Viral STDs Protozoal STD Herpes (viral ulcerative STD) Genital Warts AIDS Protozoal STD Trichomoniasis

Genital Herpes Causative agent herpes-simplex virus type 1 & 2 Enveloped DNA virus Latent virus

Signs & Symptoms Genital itching and burning, fever, myalgia and malaise Numerous fluid filled blisters on genitals Burst and form lesions Lesions heal spontaneously Most patients will have recurrence

Enveloped virus fuses with host cell membrane Genome enters cell and begins replication Viruses are released by budding and cell lysis Blisters form when epithelial cells are killed Rupture to produce painful ulcerations Releases millions of viral particles

Ocular Herpes Whitlow – herpes of skin Oral Herpes

Latency follows ulceration Viral DNA hides within ganglia Re-infect cells supplied by infected nerve

Neonatal herpes 1 in 3 newborns affected if mother infected at birth Debilitating and potentially lethal Requires cesarean delivery

Epidemiology 4 billion infected worldwide No animal reservoir Non-sexual transmission may occur Transmission most likely occurs during first days illness Transmission can happen in absence of symptoms

Treatment There is no cure for genital herpes Once infected there is lifelong risk of transmission Acyclovir and derivatives reduce severity Condoms may not be effective in prevention!!!

Genital Warts (papillomas) Causative agent: Human papillomaviruses 30 different HPV strains cause warts Most common STD in US

Warts on genitals, vagina and cervix Slight pain or itching may occur May form condylomata acuminata Warts typically not dangerous HPV linked to 99% of cervical cancers May also cause anal, penile, vaginal and oral cancers

HPV infects approximately 20 million people in the United States ~ 6.2 million new cases each year Pap smears don’t detect HPV only abnormal cells DNA test is available that detects all 13 strains linked to cervical cancer

Treatment: Not prevented by condoms!!! New vaccine currently available Gardasil Treatment: Removal of warts by freezing, laser or acid Typically reoccur

AIDS Acquired Immunodeficiency Syndrome Causative agent: Human Immunodeficiency Virus (HIV) Most US cases causes by HIV-1 Most African cases caused by HIV-2 Enveloped, RNA retrovirus

Signs & Symptoms (of HIV disease): Fever; head and muscle aches; enlarged lymph nodes; rash Some individuals are asymptomatic for years AIDS is characterized by the presence of several opportunistic or rare infections and a T cell count of lower than 200/µl

RNA reverse transcribed to DNA HIV infects host cells RNA reverse transcribed to DNA DNA integrates as provirus in host chromosome Virus may leave genome and kill host cell Releases additional viruses Immune system becomes impaired

Epidemiology HIV is spread mainly through sexual contact, needles or from mother to newborn Global pandemic 40 million cases ~1/3 have developed AIDS

Prevention: No vaccine available Interruption of mother to child transmission via chemotherapy Needle exchange programs Educational programs targeting at risk populations Treatment of other STDs to lessen risk

Treatment: Designed to block replication and release of virus Generally with cocktail of medication (HAART) Include reverse transcriptase inhibitors; protease inhibitors; and nucleotide analogs

Trichomoniasis Causative agent Trichomonas vaginalis Flagellated leaf shaped protozoan with undulating membrane

Signs & Symptoms Most women symptomatic Most men are asymptomatic Itching of vulva and inner thighs Itching and burning of the vagina Frothy, odorous yellowish-green vaginal discharge Most men are asymptomatic penile discharge, pain on urination, tender testes or prostatitis

Pathogenesis No encysted stage so it can’t survive in environment Reproduces at pH of 5-6 Reddening and swelling of vagina attributed to trauma of moving protozoan Frothy discharge most likely due to gas production by organism

Epidemiology Humans are the only known host Worldwide distribution 170 new cases worldwide annually 7.5 million in US Most common curable STD in women Transmission usually sexual contact; fomites; newborns infected in birth canal

Treatment Single dose of metronidazole Both partners should be treated to prevent re-infection Vinegar douche for pregnant or nursing women