Infectious Diseases Lessons

Azoles are used very frequently, has many drug-drug interactions to be known. Especially, Itra, and Voriconazole.

We had 3 presentations today:

1- A 6 year old kid, who lives in Brazil, and 1 day after a field trip to the zoo presented with:

• Fever, earache, headache
• Abdominal pain, nausea, vomiting, diarrhea
• severe lethargy
• Respiratory failure after 3 days-> intubation
• Shock
• Bilateral conunctivitis
• Morbilliform rash
• Abnormal LFTs
• Bandemia

Diagnosis: Strep Toxic Shock syndrome

we got distracted with the exposure history, bu the diagnosis would have been very easy if you think:

Shock = Septic or Toxic Shock

When suspect toxic shock, you will find all the classic criteria!

Ref:

Clin Infect Dis, 2009. 49 (9) 1377-9

Pediatrics, 1984. 74(1): 112-7

Clini Infect Dis, 1999. 28 (4) 800-7

2- 57 y old patient with lung transplant patient who comes for cough productive of yellow purulent sputum and mild bilateral infiltrates, found to have RSV. Discussed the controversy of treating RSV and medications to treat.

Ref:

Transplantation 2010; E

J hear Lung transplant. 2004; 23(S2): S43-4

Transplant Infectious Disease. 2010;12:38-44

3- A 25 year old hispanic male with AIDS, Cd 4 count 34. He was on Dapsone for PCP prophylaxis.

He had complicated picture but after extubating him, he became cyanotic with ABGs that are much better. Discordance of Pox and PO2–> MetHb

Discussion about Methemoglobinemia due to Dapsone, diagnosis and therapy.

MetHb in Leukemia

MetHb and dapsone in leukemic patients

Our core curriculum today was just a review of the gram stain:

1. Search for neutrophils: if no neutrophils=no infection
2. Search for epithelial cells: many = recollect

Gram positive:

Cocci in chains= Streptococcus or Enterococcus

Cocci in clusters= Staph species: aureus or coag negative staph

Cocci in tetrads = micrococcus

Coccobacilli = Listeria

Bacilli:

• Small: Corynebacterium or P. acnes
• Large: Bacillus or Clostridium

Branching/filamentous:

• Nocardia: also weak AFB +
• Actinomycosis: AFB -

Gram negatives:

Cocci: Neisseria: diplococcus

• N. gonorrhae
• N. meningitidis

but also Moraxella

Can be confused easily with Acinetobacter(cocco-bacillus)

Bacilli pleomorphic= Haemophilus (Pasteurella, Bordetella, Brucella)

Weak gram negative pleomorphic (may not be seen)=Bacteroides

Curved gram negative bacilli: Helicobacter, Campylobacter, Vibrio

Large gram negative bacilli = Enterobacteriaceae

• KEEY: non-lactose fermenter
• PPSSS: lactose fermenters
  

We had an adult presentation of a patient who comes for:

-Neurological complaints over 2-3 weeks with no fever: focal co

• Hemiparesis
• Diplopia
• Facial paralysis

The classic diagnosis:

• Brain abscess and its complication (cavernous sinus thrombosis)
• all types of bacteria…
• In this case, it end up Basilar brain abscess with no sinusitis or any other focal infection that explains it: IE, PNA,..
• It was conculded that the patient has “cryptogenic” brain abscess and it end up: Haemophilus aphrophilus (HACEK agent)
• The 2 D Echo was done to search for patent foramen ovale because of classic association and it was found!
• The treatment with CTX was complicated with acute hepatitis that was thought due to CTX, and switched to Ciprofloxacin (the MIC of this germ was extremely low)
• Dr. E thought that we can not for sure exclude IE with TEE because the patient got azithromycin as outpatient but the therapy would not matter because therapy should be lengthy anyway for the brain abscess

The pediatric presentation was a premature baby who comes for apnea and hypothermia: Septic

• Classic organisms: Group B Strep
• Others: Listeria, E. Coli the most common

Even though the ring enhancing lesions suggest: CNS toxoplasmosis, it can be due to other infections:

• Tuberculomas
• Fungal infections:
  • Cryptococcoma
  • Histoplasmosis
  • etc..

During my research I encountered 2 patients, who got diagnosed with Tuberculosis but the headaches were not worked up. After discharge on RIPE, they end up back with worsening headache and neurological symptoms: paradoxical reaction.

