Genital tract infections - Introduction, Transmission, Types, STI

Introduction t Genital tract infections

Genital tract infections are mostly caused by resident microbial flora which becomes pathogenic due to immunosuppression, pH change, or excessive build-up of microflora.

Normal flora of the female genital tract varies with pH and estrogen concentration of the mucosa depending upon the host’s age.

Prepubescent and postmenopausal women primarily harbor Staphylococcus and Corynebacteria whereas women of reproductive age may harbor a large number of facultative bacteria such as Streptococci, Enterobacteriaceae, Staphylococci (CoNs) as well as anaerobes such as Lactobacilli, non-spore-forming bacilli and cocci, and clostridia. Lactobacilli are predominant. Some women also carry group B beta-hemolytic Streptococci (Streptococcus agalactiae).

Although yeasts (acquired from the GT tract) may be transiently recovered, they are not considered normal flora.

The vulva and penis (acquired area under prepuce) contain/harbor Mycobacterium smegmatis along with other gram-negative bacteria.

Types of Genital tract infections

Genital tract infections are classified as:

Exogenous

• acquired by sexual intercourse

• referred to as STD (Sexually transmitted diseases) / STI (sexually transmitted Infection)

Endogenous

• results from normal genital flora

*vaginitis = infection of the vaginal mucosa

Lower genital tract infections are commonly acquired by sexual or direct contact. Upper genital tract infections are frequently an extension of lower tract infections in which organisms from the vagina travel to the uterine cavity and on through the endothelium to the fallopian tubes and ovaries.

In males, the organisms can spread along contiguous mucosal surfaces from a lower genital tract site of infection (i.e. urethra) and cause infection in reproductive organs such as epididymis.

Routes of transmission of Genital tract infections

* can be both endogenous and exogenous

Sexually transmitted infections (STI) include Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, HIV (Human immunodeficiency virus), Treponema pallidum, Ureaplasma urealyticum, Mycoplasma hominis, HSV, Mycoplasma, Klebsiella granulomatis.

Individuals’ sexual habits and practices dictate potential sites of infection. Homosexual practices and increasingly common heterosexual practices and anal-genital or oral-genital intercourse allow for the transmission of genital tract infection to other body sites such as the pharynx or anorectic region.

Intestinal protozoa such as Entamoeba histolytica, Giardia lamblia, and Cryptosporidium spp, and fecal pathogens such as Salmonella, Shigella, Campylobacter, and Microsporidium are often transmitted sexually.

Uro-genital practices also provide an opportunity for Neisseria meningitides to colonize and infect the genital tract.

Organisms may also be introduced into the genital tract via other routes such as instrumentation, the presence of a foreign body, or irritation that can subsequently cause infection.

Infection can also be transmitted from mother to infant either in vivo or during delivery by direct contact with an infectious lesion or discharge in the mother and a susceptible mucous membrane such as the infant’s eye. E.g: Chlamydia trachomatis, Neisseria gonorrhoeae, Group B Streptococci, E. coli, and Listeria monocytogenes.