Human papillomavirus (HPV) is a genus of papillomavirus A belonging to the family Papillomaviridae, a spherical DNA virus that causes proliferation of the squamous epithelium of the human skin mucosa. More than 130 types of HPV have been isolated, and different types cause different clinical manifestations, which can be classified according to the invasion of different tissue sites:
(1) Low-risk skin types: HPV 1, 2, 3, 4, 7, 10, 12, 15, etc. are associated with common warts, flat warts, plantar warts, etc;
(2) High-risk skin types: HPV5,8,14,17,20,36,38 are associated with warty epidermal dysplasia, and other malignant tumors that may be associated with HPV infection include: vulvar cancer, penile cancer, anal cancer, prostate cancer, and bladder cancer;
(3) Mucosal low-risk types such as HPV-6, 11, 13, 32, 34, 40, 42, 43, 44, 53, 54, etc. are associated with infection of the genital, anal, oropharyngeal, and esophageal mucosa;
(4) Mucosal high-risk HPV-16, 18, 30, 31, 33, 35, 39 and cervical cancer, rectal cancer, oral cancer, tonsil cancer, etc.
Biological activity: HPV is resistant, tolerates drying and long-term storage, and can be inactivated by heating or by formalin treatment, so high-temperature disinfection and 2% glutaraldehyde disinfection can be inactivated. [1-3]
Epidemiology
Skin type HPV infection rate in the population is very common, such as the above common common warts, toe warts, flat warts, etc. It is not possible to get the specific rate of infection, more attention is drawn to the high-risk HPV infection and genital warts and cervical cancer caused by low-risk HPV infection in the external genitalia, according to statistics in the global STD, HPV infection caused by genital warts accounted for 15-20%.
Regarding the prevalence of HPV infection in the female genital tract, according to a 2003-2004 survey from the National Health and Nutrition Research Program in the United States, the total HPV infection rate among 14-59 year olds was 26.8%, so the burden of HPV infection in women exceeds previous estimates. Epidemiological screening for HPV infection in China has not been reported in large samples, but the incidence of condyloma acuminata, a sexually transmitted disease caused by HPV infection, is rapidly increasing, and the incidence is estimated to be the highest among sexually transmitted diseases because of substantial underreporting and underreporting. There are about 131,500 new cases of cervical cancer detected in China every year, and the reported incidence and mortality rates are increasing, and the age of cervical cancer onset is young, so it is predictable that Hpv infection is causing huge damage in China.
Route of infection
1.Sexual transmission route;
2.Close contact;
3.Indirect contact: through contact with the infected person’s clothes, daily necessities, utensils, etc;
4, medical source of infection: medical personnel in the treatment and care of poor protection, resulting in their own infection or through medical personnel to patients;
5.Mother-to-child transmission: close contact from infants through the birth canal of pregnant women.
Clinical manifestations
Low-risk HPV infection 1, benign skin manifestations
(1) common warts: rice grain-sized papules, the surface keratinization is obvious, rough and uneven, the tip of the spiny, hard texture, lesions can be single, or multiple, can be self-inoculated and gradually increased. Mostly occur in hands, feet, etc.
(2) special site performance disease.
The skin of the skin is also covered with a variety of other skin types.
2, external genital disease benign performance
(1) genital warts (condyloma acuminatum): including three states: typical performance, subclinical infection, latent infection.
(a) typical performance: typical lesions visible to the naked eye: morphological papilloma-shaped, cauliflower-shaped, granular, cockscomb-shaped, etc.;
(b) Subclinical manifestations are not easily recognizable to the naked eye and can only be observed with the aid of magnification and vinegar-white tests, with pathological changes typical of HPV in histological and cytological tests;
(c) Latent infection is the entry of HPV into the cells of the skin mucosa, which does not cause any clinical manifestations and histocytological abnormalities, but can be detected in the cells of the skin mucosa by molecular biological methods, nucleic acid hybridization, etc.
Prevalent sites: female vulva, vagina, cervix and perineum, intra-anal canal, urethra; male vulva, penis, testicular surface, urethra, perineum, intra-anal canal, etc.
Rare sites: armpit, umbilicus, between the toes, under the breast, etc.
(2) Special sites: wart-like damage on the surface of oral mucosa, recurrent respiratory papillomatosis, etc.
High-risk HPV infection 1. Skin manifestations
Some data suggest that epithelial tumors such as Bowen’s disease, basal cell carcinoma, Paget’s disease, and squamous cell carcinoma of the skin are also associated with this type of virus infection.
2.Mucosal manifestations
Cervical cancer, anal canal cancer, tonsil cancer, oral cavity cancer, larynx cancer, nasal cavity cancer, esophageal cancer, etc.
Diagnosis and differentiation
Auxiliary examination
1.Vinegar white test;
2. Histological examination;
3.Molecular biology: PCR, nucleic acid molecular hybridization technology, etc;
4.Cytological pathology examination.
Differential diagnosis
External genital warts need to be differentiated from villous labia minora, penile pearl rash, sebaceous ectopia, flat warts, and pseudowarts. [2]
Disease prevention
Prophylactic quadrivalent vaccines (HPV 6, 11, 16, 18) and others are available internationally to prevent infection with these four virus types, as most cervical cancers are contracted by types 16 and 18, so they can reduce most cervical cancers, and some scientific studies have shown some protection against other types. However, the vaccine does not work for people who are already infected. Circumcision of male overcircumcised skin is an important measure to prevent cervical cancer in women and also to prevent men from contracting various types of STDs themselves. Circumcision of newborns and young children in some countries is a very good way to prevent HPV infection and cervical cancer in spouses as adults.
Disease Treatment
Treatment modalities
(1) Physical therapy: aims to remove neoplasms and subclinical infections that are visible to the naked eye
Methods include: laser, microwave, freezing, electrocautery, surgical excision (LEEP knife in gynecology, etc.), photodynamic therapy, etc.
(2) Medication: 0.5% tincture of pediculosis lipotoxin, 5% imiquimod, 50% trichloroacetic acid, fluorouracil ointment, etc.
(3) Immunotherapy: interferon, interleukin, thymidine, transfer factor, BCG vaccine, isotretinoin, autologous vaccine, etc., to reduce recurrence and speed up the clearance of lesions
(4) Therapeutic vaccine: There is no effective therapeutic vaccine.