it was relatively common until the widespread use on penicillins in the 1950's when it became rare in Western cultures but has been gradually increasing with increased general sexual promiscuity and drug use in the 1980's but massive campaigns against HIV / AIDS and advice of safe sex and reducing risk of sexual misadventures reduced its prevalence in the 1990's. Unfortunately, it is again on the rise in line with massive rises in other sexually transmitted infections (STDs/STIs) as adherence to safe sex practices are no longer widespread.
cannot be cultivated in vitro and is too small to be seen under the light microscope, but can be detected using dark-field microscopy or direct immunofluorescence staining of fixed smears
rapidly penetrates intact mucous membranes or microscopic dermal abrasions
it can also be spread:
from mother to baby in utero (“congenital syphilis”)
via blood transfusions
from breaks in the skin contacting syphilitic open skin lesions
incubation period from exposure to development of primary lesions 10-90 days with average of 3 weeks
pathology is characterised by obliterative endarteritis
repeated infections are possible
Epidemiology
appears to have arisen in South America and brought to Europe in the late 15th century by Columbus' crew
the origins and early diversification of Treponema pallidum subspecies, which cause syphilis, yaws, and bejel, remain poorly resolved
a 5,500-year-old Treponema genome was recovered from Middle Holocene-age human hunter-gatherer remains from Colombia, although this TE1-3 strain is genetically diverse and distinct from modern strains and is thought to have diverged from their line 13,700yrs ago but possesses the T. pallidum virulence-associated genes, suggesting conserved pathogenic capacity 1)
it became rare in Western countries in the second half of the 20th century, apart from in indigenous populations but is now rising again
in Victoria, 19 cases of congenital syphilis have been recorded between 2017-2024 emphasising the need for antenatal testing in 1st trimester and again at 26-28wks gestation and at 36 weeks or at delivery (whichever is earlier) with positives being treated with long acting (benzathine) penicillin
in addition, any pregnant person presenting with signs and symptoms suggestive of a sexually transmissible infection (STI) or who has been exposed to an STI, should be tested for syphilis.
congenital syphilis
high rate of spontaneous abortion and stillbirth
the first 2 years of life, symptoms are similar to severe adult secondary syphilis with widespread condylomata lata and rash
Snuffles” describes the mucopurulent rhinitis caused by involvement of the nasal mucosae
“saddle nose” (due to destruction of the nasal septum)
“saber shins” (due to inflammation and bowing of the tibia)
“Clutton’s joints” (due to inflammation of the knee joints)
“Hutchinson’s teeth” (in which the upper incisors are widely spaced and notched)
“mulberry molars” (in which the molars have too many cusps)
Tabes dorsalis and general paresis may develop
8th cranial nerve deafness and optic nerve atrophy may occur
4 classical stages of acquired syphilis
primary syphilis
the initial painless primary chancre lesion on the skin at site of initial transmission
the lesion has a punched-out base and rolled edges and is highly infectious
secondary syphilis
develops about 4-10 weeks after the appearance of the primary lesion as the bacteria spread throughout the body and multiply
clinical features can be diverse but usually include:
malaise
fever
myalgias & arthralgias
lymphadenopathy
rash:
generalised mainly macular rash which may involve the palms, soles, and oral mucosae
can be pustular, annular, or scaling
wet mucous patches are the most contagious
condylomata lata
painless, highly infectious gray-white lesions that develop in warm, moist sites such as genitalia/perianal areas
patchy alopecia often with a “moth-eaten” appearance
immune reaction is at its peak
latent syphilis
resolution of features of secondary stage but patient remains seropositive
may have recurrence of rash
1/3rd will develop tertiary syphilis
remainder will remain asymptomatic
early latent syphilis
1st 2 yrs
late latent syphilis
After 2yrs, no longer infectious sexually but can still be transmitted to fetus from pregnant women
tertiary syphilis
rare
slow inflammatory damage to tissues, especially to cardiovascular system and central nervous system
3 categories:
gummatous syphilis:
gummas are painless rubbery granulomas which may affect any tissue but particularly, liver, bones, testes, and which break down with necrotic centres and may form ulcers