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33 Cards in this Set
- Front
- Back
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Gonorrhea Symptoms
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• Symptoms – Incubation period 2 to 5 days post exposure – Asymptomatic infection can occur on both sexes
– In men symptoms characterized as urethritis with • Pain on urination • Discharge from penis – In women symptoms are • Painful urination • Mild discharge – May be overlooked – Women more likely to be asymptomatic carriers |
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Gonorrhea Causative agent
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– Neisseria gonorrhoeae • Gram-negative
• Diplococcus • Typically found on or in leukocytes in urethral pus • Infect only humans • Most strains do not survive well outside host • Transmitted primarily via intimate sexual contact • Increasing number of strains resistant to antibiotics |
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Gonorrhea Pathogenesis
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– Attach to non-ciliated epithelial cells via pili • Particularly of the urethra, uterine cervix pharynx and
conjunctiva • Bacterial proteins bind CD4 lymphocytes – Prevents activation of immune response – Antigenic variation allows escape from antibody • Variation interferes with ability to make effective vaccine – Untreated disease in men can lead to complications including • Urinary tract infections • Orchitis • Sterility |
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Chlamydial Genital System Infections Symptoms
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– Generally appear in 7 to 14 days
– In men • Thin grayish-white discharge from penis • Sometimes painful testes – In women • Increased vaginal discharge • Often painful urination • Abdominal bleeding • Upper and lower abdominal pain • Women often asymptomatic |
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Chlamydial Genital System Infections Causative agent
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– Chlamydia trachomatis
• Spherical • Obligate intracellular bacterium • Form inclusion bodies – Used for rapid identification • Approximately eight types responsible for STD |
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Chlamydial Genital System Infections Pathogenesis
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– Infectious form attaches to host epithelial cells
• This form called elementary body • Cells take up organism through endocytosis – Bacterial enlarges in vacuole • Becomes non-infectious – Form called reticular body – Reticular body divides repeatedly • Produces numerous elementary bodies – Much tissue damage results from cellular immune response In men • Infection spreads from urethra to tubules – Results in acute swelling In women • Infection commonly involves cervix, uterus and fallopian tubes – Resulting in PID, ectopic pregnancy or sterility |
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Chlamydial Genital System Infections Epidemiology
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– Reportable infectious disease
• Number of reported cases tends to rise each year – Estimated 4 million reported in United States – According to study 14% of sexually active high school and college women are asymptomatic carriers – Non-sexual transmission also occurs • Major source is non-chlorinated swimming pools – Newborns contact conjunctivitis much like with gonorrhea |
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Chlamydial Genital System Infections Prevention and Treatment
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• Prevention and Treatment – Abstinence – Monogamous relationship – Use of condom
– All sexually active women should get tested annually • Semi annually if multiple partners – Azithromycin effective single dose treatment – Tetracycline erythromycin less expensive alternatives |
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Syphilis Symptoms
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– Occurs in numerous forms
• Easily confused with other diseases – Manifestation occurs in three stages • Primary stage • Secondary stage • Tertiary stage – Primary stage • Occurs about 3 weeks post infection • Characterized by a painless red ulcer – Ulcer called a hard chancre – Chancre appears at the site of infection » Usually on the genitalia • Local lymph nodes become enlarged • Spontaneous healing of chancre – Primary syphilis often goes unnoticed in women and homosexual men |
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Syphilis Causative agent
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– Treponema pallidum
• Motile spirochete • Cannot be cultivated in laboratory – Darkfield microscopy used for identification |
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Syphilis Pathogenesis
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– Organism penetrates mucous membranes
and abraded skin – Very low infecting dose • Less than 100 organisms – Organism multiplies in localized area – Primary syphilis • Characterized by hard chancre from inflammatory response • Chancre disappears in 2 to 6 weeks with or without treatment – Secondary syphilis • Characterized by mucous patches on skin and mucous membranes – Disease can be transmitted by kissing at this stage • Stage may last weeks to months – Followed by extended latent period • Spreads to lymph nodes and bloodstream – Three stages of disease • Primary stage • Secondary stage • Tertiary stage – Tertiary syphilis • Stage characterized by gumma – Necrotizing mass of tissue • Patient no longer infectious – Congenital syphilis • Organism readily crosses placenta – Most dangerous during fourth month • Children often develop deformities of face, teeth and other body parts later in childhood |
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Chancroid Symptoms
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– Characterized by single or
multiple painful genital sores – Sores are soft chancres • Unlike hard chancres of syphilis – Groin lymph nodes tender and swollen • Often pus filled |
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Chancroid Causative agent
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• Causative Agent
– Haemophilus ducreyi – Pleomorphic Gram-negative rod |
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Chancroid Pathogenesis
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– Pimple appears at site of entry • Pimple ulcerates and enlarges within a few days
– Organisms reach lymph nodes and initiate intense immune response |
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Chancroid Epidemiology
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– Epidemics generally associated with
prostitution – Lesions promote AIDS transmission |
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Genital Herpes Symptoms
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– Begin 2 to 20 days
