Syndrome Flashcards
DDx acute febrile illness in South India?
Dengue
Scrub typhus
Malaria
Leptospirosis
Typhoid
What is the organism that causes Scrub typhus?
Orientia tsutsugamushi
What is the vector for scrub typhus?
Larval trombiculid mites
-Mite islands in jungle clearings
-Leave schars
Where is scrub typhus endemic?
Tsutsugamushi triangle
-Pakistan to Eastern Russia to Northern Australia
Symptoms of scrub typhus?
-Fever
-Fatigue
-Frontal headaches
-Myalgia
-Cough
-55% painless eschar
-Delayed generalised maculopapular rash
-Lymphadenopathy
-End organ failure (34%)
Pregnancy - stillbirth and LBW
DDx: Dengue
Patient presents from South India with chills, rigors and splenomegaly. Found to have thrombocytopenia, bilirubinemia, AST and ALT elevation. Likely dx?
Malaria (P falciparum)
Pt. from Thailand has body aches, bleeding on presentation. Exam shows rash, petechiae, subconjunctival hemorrhage and HM. Labs show leukopenia and thrombocytopenia. Dx?
Dengue
Pt. from Florida presents with myalgias and headache. Found to have conjunctival suffision and subconjunctiva hemorrhage. Leukocytosis, AKI and hepatitis on labs. Dx?
Leptospirosis
Pt. from India has eschar, headache and breathlessness. Labs show leukocytosis, thrombocytopenia, and elevated AST and ALT. Dx?
Scrub typhus
Pt from India has non-specific fever, chills, abdo pain and confusion. Found to have splenomegaly on exam. RDT for malaria is negative. Dx?
Typhoid
Tx of Scrub Typhus?
Doxycycline
Azithromycin
Chloramphenicol
How long are you contagious for C. diptheriae for without abx?
2-6 wks
How long are you contagious for C. diptheriae for without abx?
~48h
Symptoms of diphtheria?
Laryngitis or pharyngitis or tonsillitis
AND
Adherent membrane of the tonsils, pharynx and/or nose OR gross lymphadenopathy
Locations to check for pseudomembrane?
Tonsils (both)
Uvula
Oropharynx
Nasopharynx
-Simple infection if only one area
-Extensive area if two or more areas
5 key management steps for probable diphtheria case?
- Isolate patient, droplet and precautions
- Give antitoxin (DAT) ASAP
- Give abx (penicillin or erythromycin) following DAT ASAP
- Monitor for complications (airway, cardiac, neuro, renal)
- Vaccinate for diphtheria
Considerations with DAT?
-Anaphylaxis <1%
-Febrile rxn 4%
-Serum sickness 9%
Only give if enough people to monitor
Sensitivity test for all candidate patients
Can give to pregnant and breastfeeding women
Dose by severity of disease not of patient
What are the indications for DAT?
- Tonsillar diphtheria/adherent plaques
- Pseudomembrane
-Shock and symptomatic signs
Dosing for DAT for tonsillar and early signs?
20,000 IU
Dosing for DAT for nasopharyngeal and extensive oral plaque?
40,000 IU
Dosing for DAT for systemic symptoms of toxicity and hemodynamically stabilizing with fluid?
80,000 IU
When not to give DAT?
> 7d of symptoms
Unresponsive
Airway compromised and non-salvageable
Shock resistant to appropriate treatment
What is the vector for Zika virus?
Aedes aegypti (day biting)
Aedes albopictus
What makes Aedes aegypti a good vector?
Day biting
Well adapted to urban environments
Multiple meals from multiple hosts
How is Zika transmitted?
Mosquito bite
Sexual transmission
Blood transfusion
Transplacental transmission
What are the clinical symptoms of Zika?
Inc: 3-12d
Most asymptomatic (80%)
-Rash and fever most common
-Arthralgia/arthritis
-Conjunctivitis + myalgia
-Itching
-Headache
-Back pain
Mild, self-limiting
What are the complications from Zika infection?
Congenital Zika syndrome
GBS
Neuro - myelitis, encephalitis, optic neuritis
What are the features of congenital Zika syndrome?
Severe microcephaly (can occur without)
Multi-organ phenotype
Craniofacial disproportion
Pointed occiput
Redundant scalp skin
Arthrogryposis
Cerebral calficiations
R diaphragmatic paralysis
CNS:
-Seizures
-Tremors
-Hypertonia
-Hyperreflexia
-Irritability
Ocular:
-Focal retinal mottling
-Macular scarring
-Cataracts
-Glaucoma
-Optic nerve atrophy
Deafness
Zika strains?
Asian strain - linked with CZS
African strain - not linked with CZS, results in embryonic death (too severe)
How to diagnose Zika virus?
PCR - short viremic period (3-5d from onset of symptoms, longer in pregnant women), urine good sample (stays positive longer), semen, CSF, placental and umbilical cord tissue
Serology - IgM (+ after first week of symptoms), repeat for IgG
-May not develop IgM if previous dengue
Yellow fever epidemiology?
South America
Africa
What are the four cycles of Yellow Fever spread?
- Sylvatic (jungle) cycle
- Athropogenic sylvatic cycle
- Village epidemic
- Urban epidemic
What YF cycles do Africa experience?
All 4:
- Sylvatic (jungle) cycle
- Athropogenic sylvatic cycle
- Village epidemic
- Urban epidemic
What YF cycles does South America experience?
Only 1 and 4
- Sylvatic (jungle) cycle
- Urban epidemic
What is the clinical picture of Yellow Fever disease?
Inc: 3-6d (<21d)
Asymptomatic or mild febrile illness in most
-0.8-7% progress to toxic phase (30-60% CFR)
What are risk factors for higher mortality risk for YF?
-Older age (>45y)
-Neutropenia
-AST >3500
-Hyperbilirubinemia
-High YFV RNA levels
-Renal dysfunction
Prevention for YF?-
- YF-Vaccine (17D) - live attenuated
- Insect repellant
- Avoid bites
- Avoid rainy season
Contraindications for YF vaccination?
-Aged <6 mo
-Those who had confirmed anaphylactic rxn to a previous dose of the vaccine
-Those who had confirmed anaphylactic rxn to a component of the vaccine
-Those who have had a confirmed anaphylactic rxn to egg
-Those with hx of thymus disorder and thymectomy following this
-Those with primary or acquired immunodeficiency
What is a possible treatment for YF?
Galidesivir - nucleoside (adenosine) analogue
Sofosbuvir?
Equation for transmission of a disease?
R0 = C x B x D
C - exposure rate of susceptible to infectious partners
B - probability of HIV transmission given exposure
D - duration of infectious period
R0 - basic reproductive number
