MDT Flashcards
Person or animal that harbors the infectious agent/disease and can transmit it to others but does not demonstrate signs of the disease
Carrier
Exposure to a source of an infection; a person who has been exposed.
Does not imply infection; it implies possibility of infection
Contact
Capable of being transmitted from person to person by contact or proximity. Does not need or utilize a vector.
Contagious
An organism that harbors a parasitic, mutualistic, or commensalism guest
Host
An organism that lives on or in a host organism and gets its food from or at the expense of its host
Parasite
Three main classes of human parasites
Protozoa
Helminths
Ectoparasites
An infectious agent or organism that can produce disease
Pathogen
Invasion of the body tissues of a host by an infectious agent, regardless if it causes disease or not
Infection
A pathway into the host that gives an agent access to tissue that will allow it to multiply or act
Portal of entry
A population of organisms or the specific environment in which an infectious pathogen naturally lives and reproduces; usually a living host of a certain species
Reservoir
A pathogen that is transmissible from non-human animals (typically vertebrates) to humans
Zoonosis
An increase, often sudden, in the number of cases of a disease above what is normally expected in that population in that area
Epidemic
Carries the same definition of epidemic but is often used for a more limited geographic area
Outbreak
The constant presence of an agent or health condition within a given geographic area or population
Endemic
An epidemic occurring over a widespread area (multiple countries or continents) and usually affecting a substantial proportion of the population
Pandemic
Any of a group of viruses that are transmitted between hosts by mosquitoes, ticks, and other arthropods
Arbovirus (arthropod-borne virus)
Resistance developed in response to an antigen (pathogen or vaccine) characterized by the presence of antibody produced by the host
Active Immunity
When a majority of a given group is resistant/immune to a pathogen. This confers protection to unvaccinated or susceptible individuals/group by reducing the likelihood of infection or spread
Herd Immunity
Transfer of active humoral immunity of ready-made antibodies produced by another host or synthesized.
Used when there is a high risk of infection and insufficient time for the body to develop its own immune response. Short term.
Passive Immunity
Describes any illness, impairment, degradation of health, chronic, or age-related disease
Morbidity
Time interval from a person being infected to the onset of symptoms of an infectious disease
Incubation period
Time interval from a person being infected to the time of infectiousness of an infectious disease
Latency period
An infection that is nearly or completely asymptomatic.
A subclinical infected person is an asymptomatic carrier of the infection
Subclinical infection
A combination of symptoms characteristic of a disease or health condition; sometimes refers to a health condition without a clear cause
Syndrome
Measure of death in a defined population during a specified time interval, from a defined cause
Mortality rate
Transmission occurs between an infected person and a susceptible person via direct physical contact with blood or body fluids
Direct contact
Transmission occurs when there is no direct human-to-human contact
Indirect contact
Often indicate the onset of a disease before more diagnostically specific signs and symptoms
Prodrome
Leading cause of domestically acquired arboviral disease in the U.S.
West Nile Virus
Organism that transports West Nile Virus
Culex Mosquito
Incubation period of West Nile Virus
2-6 days, can range 2-4
WNV
Mosquitoes become infected when they feed on infected _____; then spread the virus to humans
Birds
Considered ‘dead-end’ hosts for West Nile Virus
Horses and Humans
Should be considered in any febrile patient or acute neurologic illness with recent exposure to mosquitoes during the summer months in endemic areas
West Nile Virus
Acute systemic febrile illness accompanied by:
- Headache, weakness, myalgia, or arthralgia
- Gastrointestinal symptoms
- Transient maculopapular rash
West Nile Virus
West Nile Virus lab diagnosis
IgM in serum or CSF
West Nile Virus Treatment
Pain control for headaches, antiemetic therapy and rehydration for associated nausea & vomiting
Most patients with non-neuroinvasive WNV disease recover completely; however, fatigue, malaise, and weakness can linger for how long?
Weeks to months
Subtypes of Malaria
Falciparum
Vivax
Ovale
Malariae
Malaria is transmitted via:
Female anopheles mosquito
Incubation period of Malaria
7-30 days
Malaria Phase
SEXUAL CYCLE in a female Anopheles Mosquito
Begins when a female anopheles mosquito takes a blood meal from an infected human
Ends when the mosquito salivary glands are filled malaria parasites
Sporogony Phase
Malaria Phase
Asexual cycle in the human liver
Exoerythrocytic Phase
Malaria phase
Asexual reproduction in RBCs
Patient is SYMPTOMATIC at this stage
Erythrocytic Phase
Presentation of Malaria can be broken into what 2 broad categories?
