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Monday, December 5, 2016

Clinical Microbiology HW#16



Concept Map: Syphilis

1. Al Capone contracted syphilis in his youth. By the time he was imprisoned in Alcatraz, he was suffering from syphilis-induced confusion and disorientation. What stage of syphilis did Mr. Capone have at this time?
Tertiary

2. Which of the following is true of the latent stage of syphilis infection?
It may never progress to tertiary syphilis.

3. Which of the following terms does NOT describe syphilis?
Attenuated

A burning Question

A 20-year-old woman comes to the local clinic complaining of lower abdominal pain and sharp burning pain on urination (dysuria) that has gone on for 1 week. She also complains of mild fever and chills. Her history and physical reveal that she has had eight sexual partners in the previous year and has used condoms only on occasion because she has been taking birth control pills. She has not visited her physician or gynecologist for 2 years. The clinic physician performs a pelvic exam and sample collection to determine the causative agent, telling the patient that she likely has contracted a sexually transmitted infection (STI).

1. Sexually transmitted infections (STIs) are a significant problem in the world. The symptoms described in the case thus far are fairly general and may apply to multiple STIs. However, many STIs can be discerned by other visual signs that accompany the general symptoms.
**Checking patients for STIs is difficult because of the wide range of signs and symptoms that may or may not be present. Many STIs share symptoms. Clinical diagnosis of STIs starts with looking for the most obvious and commonly seen signs.

On further examination, the physician finds no obvious external lesions on or around the patient’s genitalia. However, the physician does note the presence of a discharge.

2. The physician performs a pelvic exam, which reveals the presence of an abnormal thin, watery vaginal discharge and inflammation of the cervix. The physician then palpates the abdomen (examines by touch and pressure) and finds that the uterus, fallopian tubes, and ovaries are enlarged and tender. The physician takes a swab sample of the cervix and sends it to the laboratory to determine the causal organism. Light microscopy and simple staining of the sample in the lab reveal an organism with a very unique life cycle. The organism is classified as gram-negative, but it stains very poorly compared to other classic gram-negative STI pathogens. The stain shows both a nonreplicating, extracellular infectious elementary body and a replicating, noninfectious reticulate body inside mucosal cells from the cervical epithelium swab. Based on the symptoms and these new laboratory findings, which of the following would be the most likely diagnosis for the patient?
Chlamydia
**The physician makes a clinical diagnosis of chlamydia. Additionally, the exam shows that the patient has signs of progressive chlamydial pelvic inflammatory disease (PID).

This just went from bad to worse for the patient. Untreated STI cases can lead to progression of disease beyond the borders of the urinary and reproductive tracts, with potentially serious complications.

3. The two most common STI organisms associated with PID in the United States are Chlamydia trachomatis and Neisseria gonorrhoeae. There are many similarities between these STIs. Which of the following statements comparing chlamydia and gonorrhea are true?
Patients may be coinfected with both gonorrhea and chlamydia.
Chlamydia is found more often in women, whereas gonorrhea is found more often in men.
Chlamydia and gonorrhea can infect a patient and be transmitted without causing obvious symptoms.
**STIs not only are hard to detect, but also are not mutually exclusive. When a patient has one STI, others may be “hiding in the shadows.” STIs spread rapidly and can have consequences outside the urinary and reproductive tracts.

The laboratory needs more time to rule out a mixed infection but does confirm the presence of Chlamydia. The patient’s symptoms suggest that this infection has been going on for a while and has progressed beyond a simple case of Chlamydia urethritis to pelvic inflammatory disease (PID). As discussed in the above question, these STIs aren’t just for the genitals anymore!

4. Chlamydia PID is just part of the overall spectrum of disease caused by Chlamydia organisms. Even though we now understand more about STIs and their complications, we are still exploring how the organisms “branch out” beyond just a single infection. Which of the following diseases have Chlamydia infection as an etiology?
infertility
inclusion conjunctivitis
pneumonia
trachoma
lymphogranuloma venereum (LGV)
cervical cancer
**Mixed STI infections (which may involve both different species and different strains of the same species) are able to manifest in an infected patient with more than just the classic “clap” symptoms. The caregiver should always be aware that more may be going on in the patient than meets the eye and act appropriately to instruct the patient on routes of spread the person might not anticipate.

Having identified the STI and potential consequences, we now need to turn to appropriate treatment for her conditions.

5. Our patient needs antibiotics to overcome this infection and prevent any further complications. Which of the following would be the best choice?
a combination therapy of cephalosporin-class AND macrolide-class

Conclusion
After 3 days of hospitalization for antibiotic therapy, monitoring, and laboratory testing to assess the function of her reproductive systems, the patient is released to go home. She is discharged with a short course of antibiotics, educational materials about STIs (with multiple copies so that she can notify and inform her partners), and instructions to follow up with her gynecologist for yearly checkups.