If you have a headache with tuberculosis, patient should get an LP/MRI and treated with high doses of steroids for long time in addition to RIPE…

TB meningitis can kill your patient.

1- An HIV adult case with:

• Pancytopenia
• Diffuse lymphadenopathies
• history of pneumonia recently
• Diarrhea
• Skin rash (nodular)
• LDH >1500
• Differential diagnosis was pretty forward:
  • Disseminated fungal infection in particular endemic mycoses: the one in Texas is Histoplasmosis without any ho travel
  • I reviewed in mind all the classic germs that causes troubles in HIV and causes skin diseases and adenopathies. Histoplasmosis (disseminated) fit all the points.
    • Crypto can cause skin rashes, cellulitis, but the rash typically are umbilicated
    • HSV/VZV causes vesicules not nodules
    • Bartonellosis: causes angiomatosis not nodules
    • MAC/TB causes adenopathies not a rash
    • Nocardiosis?
    • Cancers due to infections:
      • Kaposi sarcoma: not the typical picture(skin)
      • Lymphoma–> may cause skin rashes

2-A pediatric case: 11 years old kid who looks very debilitated, chronically ill, comes for acute pneumonia with cavitary lesion, and bilateral infiltrates, abdominal abscesses, skin rashes and very cachectic.

The clue is that he had an adenopathy since a child that never went away and he was + for PPD.

The diagnosis of disseminated infection was evident, we thought about TB but that was not the ‘miliary’ picture. More diagnoses should be looked for, and as we must think, underlying immune deficiecency: AIDS in adults, he had no AIDS, and he was a kid: What classic immune deficiency that may have that fit the picture: CGD: Chronic granulomatous disease. I thought it should be only in the book, but obviously it exists.

CGD causes classically:

• Staph infections
• Aspergillosis
• Nocardiosis
• gram negatives

In this case, it was a mold infection!

We had one hour lecture about 4 different bacteria:

• Nocardiosis
• Actinomycosis
• Rhodococcus equi
• Burkholderia pseudomallei

Nocardiosis:

Dr. T presented a patient with pulmonary nodule/mass with ‘halo’ sign, brain mass

• clinically:
  • pulmonary pneumonia: fungus-like picture, nodule, slowly progressing and necrotizing slowly (typically)
  • CNS abscess (pulmonary + neuro) 50% with pneumonia
  • Cutaenous form (sporotrichoid progression) and fistulas (sulfur granules)
    
• Many species:
  • N. asteroides: invasive disease
  • N. braziliensis: skin infections
  • N. nova: bacteremia
  • N. farcinica: the more virulent form, classic Bactrim R
• Predisposing factor:
  • T-cell mediated issues or none
  • CGD
  • TB, other mycobacteria
  • Steroids
  • AIDS
  • TNF blockers
• Exposure to soil and vegetables
• Diagnosis:
  • crooked, branching, beaded, gram-positive filaments
  • weak + AFB
  • slow grower
• Treatment:
  • Sulfa drugs except in Farcinica
    
  • Sensitive to:
    
    • po: minocycline, linezolid
      
    • IV: carbapenem, 3rd gen cephalosporins, aminoglycosides
  • duration: long enough 3-12 months! to prevent relapses
    
  • Combination therapy is not always recommended as Dr. Ch commented.
• Nocardia review
• Nocardia in Mandell

Actinomycosis:

Dr. T prsented case of oral actinomycosis with fistula

• Clinically: indolent, slowly progressing
  • oral form with fistula formation and sulfur granules drainage
  • thoracic form
  • abdominal: typical IUD–>GU complication
  • do NOT respect fascial planes
• Micro:
  • anaerobic
  • colonize the oral flora, vagina and GI tract
  • combined with other bacteria frequently
  • Israelii: the most common
• Not associated with immune system dysfunction: requires disruption of  the normal mucosa
• Diagnosis: difficult without pathology, diagnosis without extensive surgery may save the patient major surgery because medical therapy alone is curative
• Treatment: classically: IV Penicillin x 2-6 wks then po penicllin. Dr. R objected this because of this old approach that is not backed by clinical studies and the difficulty of getting penicillin IV v/s other therapy once daily.
  • PCN alternatives: Clinda, tetracyclines, erythromycin and others
• Duration: long enough, one year or more
• Ref: Actinomycosis in Mandell
• Actinomycosis review

