Haemophilus ducreyi Explained: From Infection to Prevention

 

Introduction of haemophilus ducreyi

Short, ovoid, Gram negative bacilli, may show bipolar staining.  They may occur in end to end pairs or short chains in smears.  Require X but not V factor for growth.

What is disease caused haemophilus ducreyi?

The bacterium Haemophilus ducreyi causes the disease Chancroid.  

What is chancroid?

Chancroid is a highly contacious yet curable sexually transmitted disease caused by bacteria haemophilus ducreyi. Chancroid increases the risk of infection with HIV and facilitates transmission of the virus. It is sexually transmitted and a common cause of genital ulceration, swollen, painful lymph glands. Worldwide chancroid appears to have declined as well, although infection might still occur in some regions of Africa and the Caribbean. Chancroid, as well as genital herpes and syphilis, is a risk factor in the transmission of HIV infection. A definitive diagnosis of chancroid requires the identification of H. ducreyi on special culture media that is not widely available from commercial sources even when these media are used, sensitivity is less than 80%.

Haw to transmission chancroid

Chancroid is transmitted in two ways: sexual transmission through skin to skin contact with open sores. Non sexual transmission when pus like fluid from the ulcer is moved to other parts of the body or to another person. A person is considered to be infectious when ulcers are present. There has been no reported disease in infants born to women with active chancroid at time of delivery.

What are the signs and symptoms of chancroid?

Symptoms usually accur within four days to ten days from exposure. The ulcer begins as a tender, elevated bump, or papule, that becomes a pus filled, open sore with eroded or ragged edges. The ulcer is soft to the touch unlike a syphilis chancre that is hard or rubbery. The term soft chancre is frequently used to describe the chancroid sore. The ulcers can be very painful in men but women are often unaware of them. Because chancroid is often a symptomatic in women, they may be unaware of the lesions. Painful lymph glands may accur in the croin, usually only on one side however, they can occur on both sides.

Haw to diagnosis chancroid

Diagnosis is made by isolating the bacteria haemophilus ducreyi in a culture from a genital ulcer. The chancre is often confused with syphilis, herpes or lymphocranuloma venereum therefore, it is important that your health care provider rule these disease out. A gram stain to identify H. ducreyi is possible but can be misleading because of other organisms found In most genital ulcers.  Specimens should be collected from the base and margins of ulcers following cleansing with a saline swab (exclude necrotic tissue).  Specimens for culture must be delivered to the laboratory with the minimum of delay.  When this is not possible the swab should be placed in Amies transport medium and delivered the same day to the laboratory or sent in an insulated cool box to reach the laboratory within 48 h.  Culture: H. ducreyi is difficult to isolate.  It is grown best from scrapings of the ulcer base on chocolate agar containing 1% IsoVitaleX and vancomycin, 3 mg/mL, and incubated in 5-10% CO2 at 33-36 °C for 2-3 days.  The organism grows slowly, producing small grey-yellow or brown colonies usually within 2–4 days. Biochemical tests: Slowly oxidase positive (colour develops after 15–20 seconds).  Catalase, urease, and indole negative.

What is the treatment for chancroid?

Successful treatment for chancroid cures the infection, resolves the clinical symptoms, and prevents transmission to others. In advanced cases, scarring can result, despite successful therapy. Antibiotics used to treat chancroid include azithromycin 1g orally, ceftriaxone 250MG intramuscularly im, ciprofloxacin 500 MG orally or erythromycin 500MG orally.

Haw can chancroid be prevented?

Absolutely not having sex mutual monogamy having sex with only one uninfected partner latex condoms for vaginal, oral and anal sex. Using latex condoms may protect the penis or vagina from infection, but does not protect other areas such as the scrotum or anal area.

Conclusion

Chancroid is a sexually transmitted infection caused by Haemophilus ducreyi, characterized by painful genital ulcers and tender inguinal lymphadenopathy. It remains a significant public health concern in areas with limited healthcare resources, where it facilitates the transmission of HIV. Early diagnosis, proper antibiotic treatment, and preventive measures such as safe sexual practices and partner management are essential to reduce its spread and complications.