Hepatitis A Virus (HAV) is an infection that typically has an abrupt onset of fever, malaise, anorexia, nausea, abdominal discomfort, dark urine and jaundice. HAV infection is acquired primarily by the fecal-oral route by either person-to-person contact or ingestion of contaminated food or water. The likelihood of symptomatic illness from HAV infection is directly related to age. In children younger than 6 years of age, most (70%) infections are asymptomatic. In older children and adults, infection is usually symptomatic, with jaundice occurring in more than 70% of patients. Until 2004, hepatitis A was the most frequently reported type of hepatitis in the United States. It is highly endemic in some areas, particularly Central and South America, Africa, the Middle East, Asia, and the Western Pacific and most common in the Western United States. Hepatitis A can evolve into fulminant disease which causes 100 death per year. Since HAV vaccines were licensed in 1995 and 1996, the incidence of the illness has steadily declined. Universal vaccination for HAV was established in 2005.
Hepatitis B Virus (HBV) infection is an established cause of acute and chronic hepatitis and cirrhosis. It is the cause of up to 80% of hepatocellular carcinomas, and is second only to tobacco among known human carcinogens. The World Health Organization estimates that more than 600,000 persons died worldwide in 2002 of hepatitis B-associated acute and chronic liver disease. HBV is characterized by the insidious onset of malaise, anorexia, nausea, vomiting, right upper quadrant abdominal pain, fever, headache, myalgias, skin rashes, arthralgias, arthritis, dark urine and jaundice. HBV causes complications through its chronic carrier state. The likelihood of acquiring the carrier state is increased the younger the infection occurs, particularly in infancy. The carrier state can lead to fulminant hepatitis B, cirrhosis, hepatocellular carcinoma, liver failure and death. About 200 to 300 Americans die of fulminant disease each year. HBV infecton is transmitted most commonly through blood and sexual contact. In 2001, there was an estimated 1 – 1.25 million carriers of chronic HBV. Recombinant hepatitis B vaccine was established in 1986 and the universal infant vaccination program in 1991.
Human papillomavirus (HPV) is the most common sexually transmitted infection in the United States. The clinical manifestations of HPV infection include anogenital warts, recurrent respiratory papillomatosis, cervical cancer precursors (cervical intraepithelial neoplasia), and cancers, including cervical, anal, vaginal, vulvar, penile, and some of the head and neck. HPV is transmitted by direct contact, usually sexual, with an infected person. Studies of newly acquired HPV infection demonstrate that infection occurs soon after onset of sexual activity. In a prospective study of college women, the cumulative incidence of infection was 40% by 24 months after first sexual intercourse. An estimated 79 million persons are infected, and an estimated 14 million new HPV infections occur annually with half of these in persons 15-24 years.. Up to 75% of new infections occur among persons 15–24 years of age. The two most common types of cervical cancer worldwide, squamous cell carcinoma followed by adenocarcinoma, are both caused by HPV. The CDC and National Cancer Institute’s United States Cancer Statistics Working Group reports that from 2005 through 2009 there were annual averages of 12,595 cases and 3,968 deaths due to cervical cancer. HPV is believed to be responsible for nearly all of these cases of cervical cancer. HPV types 16 and 18 are associated with 70% of these cancers. In addition to cervical cancer, HPV is believed to be responsible for 90% of anal cancers, 71% of vulvar, vaginal, or penile cancers, and 72% of oropharyngeal cancers. The first vaccine to prevent infection with four types of HPV was licensed in 2006. The newest vaccine now prevents infection with nine types of HPV was licensed in 2015.
Adapted from www.cdc.gov/vaccines/pubs/pinkbook/downloads/hpv.pdf
Influenza is a viral infection that has caused four pandemics over the last two centuries. There are an average of more than 200,000 hospitalizations per year are related to influenza. “Classic” influenza disease is characterized by the abrupt onset of fever, myalgias, sore throat, nonproductive cough, rhinorrhea and headache. The peak influenza season in the United States occurs most frequently in January and February but extends from December through April. The complications of influenza are pneumonia, Reye syndrome, myocarditis and death. Influenza vaccination is indicated universally for children and adolescents six months of age and older. It is highly recommended for high risk patients with chronic health conditions such as asthma, chronic lung disease, diabetes, sickle cell anemia, congenital heart disease, HIV and neuromuscular disorders. The first inactivated influenza vaccine was developed in the 1940s. The live attenuated influenza vaccine was approved for use in the United States in 2003.
Adapted from www.cdc.gov/vaccines/pubs/pinkbook/downloads/flu.pdf
Measles is a viral infection characterized by fever, cough, coryza (runny nose), conjunctivitis and both an oral and a cutaneous rash. The World Health Organization estimates there were more than 30 million cases and 454,000 deaths from measles worldwide in 2004. The complications of measles include otitis media, pneumonia, encephalitis, seizures and death. Measles outbreaks in the United States occur in pockets due to low vaccination coverage and international travel as the disease is imported through travel. In 2011, CDC reported 16 outbreaks of measles and 220 measles cases, most of which were imported cases in unvaccinated persons. Among the U.S. measles cases in persons 16 months through 19 years reported in 2011, 62% were in persons not vaccinated for a nonmedical reason. The first measles vaccines were licensed in 1963. The incidence of measles decreased by more than 98% following licensure of the vaccine.