Rhodococcus equi:

Dr T presented a patient with AIDS, with pneumonia

• Microbiology:
  • Cocobacilli
  • acid fast
  • gram positive
  • used to be corynebacterium equi
• Clinically many types of infections:
  • Typically: TB like picture
• equi: from equine, but also exposure to cattle, sheep.
• Culture: rhodococcus: red, salmon color
• Intracellular pathogen of macrophages!
• Immunocompromised host: HIV or other
• Treatment:
  • Vancomycin: drug of choice
  • other abx:
    • Rifampin
    • Clindamycin
    • Bactrim
    • Macrolides

    Duration: long enough, may need chronic suppressive therapy

  • R. equi in Mandell

Cases of Leptospirosis in California

We had a case in the inservice, a patient with high AST/ALT, high Cr, high Bilirubin, general complaints: fever, headache, myalgias, conjunctival suffusion.

He just came back from Peru, works with animals (dogs, cats).

Differential diagnosis:

• Classic issues:
  • Hepatitis A, B, C
  • EBV, CMV
  • Ascending cholangitis
• Dengue
• Yellow fever
• Malaria
• Hepatic peliosis (bartonella)
• Oroya fever
• Meningitis
• Rickettsioses & family
• Acute leishmaniasis
• Acute schistosomiasis
• Liver flukes

Review of the difference clinically to be looked for in details.

We did our in service exam today, it was pretty interesting test, most questions are short, straight forward cases.

Almost all the cases are clinical cases, where you need to guess the diagnosis, and know the treatment or the next step in management.  Only few cases are non-infectious. Some microbiology questions that we were not expecting and we need to study specifically: major gram negatives and streptococci.

What is interesting is that in studying, we should be smarter in making the differential diagnosis and focusing on the clinical characteristics that differentiate them such as in: oral and genital ulcers, encephalitis syndromes, pneumonia.

Basics of the questions I remembered:

