of transmission are possible. Occasionally, a pregnant woman can pass the infection to her unborn baby. In theory, the infection can also be transmitted by blood transfusion or sexual contact, but such cases have rarely been documented. This information is not meant to be used for selfdiagnosis or as a substitute for consultation with a health care provider. If you have any questions about the parasites described above or think that you may have a parasitic infection, consult a health care provider. |
How to diagnose Parasites - African Trypanosomiasis (also known as Sleeping Sickness) ? |
The diagnosis of African Trypanosomiasis is made through laboratory methods, because the clinical features of infection are not sufficiently specific. The diagnosis rests on finding the parasite in body fluid or tissue by microscopy. The parasite load in T. b. rhodesiense infection is substantially higher than the level in T. b. gambiense infection. T. b. rhodesiense parasites can easily be found in blood. They can also be found in lymph node fluid or in fluid or biopsy of a chancre. Serologic testing is not widely available and is not used in the diagnosis, since microscopic detection of the parasite is straightforward. The classic method for diagnosing T. b. gambiense infection is by microscopic examination of lymph node aspirate, usually from a posterior cervical node. It is often difficult to detect T. b. gambiense in blood. Concentration techniques and serial examinations are frequently needed. Serologic testing is available outside the U.S. for T. b. gambiense; however, it normally is used for screening purposes only and the definitive diagnosis rests on microscopic observation of the parasite. All patients diagnosed with African trypanosomiasis must have their cerebrospinal fluid examined to determine whether there is involvement of the central nervous system, since the choice of treatment drug(s) will depend on the disease stage. The World Health Organization criteria for central nervous system involvement include increased protein in cerebrospinal fluid and a white cell count of more than 5. Trypanosomes can often be observed in cerebrospinal fluid in persons with second stage infection. More on: Resources for Health Professionals: Diagnosis |
What are the treatments for Parasites - African Trypanosomiasis (also known as Sleeping Sickness) ? |
All persons diagnosed with African Trypanosomiasis should receive treatment. The specific drug and treatment course will depend on the type of infection (T. b. gambiense or T. b. rhodesiense) and the disease stage (i.e. whether the central nervous system has been invaded by the parasite). Pentamidine, which is the recommended drug for first stage T. b. gambiense infection, is widely available in the U.S. The other drugs (suramin, melarsoprol, eflornithine, and nifurtimox) used to treat African trypanosomiasis are available in the U.S. only from the CDC. Physicians can consult with CDC staff for advice on diagnosis and management and to obtain otherwise unavailable treatment drug. There is no test of cure for African trypanosomiasis. After treatment patients need to have serial examinations of their cerebrospinal fluid for 2 years, so that relapse can be detected if it occurs. More on: Resources for Health Professionals: Treatment |
How to prevent Parasites - African Trypanosomiasis (also known as Sleeping Sickness) ? |
There is no vaccine or drug for prophylaxis against African trypanosomiasis. Preventive measures are aimed at minimizing contact with tsetse flies. Local residents are usually aware of the areas that are heavily infested and they can provide advice about places to avoid. Other helpful measures include: Wear longsleeved shirts and pants of mediumweight material in neutral colors that blend with the background environment. Tsetse flies are attracted to bright or dark colors, and they can bite through lightweight clothing. Inspect vehicles before entering. The flies are attracted to the motion and dust from moving vehicles. Avoid bushes. The tsetse fly is less active during the hottest part of the day but will bite if disturbed. Use insect repellent. Permethrinimpregnated clothing and insect repellent have not been proved to be particularly effective against tsetse flies, but they will prevent other insect bites that can cause illness. Control of African trypanosomiasis rests on two strategies: reducing the disease reservoir and controlling the tsetse fly vector. Because humans are the significant disease reservoir for T. b. gambiense, the main control strategy for this subspecies is active casefinding through population screening, followed by treatment of the infected persons that are identified. Tsetse fly traps are sometimes used as an adjunct. Reducing the reservoir of infection is more difficult for T. b. rhodesiense, since there are a variety of animal hosts. Vector control is the primary strategy in use. This is usually done with traps or screens, in combination with insecticides and odors that attract the flies. |
What is (are) Parasites - Lice - Pubic "Crab" Lice ? |
Also called crab lice or "crabs," pubic lice are parasitic insects found primarily in the pubic or genital area of humans. Pubic lice infestation is found worldwide and occurs in all races, ethnic groups, and levels of society. |
Who is at risk for Parasites - Lice - Pubic "Crab" Lice? ? |
Pubic ("crab") lice infestation is found worldwide and occurs in all races and ethnic groups and in all levels of society. Pubic lice usually are spread through sexual contact and are most common in adults. Occasionally pubic lice may be spread by close personal contact or contact with articles such as clothing, bed linens, and towels that have been used by an infested person. Pubic lice found on the head or eyelashes of children may be an indication of sexual exposure or abuse. Pubic lice do not transmit disease; however, secondary bacterial infection can occur from scratching of the skin. |
