Diagnosis and Treatment of STDs

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Chapter 2
Diagnosis and Treatment of STDs

There are more than twenty different organisms that can infect humans through sexual activity resulting in disease. Because STDs can arise from such a wide array of infectious organisms and because different STDs can produce similar symptoms, or no symptoms, diagnosis and treatment of STDs can be difficult. Precise diagnosis is essential, however, for two reasons: Sexually transmitted diseases do not go away by themselves, and successfully treating an STD depends on prescribing the correct drug or therapy for each disease.

The Importance of Early Detection

No matter which STD an individual is infected with, the time between initial infection and treatment is an important factor in the outcome of the disease. STDs that are treated soon after they are acquired have the best prognosis since there is less chance that the infection will spread to other parts of the body and develop into a more serious condition. Also, finding out about an STD sooner rather than later helps to curtail its spread, since STDs can be eliminated through treatment or the infected person can take precautions to prevent transmission.

Early diagnosis is more likely when symptoms of an STD are immediate, painful, and too alarming to be ignored. Tom, who was fifteen when he acquired an STD that produced symptoms quickly, did not wait long before visiting his doctor. Tom says, "The burning sensation that I felt [when urinating] was so intense that I couldn't stand it anymore."6 Common symptoms such as discharge from the vagina or penis; the appearance of blisters or sores on the genitals; and pain, itching, or burning sensations during urination or sexual intercourse may arise within days of acquiring an STD. As in Tom's case, the onset of symptoms such as these is a clear indication that something is wrong, and the location of the infection is obvious to both the sufferer and the physician. Not surprisingly, these kinds of STDs are the easiest to diagnose.

Unfortunately, many people do not receive treatment in a timely manner because some STDs do not produce obvious symptoms; an infected person simply does not know that he or she is infected. The initial symptoms of an STD may be too subtle to notice or similar to the mild symptoms of other common illnesses, and may not be related to the genitals. HIV infection, for example, initially causes only mild flulike symptoms that go away within a few days; other STDs may cause rashes or sores on the arms or torso that an infected person might mistake for an allergic reaction or insect bite.

One of the most problematic aspects of STDs, and a major reason why many people do not seek prompt medical treatment, is that the majority of STDs remain completely silent for months and often years before triggering symptoms. Nevertheless, throughout the asymptomatic stages the infection may be progressing and damaging the body. This lag in the development of symptoms is obviously detrimental to preventing the spread of STDs, as many people will transmit the disease before they are aware of the infection. Felicia Stewart, a reproductive-health expert with the health maintenance organization Kaiser Permanente, cites the asymptomatic nature of STDs as a major reason why they are so easily transmitted. Felicia says, "There's no way to know if you have an STD without getting tested. Even the doctors don't know."7

STD Testing Sites

Although the signs of STD infection may not be apparent, all STDs can be accurately diagnosed with medical assistance and testing. This means that they can be detected and treated during the earliest stages of infection, before the most serious damage occurs. For this reason health care professionals recommend that all sexually active people be screened for STD infections once a year, or more frequently if they have had more than one sexual partner during that time. An immediate medical checkup is warranted if a current or past sexual partner is diagnosed with an STD, since the risk that the disease has been transmitted is high. Diagnosing an STD early on is preferable to letting the infection progress; however, taking steps to avoid becoming infected in the first place is better still. Therefore the best time to be screened for an STD is before initiating a new sexual relationship. If prospective partners are tested and treated for STDs prior to engaging in sexual activity with each other, the risk of transmitting an STD can be virtually eliminated.

Once a person decides to be tested for STDs, the next step is to find a place to perform the tests and diagnosis. The range of choices in most communities is wide. Most family practice or internal medicine physicians in private practice can perform STD testing in their offices. Most cities sponsor public health clinics that specialize in STD screening along with prenatal care or immunizations. The choice between a private doctor's office and a clinic is usually influenced by cost, privacy, and convenience. Many public clinics are free and offer anonymous testing; instead of creating a medical record naming the patient, as most private physicians do, these clinics use only a number to associate patients with their STD test results. On the other hand, the service provided by a private doctor is often more personalized and may be closer to home. Some people are more comfortable discussing an STD with a doctor with whom they have a long history; others find it embarrassing to broach the topic with their family doctor. Both private doctors and STD clinics are medically competent to diagnose and treat these diseases; patients are advised to choose the facility where they will be most comfortable, most free to ask questions, and most receptive to advice.

The STD Testing Procedure

Regardless of where a person goes to be tested for an STD, the testing process is similar. Patients are asked to provide their medical history and specific information about their sexual activity, safe-sex practices, and symptoms. Responses to these questions help the health care professional to determine which STDs the patient should be tested for. Although a description of the symptoms that the patient is experiencing can assist the health care professional in making a diagnosis, it is rarely sufficient. Different STDs can exhibit similar symptoms and a single type of STD can manifest itself in remarkably different ways depending on the individual.

