Is it Possible to Spread Syphilis Through Saliva?

Syphilis is a chronic infectious disease caused by Treponema pallidum (TP), which is transmitted mainly through sexual contact and blood. The disease is extremely dangerous and can invade various tissues and organs throughout the body or cause abortion, premature delivery, stillbirth and fetal syphilis through placental transmission. According to the course of the disease, it can be divided into three stages. One stage of syphilis is the early stage of infection, which is mainly manifested by hard chancre and sclerosing lymphadenitis, and generally has no systemic symptoms.

Basic Information

English name: primary syphilis
Visiting department: dermatology
Common causes: Caused by Treponema pallidum (TP)

Common symptoms: Hard chancre and sclerosing lymphadenitis
Contagious: Have
way for spreading: Sexual contact, vertical transmission, etc.

Causes and pathogenesis of primary syphilis

TP is also called pale spiral body. It consists of 8 to 14 regular, fixed, and highly refractive spirals. It has a length of 4 to 14 m and a width of 0.2 m. It can rotate, snake, and retract in three ways. TP is an anaerobic microorganism, which is difficult to survive without leaving the human body. It can be quickly killed by boiling, drying, sunlight, soapy water and ordinary disinfectants, but its cold resistance is strong, it can survive for 3 days at 4 , and it can be stored at -78 for several years. Still contagious.

Mucopolysaccharase on TP surface may be related to its pathogenicity. TP has a high affinity for mucopolysaccharide-rich tissues such as skin, aorta, eyes, placenta, and umbilical cord. It can be adsorbed on the surface of the above tissue cells by its mucopolysaccharide enzyme, which breaks down mucopolysaccharides and causes tissue blood vessels to collapse and blood supply to be blocked. Then it leads to luminal occlusive endarteritis, periarteritis, necrosis and ulcers.

Route of transmission of primary syphilis

The only source of syphilis is patients with syphilis, who have treponema present in skin lesions, blood, semen, breast milk, and saliva. The common transmission channels are as follows:

1. Sexual contact

Most patients are infected through sexual contact with minor damage to the skin and mucous membranes. Untreated patients are highly infectious within 1 to 2 years after infection. As the disease period prolongs, the infectivity becomes smaller and smaller, and patients infected for more than 4 years are basically non-infectious.

2. Vertical spread

After 4 months of pregnancy, TP can be transmitted from the mother to the fetus through the placenta and umbilical vein. It can cause miscarriage, premature delivery, stillbirth, or fetal syphilis. Its infectivity gradually decreases with the prolongation of the disease. The probability of vertical transmission of latent and late latent syphilis pregnant women is 70% to 100%, 40%, and 10%, respectively. Contact infection can also occur in the head and shoulder abrasions when the newborn passes through the birth canal during delivery.

3 Other ways

The blood of syphilis patients within 3 days of refrigerated storage is still contagious. Infection of this type of blood can cause infections; a small number of patients can be infected by iatrogenic routes, kissing, shaking hands, breastfeeding or touching contaminated clothing and equipment.

Clinical classification and staging of primary syphilis

According to different transmission routes, it can be divided into acquired (acquired) syphilis and fetal (congenital) syphilis; according to the course of disease, it can be divided into early syphilis and late syphilis.

Clinical manifestations of primary syphilis

The primary manifestations of syphilis are hard chancre and sclerosing lymphadenitis, which generally have no systemic symptoms.

1. Hard chancre

Painless inflammatory response caused by TP at the site of invasion. Occurs in the external genitalia. Males are more common in the penis coronal groove, glans, foreskin and lacing. Females are more common in the labia majora, labiata perineum, perineum and cervix. It is rare to occur outside the genitalia. The latter is easily missed or misdiagnosed. The typical hard chancre is a small patch of erythema at the beginning, which quickly develops into a painless inflammatory papules. Within a few days, the papules expand to form a sclerosis, and the surface necrosis occurs to form a single round or oval painless ulcer with a diameter of 1 to 2 cm. The state is clear , Peripheral edema and bulging, flesh-red base, cartilage-like hardness on the touch, serous secretions on the surface, containing a large amount of TP, highly infectious. The untreated hard chancre can last for 3 to 4 weeks. The treated person subsides after 1 to 2 weeks, leaving a dark red superficial scar or hyperpigmentation.

2. Sclerosing lymphadenitis

Occurs 1 to 2 weeks after the appearance of hard chancre. Often involved unilateral groin or lymph nodes near the affected area, showing a hard texture of the bulge, no redness and swelling on the surface, generally not painful. It usually takes months to subside. A large number of TP was seen on the lymph node aspiration.

Primary syphilis test

Can be divided into TP direct examination, syphilis serum test and cerebrospinal fluid examination.

1, TP direct inspection

The lesion tissue exudate, lymph node puncture solution, or tissue grinding solution can be selected, and the method should be dark field microscopy, silver plating, Giemsa staining, or direct immunofluorescence.

2.Syphilis serum test

The syphilis serum test is the main test method and the main basis for the diagnosis of syphilis. It is divided into non-specific tests (including RPR, TRUST, and VDRL tests) and specific tests (including TPHA, TPPA, and FTA-ABS).