Chapter 26 Reading Questions

1. If a patient is diagnosed with trichomoniasis, which treatment should be prescribed?
Metronidazole

2. Which disease or microbe is NOT transmitted across the placenta to the unborn fetus?
ophthalmia neonatorum
**Ophthalmia neonatorum is not transmitted across the placenta; the infant acquires it during passage through the birth canal.

Diseases in Focus Chapter 26 – Male, age 23

Medical History (Hx)
The patient is a 23-year-old male. He is from Loveland, Colorado. He was admitted to the clinic seeking sexually transmitted infection (STI) testing. An initial physical examination of the patient shows several small, blisterlike bumps on his penis. The patient is a student and also plays drums in a band. He is in a monogamous heterosexual relationship of six months, and reports consistent use of spermicidal condoms during intercourse. He estimates that he has sex with his girlfriend roughly twice a week. He lives in an apartment with one male roommate; however, he frequently stays at his girlfriend’s house. His most recent travel was a cruise he and his girlfriend took in Alaska a month ago. Neither he nor his girlfriend owns any pets. He does not report using any drugs of abuse. He does not have a family history of genetic disease. He is lactose intolerant. Two weeks ago, he noticed an unusual tingling sensation in his genitalia. He did not mention it to his girlfriend, nor did he seek any specific medical attention. He subsequently began to notice a burning sensation during urination, along with a few small red bumps resembling pimples at the base of his penis. After a few days, he noticed that the bumps had multiplied and some had started to become blisters. At this point, he and his girlfriend decided to seek STI testing. She is with him upon admittance to the clinic. She has not experienced any similar symptoms; however, she would also like to be tested as a precautionary measure.

Differential Diagnoses
Differential diagnosis is the process of identifying a disease from a list of possible diseases that fit the information derived from examining a patient. Your job will be to synthesize information from a patient whose main presenting symptoms are consistent with a microbial disease of the reproductive system. Use the Chapter 26 Disease Tables 26.1, 26.3 and Diseases Associated with AIDS and your knowledge about microbial diseases of the urinary and reproductive systems to identify the patient's risk factors and symptoms, evaluate diagnostic evidence, formulate and test a diagnosis about the pathogen responsible for the patient's woes, and suggest a course of treatment.

1. Identify relevant information
Review the patient's medical history, and then identify risks and concerns that are relevant to your diagnosis (and the patient's treatment).
Relevant:
Risk of travel-related disease exposure
Not Relevant:
Age-related risk of disease
Occupational risk of disease
Risk of sexually transmitted infection
Risk of vector-borne disease
Risk of drug-related disease exposure
Risk of genetic/familial disease
Special concerns for treatment
Risk of immunocompromised
**You've reviewed your patient's medical history. He has traveled recently, which could increase his exposure to novel pathogens and vector organisms. This does not give you very much to go on, though; especially since your patient's symptoms suggest that he has an STI. You decide to try to focus your hypothesis--perhaps if you have a better understanding of what STIs suit his symptoms, you will be better able to identify the relevant information in his medical history.

Review possible diagnoses.
Now that you have considered the evidence at hand, you should start to build a hypothesis about what disease your patient has based upon the symptoms he presents. In the beginning of your diagnostic process you should try to think broadly and consider any and all reasonable possibilities. You can then narrow down these possibilities by performing diagnostics that can support or refute your hypothesis.

2. Given your current information, which of the following diseases do you think could be responsible for your patient's symptoms?
genital herpes
**You suspect your patient may have genital herpes!

3. Select a diagnostic.
You would like to perform some diagnostics to help you confirm your hypothesis. Which of the following would you like to do to help you make a diagnosis of genital herpes?
culture of fluid from vesicle
PCR testing on fluid from vesicle
Serology
**You take a blood sample and sample of cells and fluid from your patient's lesions. You also take a blood sample and vaginal swab from his girlfriend. You release the couple from the clinic and let them know that their results will be available in a couple of days. You decide to order antibody testing, virus cultures, and PCR for your samples. Which herpes viruses should you focus on, though?

4. Refine your hypothesis
The viruses responsible for genital herpes belong to the family Herpesviridae. Genital herpes is only one of several conditions caused by viruses of this family. Eight types of herpesvirus are currently known to cause disease in humans. Match each type of herpes virus to the disease it causes.
HHV-1: cold/canker sores, oral herpes, genital herpes
HHV-2: cold/canker sores, oral herpes, genital herpes
HHV-3: chicken pox, shingles
HHV-4: infectious mononucleosis
HHV-5: CMV inclusion disease, retinitis
HHV-6: roseola, roseola infantum (measleslike rash in infants)
HHV-7: roseola, roseola infantum (measleslike rash in infants)
HHV-8: Kaposi’s sarcoma
** Human herpesvirus 1 and 2 are responsible for both oral and genital herpes.

