Infectious Disesae Flashcards
1
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Atypical Mycobacterial Infections
2
Q
What are Atypical Mycobacterial Infections?
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- Mycobacterium avium complex (MAC)
- Considered an AIDS-defining illness. Patients with CD4 counts <50/mm3 are at highest risk.
3
Q
What are the signs and symptoms of Atypical Mycobacterial Infections?
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- Disseminated disease:
- Fever
- Malaise
- Weight loss
- Night sweats
- May have gastrointestinal (GI) symptoms
4
Q
How do we diagnose Atypical Mycobacterial Infections?
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- Diagnosis by culture from blood, bone marrow, or tissue
5
Q
How do we treat Atypical Mycobacterial Infections?
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- Two Drug regimen:
- Either clarithromycin or azithromycin
- Plus ethambutol, rifabutin, rifampin, ciprofloxacin, or amikacin. (Fluconazole can decrease the level of rifabutin by 80%. Rifabutin can color body secretions such as urine, sweat, and tears bright orange.
Prophylaxis:
- For CD4 < 50: Azithromycin once a week
6
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Pinworms
7
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What are pin worms?
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- Humans are the only host of Enterobius vermicularis. There is a worldwide distribution, and children are more infected than adults
8
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How are pinworms transmitted?
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Mode of Transmission:
- Hand to mouth
- Infection is easily passed through hands, food, drink and fomites. The eggs are swallowed and hatch in the duodenum; larvae pass to the cecum and mature in 3-4 weeks. The life span is 30-45 days.
9
Q
What are the signs and symptoms of pinworms?
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- Many patients are asymptomatic
- Characteristic symptoms include perianal pruritus (crawling sensation that is worse at night), insomnia, weight loss, enuresis, and irritability. Examination at night may reveal worms in the anus or in the stool. Scratching causes excoriations and secondary skin infections (i.e., impetigo).
- Migration can cause vulvovaginitis, diverticulitis, appendicitis, cystitis, and granulomatous reactions.
10
Q
How are pinworms diagnosed?
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- Eggs can be captured on a piece of cellophane tape over the perianal skin; three tries over three consecutive nights yields a 90% success rate.
11
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What is the treatment for pinworms?
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- All members of the household should be treated concurrently.
- Albendazole or mebendazole or pyrantel pamoate 11 mg/kg (max dose, 1 g PO x 1)
- Hand washing after defecation and before meals must be stressed. Linens should be washed thoroughly
12
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EBV
13
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What causes EBV?
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- EBV is human herpes virus 4, a universal virus transmitted via saliva
- The most characteristic disease is mononucleosis (the “kissing disease”). EBV has also been implicated in Burkitt lymphoma, nasopharyngeal carcinoma, pediatric leiomyomas, collagen vascular diseases, and other disorders
14
Q
What are the signs and symptoms of EBV?
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- After the incubation period of several weeks, patients develop fever and sore throat. Oral lesions include exudative pharyngitis, tonsillitis, gingivitis, and soft palate petechiae. Severe infections also exhibit malaise, anorexia and myalgias.
- Lymph nodes, typically the posterior cervical nodes, are enlarged, discrete, and nonsuppurative, with minimal pain
- Splenomegaly is present in 50% of cases
- A maculopapular and occasionally petechial rash develops in 15% of cases; administration of amoxicillin raises the incidence of rash to 90%.
15
Q
How is EBV diagnosed?
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- Any clearly granulocytopenia is followed by a lymphocytic leukocytosis. Atypical lymphocytes appear as larger cells that stain darker and are frequently vacuolated
- Hemolytic anemia and thrombocytopenia may develop
- Heterophile antibodies and screening mononucleosis tests are usually positive within 4 weeks. A false positive syphilis test (Venereal Disease Research Laboratory [VDRL] or rapid plasma reagent [RPR]) occurs in 10% of infected patients.
- Increased hepatic aminotransferases, increased bilirubin, and decreased cryoglobulins also may be found.
16
Q
What is the treatment for EBV?
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- Treatment is symptomatic, with nonaspirin antipyretics and anti-inflammatories. Antivirals will decrease viral shedding but do not affect the course of the illness
- Patients with splenomegaly should avoid contact sports
- Steroids are indicated for thrombocytopenia, hemolytic anemia, or airway obstruction secondary to enlarged lymph nodes
17
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Herpes Simplex
18
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What are the signs and symptoms of Herpes?
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- There are three distinct patterns of the disease:
• Cutaneous disease: Involves the skin, mouth and eyes. Vesicular eruptions appear around 7-10 days of life, usually on presenting part. If not recognized promptly, can progress to disseminated disease - Encephalitic disease: Occurs at second to third week of life. Clinical signs include lethargy, irritability, poor suck, and seizures. Cutaneous lesions may be absent.
- Disseminated disease: sepsis-like picture (apnea, irritability, hypotonia, hypotension). Cutaneous lesions may be absent.
19
Q
How do we diagnose HSV?
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- HSV can be isolated in cell culture from skin lesions or nasopharyngeal swabs
- Polymerase chain reaction (PCR) is a sensitive tool for HSV detection
20
Q
How is Herpes Simplex treated?
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- Acyclovir is very effective in the treatment of HSV
- Course treatment is often prolonged (21 days) for encephalitic disseminated forms
21
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Influenza
22
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What is influenza?
A
- Viral respiratory illness
- Influenza is an orthomyxovirus
- It is readily transmitted through droplet nuclei and occurs in epidemics and pandemics during the fall or winter
Etiology:
- Influenza A and B – epidemic disease: H1N1 (influenza A)
- Influenza C- sporadic
- Major change is a shift
- Minor change is a drift
23
Q
What are the signs and symptoms of influenza?
A
- Incubation period: 1-3 days
- Sudden onset of fever, frequently with chills, headache, malaise, diffuse myalgia, and nonproductive cough
- Conjunctivitis, pharyngitis
- Typical duration of febrile illness is 2-4 days
- Complications include otitis media, pneumonia, myositis and myocarditis
- Diarrhea and vomiting (H1N1)