Uncomplicated & Severe
Paroxysmal (cyclical) fever
Influenza-like symptoms including chills, headache, myalgias, and malaise
Jaundice & mild anemia secondary to hemolysis
Uncomplicated Malaria
Malaria with the following symptoms:
- Small blood vessels infarction, capillary leakage and organ dysfunction
- Altered consciousness
- Hepatic failure and renal failure
- Acute respiratory distress syndrome
- Severe Anemia
Severe Malaria
Hallmark of Malaria
Paroxysmal fevers
Life cycle of malaria
48-72 hours
Both positive and negative Rapid Malaria Testing must always be confirmed by:
Microscopy
Two reliable-supply treatments for Malaria
Atovaquone-proguanil (Malarone)
Artemether-lumefantrine (Coartem)
Treatment of uncomplicated Malaria
Chloroquine phosphate 1g (600mg base) PO
THEN 0.5g in 6 hours
THEN 0.5g daily for 2 days
Treatment of malaria in areas with chloroquine resistance
Malarone (Atovaquone 250mg/Proguanil 100mg) 4 tabs PO QD for 3 days
Treatment for severe Malaria
Artesunate 2.4mg/kg IV at 0, 12, 24, 48 hours
Followed by doxycycline 100mg BID x 7 days after parenteral therapy
Treatment of P. ovale
Artesunate 2.4mg/kg IV at 0, 12, 24, 48 hours
Followed by Doxycycline 100mg BID x 7 days after parenteral therapy
Add Primaquine 52.6mg PO QD x 14 days
Malaria Prevention
The most important protective measures are:
Proper clothing and awareness
How many subtypes of dengue are there?
Four
DENV-1, DENV-2, DENV-3, DENV-4
Dengue is transmitted by which mosquito?
Aedes aegypti mosquito
Three phases of Dengue Fever
Febrile
Critical
Convalescent
Dengue Fever
Febrile stage typically lasts __ days and can be biphasic
2-7 days
Headache; retroorbital pain; muscle, joint, and bone pain; macular or maculopapular rash
Minor hemorrhagic manifestations
Dengue Fever
Mild Dengue Fever
Critical phase of dengue typically lasts ___ hours
24-48 hours
Mild Dengue Fever
Most patients clinically improve during the phase and move on to recovery and convalescence stage
Critical Stage
Mild Dengue Fever - ______ Stage
Plasma leakage subsides
Pt begins to reabsorb extravasated intravenous fluids, pleural, and abdominal effusions
Patient continues to improve, hemodynamic status stabilizes and diuresis ensues
Recovery
Dengue Fever
Hypotension develops, systolic blood pressure rapidly declines, and irreversible shock and death may ensue despite resuscitation efforts
Dengue Shock Syndrome
Dengue
Relatively accurate way to get a general determination a patients’ capillary fragility or hemorrhagic tendency.
