65 articles
Antibiotic resistant Neisseria gonorrhoeae
Antibiotic resistant Neisseria gonorrhoeae, or drug-resistant gonorrhoea (super gonorrhoea), strains resistant to all gonorrhoea antibiotic classes; ceftriaxone is the last first-line drug, with penA 60.001-mediated resistance spreading globally.
Cervical cancer
Cervical cancer, a malignant neoplasm of the cervix caused by persistent high-risk HPV (types 16 and 18 dominate), is the fourth most common cancer in women, with about 662,000 cases and 349,000 deaths in 2022, preventable by HPV vaccination and HPV-based screening.
Cervical intraepithelial neoplasia
Cervical intraepithelial neoplasia (CIN), also known as cervical dysplasia, is an abnormal, noncancerous change in cervix surface cells, usually caused by HPV and graded 1 to 3 by severity.
Chancre
A chancre is the painless, firm ulcer marking the primary stage of syphilis, caused by Treponema pallidum, appearing about 3 weeks after exposure at the site of infection.
Chancroid
Chancroid, also called soft chancre (ulcus molle), is a sexually transmitted genital ulcer disease caused by Haemophilus ducreyi, marked by painful genital ulcers and inguinal buboes, treated with single-dose azithromycin or ceftriaxone, and now rare worldwide.
Chlamydia (genus)
Chlamydia (genus Chlamydia, family Chlamydiaceae): gram-negative obligate intracellular bacteria with a biphasic cycle of infectious elementary bodies and replicative reticulate bodies; includes human pathogens C. trachomatis, C. pneumoniae, and C. psittaci.
Chlamydia trachomatis
Chlamydia trachomatis, an obligate intracellular bacterium with a biphasic EB/RB developmental cycle, causes trachoma and the world's most common bacterial STI; treated with doxycycline, no vaccine exists.
Congenital syphilis
Congenital syphilis is fetal or newborn infection with Treponema pallidum passed during pregnancy, causing stillbirth, neonatal death, and deafness, blindness, and bone deformities; preventable by prenatal penicillin treatment, it has resurged in the US with nearly 4,000 cases in 2024.
Diagnosis of HIV/AIDS
Diagnosis of HIV/AIDS: detecting HIV infection via NAT, antigen/antibody, and antibody tests with defined window periods, CDC screening and algorithm guidance, self-testing reliability, and the history from the 1985 ELISA onward.
Epidemiology of HIV/AIDS
Epidemiology of HIV/AIDS: global distribution, incidence, prevalence, and mortality of HIV infection and AIDS. 41.0 million people living with HIV in 2025, 1.2 million new infections, 570,000 deaths, concentrated in the WHO African Region and key populations.
Epidemiology of syphilis
Epidemiology of syphilis: distribution and trends of Treponema pallidum infection. WHO estimates 8 million adult cases in 2022; resurgence since 2000 among MSM, with congenital syphilis rising sharply in the US and Europe.
Gardasil
Gardasil is Merck's quadrivalent HPV 6/11/16/18 vaccine, FDA-approved in 2006 as the first cervical cancer-preventing vaccine; Gardasil 9 (2014) adds five types and is the only HPV vaccine in the U.S.
General paresis of the insane
General paresis of the insane (GPI), or paralytic dementia, is late neurosyphilis: chronic Treponema pallidum brain infection causing progressive dementia and paralysis 10–30+ years after syphilis, once common in asylums, now rare and penicillin-treatable.
Genital herpes
Genital herpes, caused by HSV-1 or HSV-2, is a lifelong STI with recurrent genital sores; about 520 million people have genital HSV-2. Treated with acyclovir, valacyclovir, or famciclovir; no vaccine exists.
Genital ulcer
Genital ulcer: an open sore on genital, anal, or perianal skin, usually caused by genital herpes or syphilis, less often chancroid, LGV, or donovanosis; diagnosis requires laboratory testing.
Genital wart
Genital warts (condyloma acuminata, anogenital warts) are benign HPV-caused growths of genital skin and mucosa, 90% from HPV types 6 or 11, treated by topical or ablative therapies and prevented by vaccination.
Gonorrhea
Gonorrhea, a common sexually transmitted infection caused by Neisseria gonorrhoeae (the gonococcus), with about 82 million annual cases, ceftriaxone as first-line therapy, and rising multidrug resistance including super gonorrhoea.
Gumma (pathology)
Gumma (plural gummata): a soft, necrotic granuloma of tertiary syphilis caused by Treponema pallidum, most often in skin, bone, and liver, treated with benzathine penicillin G.
Hepatitis C and HIV coinfection
HIV/HCV coinfection, simultaneous infection with HIV and hepatitis C virus, affects about 21% of US adults with HIV and up to 82% of those who inject drugs; HIV accelerates liver fibrosis, but direct-acting antivirals cure HCV in over 94% of coinfected patients.
Herpes simplex virus
Herpes simplex virus (HSV-1, HSV-2) is a human virus causing oral and genital herpes, establishing lifelong latency in sensory neurons with periodic reactivation; no cure exists, but acyclovir, valacyclovir, and famciclovir control symptoms.
History of syphilis
History of syphilis: Treponema pallidum infection, first epidemic in Europe in 1495, named by Fracastoro in 1530; treated with mercury, Salvarsan, then penicillin (1943); includes the Tuskegee untreated-syphilis study (1932–1972) and modern resurgence.
HIV/AIDS in Africa
HIV/AIDS in Africa: the world's hardest-hit regional HIV epidemic, with 64% of 41 million people living with HIV in the WHO African Region, heterosexual transmission, ART-driven life-expectancy gains, and a 2025 US funding crisis threatening PEPFAR-supported treatment.
HIV/AIDS in India
HIV/AIDS in India, also called AIDS in India, is the national HIV epidemic: 2.561 million people living with HIV in 2024, with adult prevalence of just 0.20%.
HIV/AIDS in Kenya
HIV/AIDS in Kenya is a generalized epidemic, first detected in 1984, that peaked at roughly 10 to 13 percent in the late 1990s and fell to 3.22% by 2026.
HIV/AIDS in South Africa
HIV/AIDS in South Africa is the world's largest national HIV epidemic, with about 8 million people living with HIV, and runs the largest antiretroviral treatment program.
HIV/AIDS in the Philippines
HIV/AIDS in the Philippines: epidemic since the 1984 first case, long "low and slow," now the fastest-growing HIV surge in Asia-Pacific under RA 8504 and RA 11166, with 4,633 new cases in Q1 2026.
HIV/AIDS in the United States
HIV/AIDS in the United States: the domestic HIV epidemic first reported June 5, 1981; over 1.2 million Americans living with HIV, about 38,000 new diagnoses in 2024, concentrated among men, Black and Hispanic people, and the South.
HIV/AIDS in Uganda
HIV/AIDS in Uganda is the national experience of a severe HIV epidemic that fell from about 15 percent of adults around 1991 to about 5 percent by 2001.
HPV vaccine
HPV vaccine (Gardasil 9, Cervarix, Cecolin): prophylactic vaccine against human papillomavirus, first approved 2006, preventing cervical and other cancers; CDC routine at 11-12, WHO supports 1- or 2-dose schedules.
Human papillomavirus infection
Human papillomavirus (HPV) infection, a common sexually transmitted infection with about 200 virus types; most clear spontaneously, but persistent high-risk types cause cervical, anogenital, and oropharyngeal cancers, preventable by HPV vaccination and screening.