1. MRSA Vancomycin MIC
2. Mechanism of SA resistance to macrolides, clindamycin and synercid
3. Mechanism of resistance: high resistance to PCN in pneumococcus
4. Cause of recurrence of SSNA prosthetic hip infection
5. Strep causing abscess in diabetes, that causes hemolysis synergy with SA, bacitracin resistant.
6. Recognizing oral actinomycosis , and its therapy
7. Bactericidal drug against VRE
8. Recognizing necrotizing fascitis/gas gangrene due to Clostridium species and its therapy, and the need for surgical intervention
9. Strep TSS and its therapy
10. Presentation and diagnostic test for rabies
11. Next test to do in frontal unique brain abscess with Streptococci (negative sinuses)
12. Recognize moraxella on gram stain and its therapy
13. CMV resistance and therapy
14. Trt of CMV colitis
15. Recognizing VZV from CMV in retinal infections
16. Recognize botulism picture
17. Recognize the germ that causes skin infection with fish handling and its systemic complications (endocarditis), resistant to TMP/SMX
18. Recognize severe M. marinum infections on Infliximab and its therapy
19. Management of TB meds with elevations of LFTs
20. TB and HIV: dosage adjusting of rifabutin
21. Recognize drug-drug interactions with Fluconazole
22. Treatment of Tetanus in addition to the toxin
23. Recognize skin anthrax and any need for isolation
24. Recognizing Listeria infection and the foods associated with it
25. Recognizing clinically Pertussis
26. Recognizing STDs: genital and anal ulcers clinical characteristics:
    1. Syphillis
    2. Chancroid
    3. HSV
    4. LGV
    5. Granuloma inguinale
27. Failure of therapy of urethritis with Cipro
28. Recognizing pneumonia picture(Cavitary and nodular bilaterally) with microbiology of gram negatives to differentiate between:
    1. Pseudomonas
    2. Burkholderia pseudomallei
    3. Aeromonas
    4. Acinetobacter
    5. etc..
29. Recognizing fulminant septic picture due to dogs in asplenic patient
30. What to do in case of AICD pocket infection: remove the AICD and the leads or do a TEE first
31. Young woman with FUO, what is the next test
32. Recognize Cambodia next to Thailand: possible B. pseudomallei, microbiology characteristics, clinical picture, and its differential
33. Recognize the clinical picture of rickettsial pox
34. Recognize the clinical picture and the transmission of R. prowazeki
35. Statistics and infection control:
    1. What is the characteristic of a test for screen: high PPV or NPV
    2. How to start investigating a outbreak: pseudomonas increase
    3. How to measure  % line infections complications
36. Factors associated with foley cath infections
37. Factors asscoiated with Central line infections
38. Trt of Kaposi/bartonella with lytic lesion in AIDS
39. Recognizing the differential of a nodule in the mouth in AIDS: Kaposi v/s bacillary angiomatosis v/s Histoplamsosis
40. Recognize Dengue hemorrhagic fever and its outcome
41. Recognize clinically Chikungunya fever
42. Recognize the cause of polybacterial bacteremia: abdomen or lines
43. Predictors of bacteremia in decubiti ulcer
44. Recognzie ischemic bowel with severe leukocytosis and its diagnosis
45. Trt of Strep PNA
46. Recognize clinically Analpasmosis or Elhrichiosis
47. HSV 2 transmission to partner
48. Trt of NH PNA caused by gram negatives with severe PCN allergy
49. Recognize Blastomycosis microscopically and clinically
50. Trt of skin dematiaceous mold therapy
51. Trt of Scedosporium pna
52. Trt of candidemia with C. parapsilosis
53. Trt of Cystitis due to C. Glabrata with renal failure
54. Recognize underlying immune deficiencies:
    1. Common variable immune deficiency: clinically and tests
    2. Chronic granulomatous disease: clinically and test
    3. Recognize late complement deficiencies
    4. Recognize Hyper Ig E syndrome
55. Differentiate IRIS v/s MAC v/s Histo v/s TB in AIDS
56. Major risk factor for GI infection
57. Recognize the cause of ascending colon colitis with negative cultures and how to investigate
58. Trt of hep B and HIV
59. Trt of hep B in HIV who refuses HAART
60. Isolation procedures for VSZ/HSV
61. Recognize which mycobacteria is resistant to PZA inherently causing typical GI TB picture
62. Recognize which mycobacteria is photochromogen! causing pna not tb or mai
63. Recognize skin infection with Leprosy and its therapy
64. Recognize classic infectious cause of granulomatous hepatitis
65. Recognize clinically measles and its vaccine type
66. Recognize rhabdomyolysis due to statin secondary to drug-drug interactions with PI
67. Recognize adrenal crisis  from sepsis syndrome
68. Recognize B-cell lymphoma in primary effusion lymphoma and its association with HHV 8
69. What is the fastest therapy for anemia, normocytic in AIDS, that may be due to parvovirus B 19 (not hemolytic)
70. Recognize viral pleurodynia
71. Recognize cyanosis and hypoxia in PCP: PTX
72. How to stop diarrhea outbreak in NH
73. Diagnosis of congenital toxoplasmosis
74. Associations of norwegian scabies from patient from latin america
75. What factor improve the prognosis of CNS lymphoma in AIDS
76. What affects survival in septic shock with MOF
77. Predisposing factors for candidemia in liver transplant
78. Trt of cholangitis after liver transplant
79. Recognizing the picture of disseminated strongy, picture of the larvae and its therapy
80. Differentiate a systemic infection with renal failure, liver abonrmalities, eye suffusion: Hemorrhagic fever, yellow fever, leptospirosis, dengue, rickettsisoses, Oroya fever, acute schistosomiasis etc…
81. Contrindications of live influenza vaccine: Asthma v/s mother with AIDS
82. Vaccination in travel medicine for patient with AIDS
83. Recognize acute chaga’s disease with its romana sign, and its therapy
84. Recognize cutaneous leishmania, biopsy and therapy
85. Recognize the agents of cutaneous larva migrans
86. Recognize babesia in a smear
87. Recognize guinea worm and how to break its transmission
88. Recognize echinococcosis of the liver
89. Recognize and trt liver fluke from acute schistosomiasis (eo high)
90. Test for pinworm
91. Recognize the therapy for amebiasis in addition to the metronidazole?
92. Recognize onchocerciasis and complication of the disease
93. Treatment of possible Aspergillosis with worsening CT scan and clinical improvement
94. Recognize beta-glucan increase causes with normal GM
95. Major cause of culture negative endocarditis: next step
96. Recognize Wegner’s granulomatosis and its differential infx
97. Recognize clinically MS
98. Recognize wegner’s granulomatosis
99. Recognize MS
100. Know Acute rheumatic fever criterias!
101. Recognizing possible underlying malignancy with PNA (lytic lesions)
102. Recognize clinically HSV and WNV
103. Recognize CJD and how to destroy prions?
104. Manage oseltamivir failure in Influenza A
105. Isolation and prevention techniques of Monkeypox
106. Prevention and therapy for Monkey bite (Herpes B)
107. Trt of  mycobacterial adenopathy adenopathy v/s observation?
108. Differentiate and recognize the differential diagnosis of Oroya fever
109. Cause of leukemoid infection in hospital on abx without diarrhea
110. Recognize lemierre’s syndrome with septic emboli to lungs
111. Trt of Tinea capitis
112. DD of skin ulcers/eo/ fever/pna/viral like
113. Post surgical osteo with negative cultures, negative gram stain and whitish pus!
114. HIV
     1. Recognize side effects: such ddi–>lactic acidosis
     2. Occupational Exposure to HIV in pregnancy
     3. Drugs to avoid in pregnancy: exposure in young female
     4. Oral ulcer management in the mouth and its differential  in AIDS
     5. Xr 4?
     6. Safety of HAART in cardiac failure
     7. Best safety profile in active ischemic cardiac disease
     8. K103 N
     9. CNS lymphoma: factors affecting prognosis
     10. Causes of positive ELISA, intermediate Western blot, in East Africa in SLE case
     11. Hep B therapy and coinfection with/without HAART
     12. Tb and HIV: drug management rifabutin dose
     13. Differentiate retinal infections types: HSV/VZV/CMV