How to diagnose Parasites - Lice - Pubic "Crab" Lice ? |
Pubic lice are short and crablike and appear very different from head and body lice. Pubic lice infestation is diagnosed by finding a ���crab��� louse or eggs on hair in the pubic region or, less commonly, elsewhere on the body (eyebrows, eyelashes, beard, mustache, armpit, perianal area, groin, trunk, scalp). Although pubic lice and nits can be large enough to be seen with the naked eye, a magnifying lens may be necessary to find lice or eggs. |
What are the treatments for Parasites - Lice - Pubic "Crab" Lice ? |
A licekilling lotion containing 1% permethrin or a mousse containing pyrethrins and piperonyl butoxide can be used to treat pubic ("crab") lice. These products are available overthecounter without a prescription at a local drug store or pharmacy. These medications are safe and effective when used exactly according to the instructions in the package or on the label. Lindane shampoo is a prescription medication that can kill lice and lice eggs. However, lindane is not recommended as a firstline therapy. Lindane can be toxic to the brain and other parts of the nervous system; its use should be restricted to patients who have failed treatment with or cannot tolerate other medications that pose less risk. Lindane should not be used to treat premature infants, persons with a seizure disorder, women who are pregnant or breastfeeding, persons who have very irritated skin or sores where the lindane will be applied, infants, children, the elderly, and persons who weigh less than 110 pounds. Malathion* lotion 0.5% (Ovide*) is a prescription medication that can kill lice and some lice eggs; however, malathion lotion (Ovide*) currently has not been approved by the U.S. Food and Drug Administration (FDA) for treatment of pubic ("crab") lice. Both topical and oral ivermectin have been used successfully to treat lice; however, only topical ivermectin lotion currently is approved by the U.S. Food and Drug Administration (FDA) for treatment of lice. Oral ivermectin is not FDAapproved for treatment of lice. How to treat pubic lice infestations: (Warning: See special instructions for treatment of lice and nits on eyebrows or eyelashes. The lice medications described in this section should not be used near the eyes.) Wash the infested area; towel dry. Carefully follow the instructions in the package or on the label. Thoroughly saturate the pubic hair and other infested areas with lice medication. Leave medication on hair for the time recommended in the instructions. After waiting the recommended time, remove the medication by following carefully the instructions on the label or in the box. Following treatment, most nits will still be attached to hair shafts. Nits may be removed with fingernails or by using a finetoothed comb. Put on clean underwear and clothing after treatment. To kill any lice or nits remaining on clothing, towels, or bedding, machinewash and machinedry those items that the infested person used during the 2���3 days before treatment. Use hot water (at least 130��F) and the hot dryer cycle. Items that cannot be laundered can be drycleaned or stored in a sealed plastic bag for 2 weeks. All sex partners from within the previous month should be informed that they are at risk for infestation and should be treated. Persons should avoid sexual contact with their sex partner(s) until both they and their partners have been successfully treated and reevaluated to rule out persistent infestation. Repeat treatment in 9���10 days if live lice are still found. Persons with pubic lice should be evaluated for other sexually transmitted diseases (STDs). Special instructions for treatment of lice and nits found on eyebrows or eyelashes: If only a few live lice and nits are present, it may be possible to remove these with fingernails or a nit comb. If additional treatment is needed for lice or nits on the eyelashes, careful application of ophthalmicgrade petrolatum ointment (only available by prescription) to the eyelid margins 2���4 times a day for 10 days is effective. Regular petrolatum (e.g., Vaseline)* should not be used because it can irritate the eyes if applied. *Use of trade names is for identification purposes only and does not imply endorsement by the Public Health Service or by the U.S. Department of Health and Human Services. This information is not meant to be used for selfdiagnosis or as a substitute for consultation with a health care provider. If you have any questions about the parasites described above or think that you may have a parasitic infection, consult a health care provider. |
How to prevent Parasites - Lice - Pubic "Crab" Lice ? |
Pubic ("crab") lice most commonly are spread directly from person to person by sexual contact. Pubic lice very rarely may be spread by clothing, bedding, or a toilet seat. The following are steps that can be taken to help prevent and control the spread of pubic ("crab") lice: All sexual contacts of the infested person should be examined. All those who are infested should be treated. Sexual contact between the infested person(s)s and their sexual partner(s) should be avoided 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 drycleaned 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. Persons with pubic lice should be examined and treated for any other sexually transmitted diseases (STDs) that may be present. |