Tourniquet Test
Dengue - Tourniquet
A positive test is ___ or more petechiae per square inch
10
Treatment for mild Dengue Fever
Hydration and Acetaminophen
Avoid skin injections and NSAIDs due to bleeding risk
Treatment for severe Dengue Fever
ICU-level monitoring and blood products
Maintenance of the patient’s body fluid volume is CRITICAL
Scientific name of Rocky Mountain Spotted Fever
R. rickettsia
Rocky Mountain Spotted Fever is transmitted by:
American dog tick (east of Rockies & Pacific Coast)
Rocky Mountain wood tick (Rocky Mountain region)
Brown tick (worldwide)
Incubation period for Rocky Mountain Spotted Fever
2-14 days
Rocky Mountain Spotted Fever is a rapidly progressive disease and without early administration of _______ can be fatal within days
Doxycycline
Fever, HA, GI symptoms, myalgias and rash
Rash usually presents 3-5 days after fever onset
-small flat pink macules on wrist, forearms, ankles and spreads to trunk
Rocky Mountain Spotted Fever
Rocky Mountain Spotted Fever late disease
R. rickettsia infects:
Endothelial cells that line blood vessels, causing vasculitis and bleeding or clotting in the brain or other vital organs
Rocky Mountain Spotted Fever
__% people have some type of rash
90%
Rocky Mountain Spotted Fever
Sign of severe disease
Petechiae
Treatment of choice for all tickborne rickettsia disease (Rocky Mountain Spotted Fever)
Doxycycline
Perform tick checks at __-hour intervals when training or operating in RMSF endemic areas
12 hour
Never let your personnel go >___ hours without a tick check
> 24 hours
Lyme Disease is transmitted via:
Blacklegged ticks
Incubation period for Lyme Disease
3-30 days
Reservoirs for Lyme Disease
Rodents (white foot deer mice, chipmunks, squirrels)
Vectors for Lyme Disease
Blacklegged ticks
Most cases, the tick must be attached for ___ hours or more before B. burgdorferi (Lyme) can be transmitted to the host
36-48 hours
Erythema migrans (red ring like rash)
Malaise, headache, fever, myalgia, arthralgia, lymphadenopathy
Lyme Disease
Cardiac manifestation of Lyme Disease
Conduction abnormalities, AV node block
Myocarditis pericarditis
Neurologic Manifestations of Lyme Disease
Bell’s palsy or other cranial neuropathy
Meningitis
Encephalitis
Late disseminated stage of Lyme Disease symptoms:
Same as acute disseminated stage with:
-Rheumatologic Manifestations
Treatment for EARLY Lyme Disease (Erythema migrans)
Doxycycline 100mg PO BID x 14 days
Treatment for early disseminated Lyme Disease (Bell’s Palsy)
Doxycycline 100mg PO BID x 14 days
Treatment for disseminated Lyme disease (Arthritis)
Doxycycline 100mg PO BID x 28 days
Lyme disease prevention medication post-exposure prophylaxis
Doxycycline 200mg PO 1 dose
Leishmaniasis organism type
Obligate intracellular protozoan PARASITE
Scientific name of Leishmaniasis
Leishmania tropica
Leishmaniasis is on every continent except:
AUS & Antarctic
Leishmaniasis is transmitted by:
Female phlebotomine sand flies
Incubation period of Leishmaniasis
2 weeks to several months and cases up to 3 years
Some >20 years
Most common manifestation of Leishmaniasis
Cutaneous Leishmaniasis
Begins as a pink colored papule that enlarges to a nodule or plaque-like lesion
Lesion ulcerates with indurated border and may have thick white-yellow fibrous material
Lesions are often painless
Cutaneous Leishmaniasis
Leishmaniasis lesions healing takes how long?
Months to years with noticeable scarring
Cutaneous Leishmaniasis Treatment
Ulcer debrided and cleaned
Anti-fungal
Incubation period of MRSA
Highly variable; typically 4-10 days but asymptomatic (years)
The highest risk of being bit by sand flies occurs at what time of day?
Dusk to dawn (typically bite at night and during twilight hours)
Any strain of S. aureus that has developed multiple drug resistance(s) to beta-lactam antibiotics
MRSA
CA-MRSA
Community Acquired
HA-MRSA
Hospital Acquired
Any strain of S. aureus susceptible (able to be killed by) beta-lactam antibiotics
MSSA
Most commonly manifestations of MRSA
Furuncles, carbuncles, and abscesses
Abscess with purulent drainage & fluctuance is a high suspicion for:
MRSA
MRSA treatment
I&D, packing, daily dressing changes
- Bactrim
- Clindamycin
- Doxycycline
An acute or chronic inflammatory process involving bone & structures secondary to infection with pyogenic organisms, including, bacteria fungi, and mycobacteria
Osteomyelitis
Among younger adults osteomyelitis, occurs most commonly in:
Trauma (Penetrating injury) and related surgery
Among older adults, osteomyelitis occurs most commonly as a result of:
Contagious spread of infection from adjacent soft tissues and joints
Patients present with dull pain at the involved joint, with or without movement
Tenderness, warmth, erythema, and swelling
Fevers
Osteomyelitis
Treatment for Osteomyelitis
Surgical Containment
IV Vancomycin & IV Ceftriaxone
Human bites occur in two basic categories
Occlusive wounds (teeth closing over and breaking the skin)
Clenched-fist or “fight bites” (skin surface strikes a tooth)
Human Bites
Typical human oral and skin flora cause infection
Eikenella
Group A Strep
Fusobacterium
Staphylococci
Antibiotic prophylaxis for Human bites
Amoxicillin-clavulanate 875/125mg PO BID x 5 days
Hand wounds are examined in what positions?
