Infectious Disease Flashcards
What is a carrier
A person or animal that harbors the infectious agent/disease and can transmit it to others but does not demonstrate signs of the disease
i.e. - COVID-19 living dormant in the body
What is contact
Exposure to a source of an infection; a person who has been exposed. Contact does not imply infection, it implies possibility of infection
What is a host
An organism that harbors a parasitic, mutualistic, or commensalism guest. The host is the house and the parasite is the freeloader
What is zoonosis
A pathogen that is transmissible from non-human animals (typically vertebrates) to humans
i.e. swine flu, bird flu
What is arbovirus (arthropod-borne virus)
Any of a group of viruses that are transmitted between hosts by mosquitoes, ticks, and other arthropods
i.e. malaria, dengue, WNV, Lyme, RMSF
What is herd immunity
When a majority of a given group is resistant/immune to a pathogen, they achieve “herd immunity”. This confers protection to unvaccinated or susceptible individuals/group by reducing the likelihood of infection or spread
What is passive immunity
Transfer of active humoral immunity of ready-made antibodies produced by another host or synthesized. Passive immunization is used when there is a high risk of infection and insufficient time for the body to develop its own immune response. Short term!
What is a parasite
An organism that lives on or in a host organism and gets its food from or at the expense of its host
What are the main classes of human parasites
Protozoa
Helminths
Ectoparasites
What is the organism type of a protozoa
One-celled organisms that are free-living or harbors on a host
What harbor in human GI track that are transmitted via fecal-oral route through contaminated food or water, or person-to-person contact
Protozoa
Protozoa are classified further into groups based on mode of movement
Sarcodina - the ameba
Mastigophora - the flagellates (Giardia, Leishmania)
Ciliophora - the cilates
Sporozoa - non motile adult stage organisms (Cryptosporidium - the leading cause of waterborne disease in the US
What is a large multicellular organism visible to the naked eye in adult stage, that are free-living or harbors on a host
Helminths
What are the types of helminths that reside in the GI tract
Flatworms (platyhelminths) - blood flukes and tape worms
Thorny-headed worms (acanthocephalins)
Roundworms (nematodes) - also reside in blood, lymph system or subcutaneous tissues such as hookworms or pinworms
What are some examples of ectoparasites
Ticks, fleas, lice, and mites - burrow into the skin and remain there for weeks to months. This category of parasites also include other blood-sucking arthropods such as mosquitos
What is the treatment for parasitic infections
Treatment is based on the affected organ, symptoms, specific parasite, and other disease secondary from parasite
What type of organism is West Nile Virus (WNV)
Single-stranded RNA virus of the family Flaviviridae and the leading cause of domestically acquired arboviral disease in the US
How is WNV transmitted
Primarily via the Culex mosquito
What is the incubation period for WNV
2-6 days, but can range from 2-14 days
Is WNV reportable
Yes
What percentage of people are asymptomatic with WNV
70-80% of human WNV infections are subclinical or asymptomatic
What is the typical patient presentation of WNV
An acute systemic febrile illness may be accompanied by:
Headache, weakness, myalgia, or arthralgia
GI symptoms
TRANSIENT MACULOPAPULAR RASH
<1% of infected patients develop neuroinvasive what? Which typically manifests as meningitis, encephalitis, or acute flaccid paralysis
West Nile virus
What lab diagnosis is used to diagnose WNV
Diagnosis via identifying IgM in serum or CSF
ELISA is used to detect IgM antibody
What is the treatment for WNV
There is no specific reatment for WNV disease, and no antiviral treatment is available
MEDEVAC is warranted if there are signs of what
Encephalitis, meningitis, or paralysis
What has an organism type of protozoan parasites of the genus plasmodium
Malaria
What are all the subtypes of malaria
P. Falciparum
P. Vivax
P. Ovale
P. Malariae
How is malaria transmitted
Via the female anopheles mosquito
What is the incubation period for malaria
7 - 30 days, depending on the species of malaria infection
Is malaria reportable
Yes
Which type of malaria is lethal
P. Falciparum - yes (blood cycle phase)
P. Vivax, p. Ovale, p. Malariae - maybe (reside in the liver)
Uncomplicated malaria is characterized by:
Paroxysmal (cyclical) fever
Influenza-like symptoms including chills, headache, myalgias, malaise
Jaundice and mild anemia secondary hemolysis
Severe malaria is characterized by:
Small blood vessels infarction, capillary leakage and organ dysfunction
Altered consciousness
Hepatic failure and renal failure
Acute respiratory distress syndrome
Severe anemia