The non-specific test uses immunological methods to detect cardiolipin antibodies in the serum as a diagnostic screening test for syphilis. This test has high sensitivity and low specificity. When a positive result is obtained, a preliminary diagnosis can be made. Quantitative test is a method to observe the effect and judge recurrence and reinfection. A false negative can occur within 2 to 3 weeks after the first stage of syphilis.

The specific test is the Treponema pallidum antigen serum test, and the positive result can confirm the diagnosis. However, it is often persistent and cannot be used to observe and judge the efficacy.

3. Cerebrospinal fluid examination

It is mainly used for the diagnosis of neurosyphilis, including white blood cell count, protein quantification, VDRL, PCR and colloidal gold test. Generally not used as a diagnostic method for primary syphilis.

Primary syphilis diagnosis and differential diagnosis

The diagnosis of primary syphilis is mainly based on contact history, incubation period, typical clinical manifestations, and laboratory tests (dark-field microscopy, silver plating, Giemsa staining, or direct immunofluorescence) to detect TP; syphilis serum tests are negative early and positive later It should be noted that syphilis cannot be ruled out only by a negative result of a syphilis serological test. Hard chancre should be distinguished from genital herpes, soft chancre, Behcet's disease, and fixed drug rash:

Genital herpes

Typical manifestations are clustered small vesicles in the genital area, consciously itching and pain, not hard, can be resolved after 1 to 2 weeks, but easy to relapse, tissue culture is herpes simplex virus, Tzank smear test is positive, PCR test is positive for herpes virus DNA .

2. Diarrheal pyoderma

The pathogenic bacteria are Staphylococcus aureus or Streptococcus. The skin lesions are similar in appearance to hard chancre, but there is no typical cartilage-like hardness, there is no dark red infiltration around it, there is no history of unclean sex, syphilis examination is negative, and nearby lymph nodes can swell, but the skin lesions heal Subside after that.

3. Soft chin

She also has a history of sexual contact. It is caused by Haemophilus ducreyi. It has a short incubation period, acute onset, significant inflammation, pain, soft nature, often skin lesions, and purulent secretions on the surface. Haemophilus ducreyi, syphilis serum test can be detected. negative.

4. Tuberculous ulcer

It is also common in the penis and glans, and the skin lesion is a single isolated superficial round ulcer. The surface is often crusted and the symptoms are mild. Mycobacterium tuberculosis can be detected, often accompanied by visceral tuberculosis.

5. Behcet syndrome

Ulcers can occur in the vulva, women can also be found in the vagina, cervix, deep ulcers, slight itching, no hard chin characteristics, often secondary oral ulcers, eye damage (iridocyclitis, anterior chamber pus, etc.) , Calf nodular erythema and migratory arthritis, syphilis serum negative.

7. Fixed drug eruption

It is a kind of drug-derived dermatitis. It can be seen in the external genitalia. It is a bright red erythema, which can form superficial erosion, conscious itching, painlessness, and no hard chancre. It has a history of taking medicine and has a negative syphilis serum response.

Primary syphilis treatment

1. Commonly used plum-driving drugs

(1) Penicillin is the drug of choice. Serum concentration of 0.03IU / ml has the effect of killing TP, but the serum concentration must be stably maintained for more than 10 days to completely remove TP from the body. Commonly used benzathine penicillin G, procaine water penicillin G, and water penicillin G. Cardiovascular syphilis does not use benzathine penicillin G.

(2) Ceftriaxone sodium has proven to be a highly effective anti-TP drug in recent years, and can be used as a preferred alternative treatment for penicillin allergies.

(3) Tetracycline and erythromycin are less effective than penicillin, and are usually used as an alternative treatment for penicillin allergies.

2.Treatment plan for primary syphilis

The benzathine penicillin G is injected intramuscularly on both sides of the buttocks once / week for 2 to 3 consecutive times; or the procaine penicillin G is injected intramuscularly for 10 to 15 consecutive days. If you are allergic to penicillin, you can use intravenous ceftriaxone sodium for 10 to 14 days, or you can take tetracycline (tetracycline, doxycycline, minocycline) for 15 days orally; or you can take erythromycin (red mold) Vegetarian) 15 days.

Precautions for syphilis

1. The disease should be treated as early as possible, in sufficient quantity and regularly to avoid cardiovascular syphilis, neurosyphilis and serious complications.

2. Sex partners are receiving treatment at the same time. Sexual life is prohibited during treatment to avoid reinfection and causing infection to others.

3 Regular follow-up should be performed after treatment, and physical examination, serological examination and imaging examination should be performed to investigate the effect. Generally adhere to at least 3 years, once every three months in the first year, once every six months in the second year, and once at the end of the third year; pregnancy syphilis should be reviewed once a month before delivery; pregnant women with syphilis Infants born should be followed up at 1, 2, 3, 6 and 12 months after birth.

4 Patients with a course of more than 1 year, relapsed patients, serum-fixed patients, and patients with vision and hearing disorders should receive cerebrospinal fluid examination to understand the presence of neurosyphilis.

5. Relapse patients should be doubled.