Fingers extended & in the clenched-fist position
Scientific name for Tetanus
Clostridium tentani
Tetanus booster should be within ___ years
10 years
Incubation period for tetanus
3-21 days, usually about 8 days
Further the inoculation the site is from CNS the longer the incubation period
An acute, often fatal, exotoxin-mediated disease
Widely distributed in soil, and the intestines & feces of farm animals
Tetanus
C. tetani spores can survive autoclaving at _____ degrees Fahrenheit for 10-15 minutes
249.8 F
Tetanus
Passive immunization was first used for treatment & prophylaxis of allied forces during:
WWI
Inactivated tetanus toxin was developed in the 1920’s and first widely used for allied forces during:
WW2
What conditions allow germination of spores and production of two exotoxins, collectively called ‘tetanus toxin’
Anaerobic conditions
Minimum lethal dose in humans for tetanus toxin
2.5 ng per kg
Tetanus
Muscle rigidity and spasms occur secondary to the disinhibition of:
Lower motor neurons
Typically the first sign is trismus or lockjaw, followed by nuchal rigidity, dysphagia, and rigidity of abdominal muscles
Hyperthermia, diaphoresis, hypertension, episodic tachycardia
Tetanus
Tetanus
Death typically occurs secondary to:
Respiratory arrest
Treatment for Tetanus
Clean/deride wounds
Supportive therapy and airway protection
Antibiotics:
- Metronidazole
- Pen G
- Tetanus Immune Globulin (500 units IM at different sites from the TDAP; part of the dose should be infiltrated around the wound)
When would patients with a completed 3-dose primary tetanus vaccination require a booster of TDAP?
Last documented dose of TDAP was > 5 years ago
Inflammation of the meninges that line the vertebral canal/skull enclosing spinal cord/brain
Meningitis
Inflammation of the brain itself
Encephalitis
Meningitis
Risk factors that increase clinical suspicion
Close contact exposure (barracks, dorms)
Incomplete vaccinations
Immunocompromised
> 65 y/o & < 5 y/o
Alcohol use disorder
Meningitis
Typically occurs through what two routes of inoculation?
Hematogenous seeding
Direct contagious spread
Febrile, HA, Nuchal rigidity, altered mental status
Meningitis
Labs/Rads for Meningitis
Lumbar puncture
CT
Treatment for Meningitis
Ceftriaxone 2g IV
OR
Pen-G 4 million units IV
Osteomyelitis
Antibiotics without activity against _______ should be avoided
E. corrodens
Meningitis
Chemoprophylaxis is indicated for close contacts of patients diagnosed with which types of meningitis?
N. meningitidis
H. influenzae type B meningitis
Chemoprophylaxis regimen for meningitis
Ceftriaxone 250mg IM one time
(or)
Ciprofloxacin 500mg PO one time
Mononucleosis organism type
Virus, one of 9 known human herpesviruses
Mononucleosis scientific name
Epstein-Barr virus
Mononucleosis is transmitted via:
Bodily fluids, primarily saliva
Mononucleosis
Has a high risk for __________ which can be fatal
Splenic rupture
Presents consistent with erythematous or exudative pharyngitis or tonsillitis
Malaise, Fever, Cervical lymphadenopathy, Splenomegaly
Rash
Mononucleosis
Mononucleosis
Diagnosis can be made clinically and confirmed with:
Monospot test (positive within 4 weeks after symptoms)
Mononucleosis treatment
Bed rest, Acetaminophen or NSAIDs
Saline gargles 3-4 times
Treat symptomatically
What drug class do you want to avoid when treated Mononucleosis?
Antivirals
Mononucleosis
Fever resolves within ___ days
Lymphadenopathy and splenomegaly may persist upwards of ____ weeks
10 days
3-4 weeks
Mono
Disposition due to risk of splenomegaly and splenic rupture
Light duty with no physical contact sports for 3-4 weeks
Rabies scientific name
Lyssavirus
How many lyssavirus genus’ cause rabies in the mammals?