What is they typical patient presentation of malaria
Paroxysmal fevers are typical and considered a clinical hallmark of the infection
Cold stage - lasts approx. 1 hour
Febrile stage - lasts 2-6 hours
Diaphoretic stage where fever drops - lasts 2-4 hours
Patient then returns to normal
Cycle repeats itself in 48-72 hours depending on species of infection
What is the treatment for malaria
Treatment options are dependent on :
Species of malaria
Severity of infection
Likelihood of drug resistance
Patients age and pregnancy status
What are the reliable-supply treatment regimens available in the US
Atovaquone-proguanil (Malarone)
Artemether-lumefantrine (Coartem)
What is the treatment of uncomplicated malaria
Chloroquine phosphate 1g (600 mg base) PO
THEN 0.5g in 6 hours
THEN 0.5g daily for 2 days
What is the treatment of severe malaria
Artesunate 2.4mg/kg IV at 0, 12, 24, 48 hours
Followed by doxy 100mg BID x7 days after parental therapy
What is the treatment of p. Ovale malaria
Add primaquine 52.6mg PO QD x 14 days
What is the treatment of malaria in areas with chloroquine resistance
Malarone 4 tabs PO QD for 3 days
What has an organism type of single-stranded RNA viruses of the genus Flavivirus
Dengue fever
How is dengue fever transmitted
Aedes aegypti mosquito
What percentage of dengue fever infections present asymptomatically and the person doesn’t realize they were infected
75%
The remaining 25% of infections present with mild to moderate, nonspecific, acute febrile illness, characterized by fatigue and malaise
What are the phases of dengue fever
Febrile phase
Critical phase
Convalescent phase
How long does the febrile phase last and what symptoms are present
Typically lasts 2-7 days and can be biphasic
May include severe headache, retroorbital pain, muscle/joint/bone pain, and TRANSIENT MACULOPAPULAR RASH, petichiae, eccymosis, purpura, epistaxis, bleeding gums, hematuria, or a positive tourniquet test result
How long is the critical phase of dengue and what symptoms preset with it
Critical phase begins at defervescence and typically lasts 24-48 hours - most patients clinically improve during this phase and move on to recovery and convalescence phase
The tourniquet test is also called what
Capillary fragility test
What is a fairly effective test used to further justify a presumptive dengue diagnosis without the ability or access to confirmatory laboratory testing
Tourniquet test
What qualifies as a positive tourniquet test
10 or more petechiae per 1 square inch
What is the treatment for dengue fever
Ensure patients stay well hydrated and avoid aspirin, aspirin containing drugs, and NSAIDS because of their anticoagulant properties
What is the treatment for severe dengue fever
Typically requires ICU-level monitoring and blood products
What is the disposition of a patient with dengue fever
MEDEVAC - medadvice on further management while awaiting MEDEVAC
Patients presenting with signs/symptoms of even mild dengue should be evacuated to definitive medical care facility as soon as possible
What has organism type of gram-negative, intracellular, coccobacillus bacterium
Tick borne illness - Rocky Mountain spotted fever (RMSF)
How is RMSF transmitted
Via American dog tick - east of Rockies and Pacific cost
Rocky Mountain Wood Tick - Rocky Mountain region
Brown dog tick - worldwide
How long is the incubation period for RMSF
Typically 2-14 days
Is RMSF reportable
Yes
What is a rapidly progressive disease and without early administration of doxy can be fatal within days
RMSF
What symptoms are typically present with RMSF during the early illness phase
Early illness (days 1-4)
Fever, headache, GI symptoms, myalgias, edema around eye and back of hands and rash
During the early illness phase of RMSF, when does a rash present
Rash typically present 2-4 days after onset of fever
Begins as small, flat, pink macula’s on wrists, forearms and ankles that spread to trunk
Can also involve palms of hands and soles of feet
Severe RMSF may cause permanent complications from:
Neurological deficits
Damage to internal organs (respiratory compromise, renal failure)
Vascular damage requiring amputation
Patients without what in the initial stages of RMSF typically experience a full recovery
Vascular damage
A classic RMSF involves a rash that appears 2-4 days after the onset of fever as small, flat, pink macules located where and at what stage of the rash
Located on the wrists, forearms, and ankles and spreads to include the trunk and sometimes the palms of the hands and soles of the feet
Early rash
What is present during the late rash stage of RMSF
A petechial rash that typically appears 5-6 days of the illness (this indicates severe disease and every attempt should be made to treat before petechiae develop)
What is the treatment of RMSF
Doxycycline = treatment of choice for all tick borne rickettsial diseases.
