Infectious diseases | Master Of Medicine

Category Archives: Infectious diseases

What is syphilis?

Syphilis is a sexually transmitted disease(STD) affecting the genital organs.Syphilis is transmitted by a spirochete bacterium named Treponema pallidum.It is most often transmitted by sexual contact, but it can also be transmitted from mother to fetus by placental route.When transmission occurs from mother to baby and when syphilis is present in an infant it is called congenital syphilis.

Syphilis has been called ” the great imitator” due to its frequent atypical features.Usually after sexual contact with an infected individual, syphilis takes about 9-90 days to establish in a new individual.This period is known as the incubation period of syphilis.During this period the signs and symptoms of the disease are not present.Syphilis passes through different stages in an individual.It can be primary, secondary,tertiary and latent syphilis.

Symptoms of syphilis

Syphilis usually presents as painless ulcer on the glans penis or in the vulval region with painless rubbery lymphadenopathy. The ulcer is described as painless punched out non bleeding ulcer.This painless feature of syphilitic ulcer is the main symptom which helps to differentiate between syphilis and other genital infections like chancroid,LGV etc.The lymphadenopathy is usually bilateral.This stage is known as primary syphilis.

In secondary syphilis, there may be bilaterally symmetrical asymptomatic skin rash on palms and soles which is the most common finding.There may be loss of hair, described as moth eaten alopecia.Arthritis and proteinuria may also be present along with condyloma lata.

In tertiary syphilis,syphilitic gumma is present.This is the phase where syphilis affects the nervous system.Neurosyphilis has two components, general paresis and tabes dorsalis.

Argyll Robertson’s pupil is another feature of syphilis.In this condition, accomodation reflex is present, but pupillary reflex is absent.

Diagnosis of syphilis

There are several tests to diagnose syphilis.They are TPHA,VDRL,TPA etc.VDRL is used for the prognosis of syphilis.

Treatment of syphilis

Penicillin is the drug of choice for the treatment of syphilis.

Types of human herpes viruses and associated diseases.

Herpes simplex virus

HHV 1- Herpes simplex virus type 1

HHV 2 – Herpes simplex virus type 2

HHV 3- Varicella Zoster virus

HHV 4 -Epstein Barr virus

HHV 5 – Cytomegalo virus

HHV 6- Human B cell lymphotropic virus

HHV 7 -RK virus

HHV 8 -Kaposi virus

Diseases associated with Herpes virus family.

HSV 1 – Usually causes lesions in and around mouth,Most common cause of sporadic encephalitis

HSV 2- Cause lesions in genital area, cause meningitis

HHV 6 causes Exanthem subitum/Roseola infantum also known as sixth disease.

HHV 8 is associated with Kaposi sarcoma and multicentric Castleman disease.

Also see diseases named first disease to sixth disease under exanthematous diseases..

Findings in congenital,primary, secondary and tertiary syphilis

Congenital syphilis

  1. First sign – Rhinitis/Snuffles
  2. Primary bullous lesions

Primary syphilis

Syphilis lesions on back

Image via Wikipedia

  1. Painless punched out non bleeding indurated ulcer
  2. Painless rubbery lymphadenopathy

Secondary syphilis

  1. Bilaterally symmetrical asymptomatic skin rash on palms and soles-MC finding
  2. Moth eaten alopecia
  3. Condyloma lata
  4. Arthritis and proteinuria

Tertiary syphilis

  1. Syphilitic Gumma
  2. Neuro syphilis – General paresis, tabes dorsalis

Measles and pertusis

There are many similarities between measles and pertusis.


  • Caused by paramyxo virus(RNA )
  • Only source of infection is a case of measles
  • No carriers
  • Virus cannot survive outside the body
  • Koplik’s spots.
  • Rubella is less communicable than measles because of he absence of cough in rubella.
  • SAR 90%


  • Incubation period 7-14 days, never more than 3 weeks
  • Most infectious during catarrhal stage
  • Source of infection is a case of pertusis
  • No evidence of subclinical infecton or chronic carrier stage.
  • SAR is 90% similar to Chickenpox and measles

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