Neisseria gonorrhea and Chlamydia trachomatis: epidemiology and pathology

Neisseria Gonorrhea & Chlamydia Trachomatis

Neisseria Gonorrhea

Incidence, Prevalence, Mortality

Commonly known as gonorrhea, this is a very contagious sexually transmitted disease caused by the bacterium, called neisseria gonorrhea (Norris, 1997; NWHRC, 2005). It is also called "the clap." Increased public awareness and the AIDS scare significantly brought the incidence down since the 80s. However, as many as 400,000 to a million still remain at risk of contracting it every year in the United States alone. The Center for Disease Control and Prevention reported 351,853 cases in 2002 alone, although it believes the number should double this. Estimated risks remain at this level on account of the private nature of the disease and the lack of tendency to report it. Most reported cases come from public health clinics (Norris, NWHRC). It increases the risk of contracting pelvic inflammatory disease or PID, infertility, ectopic pregnancy, and HIV (Justensen, 2007).

Nationally reported cases in the Western regions went up from 57.2 to 81.5 cases per 100,000 population or 42% from 2000 to 2005 (Justesen, 2007). The increase was noted in both men and women, in all risk ages, and in all racial or ethnic groups. Authorities attribute the increase in incidence to increases in the number of tests actually performed, the trends in the tests and the actual increases in occurrence. These States were Alaska, California, Hawaii, Nevada, New Mexico, Oregon, Utah and Washington. The 21 public health laboratories in these States registered 87.1% in 2004, as compared with those in non-Western States (Justesen).

Gonorrhea can infect anyone of any age, race and socioeconomic status (Norris, 1997; NWHRC, 2005). However, 80% of those infected are adolescents and young adults aged 15-29 for women and aged 20-24 for men. Also at high risk are those with multiple sexual partners and those not using contraception devices, such as condoms. Both men and women can contract gonorrhea through oral, anal or vaginal intercourse. An infected male can pass it on to a women 60-90% with a single intercourse. An infected mother can also pass it on to her infant during delivery. As the second most reported sexually transmitted disease, gonorrhea can cause fertility and its complications can cost the economy as much as $1 billion each year (Norris, NWHRC). Gonorrhea is highly infectious but has low mortality (Todar, 2004).

Signs and Symptoms, Body Systems Involved, Pathologic Changes

Gonorrhea affects the mucous membranes of the genitals (Norris, 1999). These membranes can get inflamed with or without symptoms. The symptoms differ in men and women. The disease usually begins as an infection of the urinary vessel and urethra in men. In women, the cervix is the most commonly infected part. Medical complications result when gonorrhea is left untreated or not early enough. Many women without symptoms do not feel the need to be tested and, thus, do not get treated. Primary symptoms and complications are concentrated in the genital, urinary and gastrointestinal systems. They usually appear one day and two weeks after catching the infection. When untreated, the disease spreads to the bloodstream and reaches the brain, heart valves and the joints. Untreated gonorrhea severely damages the reproductive system and cause sterility (Norris; Sullivan, 2004).

One reason for underreporting is the absence of symptoms in 80% of infected women (Norris, 1999). In the rest of the cases, symptoms include bleeding in-between menstrual periods, chronic abdominal pain, painful urination, vaginal cloudy or yellow discharge, a sore throat in case of oral infection, and rectal itching or discharge in case of anal infection. In women who have no symptoms, complications will likely show up as the disease gets worse. The most common complication is pelvic inflammatory disease or PID, which occurs in 40% of the cases. This condition damages the fallopian tubes and leads to ectopic pregnancy or sterility. If the woman is pregnant, gonorrhea can infect the infant at birth and cause blindness. Infected men, on the other hand, experience different symptoms. There may be thick and cloudy discharge from the penis, burning or painful urination, more frequent urination, a sore throat if the infection is oral and rectal itching or discharge if the infection is anal. Complications can damage the prostate, testicles and proximate glands. These can be followed by inflammation, death of tissue, abscesses, scarring and sterility (Norris; Sullivan, 2004).

Mode of Transmission

Gonorrhea in the anus or rectal area occurs most frequently in women and in men who have sex with men (Miller, 2006). Symptoms range include itch and itchy discharge, often with bowel movement. Pain in the rectum, tenesmus and bleeding are more common in infected men who have sex with men. Gonorrhea in the throat or pharynx occurs after oral sex but the symptoms are mild or absent. Most cases disappear on their own without need for treatment or harmful consequences. Children, on the other hand, can acquire gonorrhea from birth if the mother is infected. It can cause neonatal conjunctivitis, pharyngitis, rectal infections and, infrequently, pneumonia, a few days after birth. Older children acquire the disease from sexual abuse. The most common symptom in preadolescent children, often girls, is vaginitis. Pharyngeal and rectal gonorrhea in children often has no symptoms. And disseminated infection can occur in 1 to 3% of infected adults in the form of polyarticular tenosynovitis and dermatitis. There can be slight joint pain, skin lesions and high fever. Symptoms in the genital area are usually absent. Skin lesions are limited to the extremities as papules, which develop into hemorrhagic pustules. The lesions may also be necrotic. The most affected joints are the wrists, ankles and those of the hands and feet. If the disease is untreated, septic arthritis may develop and involve the elbows, wrists, knees and ankles (Miller).

