Presentation on theme: "Introduction to Infectious Disease Epidemiology - STDs - Hsci 436 – Health Concerns of the Adolescent Dr. E. Frank Spinello."— Presentation transcript:
Introduction to Infectious Disease Epidemiology - STDs - Hsci 436 – Health Concerns of the Adolescent Dr. E. Frank Spinello
Pathogens Bacterial –About 1 million on the head of a pin –Salmonella, botulism, anthrax Viral –About 230 million HIV on the head of a pin. –Not affected by antibiotics Chemical toxins –Organic and inorganic –Allergens, carcinegens, neurotoxins, teratogens Parasitic (multi-cell) – tapeworms, trichinosis, schistosomes Fungal –yeast infections, Candida Protozoa –Single cell organisms Prions –Relatively new discovery –Infectious agent with protein-like qualities –Thought to be responsible for BSE (mad cow disease) and vCJD –Difficult to disinfect
Historical Overview Traditionally, infectious disease was the biggest health threat to human civilization. As medical technology and public health reduced the threat of infectious diseases, lifespans increased to the point of making chronic diseases more prevalent.
Infectious Diseases in History In the mid-1300’s about 23 million people in Europe died from plague. –Plague-related deaths represented 10-15% of each new generation for a period of about 100 years. –The population shifts changed the cultural and political makeup of Europe
Influenza By many estimates, major flu outbreaks occur about every 11 years. The 1918 flu pandemic killed 50-100 million people within about 18 months. –More people died worldwide than in all of the wars of the 20 th century, combined. The 1976 swine flu scare resulted in a national immunization program. –The fear was that the swine flu was a close variant of the 1918 virus and would trigger another pandemic.
Syphilis Is thought to have been brought back by Columbus’ crew from the New World to Europe. –Often treated with mercury, which resulted in many individuals with mercury poisoning.
HIV/AIDS Human Immunodeficiency Virus was first detected in 1980. –Confirmed index patient was a Canadian flight steward. –The earliest known case may date back to 1958.
New Concerns Increased frequency of travel combined with short travel times mean that pathogens are no longer geographically isolated –One reason that Ebola has never spread has been the remote areas in which it is found. MDRs – Multiple drug resistant bacterial strains. –A variety of bacteria no longer respond to traditional antibiotics as they have begun to mutate and adapt. –Partially due to inappropriate antibiotic use.
Sexually Transmitted Diseases Most common include: –Chlamydia –Syphilis –Gonorrhea –Genital herpes –Genital warts (caused by the human papillomavirus) –Hepatitis B
PID Complications Pelvic Inflammatory Disease (PID) is a common complication of many STD’s in women: –May be asymptomatic –When symptoms are present, they can be very severe and can include abdominal pain and fever –abscesses (pus-filled “pockets” that are hard to cure) and long-lasting, chronic pelvic pain –can damage the fallopian tubes enough to cause infertility or increase the risk of ectopic pregnancy
Chlamydia Caused by the bacterium, Chlamydia trachomatis The most frequently reported bacterial sexually transmitted disease in the United States Often undiagnosed due to lack of initial symptoms –about three quarters of infected women and about half of infected men have no symptoms. If symptoms do occur, they usually appear within 1 to 3 weeks after exposure. Symptoms include pain, discharge, bleeding.
Chlamydia Untreated women –About 40% of women develop PID –Can cause permanent damage to fallopian tubes, uterus, and surrounding tissue –5 times more likely to become HIV infected if exposed. –Chlamydia is a leading cause of early infant pneumonia and conjunctivitis (pink eye) in newborns. Untreated men –Complications are rare –Sterility, eye infections, arthritis, skin lesions
Chlamydia Diagnosis –Urine or discharge specimen Treatment –A single dose of azithromycin or a week of doxycycline (twice daily) are the most commonly used treatments. Prevention –Retesting should be considered for women, especially adolescents, three to four months after treatment. This is especially true if a woman does not know if her sex partner received treatment. –Condoms can reduce infection risk –Upon diagnosis, all sex partners must be notified
Syphilis Caused by the bacterium Treponema pallidum. It has often been called “the great imitator” because so many of the signs and symptoms are indistinguishable from those of other diseases. Most cases occur in people age 20 to 39 About 3.5x more men than women Rates are decreasing in women but increasing about 12.5% in men due to MSM
Syphilis Transmission –Direct contact with syphilis sore –Genitals, lips, and mouth Symptoms –ES may not present symptoms for years –Primary stage Initial sore at point of contact w/in 90 days, heals w/o treatment –Secondary Stage Non-itchy rash (appearing as red blotches or spots) on genitals, hands and feet Swollen glands, hair loss, headaches, weight loss, muscle aches, fatigue –Latent syphilis Initial symptoms disappear Up to years later -- damage to internal organs and brain, nerves, eyes, heart, blood vessels, liver, bones, and joints Symptoms include: difficulty coordinating muscle movements, paralysis, numbness, gradual blindness, and dementia, and death
Syphilis Diagnosis –Requires smear from cancre sore. Dark field microscopy is used Blood test to detect antibodies Implications –Genital sores (chancres) caused by syphilis make it easier to transmit and acquire HIV infection sexually. There is an estimated 2- to 5-fold increased risk of acquiring HIV infection when syphilis is present.