Blood, urine, or specimens from areas of the body that are likely to be infected are usually collected from the patient for analysis by a clinical laboratory, which may take up to two or three weeks. In addition, a physical examination is conducted to check for visible signs of STD infection. The precise areas of the body that are examined depends on the patient's sex and the likelihood that the patient has been exposed to particular STDs. At some stage of the visit, patients are usually given the opportunity to discuss any concerns they may have about STDs with the health care professional. In addition to answering questions about disease progression and treatment, the health care professional can provide valuable information about the prevention of STDs. Clinics that specialize in STD screening usually offer pamphlets on a range of related topics, which can also be helpful to the patient. After the examination, patients are told how they can find out the results of the tests. Sometimes the patient can access the results by telephone or mail, with the understanding that a follow-up appointment will be necessary to begin treatment if a positive diagnosis is made.

Diagnosing STDs means differentiating between four main categories of infectious agents. A few STDs are caused by tiny insects that can be seen with the naked eye. The majority of STDs, however, are caused by germs that are too small to be seen without the aid of a microscope. In general the germs responsible for STDs fall into the classes of protozoa, bacteria, or viruses.

Diagnosing and Treating Curable STDs

STDs caused by insects can be easily cured. Among all curable STDs, pubic lice and scabies are the easiest to diagnose because the characteristic symptom of intense itching at the site of infection is nearly unmistakable and the infecting insects can be seen on close visual examination. Adult pubic lice, also known as Pthirus pubis, look like little crabs about one millimeter in length. Sarcoptes scabiei, the mites that cause scabies, are about the same size as pubic lice but resemble a tiny tick. Because these insects can be seen without a microscope, laboratory tests are not required for a health care professional to make a definitive diagnosis. Both pubic lice and scabies can be cured by the application of prescriptive lotions or shampoos that contain chemical ingredients that kill these insects. However, the ability of these insects to survive for extended periods of time without human contact means that reinfestation is possible. In order to eliminate all possible sources of reinfestation, all clothing and furniture that have been in contact with the infected person must be treated or laundered with special chemical agents. Alternatively, washable items can be laundered in very hot water (125 degrees Fahrenheit), dried at a high temperature, and ironed at high heat.

Unlike pubic lice and scabies, most STDs cannot be diagnosed simply by looking for the infecting organism with the naked eye. The identification of organisms that are microscopic in size is necessarily more complex and relies on the use of specialized technology. Many of the infecting germs are large enough to be seen with a standard laboratory microscope and sometimes visual identification is all that is required to diagnose the disease. This is the case for the protozoan STD trichomoniasis, a disease that primarily strikes females and causes pain and vaginal discharge. Because the infecting protozoan, Trichomonas vaginalis, is one of the largest STD germs and is distinctively shaped like a tiny oval jellyfish, it can be easily diagnosed by microscopic examination of a vaginal swab. Treatment of trichomoniasis is also quite simple, requiring only oral antibiotics to cure the infection.

Several STDs caused by bacteria can also be easily visualized under the microscope. However, because many bacteria are of similar shape and size, visualization of these germs is not always helpful in diagnosing a specific STD. Conclusive diagnosis requires that the bacteria from an infected person be cultured in the laboratory so that additional tests can be performed. To accomplish this, samples of the patient's blood, urine, or specimens from other likely sites of infection are added to several types of bacterial growth media and incubated at body temperature for several days. If a sufficient quantity of the bacteria can be cultured, a variety of biochemical tests are conducted in order to precisely identify the bacteria.

One advantage of this type of diagnosis is that fluid samples can be taken even in the absence of an active, or symptomatic, out break, detecting infection even during a "silent" stage. It is not always successful, however, due to the difficulty of growing bacteria in culture. Ways to get around this problem have been recently devised to distinguish between certain bacterial STDs based on their unique genetic content. Because this type of analysis requires only a small quantity of bacteria, the amount of bacteria contained within the patient's original sample is sufficient and growth of the bacteria is not necessary.

Once the bacteria has been identified, treatment is relatively straightforward. All STDs of bacterial origin can be treated with antibiotics, although the specific kind of antibiotic prescribed will depend on the type of bacteria that is causing the disease. For chlamydia, gonorrhea, and bacterial vaginosis, oral antibiotics are sufficient to completely cure the disease. A more aggressive treatment consisting of injectable antibiotics is required to cure the bacterial STDs syphilis and chancroid.

Diagnosis and Treatment of Incurable STDs

In comparison with other STDs, the treatment options available for people infected with genital warts, herpes, hepatitis B, and AIDS are not very effective. All of these STDs are caused by a type of germ known as a virus. Unlike most bacteria and protozoa, viruses actually enter the cells of their host organism and destroy them from within, spending a significant amount of their life cycle inside the cells that they infect. This makes it difficult to kill virus particles without also killing the cells of the infected person and risking the person's life. For this reason most viral STDs cannot be cured.