Doxy - 100 mg PO BID for 5-7 days
What is the typical disposition of a patient with RMSF
MEDEVAC patient to higher echelon of care - IDC should initiate treatment with doxycycline
What is the organism type Lyme disease
Bordelaise burgdorferi complex
How is Lyme disease transmitted
(Black legged) ticks
What is the incubation period for Lyme disease
Typically 3-30 days
Is Lyme disease reportable
Yes
Ticks attach to any part of the host but often prefer groin axils, and scalp; how long must the tick be attached
In most cases, the tick must be attached for 36 to 48 hours or more before b.burgdorferi can be transmitted to the host
What are the stages of Lyme disease
Early localized stage
Acute/early disseminated stage
Neurologic manifestation
What symptoms are present for early localized stage of Lyme disease
Flu-like symptoms - malaise, headache, fever, myalgia, arthralgia, lymphadenopathy
At what stage of Lyme disease does erythema migrans (EM) present
Early localized stage
What is early migrans (EM)
Red ring-like or homogenous expanding rash; classic rash, not present in all cases
When does EM appear during the early stage of Lyme disease
EM appears about 1 week after the initial infection
How does the EM rash start and progress in Lyme disease
Begins as a slightly raised red lesion at the site of the tick bite
After several days, the rash expands out from the central lesion sometimes appearing as a “bulls-eye/target” lesion but more often as a muddled circular rash
What are the constitutional symptoms of the acute/early disseminated stage of Lyme disease
Multiple secondary annular rashes
Flu-like symptoms
Lymphadenopathy
What are the cardiac manifestations of the acute/early disseminated stage of Lyme disease
Conduction abnormalities
Myocarditis, pericarditis
What are the neurologic manifestations of the acute/early disseminated stage of Lyme disease
Bell’s palsy or other cranial neuropathy
Meningitis
Encephalitis
What symptoms present with late disseminated stage of Lyme disease
Same symptoms as acute disseminated stage with:
Rheumatologist manifestations - transient, migratory arthritis and effusion in one or multiple joints, migratory pain in tendons, bursae, muscle and bones
Serologic tests should NOT be performed for what in regards to Lyme disease
Asx patient in endemic areas
Asx patient after a tick bite
Patient with non-specific symptoms (subacute myalgias, arthralgias, or fatigue)
What serologic testing should be performed on acute/early disseminated Lyme disease
2 ELIZA test
What serologic testing should be done on late disseminated Lyme disease
Either 2 ELIZA tests or
1 ELIZA test followed by 1 Western blot
In persons with illness duration of Lyme disease of more than 1 month, what can detect the disease
IgG or combined IgG/IgM
What is the treatment for early Lyme disease (erythema migrans) and early disseminated (Bell’s palsy)
Doxycycline 100mg PO BID x 14 days
What is the treatment for late disseminated (arthritis) Lyme disease
Doxycycline 100mg PO BID x 28 days
What is the medication post-exposure prophylaxis
Doxycycline 200mg PO 1 dose - prophylaxis can be started within 72 hours of tick removal
What are some of the precautions that can be taken fr those with Lyme disease exposure
Wear protective clothing
Check skin for attached ticks and remove <24 hours - tick checks should be done every 12 hours
Bug sprays and creams containing DEET
What is the disposition of Lyme disease
Clinical suspicion of Lyme disease will necessitate MEDADVICE and treatment at the IDC level - abx treatment
What is the organism type of leishmaniasis
Obligate intracellular protozoan parasites
What are the subtypes of leishmaniasis
Old world (eastern hemisphere)
New world (Western Hemisphere)
What is the vector for leishmaniasis
Sand fly or sand flea (depending on where you’re from)
What is the incubation period for leishmaniasis
2 weeks to several months and in cases up to 3 years; some >20 years
Is leishmaniasis reportable
Yes
The most common manifestation of cutaneous leishmaniasis is characterized as what
Gradual-onset cutaneous lesions
How do infections of cutaneous leishmaniasis differ from normal sand fly bites
Begin as a pink colored papule that enlarges to a nodule or plaque-like lesion
Lesion ulcerates with infuriated border and may have thick white-yellow fibrous material
Lesions are often PAINLESS
(Lesions gradually heal over months to years with noticeable scarring at site)
What is the IDC treatment/first-line for cutaneous leishmaniasis