Syphilis Treatment –Syphilis is easy to cure in its early stages. A single intramuscular injection of penicillin, an antibiotic, will cure a person who has had syphilis for less than a year. Prevention –Abstinence –Avoid risky behavior –Condom use, although N9 spermicide may cause lesions and increase risk.
Gonorrhea caused by Neisseria gonorrhoeae, a bacterium that can grow and multiply easily in the warm, moist areas of the reproductive tract, including the cervix (opening to the womb), uterus (womb), and fallopian tubes (egg canals) in women, and in the urethra (urine canal) in women and men. The bacterium can also grow in the mouth, throat, eyes, and anus.
Gonorrhea: Overview CDC estimates that more than 700,000 persons in the U.S. get new gonorrheal infections each year. –About ½ are reported to CDC Transmission –Sexual contact –Highest reported rates of infection are among sexually active teenagers, young adults, and African Americans.
Gonorrhea: Signs and Symptoms Males –May have no symptoms at all –5 to 30 days after infection: Burning sensation during urination White, yellow, or green discharge Swollen/painful testicals (not all) Females –Most have no symptoms –Often non-specific and mistaken for bladder or yeast infection –Initial symptoms and signs in women include a painful or burning sensation when urinating, increased vaginal discharge, or vaginal bleeding between periods –Sore throat
Gonorrhea: Complications Males –gonorrhea can cause epididymitis, a painful condition of the testicles that can lead to infertility if left untreated –can spread to the blood or joints –Increases risk of HIV infection Females –PID - abdominal pain and fever –can spread to the blood or joints –Increases risk of HIV infection
Gonorrhea: Treatment and Prevention Diagnosis –Doctors office can perform a Gram stain of a sample from a urethra or a cervix allows the doctor to see the gonorrhea bacterium under a microscope Treatment –Multiple antibiotics are generally used due to co-morbidity with chlamydia –Resistant strains are now being increasingly encountered
Hepatitis B Viral infection passed through bodily fluids from one person to another. High Risk Groups: –Persons with multiple sex partners or diagnosis of a sexually transmitted disease –MSM –Sex contacts of infected persons –Injection drug users –Household contacts of chronically infected persons –Infants born to infected mothers –Infants/children of immigrants from areas with high rates of HBV infection (view map)view map –Health care and public safety workers Hemodialysis patients
Hepatitis B - Prevalence Number of new infections per year has declined from an average of 260,000 in the 1980s to about 78,000 in 2001. Highest rate of disease occurs in 20-49-year- olds. Greatest decline has happened among children and adolescents due to routine hepatitis B vaccination. Estimated 1.25 million chronically infected Americans, of whom 20-30% acquired their infection in childhood.
Hepatitis B – Signs and Symptoms About 30% have no symptoms Symptoms include: –jaundice –fatigue –abdominal pain –loss of appetite –nausea, vomiting –joint pain Death from chronic liver disease occurs in 15- 25% of chronically infected persons
Hepatitis B - Treatment Adefovir dipivoxil, alpha interferon, and lamivudine are three drugs licensed for the treatment of persons with chronic hepatitis B.Adefovir dipivoxilalpha interferon lamivudine These drugs should not be used by pregnant women. Drinking alcohol can make your liver disease worse.
Hepatitis B – Prevention Vaccination is best defense for high-risk individuals. Recommended for public health and public safety workers. Effectiveness of condom use is unknown but they are likely to help protect against it. Reduce IV drug use / syringe sharing Discourage sharing of personal items (razors, etc.) Consider risks of tattoos and body piercing
Genital Herpes - Overview Genital herpes is a sexually transmitted disease (STD) caused by the herpes simplex viruses type 1 (HSV-1) and type 2 (HSV-2). Most genital herpes is caused by HSV-2. Most individuals have no or only minimal signs or symptoms from HSV-1 or HSV-2 infection. When signs do occur, they typically appear as one or more blisters on or around the genitals or rectum. The blisters break, leaving tender ulcers (sores) that may take two to four weeks to heal the first time they occur. Typically, another outbreak can appear weeks or months after the first, but it almost always is less severe and shorter than the first outbreak. Although the infection can stay in the body indefinitely, the number of outbreaks tends to decrease over a period of years.