Meningococcal disease is an acute, potentially severe illness caused by the bacterium Neisseria meningitidis. N. meningitidis is a leading cause of bacterial meningitis and sepsis in the United States. It can also cause focal disease, such as pneumonia and arthritis. Meningitis presents with symptoms of fever, headache, and stiff neck, often accompanied by other symptoms, such as nausea, vomiting, photophobia (eye sensitivity to light), and altered mental status. Meningococcal sepsis (bloodstream infection) is characterized by the abrupt onset of fever and a rash. Complications of meningococcal infection include multi-organ failure, adrenal hemorrhage, shock, hearing loss, neurologic damage, loss of a limb and death. Approximately 2,000 to 3,000 cases of meningococcal disease are reported each year in the United States. In 2004, an estimated 125 deaths due to meningococcal disease occurred in the United States. The first vaccine for meningococcus was licensed in 1978. The MCV4 vaccine in current use was licensed in 2005. This vaccine covers four strains of the meningocosaal bacteria. The most common strain, strain B, is covered by the meningococcal B vaccine. This separate vaccine was licensed in 2015.
Mumps is an acute viral illness. The symptoms are nonspecific and include myalgias, anorexia, malaise, headache, and low-grade fever. Mumps can cause of number of infections including parotitis (inflammation of the salivary glands), orchitis (testicular inflammation), aseptic meningitis, encephalitis, hearing loss, pancreatitis and oophoritis (ovarian inflammation). The most recent mumps outbreak occurred in 2006 and resulted in 6,000 reported cases. The current live attenuated mumps virus vaccine was licensed in December 1967. The vaccine was recommended for routine use in the United States in 1977.
Pertussis, or whooping cough, is an acute infectious disease caused by the bacterium Bordetella pertussis. The illness occurs in three stages which begin with fever and cold symptoms. The cough then rapidly progresses to paroxysms or frequent coughing spells followed by a long inspiratory effort accompanied by a characteristic high-pitched whoop. Children and young infants, especially, appear very ill and distressed. Duration of the illness is 2- 3 months with gradual improvement occurring over that time. The disease is most commonly transmitted from adolescents and adults to infants. Complications of pertussis include pneumonia, seizures, encephalopathy and death. Despite vaccination, immunity to this illness wanes over time, 5 -10 years following the last dose. Pertussis incidence has been gradually increasing since the early 1980s. A total of 25,827 cases were reported in 2004, the largest number since 1959. Sixty percent of the cases occurred in individuals 11 years and older. Vaccination for pertussis occurs in two phases. The primary series was developed in the 1930s. In response to the increasing incidence of disease amongst adolescents and adults, the pertussis component was added to the tetanus booster in 2005.
Streptococcus pneumoniae, or pneumococcus, causes acute bacterial infections of the skin, ears, upper respiratory tract, lower respiratory tract, joints and bones. The major clinical syndromes of pneumococcal disease are pneumonia, bacteremia (bacteria in the bloodstream), and meningitis. As many as 175,000 hospitalizations from pneumococcal pneumonia are estimated to occur annually in the United States. An estimated 3,000 to 6,000 cases of pneumococcal meningitis occur each year. Before routine use of pneumococcal conjugate vaccine, an estimated 200 children died every year as a result of invasive pneumococcal disease. The pneumococcal vaccine was licensed in the United States in 1977. In 1983, the a 23-valent polysaccharide vaccine (PPV23) was licensed. This version of the vaccine is used in special circumstances. The current pneumococcal conjugate vaccine (PCV7) was licensed in the United States in 2000. It was updated to incorporate six additional strains in 2009. The current pneumococcal conjugate vaccine (PCV13) is used for routine infant care.
Rubella, or the “German measles,” causes symptoms including rash, cough, runny nose and low-grade fever. The rash usually occurs initially on the face and then progresses from head to foot. Complications of rubella include neuritis, orchitis, low platelet count, and encephalitis. In addition to its symptoms and complications, rubella can also affect the developing fetus causing congenital rubella syndrome (CRS). Maternal infection during pregnancy may lead to fetal death, spontaneous abortion, or premature delivery. CRS is characterized by sensorineural deafness, cataracts, congenital heart disease, and a characteristic “blueberry muffin” rash. Children with CRS are at increased risk for developing growth retardation, diabetes, glaucoma, developmental delay and learning disabilities. A rubella epidemic in the United States in 1964–1965 resulted in 12.5 million cases of rubella infection and about 20,000 newborns with CRS. The first rubella vaccines were licensed in 1969. Due to the success of the vaccine, in 2004 there were no cases of CRS reported.
Tetanus is an acute, often fatal, disease caused by a toxin produced by the bacterium Clostridium tetani. This organism is found primarily in the soil and intestinal tracts of animals and humans. It is transmitted primarily through contaminated wounds. It is characterized by generalized rigidity and convulsive spasms of skeletal muscles. The muscle stiffness usually involves the jaw (lockjaw) and neck and then becomes generalized. Laryngospasm (spasm of the vocal cords) and/or spasm of the muscles of respiration lead to interference with breathing. Fractures of the spine or long bones may result from sustained contractions and convulsions. Hypertension and an abnormal heart rhythm may also occur. Tetanus toxoid was developed by in 1924. In the late 1940s, tetanus toxoid was introduced into routine childhood immunization schedule. Tetanus toxoid is included as a component of several combination vaccines.