Chancroid 

Chancroid is a sexually transmitted disease (STD) characterized by painful necrotizing genital ulcers that may be accompanied by inguinal lymphadenopathy. It was once endemic to many areas of the world, but social awareness of the disease and subsequent changes in characteristics of commercial sexual networks, along with improved diagnosis and treatment options, have eliminated chancroid as an endemic disease in industrialized countries. It remains prevalent in certain underdeveloped regions such as Asia, Africa, and the Caribbean. Chancroid is a subclass of sexually transmitted genital ulcerative diseases that are of worldwide concern due to their role as cofactors in the transmission of HIV.^{[1, 2]}

Chancroid is caused by Haemophilus ducreyi a, a small, gram-negative, facultative anaerobic bacillus. It produces a cytocidal distending toxin that appears to be responsible for its toxic effects. Chancroid is transmitted sexually by direct contact with purulent lesions, and by autoinoculation to nonsexual sites such as the eye and skin. The organism has an incubation period from 1 day to 2 weeks, with a median time of 5-7 days. The disease typically begins as a small inflammatory papule at the site of inoculation; within days, the papule erodes to form an extremely painful deep ulceration. Without treatment, the lesions may last weeks to months, and complications such as suppurative lymphadenopathy are more likely.^{[3, 4, 5]}

Frequency

United States

Information regarding STD prevalence in the United States is obtained from the Centers for Disease Control (CDC), which collects data from state health departments. It has published information regarding prevalence of chancroid dating back to 1941, when 3,384 cases were reported. More recently, the incidence of chancroid has declined steadily from 1987 when over 5000 cases were reported to the CDC. In 2008, 25 cases were reported from 9 different states.

In the past, the disease was considered endemic in several large US cities but is currently seen in sporadic cases associated with low socioeconomic status, poor hygiene, prostitution among sex workers, and drug abuse. In 2008, only 25 cases were reported to the CDC, with 8 of these cases from Texas. The true incidence is difficult to determine, and underestimated, because of unavailable diagnostic resources in underdeveloped countries where the disease is most prevalent, and because of the difficulties in culturing H ducreyi even when laboratory resources are available.^[6]

International

The true incidence of chancroid worldwide is unavailable because no specific monitoring for this disease exists. Data from the World Health Organization (WHO) in 1995 suggested that 7 million cases of chancroid existed worldwide. Globally, it has been surpassed by HSV-2 as the most common genital ulcerative disease. Chancroid is prevalent in Africa, the Caribbean basin, and Southwest Asia. It is thought to be the most common cause of genital ulceration in Kenya, Gambia, and Zimbabwe.^{[7, 8, 9]}

Mortality/Morbidity

• Chancroid is not a lethal disease. It is characterized by one or more painful genital ulcers that are associated with unilateral painful inguinal lymphadenopathy in 50% of the cases. Left untreated, suppurative bubo formation occurs in approximately 25% of cases, which can progress to spontaneous rupture with formation of a deep nonhealing inguinal ulcer. Chancroid is easily curable with appropriate antibiotic therapy, although patients with HIV require longer courses of therapy. The true impact of the disease lies in the well-known association of genital ulcer disease with increased transmission rates of HIV and other STDs. Previous infection does not confer immunity against the disease, and reinfection is possible.^[10]
• Superinfection of lesions, known as phagedenic chancroid, may lead to widespread disfiguring necrosis and may require surgical excision.

Race

Although no proven racial predilection exists, chancroid is most commonly observed in nonwhite people.

Sex

Chancroid is most commonly observed in nonwhite men who are uncircumcised. Women represent only 10% of known cases because they are more likely to be asymptomatic carriers.

Chancroid is more commonly identified in individuals of lower socioeconomic status, prostitutes and travellers from endemic areas. According to Benson and Hergenroeder,^[11] there have been no reported cases of chancroid among homosexual males, bisexuals or lesbian females.

Age

Although it can affect people of any age, chancroid predominantly affects younger sexually active people. Females aged 15-19 years have the highest prevalence among women in the United States, followed by those aged 20-24 years. In males, the highest prevalence is in those aged 20-24 years.