Genital Herpes Prevalence –45 million people ages 12 and older, –one out of five adolescents and adults, have had genital HSV infection. –Between the late 1970s and the early 1990s, the number of Americans with genital herpes infection increased 30 percent. –Genital HSV-2 infection is more common in women approximately one out of four women almost one out of five men This may be due to male-to-female transmissions being more likely than female-to-male transmission. –HSV-1 can cause genital herpes, but it more commonly causes infections of the mouth and lips, so-called “fever blisters.” HSV-1 infection of the genitals can be caused by oral-genital or genital- genital contact with a person who has HSV-1 infection. Genital HSV-1 outbreaks recur less regularly than genital HSV-2 outbreaks.
Genital Herpes – Signs and Symptoms Most HSV-2 people are not aware of first infection. First outbreak is generally 1-2 weeks after infection and may last 3-4 weeks. –First outbreak is generally accompied with swollen glands, fever, flu-like symptoms. –4 to 5 five outbreaks in the first year, with decreasing frequency thereafter. –Often mistaken for insect bites Complications –Recurrent painful outbreaks –Infections in babies can be fatal –Increases HIV susceptibility Diagnosis –Visual inspection –Blood test to detect antibodies –Lab test of sore samples Treatment –No cure but antiviral drugs can shorten and prevent outbreaks Prevention –Control outbreaks to reduce risk of transmission –Abstinence during outbreaks –Condoms may help reduce transmission risk but may not entirely cover infected areas
Genital Warts Overview –Caused by Human Papillomavirus (HPV) About 100 strains, of which 30 are sexually transmitted High risk strains (about 10 of 30) can lead to abnormal pap smears and cause cancer of the cervix, vulva, vagina, anus, or penis Low risk types may cause mild Pap test abnormalities or genital warts. Genital warts are single or multiple growths or bumps that appear in the genital area, and sometimes are cauliflower shaped. Prevalence –At least 50 percent of sexually active men and women acquire genital HPV infection at some point in their lives –By age 50, at least 80 percent of women will have acquired genital HPV infection –Most people will be asymptomatic and fight off infection on their own
Genital Warts Diagnosis –Visual inspection –Often appear within weeks or months of contact, or not at all –Usually appear as soft, moist, pink, or flesh-colored swellings, usually in the genital area. They can be raised or flat, single or multiple, small or large, and sometimes cauliflower shaped. Treatment – No cure, but they will often go away on their own –Regular pap smears can help detect pre-cancerous conditions for early treatment Complications –Can cause cervical cancer Prevention –Abstinence, particularly during outbreaks –Effectiveness of condoms against HPV is unknown but condom use has been associated with a somewhat lower incidence of cervical cancer
Current Research and STD Prevention Programs Debate between safer sex an abstinence programs. –Research has tended to focus on one-time abstinence programs with no follow- up. –Both approaches appear to work in the short term but SS programs tend to have longer term effects among sexually active teens Abstinence and safer sex among adolescents. Author: Masdeu JC Source: JAMA (JAMA : the journal of the American Medical Association.) 1999 Apr 28; 281(16): 1486-8 Libraries Worldwide: 3891Abstinence and safer sex among adolescents.Libraries Worldwide Abstinence and safer sex HIV risk-reduction interventions for African American adolescents: a randomized controlled trial. Author: Jemmott JB 3rd; Jemmott LS; Fong GT Source: JAMA (JAMA : the journal of the American Medical Association.) 1998 May 20; 279(19): 1529-36Abstinence and safer sex HIV risk-reduction interventions for African American adolescents: a randomized controlled trial. Haglund K found that African American’s description of abstinence only tended to include intercourseHaglund K –Still at risk for STDs –Sexually abstinent African American adolescent females' descriptions of abstinence. Author: Haglund K Source: J Nurs Scholarsh (Journal of nursing scholarship : an official publication of Sigma Theta Tau International Honor Society of Nursing / Sigma Theta Tau.) 2003; 35(3): 231-6Sexually abstinent African American adolescent females' descriptions of abstinence.