Ulcer should be derided and kept clean to avoid secondary infections from developing
What is the FDA approved treatment for cutaneous leishmaniasis
Oral miltefosine for treatment of CL, MCL, and VL caused by certain Leishmania species
What is the most commonly used drug to treat leishmaniasis in most areas
Pentavalent antimonials
Orally administered “azoles” (ketoconazole, itraconazole, and fluconazole) and topical formulations of paromomycin for CL
What is the organism type for methicillin-resistant staphylococcus aureus (MRSA)
gram-positive genetically distinct strain of staphylococcus aureus
What is the incubation period for MRSA
Variable; typically 4-10 days
What is the definition of MRSA
Any strain of S.aureus that has developed multiple drug resistance(s) to beta-lactation antibiotics
True or false: areas of fluctuance and purulent drainage are commonly present with MRSA
True
What is the mainstay of therapy for any fluctuant lesion secondary to MRSA
Incision and drainage
What antibiotics and dosages may be used to treat a MRSA infection
TMP-SMX (160mg/800mg) PO BID x 5-10 days
Clindamycin 300-600mg PO BID x 5-10 days
Doxycycline 100mg PO BID x 10 days
What is the disposition of a MRSA patient
Unless complications develop, most cases of MRSA should be retained onboard and treated by the IDC
Patients with recurring infections should be referred to a MO
How should “fight-bite” injuries be examined
Must be inspected with fist closed
What is the patho-anatomy of a fight-bite
Teeth lacerate overlying skin and penetrate capsule of MCP joint during kinetic impact
Mouth flora (bacteria) enter joint
Bacteria are trapped under extensor tendon and/or joint capsule as fist is released from clenched position
What immunizations should be assessed after a fight-bite injury
TDAP
HBV
HIV
Why should human bite wounds not be closed
Due to the high risk for the development of infection
What kind of human bites do not require prophylaxis
Human bites that do not break the skin or are very superficial
What antibiotics should be avoided when treating a patient for MRSA
ABx without activity against Eikenella Corrodens should be avoided - meaning you cannot use:
Cephalexin (keflex)
PRPs (dicloxacillin)
Macrolides (erythromycin and azithromycin)
What is an early antibiotic prophylaxis that can be used for MRSA
Amoxicillin/clavulanate 875/125mg PO BID x 5 days is preferred
If concerned for osteomyelitis, what labs can be drawn
CBC
ESR
CRP
When is MEDADVICE warranted for human bite/MRSA patients
Clenched-fist wounds
Complex facial lacerations
Deep wounds, especially if significant avulsion or amputation present (likely MEDEVAC)
Wounds associated with neurovascular compromise (likely MEDEVAC)
What are some risk factors for OM
Bacteremia
Endocarditis
IV drug use
Trauma
Open fractures
What are some common local sx of OM
Acute OM typically presents with gradual onset of sx over several days
Patients present with dull pain at the involved site, with or without movement
Local findings (tenderness, warmth, erythema, and swelling)
Systemic symptoms (fever, rotors)
What are the pillars of treatment for OM
Surgical containment and prolonged antibiotic therapy
What is the process of surgical containment treatment for OM
Surgical debridement of all diseased bone is often required due to poor antibiotic penetration
What empiric ABx therapy is used for OM
IV Vancomycin and IV Ceftriaxone
What is the organism type for tetanus
Spore-forming, ANAEROBIC, gram-positive bacterium
What is the incubation period for tetanus
3-21 days, usually about 8 days - the further the inoculation site is from CNS, the longer the incubation period
What is an acute, often fatal, exotoxin-mediated disease produced by gram positive, spore-forming anaerobic rod, HINT: clostridium tetani
Tetanus
What are the commonly present presentations of tetanus in a descending pattern
The first sign is trismus or lockjaw, followed by unchallenged rigidity, dysphasia, and rigidity of abdominal muscles - muscle spasms may occur frequently (q10-15min) and other sx such as hyperthermia, diaphoresis, hypertension and episodic tachycardia
Do you prescribe antibiotics for PROPHYLAXIS against tetanus
No; they literally do not provide any benefit
If tetanus is actually suspected in a patient, what antibiotics are administered
Metronidazole 500mg IV Q6-8hours for 7-10 days
Pen G 2-4mil units IV Q4-6hours (alternate)
What is meningitis
Defined as inflammation of the meninges
