Chancroid
Chancroid is a sexually transmitted disease (STD) caused by the bacterium Haemophilus ducreyi, primarily characterized by painful sores on the genitalia. This infection is particularly prevalent in developing countries and poses an increased risk for contracting other sexually transmitted infections, including HIV. Symptoms typically manifest within three to five days, starting as a raised lesion that develops into a painful ulcer with pus. While men often present with a single ulcer, women may experience multiple ulcers, and many infected women can be asymptomatic.
Diagnosis can be challenging, as chancroid may be confused with syphilis, but effective screening methods exist. Treatment typically involves antibiotics, with azithromycin being a common choice. Preventive measures, such as using latex condoms, can reduce the risk of transmission. However, individuals do not develop lasting immunity after infection, highlighting the importance of awareness and safer sexual practices.
Chancroid
Anatomy or system affected:Genitalia, skin
Also known as: Soft chancre, ulcus molle
Definition
Chancroid is a sexually transmitted disease (STD) caused by the bacterium Haemophilus ducreyi. The disease, which causes painful sores on the genitalia, is most common in developing countries. Chancroid increases the risk of infection by other sexually transmitted pathogens, including the human immunodeficiency virus.
Causes
Chancroid is caused by H. ducreyi, a sexually transmitted, gram-negative, facultatively anaerobic, coccobacillus. The bacterium grows in chains and requires hemin for growth. The bacterium needs breaks in the host’s epidermal layer to initiate infection.
Risk Factors
Chancroid is more common in uncircumcised males and in persons who have sex with sex workers in developing countries.
Symptoms
The initial appearance after infection is a reddened, raised lesion on the genitalia three to five days after exposure, although the infection can appear in as little as one day or in as many as fourteen days. Within twenty-four hours, the lesion converts to a painful, soft-edged ulcer with irregular borders that often secrete pus. Men often have a single ulcer and women usually have four or more.
Swollen, painful lymph nodes are also present in approximately one-half of cases. These swollen nodes, called buboes, may rupture and form abscesses that drain pus. Women tend to have milder symptoms than men, and more than 50 percent of infected women are asymptomatic. Self-inoculation with the fingers can transfer the bacteria, so that chancroid ulcers appear at other locations on the body, especially on the conjunctiva, a membrane that covers the eye and lines the inner surface of the eyelid.
Screening and Diagnosis
Chancroid can be confused with the hard chancre of syphilis, but chancre, unlike chancroid, is usually painless, does not exude pus, and heals on its own within six weeks. Samples from a skin ulcer can also be looked at with dark-field microscopy; a lack of visible spirochetes indicates chancroid rather than a syphilitic chancre. Definitive diagnosis depends on isolating the bacteria and growing it on one of three specialized media, although this test is only 80 percent effective in diagnosis.
Treatment and Therapy
Chancroid responds well to antibiotics. The most common regimen is a single dose of azithromycin. Other possible treatments include a single intramuscular injection of ceftriaxone, oral ciprofloxacin twice daily for three days, or erythromycin four times a day for a week. Infections in uncircumcised males are more resistant to antibiotic therapy. Sex partners of infected persons are also treated, even if they show no signs of chancroid.
Prevention and Outcomes
The use of latex condoms decreases the likelihood of infection. Infection does not cause lasting immunity, and no effective immunizations have been developed.
Bibliography
Klausner, Jeffrey D., and Edward W. Hook III. Current Diagnosis and Treatment of Sexually Transmitted Diseases. New York: McGraw-Hill, 2007.
Larsen, Laura. Sexually Transmitted Diseases Sourcebook. Detroit: Omnigraphics, 2009.
Murphy, T. F. “Haemophilis Infections.” In Mandell, Douglas, and Bennett’s Principles and Practice of Infectious Diseases, edited by Gerald L. Mandell, John E Bennett, and Raphael Dolin. 7th ed. New York: Churchill Livingstone/Elsevier, 2010.
Spinola, Stanley M., Margaret E. Bauer, and Robert S. Munson, Jr. “Immunopathenogenesis of Haemophilus ducreyi Infection (Chancroid).” Infection and Immunity 70 (2002): 1667-1676.
Workowski, Kimberly A., and Stuart M. Berman. “Diseases Characterized by Genital Ulcers.” Morbidity and Mortality Weekly Report 55 (2006): 14-30.