All 14
Incubation for Rabies
1-3 months, depends on site of inoculation
Lethality of rabies
One the rabies virus reaches the CNS it has a __% fatality rate
99.9%
Fatal, acute, progressive encephalomyelitis caused by neurotropic viruses in the family Rhabdoviridae, genus Lyssavirus
Rabies
The only U.S. state that has never had a lab-confirmed case of rabies is:
Hawaii
All mammals are believed to be susceptible to infection, but major rabies reservoirs are:
Terrestrial carnivores and bats
Clinical illness in humans begins following invasion of the peripheral nervous system; and then central nervous system; culminating in acute fatal encephalitis
Rabies
First symptoms of Rabies
Pain and paresthesia at the site of exposure
Anxiety, paresis, paralysis, and other signs of encephalitis; spasms of swallowing muscles can be stimulated by the sight, sound, or perception of water (hydrophobia); and delirium and convulsions can develop, followed rapidly by coma and death
Rabies
Clinical rabies typically manifests as what two major forms?
Encephalitic “Furious”
-Fever, hydrophobia, pharyngeal spasms, hyperactivity subsiding to paralysis
Paralytic “Dumb”
-Ascending paralysis that is similar to Guillain-Barre
Most characteristic feature of Rabies; patient becomes afraid of water due to involuntary pharyngeal muscle spasms when they attempt to drink
Hydrophobia
Rabies
Pathognomonic pharyngeal muscle spasms triggered by feeling draft of air
Leads to aspiration, coughing, choking, and if severe asphyxiation and respiratory arrest
Aerophobia
Diagnostic confirmation of rabies
Post-mortem brain tissue samples
Rabies
Offending animals that appear well will be placed in isolation for ___ days for observation
10-14 days
Diarrhea is defined as ___ or more loose or water stools within a 24 hour period
3 or more
Acute Diarrhea = ___ days
Persistent = ___ days
Chronic = ___ days
Acute = < 14 days
Persistent = 14-30 days
Chronic = > 30 days
Presents with blood in loose-watery stools and fever
Secondary tissue damage to lining of the colon from certain bacteria, and/or toxins
Inflammatory Diarrhea
Watery stools with no blood & absence of fever
Non-inflammatory Diarrhea
Community outbreaks of infectious Diarrhea are highly suggestive of:
Common food source, or viral etiology
Bacterial Etiologies of infectious Diarrhea
Enterotoxigenic Escherichia coli
Campylobacter jejuni
Shigella spp.
Salmonella spp.
Bacterial toxin-releasing
Viral Etiologies of Infectious Diarrhea
Norovirus
Rotavirus (primarily children)
Protozoal etiologies of infectious Diarrhea
Giardia
Entamoeba histolytica
Viral infectious Diarrhea
Norovirus
Norovirus activity peaks during what season
Winter
Predisposing factors for Viral infectious Diarrhea
Ready-to-eat cold foods (sandwiches and salads)
Raw shellfish especially oysters, contaminated ice
Close quarters living with high population density
Viral infectious Diarrhea is transmitted via:
Fecal-oral route
Aerosols of vomitus
Contaminated environmental surfaces/objects
Incubation period for Viral infectious Diarrhea
12-48 hours
Acute onset of nausea, vomiting, and non-bloody diarrhea
Abdominal cramps, and sometimes a low-grade fever
Illness is generally self-limited, and full recovery can be expected in 1-3 days for most patients
Viral infectious Diarrhea
E. coli
AKA Traveler’s diarrhea or Montezuma’s revenge
Enterotoxigenic E. coli (ETEC)
E. coli
Also called Shigatoxigenic Escherichia Coli or STEC
Enterohemorrhagic E. coli (EHEC)
E. coli Inflammatory Diarrhea is transmitted via:
Fecal-oral route
Salmonella
Most common clinical presentation of infection
Gastroenteritis
Symptoms typically consist of acute diarrhea, abdominal pain, fever, and vomiting for 4–7 days. Patients typically recover without treatment
Salmonella
Salmonella Inflammatory Diarrhea
Treatment for patients with severe diarrhea, high fever, or manifestations of extraintestinal infection
Fluoroquinolones
Transmission routes for Campylobacter infectious Diarrhea
Eating contaminated foods (undercooked chicken/raw chicken)
Contaminated water or unpasteurized milk
Characterized by diarrhea (frequently bloody), abdominal pain, fever, and occasionally nausea and vomiting.
Severe infections can include dehydration, bloodstream infection, and mimic acute appendicitis or ulcerative colitis.
Generally self-limiting & lasting < 1 week
Campylobacter
Diarrhea of the _______ tend to be more frequent, smaller volume and are often more painful.