What is encephalitis
Inflammation of the brain itself
What are the bacterial etiologies of meningitis/encephalitis
Streptococcus pneumonia, group B streptococcus, N. Meningitidis, H. Influenza, HSV, VZV, EBV, arboviruses
What are some risk factors for meningitis
Close contact exposure
Incomplete vaccinations
Immunosuppression
> 65 y/o and <5 y/o
Alcohol use disorder
Meningitis typically occurs through what routes of inoculation
Hematogenous seeding - the bacteria cross the blood-brain barrier
Direct contiguous spread - organisms enter CSF via neighboring anatomic structures or foreign objects
What is the classic meningeal tetrad
Fever
Nuchal rigidity
Altered mental status
Severe headache
The presence of all four signs is not necessary for clinical diagnosis; many patients may only have 2-3 out of the four signs
What imaging can confirm meningitis
CT is the preferred imaging modality
Ideally, CT should be done prior to lumbar puncture and CSF collection
What is the antibiotic treatment for meningitis
Ceftriaxone 2g IV Q12H x 7days
Pen-G 4 million units IV Q4H x 7days
What is the chemoprophylaxis regimen for meningitis
Ceftriaxone 250 mg IM one time OR
Ciprofloxacin 500 mg PO one time
What is the scientific name of infectious mononucleosis
Epstein-Barr virus
What is the incubation period for infectious mono
Typically 4-6 weeks
Is infectious mono reportable
No
What is the initial presentation of infectious mono
Presents consistent with erythematous or exudative pharyngitis or tonsillitis
What are some symptoms that present with infectious mono
Malaise
Fever
Cervical lymphadenopathy (typically posterior)
Splenomegaly (typically post-infection)
What type of rash presents with infectious mono
Generalized maculopapular rash may occur in patients treated with cillin-class antibiotics for strep pharyngitis
What labs may present abnormal with infectious mono
CBC: leukocytosis with lymphocytosis is most often seen
May present with anemia, thrombocytopenia
LFT: potentially elevated aminotransferases
What is the treatment for infectious mono
Treated symptomatically:
Bed rest, Tylenol or NSAIDs
Saline gargles 3-4 times a day
AVOID THE USE OF ANTIVIRALS
What is the typical disposition for a patient with infectious mono
Patients should be placed SIQ until acute symptoms subside - fever resolves within 10 days, but lymphadenopathy and splenomegaly may persist upwards of 3-4 weeks
Isolation is not necessary
MEDEVAC may be advised in severe cases where airway issues, or other complications arise
What is the scientific name of rabies
Lyssavirus
What is the incubation period for rabies
1-3 months, length of incubation period dependent on site of inoculation
Is rabies reportable
Yes
Clinical rabies typically manifests as what forms
Encephalitic “furious” - fever, hydrophobia, pharyngeal spasms, hypersalivation, diaphoretic, dilated pupils
Paralytic “dumb” - ascending paralysis that is similar to Guillain-Barre, loss of DTR and plantar reflex
What is hydrophobia
Most characteristic feature of rabies; patient becomes afraid of water due to involuntary pharyngeal muscle spasms when they attempt to drink
What is aerophobia
Pathognomonic pharyngeal muscle spasms triggered by feeling draft of air - leads to aspiration, coughing, choking, and if severe, asphyxiation and respiratory arrest
Can rabies be managed by the IDC
No; a rabies case is far beyond the scope of an IDC, and requires immediate referral - patient should be referred to a higher echelon of care
What is diarrhea
3 or more loose or watery stools within a 24-hour period
What are the timeframes to diarrhea
Acute diarrhea - < 14 days
Persistent diarrhea - more than 14 days
Chronic diarrhea - > 30 days
What diarrhea presents with blood in loose-watery stools and has a fever
Inflammatory diarrhea
What are watery stools with NO blood and a scene of fever
Non-inflammatory Diarrhea
Community outbreaks of diarrhea are highly suggestive of what
A common food source or viral etiology
How is mild travelers diarrhea defined
Diarrhea that is tolerable, is not distressing, and does not interfere with planned activities
How is moderate travelers diarrhea defined
Diarrhea that is distressing or interferes with planned activity
How is severe travelers diarrhea defined
Diarrhea that is incapacitating or completely prevents planned activities; all dysentery is considered severe
What are the viral etiologies of diarrhea
Norovirus
Rotavirus (primarily in children)
