Granuloma inguinale isachronicfibrosingSTDcausedbyC. granulomatis. Theinitialpapularlesiononthegenitaliaexpandsandulcerates,withformationofurethral,vulvar,oranalstricturesinsomecases.Microscopicexaminationrevealsgranulationtissueandintenseepithelialhyperplasiathatcanmimicsquamouscellcarcinoma.Organismsarevisibleassmallintracellularcoccobacilliwithinvacuolatedmacrophages(Donovanbodies).
T. vaginalis is a sexually transmitted protozoan that is a frequent cause of vaginitis. The trophozoite form adheres to the mucosa, where it causes superficial lesions. In females, T. vaginalis infection often is associated with loss of acid-producing lactobacilli. The incubation period is 4 to 28 days. It may be asymptomatic or be associated with pruritus and a profuse, frothy, yellow vaginal discharge. Urethral colonization may cause urinary frequency and dysuria. T. vaginalis infection typically is asymptomatic in males but in some cases may manifest as nongonococcal urethritis. The organism usually is demonstrable in smears of vaginal scrapings.
Genital herpes infection, or herpes genitalis, is a very common STD. According to CDC, approximately 800,000 people get new infections every year in the United States. One in six persons between the ages of 14 and 49 has HSV-2 infection in the US. With increasing rate of HSV-1 infections the overall prevalence of genital herpes is likely much higher. Although both herpes simplex virus 1 (HSV-1) and HSV-2 can cause anogenital or oral infections, most cases of anogenital herpes are caused by HSV-2. However, recent years have seen a rise in the number of genital infections caused by HSV-1, in part due to the increasing practice of oral sex. Genital HSV infection may occur in any sexually active population. As with other STDs, the risk for infection is directly related to the number of sexual contacts. Up to 95% of HIV-positive men who have sex with men are seropositive for HSV-1 and/or HSV-2. HSV is transmitted when the virus comes into contact with a mucosal surface or broken skin of a susceptible host. Such transmission requires direct contact with an infected individual, because the virus is readily inactivated at room temperature, particularly if dried.
MORPHOLOGYTheinitiallesionsofgenitalHSVinfectionarepainful, erythematous vesicles onthemucosaorskinofthelowergenitaliaandadjacentextragenitalsites.Theanorectalareaisaparticularlycommonsiteofprimaryinfectionamongmenwhohavesexwithmen.Histologicchangesincludethepresenceofintraepithelial vesicles accompaniedbynecroticcellulardebris,neutrophils,andcellsharboringcharacteristicintranuclearviralinclusions.TheclassicCowdry type A inclusion appearsasalightpurple,homogeneousintranuclearstructuresurroundedbyaclearhalo.Infectedcellscommonlyfusetoformmultinucleatesyncytia.TheinclusionsstainwithantibodiestoHSV,permittingarapid,specificdiagnosisofHSVinfectioninhistologicsectionsorsmears.