ANGIOSTRONGYLIASIS: Rat lung worm

• A. cantonensis–> Eo meningitis

ANISAKIASIS:

• causes abdominal complaints: Eo gastritis
• c/o after only few hours of abdominal pain
• Areas: Scandinavia, netherlands, south america, pacific coast
• Trt: endoscopic or surgical removal

BAYLISASCARIASIS: Raccon worm

• Cause of Eo meningitis and eye infiltration

CAPILLARIASIS:

TROPICAL PULMONARY EOSINOPHILIA:

GNATHOSTOMIASIS:

• Cutaneous larva migrans from eating fish

GONGYLONEMIASIS:

MONILIFORMIS:

TRICHOSTRONGYLUS:

• Trt: Praziquantel or niclosamide

Taenia solium:

• Pork tapeworm: undercooked pork (encysted larvae)
• May cause Cysticercosis when ingesting the egg instead of the larvae
• high Eo
• trt: albendazole or praziquantel

Taenia saginata:

• Beef tapeworm

Diphyllobotrium latum

• Fish tapeworm
• B12 deficiency

BLOOD FLUKES:

Schistosoma:

• found in freshwater
• Enter venous system via skin
• Can not multiply in humans–> mate and lay eggs
• Symptoms due to immune system reaction against eggs
• Molecular mimicry: hide from the immune system
• 3 phases:
  1. swimmer’s itch
  2. Katayama fever: 4-8 wks after, lasts 3 wks
     
  3. Chronic fibrosis of organs
• Diagnosis: eggs or serology
• Trt: Praziquantel –> may induce exacerbation
• 3 Types:
  
  • S. japonicum in eastern asia (GI)
  • S. mansoni in south america and africa (GI)
  • S. haematobium in Africa (GU

LIVER FLUKES:

• 1. FASCIOLA HEPATICA: Sheep liver fluke
     • Areas: Japan, Lantin America
     • Ingestion of watercress (herb)
       
     • Operculated egg
     • trt: Praziquantel NOT effective as opposed to F. Buski (Intestinal fluke)
     • Bithionol or Triclabendazole
  2. Opisthorchis Sinsensis: Chinese liver fluke
     • Uncooked freshwater fish
     • Areas: China, Japan, Korea and Vietnam
       
     • Diag: egg
       
     • Mild disease
     • Trt: Praziquantel
       


LIVER FLUKES:

LUNG FLUKE:

PARAGONIMUS WESTERMANI

• Ingestion of crabs and crayfish
• Areas: Asia, Africa, India, Latin america
• US form: P. kellicotti
• May migrate from the lungs to CNS, skin
• Diag: egg in sputum and feces and serology
• Trt: praziquantel