What are the bacterial etiologies of diarrhea
ETEC
Campylobacter jejuni
Shigella
Salmonella
Bacterial toxin-releasing
What are the protozoan etiologies of diarrhea
Giardia
Entamobea histolytica
What symptoms are present with norovirus diarrhea
Acute onset of abdominal cramps, nausea, vomiting, and non-bloody diarrhea
Illness is generally self-limited and full recovery can be expected in 1-3 days for most patients
What is the treatment for E. Coli (travelers diarrhea)
Treatment can prolong bacterial shedding
Tx consideration consists of oral rehydration therapy, anti motility agents and antiemetics, depending on illness severity level
What is salmonella enterica
A gram-negative, rod-shaped bacillus
What is campylobacter jejuni
A gram-negative, spiral-shaped microaerophilic bacteria; normally carried in intestinal tracts of domestic and wild animals
What are the symptoms of campylobacter jejuni diarrhea
Characterized by diarrhea (frequently bloody), abdominal pain, fever, and occasionally nausea and vomiting
What is the treatment for campylobacter jejuni diarrhea
Generally self-limiting and lasting < 1 week; ABx therapy decreases duration of symptoms and bacterial shedding if administered early in the course of the disease
What antibiotic therapy can be used for campylobacter jejuni diarrhea
Severe disease with bloody stools, high fever, worsening or relapsing symptoms or sx lasting longer than 1 week - suggest Z-pac 500mg PO daily x 3days
What is the organism type for Giardia
Protozoan parasite
What is the incubation period for Giardia
1-14 days; mean incubation time is 7 days
Is Giardia reportable
Yes
What is the presentation for asymptomatic giardiasis
Many infected people are asymptomatic, but shed cysts in their feces and serve as a carrier of the protozoan parasite
What is the patient presentation of acute giardiasis
Symptoms typically develop 1-2 weeks after exposure and generally resolve within 2-4 weeks with diarrhea characterized as foul-smelling and greasy
Gradual onset of 2-5 loose stools per day and gradually increasing fatigue
What is the treatment for giardiasis
Primary treatment consists of drug regimen with activity against bacteria and protozoa - tinidazole 2pm PO single dose (non-AMAL)/ Metronidazole (Flagyl) 250 mg PO TID x 5-7 days (AMAL)
Avoid going into water until asymptomatic for 48 hours
What is the timeline of symptoms and food history for infectious diarrhea
Within 6 hours of food consumption - suggest possible toxin from S. Aureus or B.cereus
Between 8 - 16 hours - suggests C.perfringens
More than 16 hours suggest viral or other bacterial etiology
What are some physical findings of infectious diarrhea
+/- fever, possible mild tachycardia and hypotension secondary to dehydration, increased hyperactive Bowel Sounds in all quadrants
What is the prophylactic antibiotics of treatment for infectious diarrhea
Not recommended for viral or unknown diarrhea suspicion
When are antibiotics considered for infectious diarrhea - severe disease
Fever plus, >10 stools/day with signs/symptoms of dehydration, significant or complete loss of operational effectiveness
When is MEDADVICE or MEDEVAC considered for infectious diarrhea
Fever >101.3 F
Episodes of bloody diarrhea with positive hemoccult
Severe dehydration (inability to hydrate the patient)
Multiple patients presenting at once with similar symptoms
Inability to control nausea and vomiting with antiemetics and Pepto
What is the incubation period for influenza
24-96 hours
Is influenza reportable
Yes
True or false: influenza is NOT highly contagious and is readily shed by infected people
False
What are the distinct glycoproteins of influenza
Hemagglutinin - 18 subtypes
Neuraminidase - 11 subtypes
What are some constitutional symptoms of Influenza
Fever/chills (100.8 F), myalgias, headache, malaise, occasional nausea, sometimes vomiting
What are some influenza specific symptoms
Nonproductive cough, sore throat, rhinitis, substernal soreness, nasal congestion
What do rapid influenza test distinguish
Distinguish between A and B but not subtypes
What is the treatment for influenza
Influenza typically resolves within 1-7 days
Treatment goal is to alleviate and control symptoms while preventing spread to other personnel
What are the steps to treating an influenza patient with antivirals and what antiviral is given
Administer as soon was possible to patient at high risk of complications even if >48 hours has elapsed; can be considered for any previously healthy adult with confirmed or suspected influenza within 48 hours of sx onset