What is (are) Parasites - Fascioliasis (Fasciola Infection) ? |
Fascioliasis is an infectious disease caused by Fasciola parasites, which are flat worms referred to as liver flukes. The adult (mature) flukes are found in the bile ducts and liver of infected people and animals, such as sheep and cattle. In general, fascioliasis is more common in livestock and other animals than in people.Two Fasciola species (types) infect people. The main species is Fasciola hepatica, which is also known as "the common liver fluke" and "the sheep liver fluke." A related species, Fasciola gigantica, also can infect people. |
Who is at risk for Parasites - Fascioliasis (Fasciola Infection)? ? |
Fascioliasis occurs in many areas of the world and usually is caused by F. hepatica, which is a common liver fluke of sheep and cattle. In general, fascioliasis is more common and widespread in animals than in people. Even so, the number of infected people in the world is thought to exceed 2 million. Fasciola hepatica is found in more than 50 countries, in all continents except Antarctica. It is found in parts of Latin America, the Caribbean, Europe, the Middle East, Africa, Asia, and Oceania. Fasciola gigantica is less widespread. Human cases have been reported in the tropics, in parts of Africa and Asia, and also in Hawaii. In some areas where fascioliasis is found, human cases are uncommon (sporadic). In other areas, human fascioliasis is very common (hyperendemic). For example, the areas with the highest known rates of human infection are in the Andean highlands of Bolivia and Peru. Special conditions are needed for fascioliasis to be present in an area, and its geographic distribution is very patchy (focal). The eggs passed in the stool of infected mammals have to develop (mature) in a suitable aquatic snail host to be able to infect another mammalian host. Requirements include sufficient moisture and favorable temperatures (above 50��F) that allow the development of miracidia, reproduction of snails, and larval development within the snails. These factors also contribute to both the prevalence and level (intensity) of infection. Prevalence is highest in areas where climatic conditions promote development of cercariae. More on: Biology Infective Fasciola larvae (metacercariae) are found in contaminated water, either stuck to (encysted on) water plants or floating in the water, often in marshy areas, ponds, or flooded pastures. People (and animals) typically become infected by eating raw watercress or other contaminated water plants. The plants may be eaten as a snack or in salads or sandwiches. People also can get infected by ingesting contaminated water, such as by drinking it or by eating vegetables that were washed or irrigated with contaminated water. Infection also can result from eating undercooked sheep or goat livers that contain immature forms of the parasite. The possibility of becoming infected in the United States should be considered, despite the fact that few locally acquired cases have been documented. The prerequisites for the Fasciola life cycle exist in some parts of the United States. In addition, transmission because of imported contaminated produce could occur, as has been documented in Europe. |
How to diagnose Parasites - Fascioliasis (Fasciola Infection) ? |
The standard way to be sure a person is infected with Fasciola is by seeing the parasite. This is usually done by finding Fasciola eggs in stool (fecal) specimens examined under a microscope. More than one specimen may need to be examined to find the parasite. Sometimes eggs are found by examining duodenal contents or bile. Infected people don't start passing eggs until they have been infected for several months; people don't pass eggs during the acute phase of the infection. Therefore, early on, the infection has to be diagnosed in other ways than by examining stool. Even during the chronic phase of infection, it can be difficult to find eggs in stool specimens from people who have light infections. Certain types of blood tests can be helpful for diagnosing Fasciola infection, including routine blood work and tests that detect antibodies (an immune response) to the parasite. More on: Resources for Health Professionals: Diagnosis |
What are the treatments for Parasites - Fascioliasis (Fasciola Infection) ? |
The first step is to make sure the diagnosis is correct. For more information, patients should consult their health care provider. Health care providers may consult with CDC staff about the diagnosis and treatment of fascioliasis. The drug of choice is triclabendazole. In the United States, this drug is available through CDC, under a special (investigational) protocol. The drug is given by mouth, usually in one or two doses. Most people respond well to the treatment. More on: Resources for Health Professionals: Treatment |
How to prevent Parasites - Fascioliasis (Fasciola Infection) ? |
No vaccine is available to protect people against Fasciola infection. In some areas of the world where fascioliasis is found (endemic), special control programs are in place or are planned. The types of control measures depend on the setting (such as epidemiologic, ecologic, and cultural factors). Strict control of the growth and sale of watercress and other edible water plants is important. Individual people can protect themselves by not eating raw watercress and other water plants, especially from endemic grazing areas. As always, travelers to areas with poor sanitation should avoid food and water that might be contaminated (tainted). Vegetables grown in fields that might have been irrigated with polluted water should be thoroughly cooked, as should viscera from potentially infected animals. |