Viruses are by far the smallest of the organisms that cause STDs. They are typically one hundred times smaller than most bacteria, so tiny that approximately 50 billion viruses could fit as a single layer on a two-by-two-inch postage stamp. The miniscule size of viruses means that they cannot be visualized using a conventional microscope. Sometimes viral STDs are diagnosed based on the distinctive physical symptoms they produce, sometimes by detecting the distinctive antibodies to the virus that the body produces in response to infection. These are indirect methods of diagnosis. It is possible to directly identify the presence of the virus itself, but this requires sophisticated techniques that are available only at specialized laboratories. These techniques produce a "molecular picture" of a virus's external features or genetic identity. In this manner, fast and reliable data is generated for the detection and identification of viruses that are present within blood samples or other specimens.

Though advanced techniques for diagnosis of viral STDs are now available, the development of effective treatment has a long way to go. The best existing treatments may reduce the symptoms or the spread of some viral STDs, but they usually fall short of a complete cure. Often people infected with a viral STD will experience recurring symptoms that appear and disappear in an unpredictable manner. In genital herpes, caused by a virus related to the chickenpox and cold-sore viruses, these recurring symptoms consist of outbreaks of painful blistering sores on or around the genitals or mouth. According to one herpes patient, "The physical pain was terrible. Walking, sitting and going to the bathroom hurt so bad, I had to bite on a towel to stand the pain. If you've ever had canker sores in your mouth, imagine having 20 of them in an even more sensitive area."8 Treatment for herpes consists of oral and topical medications that inhibit viral replication, thereby decreasing the frequency and occurrence of outbreaks and reducing the chance of transmission to sexual partners. Despite these benefits, the treatments are rarely successful in alleviating all symptoms and do not provide a cure for the virus, so the infection remains for life.

Infection by HPV is also lifelong. This virus results in the development of warts on or within the genitals. Although genital warts are rarely painful, they can be unsightly and contagious and may cause problems during urination, intercourse, or childbirth. The treatment of genital warts is relatively time-consuming, requiring repeated visits to the doctor or clinic to remove the warts by cryosurgery, or freezing. Because this treatment does not eliminate the infecting virus, the warts can grow back after they are removed. Even when the warts are gone, a person may still be contagious. Michele, a twenty-four-year-old woman who is currently receiving cryotherapy treatment for genital warts, knows the risks only too well. She says, "At first I was mad at my boyfriend for not telling me, but he had his genital warts removed 10 years ago and he didn't think he could spread the virus after having them removed."9 One of the more insidious aspects of HPV is that it can be transmitted to others even if warts never appear. The fact is that only 1 percent of those infected by HPV develop warts. According to Marshall Glover, director of the National STD Hotline, "The body is really good at keeping this virus in check. Many people also think you can't get a disease like genital warts unless you can see warts on your partner. That's not true."10 Glover says that the silent nature of HPV explains why transmission rates continue to soar. For females, the consequences of becoming infected with HPV can be much more serious than the potential development of genital warts, as it increases the risk of developing cervical cancer. For this reason, females who are diagnosed with HPV are urged to have an annual Pap smear to detect any signs of cervical cancer as early as possible.

Hepatitis B is unique among STDs in that it rarely requires medical intervention. Although infection by the hepatitis B virus can result in liver function disorders, most of the symptoms are self-limiting and not severe enough to warrant treatment. However, in some cases infection with this virus progresses to cirrhosis, chronic hepatitis, and the development of liver cancer. In these cases, oral drugs will be used to control the disease, but in cases where the disease progresses and becomes life-threatening, the patient may require a liver transplant. For the vast majority of those infected by hepatitis B, the symptoms of infection resolve themselves and the virus remains more or less dormant inside the body.

AIDS, the syndrome caused by the most well-known STD virus, HIV, is a fatal disease in a category of its own. HIV destroys an infected person's immune system, or ability to fight disease, and so treatments focus on the many so-called opportunistic diseases that AIDS patients fall victim to, including pneumonia, cancer, and serious central nervous system infections. Treatment regimens also focus on inhibiting HIV replication within the body, or keeping the virus in check as long as possible, thereby delaying the destruction of the body's essential immune-system cells as long as possible. The sooner treatment begins, the longer an AIDS patient will be able to live and work normally.

STDs Are Unpredictable

Even though most STDs are not life-threatening, early medical intervention for STDs is also important for the simple reason that these diseases are unpredictable. Because in most cases people cannot reliably identify an infected partner and therefore cannot be certain that they themselves are disease-free, the routine screening of everyone who is sexually active is recommended for early detection of disease. Furthermore, because the unique physiology of the infected person affects disease progression, it is often difficult to anticipate the outcome of an STD. STDs such as HPV and hepatitis B may remain asymptomatic in most people but can be life-threatening in others. Regular follow-up by a trained medical professional is indispensable for preserving the health of people with STDs. Careful monitoring of those with asymptomatic STDs allows subtle changes that can be indicative of disease progression to be detected and allows the health care professional to take immediate action to prevent further deterioration. Although the effects of all STDs can be lessened by medical intervention, the deadly and incurable nature of many of these diseases and the complexity and costs of available treatment for STDs lead strongly to the conclusion that prevention is the best strategy for stopping the STD epidemic.