Zoology · Ch 3 — Reproductive Health
Bacterial, Viral, Fungal and Protozoan STIs
Bacterial, Viral, Fungal and Protozoan STIs
Bacterial, Viral, Fungal and Protozoan STIs
STIs are not a single kind of disease — they are caused by four completely different classes of organism, and that classification matters clinically because it determines whether the infection can be cured or only managed.
Bacterial STIs — gonorrhoea, syphilis, chancroid, chlamydiasis and lymphogranuloma venereum — can be treated and cured with antibiotics. Gonorrhoea (Neisseria gonorrhoeae) inflames the urethra, rectum, throat and (in women) the cervix, with pus discharge and burning urination appearing within 2–5 days. Syphilis (Treponema pallidum) is unusual in progressing through three distinct stages over weeks to months — a painless genital ulcer first, then skin rashes and joint swelling, and finally, if untreated, severe chronic damage to the nose, legs, palate, nervous system and heart. Chlamydiasis and lymphogranuloma venereum, both caused by Chlamydia trachomatis, cause urinogenital and, in the latter case, more locally destructive tissue damage.
Viral STIs — genital herpes, genital warts, Hepatitis-B and AIDS — cannot be cured outright; only their symptoms can be controlled with antiviral medication. Genital herpes causes painful genital sores; genital warts (caused by HPV, the same virus linked to cervical cancer) cause hard outgrowths on the genitalia; Hepatitis-B can progress to liver cirrhosis and failure; and AIDS (caused by HIV) produces a slow-building set of symptoms — swollen lymph nodes, persistent fever, weight loss — that can take anywhere from weeks to over a decade to appear. …
| Name of the Disease | Causative agent | Symptom | Incubation period |
|---|---|---|---|
| Bacterial STI | |||
| Gonorrhoea | Neisseria gonorrhoeae | Affects the urethra, rectum and throat; in females the cervix is also affected. Pain and pus discharge in the genital tract and burning sensation during urination. | 2 to 5 days |
| Syphilis | Treponema pallidum | Primary stage: formation of painless ulcer on the external genitalia. Secondary stage: skin lesions, rashes, swollen joints, fever and hair loss. Tertiary stage: chronic ulcers on nose, lower legs and palate; loss of movement, mental disorder, visual impairment, heart problems, gummas (soft non-cancerous growths). | 10 to 90 days |
| Chlamydiasis | Chlamydia trachomatis | Trachoma; affects the cells of the columnar epithelium in the urinogenital tract, respiratory tract and conjunctiva. | 2 to 3 weeks, or up to 6 weeks |
| Lymphogranuloma venereum | Chlamydia trachomatis | Cutaneous or mucosal genital damage, urithritis and endocervicitis; locally harmful ulcerations and genital elephantiasis. | — |
| Viral STI | |||
| Genital herpes | Herpes simplex virus | Sores in and around the vulva, vagina, urethra in females or sores on/around the penis in males; pain during urination, bleeding between periods, swelling in the groin nodes. | 2–21 days (average 6 days) |
| Genital warts | Human papilloma virus (HPV) | Hard outgrowths (tumour) on the external genitalia, cervix and perianal region. | 1–8 months |
| Hepatitis-B | Hepatitis B virus (HBV) | Fatigue, jaundice, fever, rash and stomach pain; liver cirrhosis and liver failure in the later stage. | 30–80 days |
| AIDS | Human immunodeficiency virus (HIV) | Enlarged lymph nodes, prolonged fever, prolonged diarrhoea, weight reduction, night sweating. | 2 to 6 weeks, even more than 10 years |
| Fungal STI |