INTESTINAL NEMATODES:

All treated by Albendazole except Strongy

1. BY INGESTION of eggs:
   
   1. Ascaris lumbricoides:
      • migrate via lungs
      • The largest
      • Can migrate to the biliary tract
      • egg
   2. Trichuris trichiura (Whipworm):
      • no Eo
      • no lung phase
      • Causes rectal prolapse
      • Egg
   3. Enterobius vermicularis (pinworm):
      1. no Eo
      2. no lung phase
      3. Severe peri-anal itch at night
      4. Scotch tape test
      5. Egg
2. BY SKIN:
   1. Necator americanus (hookworm):
      • migrate via lungs
      • Causes anemia
      • Egg
   2. Strongyloides stercolaris: Ivermectin, exception
      • migrate via lungs
      • Stools: larvae not egg
      • Association with HTLV1

   3-Trichinella Spiralis

• Causes periorbital edema and eosinophilia
• Larvae invade the body–> muscles, brain
• CPK high
• Trt: Albendazole

BLOOD and TISSUE NEMATODES:

• Transmitted by arthropods
• Do not lay eggs
• Adult live in the lymphatic tissue and give birth to microfilariae
• Symbiosis with Wolbachia killed by Doxy

1. Onchocerca volvulus:
   • Black flies
   • Adults in s/c tissue (nodules)
   • pruritic skin rash (lizard skin): microfilariae migrating
   • river blindness
   • Diagnosis: biopsy
   • Trt: Ivermectin kills the microfilariae, the adult die from old age
2. Loa Loa:
   • Adult in s/c tissue
   • The eye worm
   • Can migrate in front of the eye ball
   • Microfilariae in blood, daytime
   • Visitors are more affected than the local population–> more frequent calabar swelling
     
   • Trt: Diethylcarbamazine kills the adults and microfilariae
     
3. Wuchereria bancrofti and Brugia malayi
   • Causes elephantiasis
   • Diagnosis: microfilariae at night in blood or serology
   • Diethylcarbamazine
4. Dracunculus medinensis:
   • Guninea worm
   • Drinking contaminated water
   • No therapy is available except extraction
   • Prevention is by breaking the cycle and  not drinking contaminated water

CUTAENOUS Larval Migrans:

• Dog and Cat hookworm
• May be caused by Strongyloides stercolaris and the hookworm(Necator americanus)
• Diag: biopsy
• Trt: Ivermectin or Albendazole

Cutaneous Lesihmania:

cutaneous or  mucucutaenous, transmitted via sandfly.

Visceral Leshmania: (L. Donovani, Chagasi) (Kala-azar)

invading the reticuloendotelial system–> abdominal distention from hepatomegaly and massive splenomegaly.

Diag: Serology or biopsy of liver. Negative skin reaction (cellular immune defect)

Trt: Antimonial stibogluconate

Chagas’ disease: T. cruzi, the american one

vector: reduviid bug (kissing bug)- in feces of the bug

Acute Chagas: Chagoma (eye or skin) then systemic infection with adenopathies–>Heart and CNS: parasite present in the blood smear

Trt: furtimox and benznidazole

Chronic Chagas–>Cardiomyopathy and Megacolon and esophgagus

May cause brain abscess in HIV with Eo

African Sleeping sickness (T. brucei rhodesiense and gambiense)

vector: tse tse fly–> ulcer then intermittent fevers and adenopathies

• West Africa: T. brucei gambiense –> slow progression to neurological disease
• East Africa: T. brucei rhodesiense–> rapid progression to neurological disease and death
• Diag: parasites in the blood, nodes or CSF. Seology.

Intermittent fevers caused by Variable surface glycoproteins (VSG)

Trt: Suramin or Pentamidine if no CNS involvement

otherwise: Melarsoprol

Basics in drug-drug interactions:

Macrolides and Ketolides:

Inhibits metabolism of many drugs (CYP3A4):

• Lovastatin, simvastatin: may trigger rhabdomyolysis
• Cyclosporine: may induce toxicity(renal)
• Warfarin: may trigger increase in INR and bleeding
• Carbamazepine : may trigger sedation, etc..
• Ergot alkaloids: may trigger severe vascular spasms

Linezolid:

• MAO inhibior: may trigger serotonin syndrome with SSRI and other antidepressants

Tetracyclines + Fluoroquinolones:

• Antacids+iron compounds+dairy products affects the absorption: you will lose the antibiotic!

