Chancroid overview and Definition

Chancroid is a highly contagious yet curable sexually transmitted disease (STD) caused by the bacteria Haemophilus ducreyi. Chancroid causes ulcers, usually of the genitals. 


The bacterium Hemophilus ducreyi enters the person through sexual contact or breakage in the skin. Then they releases the exotoxins which might result in the cytolethal effect that is the occurrence of cell death by the bacterium. This bacterium increases the oxidative stress and result in release of free radicals leading to cell burst. It also causes irreversible epithelial damage.


 The size of the chancroid lesion ranges from 1-2 cm and it is very painful. It has a well defined erythematous base and well demarcated borders and ragged edges. It might secreate gray or yellow purulent exudate. The affected genital areas and draining lymph nodes in men includes Corona, prepuce or glans of penis. In women it might include Labia, introitus and perianal areas. If vaginal and cervical areas are affected then the drainage occurs by the lymph nodes surrounding the vagina and cervical areas. 50% of the population develops tender, unilateral inguinal lymphadenopathy. 25% of the population develops buboes with subsequent ulceration within 2 weeks. It is characterized by painful ulcers with suppurative inguinal lymphadenopathy. The ulcer edge is typically ragged and also it shows underdetermined edges.

Structure of bacteria Haemophilus ducreyi:

It is a gram negative bacteria. The shape of the bacteria is the coccobacilli. It is non sporing bacterium. It is facultative anaerobe meaning it is predominantly lives in oxygen free environment but it can  make it survival in oxygenated environment also. It lacks flagella and hence it non motile, it cannot move. Since it is a gram negative bacteria it has well defined lipopolysaccharide coating which makes it resistant to the damage of the bacterias cells by the host immune mechanisms.

Clinical signs & symptoms

Inflammation of the urethra- urethritis

Vaginal discharge


Bleeding in the sore

Dysuria- A condition caused by the urethral discharge

Routes of transmission:

Sexual route

Sometimes by blood products.

Differential Diagnosis

Gram stain:

In gram stain the organisms shows rail track appearance or school of fish appearance.

Fine needle aspiration cytology:

This procedure draws the blood from the site of the infection and this is send to the laboratory for further investigation purposes.

Polymerase chain reaction:

It uses H.ducreyi DNA amplification and reveal the results.

H ducreyi is a fastidious bacterium requiring a relatively expensive nutritive base to grow on and is an extremely difficult organism to culture from clinical specimens in the hands of inexperienced laboratory staff. As a result, conventional laboratory culture facilities are often not available in STD clinics or simply not affordable in resource poor countries. In those clinical settings with laboratory support, clinicians are often faced with the dilemma of whether to treat a patient empirically for chancroid at the first visit or whether to request staff in their microbiology laboratory to provide a suitable medium with which to culture H ducreyi on a subsequent day in the hope that the patient is not lost to follow up. Even if culture facilities are available, it often takes several days for results to become available.

The role of Stuart’s, Amies’, and thioglycolate hemin based transport media has been evaluated as transport media for H ducreyi. Increased survival of H ducreyi from less than 24 hours to up to 4 days was seen when specimens were held at 4°C. The use of transport media in locations with a refrigeration facility may overcome the significant cost of distribution of culture media with short shelf lives to clinics where the disease is only seen sporadically. There did not appear to be any major advantage in the overall rate of recovery of H ducreyi using transport media compared to direct plating.


Recovery and prognosis of the chancroid purely depends upon the size  and severity of the ulcer sores. Large ulcers from chancroid might take 2-3 weeks to heal fully.



  • Limiting or reducing the number of sexual partners
  • using protection during sexual contact or intercourse at all times
  • regularly checking the genital region for signs of abnormal bumps, sores, or swollen lymph nodes
  • talking with sexual partners about testing for STIs or their STI status before engaging in sexual contact
  • asking sexual partners about any unusual sores or bumps in their genital region
  • talking with a doctor about unexplained groin pain
  • getting regular STI testing
  • avoiding or limiting alcohol use and avoiding recreational drug use as these may impair judgment in making healthy choices
  • screening of the blood and other products before transfusion