Morphology

The family of bacteria, called Neisseriaceae, contains gram-negative aerobic bacteria belonging to 14 genera (Todar, 2004). These genera include Neisseria, which contains two human pathogens, namely Neisseria gonorrhea and Neisseria meningitides. Neisseria gonorrhea causes gonorrhea and Neisseria meningitidis causes meningococcal meningitis. The bacterium attaches itself to non-ciliated epithelial cells through the fimbriae and by producing a toxin. It also produces IgA proteases to produce the itch. Many normal persons may Neisseria meningitidis may be found in the upper respiratory tract but Neisseria gonorrhea can only be in normal tissue after an infection (Todar).

Culturing

The bacterium has a typical gram-negative membrane, consisting of proteins, phospholipids and lipopolysaccharide or LPS (Todar, 2004). The LPS in gonorrhea is referred to as lipooligosaccharide or LOS. It releases outer fragments, called "blebs," while it grows. The "blebs" are said to participate in the development of the disease. The bacterium is a relatively weak organism, which is vulnerable to temperature changes, drying, uv light and other conditions in the environment. It requires a medium containing hemoglobin, NAD, yeast extract and 35-36 degrees to culture it. During infection, bacterial lipooligosaccharide and peptidoglycan are released. They activate the host while LOS stimulates the tumor necrosis factor or TNF. TNF causes cell damage. Neutrophils are drawn to the site and eat the bacteria (Todar).

Treatment

The Centers for Disease Control and Prevention revised its guidelines and now recommends the use cephalosporins in the treatment of gonorrhea and PID (Armstrong, 2007). This class of drugs has replaced fluoroquinolones, which have been popularly used since 1993. Fluoroquinolones have been the choice drugs because of their effectiveness, availability and convenient single dose. But resistance to the drugs soon became prevalent in gonorrhea cases, necessitating modifications in the therapy. Incidents were initially reported as occurring in Hawaii, followed by cases in California and the Western States. The resistance trend was first noted among men at 30% in 1994 who have sex with men, then in other groups (Armstrong; Norris, 1999). The incidence persisted and necessitated a change into another regimen. CDC currently recommends a single 125-mg intramuscular shot of ceftriaxone as treatment for uncomplicated urogenita and anorectal gonorrhea. The oral dose is 400 mg of cefixime. Cefixime may be used as an alternative regimen in combination with 1 gram of cefuroxime. CDC also recommends a single intramuscular shot of ceftriaxone for pharyngeal gonorrhea (Armstrong). The list of new class of antibiotics taken orally or given by injection consists of ciprofloxacin, ofloxacin, azithromycin, amoxicillin, doxycycline, and ceftriaxone. Patients who are allergic to penicillin should be treated instead with erhythromycin (Norris).

Alternative treatments include herbs and minerals as supplements (Norris, 1999).

Lactobacillus acidophilus or live-culture yogurts may replenish gastrointestinal flora. Zinc, multivitamins, especially Vitamin C, minerals and garlic help improve the body's immune system. Herbs like kelp, calendula, myrrh, and thuja have demonstrated values on the body's systems. Hot baths also help reduce pain and inflammation. Fasting and juices contribute to cleaning up the urinary and gastrointestinal systems. So do acupressure and acupuncture (Norris).

Prognosis

If the diagnosis is made early and the treatment is correct and complete, the disease can be entirely treated (Norris, 1999). Otherwise, 40% of untreated female patients can develop PID, liver infection and sterility. When the disease spreads throughout the body, the gonococcal infection is likely to cause fever, arthritic joints and skin lesions. The best prevention is still abstinence or exclusive sex with one partner. Infection may also be prevented with the use of contraceptive devices, such as condoms (Norris).

Name of Bacteria: Chlamydia Trachomatis

Disease: Chlamydia or Genital Chlamydia

Body System Involved: Uro-genital System

Taxonomy

Domain - Bacteria

Class - Chlamydiae

Order - Chlamydiales

Family - Chlamydiacea

Genus - Chlamydia

Species - C. Trachomatis

Identification

Chlamydia trachomatis are gram-negative, aerobic, intracellular pathgens (Stephanie, 2008). They are typically coccoid or rod-shaped. They need growing cells to remain alive but can be artificially grown in a suitable medium. They cannot synthesize their own ATP. They were previously believed to be viruses (Stephanie).