Sulfonamides:

• May trigger toxicity: by reduction of metabolism+serum protein displacement
  • Warfarin
  • oral hypoglycemics
  • Phenytoin

Rifampin: too many drug-drug interactions

• induces P450
  • Protease inhibitors: loss of viral suppression
  • Oral contraceptives: pregnancy
  • warfarin: decrease INR–>strokes
  • Cyclosporine and prednisone–>organ rejection

Metronidazole:

• Causes with alcohol: disulfiram-like syndrome
  

Our core curriculum was about TSS

Reminders:

• Think of it each time you see hypotension: septic shock v/s TSS
• Major cause of liability if missed because it attacks young people and it is lethal if missed
• Think of it if you have shock disproportional to the infection
• Think of it with no focus of infection: tampons!!! Removing early is key
• Think of it because you need to change therapy: Clindamycin or Linezolid and IV Ig
• Think of it and get the surgeon urgently if the infection is severe with foreign body to remove, or like necrotizing fascitis to debride.
• Current recommended therapy: Vanc + Clinda
• Staph TSS: won’t have significant infections but occult
• Strep TSS: should have positive blood cultures and evident infection

There are so many causes of culture-negative meningitis, and it seems frequently the tests are not ordered for treatable causes:

Viral:

• Treatables:
  • HSV1, HSV2, VZV
  • CMV, HHV6
  • HIV: check viral load, Cd4/Cd8
    
• Untreatables:
  • EBV
  • Enteroviruses
  • Arboviruses
    

Bacterial:

• Mycobacterium tuberculosis: can not miss, treat empirically if highly suspicious on MRI and clinically
  • MRI may show leptomeningeal enhancement, bleeding, ischemia
  • Clinically when severe or with change in mental status, and cranial nerves involvement: treat empirically
  • Send high volume of CSF for AFB cultures, check the lungs
  • Rule out all other treatables: fungi!
• Spirochetes:
  • Treponema pallidum(Neurosyphillis)
  • Borrelia burgdorferi (Lyme disease)
  • Leptospirosis
• Rickettsioses:
  • RMSF
  • others
• More Zoonoses:
  • Brucella! treatable disease not to be forgotten with history of travel
    

Fungals:  very important

• Cryptococcus neoformans: even without known immune defects, check Crypto antigen
• Endemic mycoses:
  • Histoplasmosis
  • Coccidioidomycosis
  • etc..

Parasites:

• Toxoplasmosis: not to be forgotten
• Many worms etc..

We had 2 case presentations today:

1-Case of patient with HIV who is on Truvada based regimen.

Blood tests shows: acidosis : non anion-gap acidosis and increase in Cr

Urine test showed: glycosuria ++ without being diabetic

This reflected RTA II  from Fanconi syndrome(proximal tubule toxicity): classic TNF toxicity.

Ref: Nephrotoxicity in HIV

2- Case of patient even with VL<48 on Kaletra/truvada, was c/o of neurological problems: numbness, back pain and sphincter issues.

DD: r/o emergencies such epidural spinal abscess that requires surgery

routine diseases:

• Crypto
• TB
• Syphillis
• HSV/VZV

Specific diseases:

• CMV polyradiculoneuropathy(usually disseminated CMV)
  • classically neutrophilic predominance
• HIV axonal polyradiculoneuritis
• HIV myopathy

We had a presentation of 60 y/o with CLL, who got SCT and end up with severe bilateral pneumonia.

The classic case of culture negative bilateral pneumonia: think chemical AIDS in these cases

• Viral:
  • Treatable: Influenza, RSV, HSV, CMV
  • Untreatable: Adenovirus, para-influenza
• Fungals:
  • PCP
  • Cryptococcus neofrormans
  • OI: Aspergillosis, Mucormycosis, other molds
  • Endemic mycoses: Histoplasmosis …
• Bacterial:
  • MAI
  • TB
  • Nocardiosis: will grow though
  • Legionella
• Parasites:
  • Toxoplasmosis
  • Disseminated Strongy

This patient end up having Cryptococcus positive blood cultures also, because they stopped his fungal prophylaxis due to increase liver enzymes.

Remember: Crypto antigen easy to get! in PNA! and Meningitis!