Fever, bloody stools, or mucus tends to be more common
Large bowel
Diarrhea of the _______ origin tend to be larger volume and watery and will tend to have more abdominal cramping, bloating and gas
Small bowel
Diarrhea within 6 hours of food consumption is suggestive of toxin possible from:
S. aureus
B. cereus
Diarrhea between 8-16 hours after eating suggests
C. perfringens
Diarrhea >16 hours after eating suggests
Viral or other Bacterial etiology
Reptiles have ______ on skin
salmonella
Diarrhea
Hiking or outdoor recreation where patient may have drunk stream water would indicate:
Giardia
Diarrhea
Being on a ship where others have had recent illness would indicate:
Norovirus
Protozoal Parasitic infectious Diarrhea is caused by:
Giardia
Most common intestinal parasitic disease affecting humans
Giardia
Incubation period for Giardiasis
1-14 days; mean of 7
Giardia life cycle
- Infectious form of the parasite
- Excreted in stool and can survive in wet environments
- After ingestion excystation occurs in the proximal small bowel releasing trophozoites
Cyst Form
Giardia life cycle
- Flagellated parasites adhere to proximal small bowel
- Trophozoites that pass to large intestine revert to cysts and excreted into the environment
Trophozoite Form
Acute Giardiasis
Symptoms typically develop in __ weeks after exposure and resolve within ___ weeks afterwards
1-2 weeks
2-4 weeks
Symptoms
- Diarrhea (foul-smelling & greasy)
- Abdominal cramps, bloating, flatulence, fatigue, anorexia, and nausea
Gradual onset of 2-5 loose stools per day and gradually increasing fatigue. Weight loss may occur over time.
Fever and vomiting are uncommon.
Giardiasis
Giardiasis lab diagnostic tests
Antigen detection assays
Stool microscopy
Giardiasis Stool microscopy
Diagnostic sensitivity increased by examining up to __ stool specimens over several days
3
Giardiasis treatment
Tinidazole
Metronidazole
Giardia
Patients need to be excluded from going into water until asymptomatic for ___ hours
48 hours
General treatment guidelines for infectious diarrhea
Rule out more serious pathologies
Rehydration
BRAT (bananas, rice, applesauce, toast) diet
Patient education regarding hygiene
Infectious Diarrhea
Symptomatic therapy/conservative treatment for mild-moderate in the absence of fever & bloody stools.
Loperamide
Bismuth subsalicylate
Severe fluid loss from infectious diarrhea should be treated with:
1-2 liters of LR
Severe fluid loss from infectious diarrhea
What tests should be utilized as a metric for improvement?
Orthostatic hypotension tests
When to consider antibiotics for infectious diarrhea?
Severe disease (Fever, >6 stools/day, signs dehydration)
Blood or mucoid stools with no clinical suspicion of E. coli
Infectious diarrhea
E.coli 0157:H7: specific strain of E.coli associated with
Undercooked fast-food hamburger meat
Infectious Diarrhea
Antibiotic treatment has no clinical benefit in a patient with
0157:H7, and can significantly worsen outcomes by causing:
Hemolytic Uremic Syndrome (HUS)
Most cases of non-inflammatory diarrhea are self-limiting and resolve within:
48-72 hours
Any patient suspected of having infectious diarrhea shall be removed from food handling & food preparation duties until symptom free for:
24 hours
When to consider MEDADVICE or MEDEVAC for a patient with infectious diarrhea
Fever >101.3
Blood in stool
Severe Dehydration (with inability to rehydrate)
Multiple patients presenting at once with similar symptoms
Inability to control symptoms with medication
Influenza scientific name
Orthomyxovirus
Subtypes of influenza
A/B/C/D
Influenza subtypes that cause illness in humans
A & B
Influenza viruses spread from person to person primarily through:
Respiratory droplet transmission
Incubation period for influenza
24-96 hours
Influenza can cause severe illness and death typically at what ages?
> 65 or <2
Epidemics of influenza usually occur during which months?