Oseltamivir 75mg PO BID x 5 days
How is hepatitis A virus transmitted
Through consumption of contaminated water or food, and fecal-oral route to include certain sex practices - incubation period average is 28 days
How is hepatitis B virus transmitted
Through exposure to infective blood, semen, body fluids, contaminated blood products, and IV drug use - incubation period average of 90 days
How is hepatitis C transmitted
Through exposure to infected blood, HCV contaminated blood and blood products, and IV drug use - sexual transmission is possible but less common
Which hepatitis infection occurs only with HBV infection
Hepatitis D (HDV)
How is hepatitis E transmitted
Through consumption of contaminated water or food
What is hepatitis
Inflammation of the liver from infection, toxins, autoimmune diseases, metabolic disorders
What is the initial presentation of hepatitis
Initially presents with non-specific flu like symptoms of fatigue, fever, muscle/joint pains, runny nose, pharyngitis, abdominal pain, nausea, vomiting, anorexia
What symptoms develop with hepatitis within 1-3 weeks
Jaundice, RUQ pain
Secondary to the virus infecting and killing hepatocytes
Hepatocyte death releases liver enzymes in the blood
Hepatic dysfunction leads to increased bilirubin and jaundice
What are the physical findings of hepatitis
Low-grade fever
Hepatomegaly with liver tenderness
Jaundice and sclera icterus
RUQ abdominal pain
Dark or brown colored urine
Gray/clay colored stool
What labs may present abnormal with hepatitis
LFT: increased levels of AST/ALT
Viral hepatitis = ALT>AST
Alcoholic hepatitis = AST>ALT
What is the organism type of TB
Rod-shaped, nonmotile, slow-growing, acid-fast bacterium
What is the scientific name for TB
Mycobacterium tuberculosis
What is the incubation period for TB
3-12 weeks. Transition from latent to active can occur from 10-60 years
Is TB reportable
Yes
What is the leading infectious cause of death worldwide
Tuberculosis
Primary infection of TB is characterized by GHON complex and GHON focus; explain
GHON focus - local granulomatous inflammation in periphery of the lung
GHON complex - may be accompanied by ipsilateral lymph node involvement
What is Bacille Calmette-Guerin
It is a vaccine against TB and is primarily used in developing nations or third-world countries
LTBI is defined as a positive result on what
TST
PPD
QuantiFERON Gold blood test
IGRA-TB blood test
What are the typical lab and rad findings of an LTBI patient
Positive TST/PPD or blood test
Normal CXR
Negative acid-fast bacilli
Has Mtb bacteria in their body that are alive, but inactive
Remains asymptomatic
Is non-infectious
What is the NAVMED 6224/7
Initial TB exposure risk assessment
The evaluation of positive tests for TB must include what
NAVMED 6224/7
Chest radiograph
Sputum examination
Baseline LFTs are not routinely indicated for patients beginning treatment for LTBI but is suggested for those with an elevated risk for a liver disorder
What is the treatment for LTBI
3HP - isoniazid and rifapentine PO once a week x12 weeks
4R - rifampin 1 PO QD x16 weeks (4 months)
3HR - isoniazid and rifampin 1 PO daily x12 weeks (3 months)
What clinical monitoring must be done for a patient with LTBI
Monthly follow-up required until completion of treatment and document evaluations on NAVMED 6224/9
With typical pulmonary - TB symptoms include what
Prolonged and productive cough with or without hemoptysis, chest discomfort and pain, low-grade fever, decreased appetite and anorexia, unexplained weight loss and night sweats
Who is post-primary re-activation TB most common in
Adults (60-80%) and can occur years to decades after primary infection
What is the specific name for cutaneous anthrax
Bacillus anthracis
Who is cutaneous anthrax more common in
Ranchers, leather workers, veterinarians, wildlife researchers
What is the incubation for cutaneous anthrax
1-7 days, upwards of 12 days in rare cases
What is a disease primarily affecting ruminant herbivores such as cattle, sheep, goats, antelope and deer that become infected by ingesting contaminated vegetation, water or soil
Zoonotic
What are the main clinical presentations of anthrax
Cutaneous, ingestion, injection and inhalation
What is the hallmark of cutaneous anthrax
Eschar with extensive surrounding edema
What is the presentation of cutaneous anthrax
Small, painless, Pruitt if papule emerge anywhere from 1-12 days after exposure
