- Lyme Disease
- Reportable Vectorborne Disease
- Etiological agent: B. burgdorferi (U.S.), B. afzeli, B. garinii, (In Europe and Asia)
- Transmitted by:
- Ixodid scapulars Ticks (Deer Ticks) in eastern U.S.
- I. pacificus ticks in western U.S.
- Pick Incidence: Spring and Summer
- Stage:
- Early Localized (80 % are localized)
- Erythema Migrans (EM) is the most common sign
- Erythema migrans usually begins as a small erythematous papule or macule that appears at the site of the tick bite 1 to 2 weeks later (range, 3 to 32 days) and subsequently enlarges.
- may be asymptom- attic, mildly pruritic, or, in rare cases, painful;
- if untreated, lesions may become 61 cm (2 ft) in diameter or larger and may last for 3 to 4 weeks before resolving
- Bull's eye appearance; 2/3rd of single EM lesion are either uniformly erythematous or have enhanced central erythema without clearing around it
- Note
- STARI (Southern Tick Associated Rash Illness)
- EM-like skin lesions are seen in STARI as well
- Lone Star Tick Bite
- Organism: Amblyomma americanum
- DDx of EM
- Single EM Lesion
- Lyme Disease Early EM
- Nummular Eczema
- Tinea
- Granuloma Annulare
- Cellulitis
- Insect bite
- Spider bite
- Hypersensitivity to tick bite
- Multiple EM lesion
- Early disseminated Lyme Disease
- Erythema Multiforme
- Urticaria
- Early Disseminated (via blood)
- Multiple smaller EM lesions is the most common sign of early disseminated disease
- Other organ involvement may or may not have skin involved
- CNS (Cranial Nerve, mostly CN VII; Meningitis)
- Carditis (seen mostly as heart block)
- Arthritis (Knee most common)
 - Late
- Potential Co-infections
- Babesia microti
- Anaplasma phagocytophilum
- Deer Tick Virus
- Borrelia miyamotoi
- Ehrlichia species Wisconsin
- Reference used:
- Additional Reading:
TICK BORN ILLNESS - Babesiosis
- Erhlichiosis
- Anaplasmosis
- RMSF
- Rickettsia rickettsii , gram-negative, obligate intracellular bacteria
- southeastern and south central states have higher incidence of RMSF
- has tropism for vascular endothelial cells - leads to direct vessel injury
- increased ADH release due to hypovolumia causes hyponatremia
- Clinical Feature is dictated by organ with vascular injury
- Lung: Pneumonitis
- CNS: Encephalitis
- Heart: Myocarditis
ANTI-BACTERIAL PHARMACOLOGY - B-lactam and others cell wall- and membrane- active agents
- Penicillin
- Cephalosporins and cephamycins
- Other B-lactam drugs
- Monobactum
- B-lactamase inhibitors
- Carbapenams
- Glycopeptide antibiotics
- Other Cell wall- or membrane- active agents
- Daptomycin
- Fosfomycin
- Bacitracin
- Cycloserine
- References:
Drug resistant bacteria / Special Circumstances
MRSA: vancomycin, linezolid, or daptomycin VRE: linezolid or daptomycin extended-spectrum b-lactamase (ESBL)–producing gram-negative bacteria: carbapenem Klebsiella pneumoniae carbapenemase (KPC): polymyxin-colistin or tigecycline Penicillin Allergy: Most penicillin-allergic patients tolerate cephalosporins, but those with a history of an immediate-type hypersensitivity reaction (eg, hives and bronchospasm) should be treated with a combination that avoids b-lactams and carbapenems, such as ciprofloxacin plus clindamycin or aztreonam plus vancomycin QUESTIONS : - 47 yr old patient with Chronic Pancreatitis. Has port of 2 yr duration. Blood culture grows Strep Metis. 2d echo and TEE negative for vegetation. Port is removed. What else to do?
- Treat with Ceftriaxone for 2 weeks.
- Treat with IV Ceftriaxone for 1 week, and switch to PO for another 1 week.
- Treat like endocarditis equivalent.
- Ans: 3.
- 47 yr old patient with Chronic Pancreatitis. Has port of 2 yr duration. Blood culture grows Strep pneumococcus. 2d echo and TEE negative for vegetation. Port is removed. What else to do?
- Treat with Ceftriaxone for 2 weeks.
- Treat with IV Ceftriaxone for 1 week, and switch to PO for another 1 week.
- Treat like endocarditis equivalent.
- Ans: 2.
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