The preferred non-culture technique today is the nucleic acid amplification, which have a 85% sensitivity and specificity (Miller, 2006). A Gram stain of mucopurulent discharge from the penis with more than 5 white blood cells per oil-immersion field and no intracellular Gram-negative diplococci can confirm urethritis. The nucleic acid amplification technique can detect and confirm C. trachomatis (Miller). Other tests are cytology, culture, antigen detection, serologic tests, and nucleic acid probes. Because chlamydia are intracellular parasites, swabs of the infected or involved sites, instead of exudates, should be submitted for examination and analysis for accuracy (Mayer, 2007).

Media for Cultivation

Specimens are merged with cultures of susceptible cells (Mayer, 2007). Infected cells are then examined for iodine-staining inclusion bodies, as iodine stains glycogen in these bodies. Their presence confirms C. trachomatis. Other species of the bacterium have no glycogen (Mayer).

Pathogenicity

These organisms are small obligate intracellular parasites (Mayer, 2007). They have their own DNA, RNA and ribosomes and make their own proteins and nucleic acids. They have an inner and outer membrane like gram-negative bacteria. The are unable to make their own ATP and, are, thus energy parasites (Mayer)..

C. trachomatis attacks and infects non-ciliated columnar epithelial cells (Mayer, 2007). They stimulate the infiltration of polymorphonuclear cells and lymphocytes. This leads to the formation of lymphoid follicle and fibrotic changes. Cell destruction follows. The host creates an inflammatory response. Long-lasting immunity is not stimulated by the infection. Re-infection brings on a repeat inflammatory response and resulting tissue damage (Mayer).

Treatment

This depends on the site of the infection, the age of the infected person and whether the infection is complicated or uncomplicated (Miller, 2006). The Centers for Disease Control and Prevention recommends a single oral dose of 1 g of azithromycin for uncomplicated chlamydial infection. The equivalent oral dose is 100 mg doxycycline twice a day for seven days. The azithromycin single dose has the advantage in that it can be administered at the doctor's office. If the patient vomits the drug within one or two hours, alternative treatment should be given. If symptoms persist after the completion of the regimen, treatment should be changed to 2 g metronidazole as a single oral dose in addition to 500 mg erhthromycin ethylsccinate, also taken orally, four times a day for seven days. An alternative dosage is 800 mg erythromycin ethylsuccinate orally four times a day for seven days (Miller).

Tetracyclines, erythromycin and sulfonamides are commonly used to treat Chlamydia and other sexually transmitted diseases (Mayer, 2007). But their effectiveness is limited where re-infection is common. Vaccines are not effective against these diseases. Only proper treatment, improved hygiene, prevention of re-infection, safe sexual practices and abstinence will help (Mayer).

Specific Disease Chosen

Genital Chlamydia or Chlamydia is the most frequently reported bacterial STD (NWHRC Health Center, 2005). Statistics say that there are more than 3 million new cases of the disease very year. The American Social Health Association reported that it is most common among teen-agers and young adults. From an invasion of the endocervix, the disease spreads to the reproductive tract. If untreated, it can lead t infertility, ectopic pregnancy and chronic pelvic pain. It has been called the "silent epidemic" in that three out of four infected persons do not develop symptoms. Yet it produces complications and damage. In 1999 alone, the annual costs incurred in treating the infection and its complications went beyond $2 billion Chlamydia is so common among young women that health authorities estimate half of all sexually active women, by age 30, will contract it some time in their lives (NWHRC Health Center).

Chlamydia usually presents symptoms (Miller, 2006). These are dysuria and discharge from the penis in men and pelvic inflammatory disease in women. Most women do not have symptoms. Despite the lack, it can cause ophthalmia neonatorum in newborns and chlamydial pneumonia. Untreated Chlamydia in men can spread to the epididymis. Oral treatment may be a single dose of azithromycin or a weekly dosage of 100 mg twice daily of doxycycline. Amoxicillin or an erythromycine base is recommended for pregnant women. CDC and the U.S. Preventive Services Task Force strongly recommend the examination of women at increased risk and women under 25 (Miller).

Prognosis

Congress allotted a budget to fund a national STD-related infertility prevention program (NWHRC Health Center, 2005). This increased the number of Chlamydia screenings. It also raised the level of awareness on the seriousness of the disease, especially on health professionals. A consequence was that States now require insurance companies to cover the costs of Chlamydia screenings (NWHRC).

When diagnosed, the disease is easily treated and cured (NWHRC Health Center, 2005). But if left untreated, it can develop serious medical problems. In women, it can produce pelvic inflammatory disease involving the upper genital tract. This includes endometritis and trubo-ovarian abscess. Acute pelvic inflammatory disease is also hard to diagnose. It has subtle signs and varying symptoms (NWHRC Health Center).