Papule s enlarge rapidly to vesicles or bulla
Vesicle or bulla start to erode and leave painless black necrotic ulcer
How is cutaneous anthrax diagnosed
vesicular fluid and ulcers should be swabbed for gram stain and culture and PCR
Eschar edges should be lifted and swabbed
Who do patients with cutaneous anthrax get referred to
Infectious disease specialist
What antibiotics protect against anthrax
Cipro - 500mg PO BID x7-10 days
Levoflaxacin - 750mg PO QD x7-10 days
Doxy - 100mg PO BID x7-10 days
What is the disposition of a patient with suspected anthrax
Immediate referral and MEDEVAC
If untreated, may result in sepsis or meningitis
What is the scientific name of chlamydia
Chlamydia trachomatis
What is the most frequently reported BACTERIAL STI
Chlaymdia
How is chlamydia transmitted
Direct sexual contact or mother to child during birth
What is known as the “silent” infection because most infected people are asymptomatic and lack abnormal physical examination findings
Chlamydia
What patient presentation will be present with a female with chlamydia
Urethritis - dysuria, pyuria, increased urinary frequency
Cervicitis (MOST frequent clinical manifestation) - increased vaginal discharge, intermenstrual vaginal bleeding, dyspareunia
What are the presentations of chlamydia in a male patient
Urethritis (MOST frequent clinical manifestation) - mucoid or clear watery discharge, dysuria, scant discharge
Epididymitis - unilateral testicular pain
Prostatitis - pelvic pain, pain with ejaculation, dysuria
Proctatitis - anorectal pain, discharge, rectal bleeding
What is the gold standard for laboratory diagnosis of chlamydia
Nuclei acid amplification testing (NAAT)
What is the preferred and alternate treatment of chlamydia
Preferred: doxy - 100mg PO BID for 7 days
Alternative: azithromycin - 1g single dose
Can treat with ceftriaxone if concerned for coinfection
When should patients with chlamydia that have been treated be retested
3 months after treatment
What is the scientific name of gonorrhea
Neisseria gonorrhoeae
What is the incubation period for gonorrhea
1-14 days, however, can be as short as 2-4 days
Most males are SYMPTOMATIC with gonorrhea and present with what symptoms
Uretheral symptoms - dysuria, white/yellow/green uretheral discharge
Testicular symptoms
Rectal infection
Sore throat but typically asymptomatic
Most women with gonorrhea are typically ASYMPTOMATIC but may present with what symptoms
Uretheral - dysuria, increased vaginal discharge, vaginal bleeding between periods
Lower abdominal discomfort
Dyspareunia
How is gonorrhea diagnosed
GC/NAAT
What is the CDC recommended treatment regimen
Ceftriaxone - 500mg IM in a single dose AND doxy 100mg PO BID x7 days
Or
Azithromycin - 1g orally in a single dose
What is the scientific name for syphilis
Treponema bacterium
What is historically called “the great pretender” as its symptoms can look like many other diseases
Syphilis
What are the distinct phases of infection for syphilis
Early stage: primary and secondary
Latent stage: tertiary
At what stage of syphilis does it begin as a painless papule that proceeds to ulcerate into a 1-2cm painless ulcer with raised margins (called a chancre)
Primary syphilis
What are some other primary syphilis patient presentation
Lymphadenopathy is typically appreciated in the inguinal lymph nodes
Chancre lasts 3 to 6 weeks
However it is often not reported because it is painless
Which phase of syphilis presents with skin rashes and/or mucous membrane lesions and has additional symptoms of fever, swollen lymph glands, sore throat, patchy hair loss, headaches, weight loss, muscle aches and fatigue
Secondary syphilis
Which phase of syphilis is a period of no visible signs and symptoms
Latent stage
Which phase of syphilis is rare and develops in a subset of untreated syphilis infections that appear 10-30 years after infection and can be fatal
Tertiary syphilis
Tertiary syphilis can develop and vary depending on the organ system such as what
Cardiovascular syphilis - aortitis
Neurosyphilis
Gummatous syphilis - very uncommon
What is a more complex and expensive test to perform therefore usually used to confirm syphilis
Treponemal test (FTA-ABS)
What is the standard treatment for all stages of syphilis
Parental penicillin G
What is Jarisch-Herxheimer reaction
An acute febrile reaction that can occur within 24 hours after initiation of therapy for syphilis and typically resolves in 12-24 hours
NSAIDs or antipyretics can help reduce symptom severity