post infection – Genital itching and burning – Pain • Primarily in women – Blisters develop on genitals – Blisters heal spontaneously • Most patients will have recurrence |
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Genital Herpes Causative agent
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– Usually herpes- simplex virus type 2
– DNA virus – Disease recurrence due to latent virus |
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Genital Herpes Pathogenesis
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– Blisters created by infected epithelial cells • Blisters contain large numbers of bacteria
– Blisters rupture to produce painful ulcerations – Latency follows ulceration • Viral DNA exists in cell in non-infectious form within nerve cell – Recurrence is due to replication of complete virions from latent DNA • Viruses re-infect area supplied by nerve – Congenital herpes can pose serious risk for newborn • 1 in 3 newborns contract herpes if mother has primary infection at time of birth • Can be debilitating and potentially lethal |
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Genital Herpes Epidemiology
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– No animal reservoir
– Virus can survive short time on fomites or in bathwater • Non-sexual transmission rarely occurs – Sexual transmission most likely occurs during first days of symptomatic disease • Transmission can happen in absence of symptoms – Once infected there is lifelong risk of transmission |
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Genital Herpes Prevention and Treatment
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– Avoidance of sexual intercourse during active symptoms
• Use of condom and spermicide reduce but do not eliminate transmission – There is no cure for genital herpes • Medications such as acyclovir and famciclovir can decrease severity |
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Trichomoniasis Symptoms
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– Women most symptomatic
– Characterized by • itching of vulva and inner thighs • Itching and burning of the vagina • Frothy, malodorous yellowish-green vaginal discharge – Most infected men are asymptomatic • Some may have penile discharge, pain on urination, painful testes or tender prostate |
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Trichomoniasis Causative agent
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– Trichomonas vaginalis – Flagellated protozoan
– Diagnosed via jerky motility on microscopic examination |
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Trichomoniasis Pathogenesis
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– Not fully understood
– Red swollen nature of vagina attributed to trauma of moving protozoan – Frothy discharge is most likely due to gas production by organism |
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AIDS Symptoms
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– Symptoms of HIV disease include
• Fever • Head and muscle aches • Enlarged lymph nodes • Rash • Symptoms usually arise 6 days to 6 weeks post infection |
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AIDS Causative agent
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– Human immunodeficiency virus (HIV)
• Most US cases caused by HSVI • Most African cases caused by HSVII – Virus is enveloped, single-stranded RNA virus of retrovirus family |
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AIDS Pathogenesis
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– HIV attacks variety of cell types • Most critical are Helper T-cells
– Attached to CD4 surface receptor – After entry, DNA copies of RNA genome produced using reverse transcriptase viral enzyme • DNA copy integrates and hides on host chromosome – In activated cells virus leaves cell genome and kills cell • Releases additional viruses to infect other cells – Macrophages have CD4 receptors • Virally infected macrophages are not generally killed but function is impaired – Eventually immune system becomes too impaired to respond |
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AIDS Epidemiology
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– HIV is spread mainly through sexual contact, needles or from mother to newborn
– Virus not highly contagious outside of risk factors – Transmission can be halted by changes in human behavior |
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AIDS Prevention and Treatment
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– Interruption of mother to child transmission via chemotherapy
– Needle exchange programs – Educational programs targeting at risk populations – Treatment of other STD to lessen risk on contracting HIV – Treatment is designed to block replication of HIV • Generally with cocktail of medication • Include reverse transcriptase inhibitors and protease inhibitor |
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Papillomavirus Genital Warts and Cervical Cancer Symptoms
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– Individual may be asymptomatic
• Especially women – Genital warts most easily recognized symptom • Often appear on the head or shaft of penis, at the vaginal opening or around anus – Warts can become inflamed or bleed – Precancerous lesion on cervix often asymptomatic • Can be detected with vaginal exam |
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Papillomavirus Genital Warts and Cervical Cancer Causative agent
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– Human papillomavirus
(HPV) – Non-enveloped, double- stranded DNA virus • Nearly 100 types of HPV – 30 are transmitted sexually – 15 types strongly associated with cancer |
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Papillomavirus Genital Warts and Cervical Cancer Pathogenesis
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– HPV enters and infects deeper
layers of tissue through abrasions • May lead to latent infection – Mechanism of wart formation is unknown • Warts usually appear about 3 months after infection • Removal of warts does not eliminate virus – HPV can be transmitted to fetus through birth canal – Most cervical cancers associated with HPV |
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Papillomavirus Genital Warts and Cervical Cancer Epidemiology
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– HPV readily spread through sexual contact
• Asymptomatic carriers can infect others with HPV – HPV most common reason for abnormal Pap smear – History of multiple sex partners is most important risk factor for acquiring HPV – Warts can develop in the mouth via oral sex |
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Papillomavirus Genital Warts and Cervical Cancer Prevention and Treatment
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– Condom use can help decrease chance of
transmission – Women should have Pap smear annually • Can identify precancerous lesions • Abnormal growth can be removed preventing development of cancer – Warts can be removed via laser treatment or freezing with liquid nitrogen |
