Microbiology Chlamydia

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).

Diagnosis

Detection of gonorrhea is performed at a public health clinic or family physician office (Norris 1999). The doctor first discusses the symptoms and elicits the patient's risk behavior or known contact. The most used tests for gonorrhea are a culture, a Gram stain, and an ELISA test. The first preferred method is the culture of secretions from the infected area, whether symptoms exist or not. A cotton swab can collect enough sample secretions to culture and test. This sample is incubated up to two days for bacteria to multiply for detection. The test has a 00% accuracy. The second test, which uses gram stains, is more accurate when used on men than in women. A small amount of the discharge from the infected area is placed on a slide, stained with a special dye and examined under a microscope. The advantage of this second test is the speed of detection. It can be performed during the first visit. The test requires skill or competence in the physician or technician. It has a70% accuracy as compared to the culture test. Other tests are used to confirm its result. And ELISA also produces quick findings. ELISA is enzyme-linked immunosorbent assay. It is much more sensitive than the gram stain. It is also more sensitive than the gram stain and more convenient than the culture test (Norris).

Physicians may call in or consult with a gynecologist in diagnosing gonorrhea (Norris, 1999). An infected male patient suffering from complications may be referred to a urologist. Referrals may also be made to specialists of infectious diseases. Doctors are required by law to report incidence of gonorrhea and information on the patient's sex partner or partners. If the patient is found infected, the partner or partners will be notified that they are at risk (Norris). The two methods used in diagnosis gonorrhea are culture and non-culture (Miller, 2006). The non-culture techniques need less manpower to perform. They approximate the accuracy of culture tests. In some cases, non-culture tests have replaced culture tests. The newest is the nucleic acid amplification test. It has 92-96% sensitivity and 94-99% specificity, as compared with culture tests (Norris). The Centers for Disease Control and Prevention recommends the maintenance of a low threshold to physicians when diagnosing pelvic inflammation disease because of the lack or absence of significant negative changes. The Center recommends diagnosing women with PID and who experience uterine and adnexal painfulness or cervical tenderness during the examination. Women who have urogenital disease can submit to the nucleic acid amplification text by endocervical or urine sample. Endocervical samples are, however, preferred, a urine samples have lower sensitivity (Miller).

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).