Thursday, June 23, 2011

Neonatal infections - Congenital syphilis

Transmission of Treponema pallidum from person to person occurs through direct contact with infectious lesions during intercourse. Pathogen enters the body at mucosal or skin lesions.Parenteral transmission by transfusion is rare because of routine serological testing of blood and blood products.There is a possibility of intrauterine transmission from infected mother to fetus appearing congenital syphilis. In utero transmission can occur as early as 9-10 weeks gestation. The most important risk factor for fetal infection is maternal stage of syphilis. Mothers with primary syphilis, secondary, early latent or late latent poses a risk of at least 50%, 50%, 40% resp 10% of a child born with syphilis.The risk of fetal infection may also be higher in more advanced stages of pregnancy. Co-Treponema pallidum infection plus maternal HIV-1 may promote transplacental transmission of each of pathogens to the fetus.Rarely the infection is transmitted at birth through contact with genital lesions.
Clinical signs:
Pathological and morphological alterations of congenital syphilis and inflammatory immune response is due to invasion by the spirochete fetus.Histopathological abnormalities are most prominent vasculitis with necrosis and fibrosis production.Most of infants with congenital syphilis are asymptomatic at birth.Children who develop clinical manifestations in the first 2 years of life are considered early congenital syphilis, while those events are close to puberty late congenital syphilisFuniculita fasciitis, an inflammatory process deeply affecting umbilical cord matrix and is accompanied by phlebitis and thrombosis, is common in babies died at birth and infants symptomatic at birth.
Clinical signs of congenital syphilis occur in approximately two thirds of babies affected during the third to eighth week of life and up to 3 months.Symptoms may be general and nonspecific: fever, lymphadenopathy, irritability, poor growth and development. Is specific triad: rhinitis, palmar-plantar bubbles and splenomegaly.Clinical disease severity can vary from medium to brilliant.Premature infants are more affected than term infants, can present only hepatomegaly, respiratory distress and skin lesions.Congenitally infected infants are smaller than gestational age (SGA).
Radiological abnormalities:Detected in 20-95% of children with early congenital syphilis, their low frequency is seen in asymptomatic children. Lesions are usually multiple, symmetric. Diafizele are affected metaphyses and long bones, especially of the lower extremities.Radiological changes include osteochondritis, periostitis, osteitis.The earliest changes occur in metaphysics and now consists of radiopaque transverse bands (sign Wagner), alternating with areas of radiolucent bone with osteoporosis.Osteochondritis becomes evident radiographically after 5 weeks of fetal infection. Metaphysis can become fragmented, focal erosions involving the proximal medial tibia (Wimberger sign).
Periosteal reaction may consist of: one starting bone (formation of new bone), several layers, periosteum sheet of onion "severe lamellar form (eg, periostitis of Pehu).
Events in the central nervous system (CNS):
A 60% of infants with congenital syphilis have CNS manifestation.Acute syphilitic meningitis is accompanied by: stiff neck, vomiting, hypertension previous fontanelle, positive Kernig sign.Cerebrospinal fluid examination (CSF) reveals: glicorahie normal, moderately high protein content and pleocytosis with morfonucleare (normal less than 200 cells / Microlut) - similar to those found in aseptic meningitis. Syphilis develops in children meningocerebral untreated chronic and manifests in late childhood with progressive communicating hydrocephalus, atrophy optic cranial nerve paralysis and leading to hemiplegia cerebral infarction or apoplexy.

Congenital syphilis late
Clinical manifestations of late congenital syphilis are given the scars that remain after therapy early congenital syphilis or persistent inflammation in untreated individuals.Dental abnormalities are secondary lesions that affect early development of dental buds and can be prevented by treatment with penicillin in the neonatal period or early childhood.Interstitial keratitis occurs in approximately 10% of patients and is often diagnosed between 5-20 years. Base deformation nose, palate vault and underdeveloped jaw are late consequences of rhinitis.Deafness in acoustic-vestibular nerve (VIII) affects 35% of patients and is due to degeneration and cochlear otic capsule osteocondritei resulting.
Positive diagnosis:
Include non-specific tests: VDRL, RPR (rapid plasma reagine).Specific serological tests: FTA-Abs (antitreponemici antibody absorption test fluorescent), MHA-TP (test for Treponema microhemaglutinare) when the test is inconclusive IgM FTA-ABS, VDRL and CSF are used as screening to all infants with suspected syphilis.
To establish treatment criteria are taken into account maternal: untreated syphilis, serology positive, inadequate treatment without penicillin treatment 4 weeks antepartum, unfair treatment.Neonatal criteria considered are clinical signs of congenital syphilis, VDRL higher four times the breast, positive microscopic examination.
Treatment is medication, antibiotics penicillin G is administered intra-venous crystal. The dose is 100. 000UI/kgc in 2 doses 12 hours in 7 days, then 8 hours. Treatment duration is 10-14 days. If treatment is interrupted for more than a day to return scheme began.

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