5. Of the two strains of virus that cause genital herpes, which strain is more likely to be responsible for your patient's outbreak?
herpes simplex virus 2
** Most cases of genital herpes are caused by HHV-2. You will perform PCR on your patient's sample for both HHV-1 and 2, however.

6. If you assume that this is your patient's first outbreak and that his condition had an incubation period, when would you guess that he acquired the virus?
three weeks ago
** If this is your patient's first outbreak of genital herpes, then you might expect that he contracted the disease roughly one week before the first onset of symptoms.

7. You would like to ask your patient about scenarios where he could have contracted the virus. Which of the following could he have acquired genital herpes from?
skin-to-skin contact with infected oral or genital area
oral sex
physical contact with an asymptomatic person with latent genital herpes
unprotected vaginal sex
anal sex
vaginal sex with condom
** Your lab results have returned. Your patient's viral culture is positive for HHV-2, which your PCR results confirm. Your patient's girlfriend's results are negative for both HHV-2 and HHV-1, however. You call your patient and his girlfriend back in, and separately inform them of their respective diagnoses.

8. Interpret your results
Your patient's girlfriend looks shocked when you deliver the news. She immediately runs out to your patient, exclaiming: "How could you cheat on me??!" Your patient stammers that he hasn't and wouldn't cheat on her. Is it possible that he is telling the truth?
Yes, he could be telling the truth.
You explain to your patient's girlfriend that is very possible that he caught the disease long before his current outbreak. Around 90% of patients with HHV-2 experience recurrences over their lifetime, and it is not uncommon for initial outbreaks of genital herpes to go completely unnoticed.

9. Treat the disease
Your patient tries to sheepishly smile at his girlfriend and reaches out for her. She is still clearly upset, but she takes his hand and sighs loudly. She turns to you and asks how you plan to cure her boyfriend. You reply that ______.
you cannot cure your patient's disease
** You inform the couple that while they can manage your patient's symptoms and outbreaks, he will never truly be "cured" of the disease.
The viruses responsible for genital herpes, like all herpesviruses, can remain latent in the body for long periods of time. After an initial infection, some people experience sporadic outbreaks as the virus (latent in the trigeminal or sacral nerve ganglia) becomes active and is transported from the neuron to the skin. Reactivation appears to be triggered by several factors, including menstruation, emotional stress, illness, or even vigorous contact with an area of infection (e.g., scratching an area, or friction from sexual contact).

10. "If I can never be cured, how can I avoid passing the disease to my girlfriend?" your patient cries.
You assure him that it is still possible for him maintain a relationship, although he will potentially have to form some new habits and take some extra precautions. You recommend that if the pair mutually agrees to continue dating, then he and/or his girlfriend should ______.
avoid sex when the infected partner is symptomatic
use additional protection during oral sex (dental dam, saran wrap)
use a condom during intercourse
take a daily prescription for valacyclovir
** You inform the couple that with forethought and proper precautions, they should be able to have the kind of relationship that suits them both. Although abstinence from sexual activities is the only method that is 100% effective against the spread of genital herpes, if the couple decides to pursue a continued sexual relationship, there are several things they can do to reduce the risk of transmission. While some methods of safe sex are more effective than others for preventing the spread of genital herpes, a combination of barrier methods, antiviral drug treatment, and thoughtful timing of sexual encounters (i.e., no sexual contact during an active outbreak) can greatly reduce the risk of spreading the disease.

Chapter 26

1. Pyelonephritis may result from
All of the answers are correct.
** systemic infections; ureteritis; urethritis; cystitis

2. Which of the following is caused by an opportunistic pathogen?
Candidiasis

3. A urine sample collected directly from the urinary bladder
is sterile.

4. The most common reportable disease in the United States is
gonorrhea.

5. Which of the following is NOT a complication of gonorrhea?
None of the answers are correct; all of these are potential complications of gonorrhea.
** arthritis; endocarditis; meningitis; pelvic inflammatory disease

6. Which of the following is the most difficult to treat with chemotherapeutic agents?
genital herpes

7. Recurring vesicles on the surface of human skin are symptoms of
genital herpes.

8. Which of the following diseases causes a skin rash, hair loss, malaise, and fever?
Syphilis

9. Infants born to asymptomatic mothers with recurrent genital herpes are less likely to acquire herpesvirus at birth than infants born to newly infected mothers because
maternal antibodies offer protection.

10. Which of the following is greater?
the number of reported cases of gonorrhea last year

11. A 25-year-old man presented with fever, malaise, and a rash on his chest, arms, and feet. Which of the following causative agents is most likely to cause these symptoms?
Treponema

12. Which of the following is treated with cephalosporins because the organism is resistant to penicillin and fluoroquinolones?
Neisseria gonorrhoeae

13. Women and men typically have the same normal microbiota in their reproductive systems.
FALSE

14. Genital candidiasis is a disease that only affects women.
FALSE

15. Trichomoniasis is the only known STI caused by a protozoan.
TRUE