Fall and winter months
Influenza
Adults are infectious from 1 day prior to symptom onset to __ days after symptom onset
5-7 days
Flu
Infectiousness is highest within __ days of onset and correlated with fever
3 days
Children and immunocompromised/severely ill may shed the flu virus for ___ days after onset of symptoms
> 10 days
Two distinct glycoproteins which are necessary for viruses to enter cells and are also how influenza undergoes periodic changes
Hemagglutinin (H1, H2, H3)
Neuraminidase (N1 and N2)
Avian influenza glycoproteins
A(H5N1)
A(H7N9)
Swine-origin glycoproteins
A(H1N1)
A(H1N2)
A(H3N2)
Fever/chills (> 100.8 F), myalgias, headache, malaise,
occasional nausea, sometimes vomiting
Nonproductive cough, sore throat, rhinitis, substernal
soreness, nasal congestion
Predominantly localized to the respiratory tract; include
nasal discharge, pharyngeal inflammation without
exudates, and occasionally rales on chest auscultation
Influenza
Influenza typically resolves within __ days
1-7 days
Treatment goal for influenza
Alleviate and control symptoms while preventing spread to others
Antiviral medication for Influenza that can shorten the duration of fever and other symptoms and reduce the risk of complications
Oseltamivir 75mg PO BID
- Transmitted through consumption of contaminated water or food and certain sex practices.
- Infections are typically mild, with most making a full recovery & gaining lifelong immunity.
- Most people in areas of the world with poor sanitation have been infected with this virus.
- Safe and effective vaccines are available
Hepatitis A Virus (HAV)
-Transmitted through exposure to infective blood, semen,
body fluids, contaminated blood products, and IV drug use.
- Poses risk to healthcare workers (needle stick injuries).
- Safe and effective vaccines are available
Hepatitis B Virus (HBV)
Transmitted through exposure to infective blood, contaminated blood & blood products, and IV drug use.
Sexual transmission is possible but less common.
There is no vaccine
Hepatitis C Virus (HCV)
Infections occur only with Hepatitis B infection
Dual infection, results in a more serious disease and worse outcome
Hepatitis B vaccines provide protection
Hepatitis D Virus (HDV)
Transmitted through consumption of contaminated water or food.
Common cause of hepatitis outbreaks in developing nations.
Vaccines exist but are not widely available.
Hepatitis E Virus (HEV)
No vaccination for Hepatitis C but can be cured with:
Antiviral Treatment
Hepatitis
Can both remain dormant in the liver and cause chronic hepatitis & hepatocellular carcinoma
Hep B & Hep C
Fatigue, fever, muscle/joint pains, runny nose, pharyngitis,
nausea, vomiting, anorexia
- Low grade fever
- Hepatomegaly with liver tenderness
- Jaundice and scleral icterus
- Right upper quadrant abdominal pain
Hepatitis
Hepatitis
Within __ weeks, jaundice & RUQ pain develops
1-3 weeks
Lab diagnostic test for Hepatitis
Hepatitis panel serologic testing
Lab findings for Hepatitis
WBC = Normal or low
UA = Proteinuria and Dark urine (bilirubinuria)
LFT = Increased levels of AST and ALT
- Viral: ALT>AST
- Alcoholic: AST>ALT
CMP Elevated bilirubin and alkaline phosphates
TB scientific name
Mycobacterium tuberculosis
Subtypes of TB
Multi-drug resistant TB (MDR-TB)
Extensively drug-resistant TB (XDR-TB)
TB is transmitted via:
Contagious patient coughs, spreading bacilli through the air
Leading infectious cause of death worldwide
TB
Characterized by local granulomatous inflammation in periphery of the lung (GHON focus) may be accompanied by ipsilateral lymph node involvement (GHON complex)
TB
Vaccines against TB
Bacille Calmette-Guerin (BCG)
Interferon-Gamma Release Assays (IGRAs)
- QuantiFERON – TB Gold In-Tube test (QFT–GIT)
- SPOT TB test (T–Spot)
TB vaccination may cause a false positive reaction to a TB skin test.
BCG
Positive result on the following labs:
(a) Tuberculin skin test (TST)
(b) Purified protein derivative (PPD)
(c) Positive QuantiFERON Gold blood test
(d) Positive IGRA-TB blood test
Patient is infected with M. tuberculosis but does not have active TB disease
Latent TB
Labs and Rads for Latent TB
(1) Positive TST/PPD or blood test
(2) Normal CXR
(3) Negative acid-fast sputum test
TB
Document History on which form?
NAVMED 6224/7, Initial TB Exposure Risk Assessment
Latent TB infection
Baseline LFTs are indicated in patients who have:
Elevated risk for liver disorder (heavy/regular ETOH use)
LTBI regimens
Isoniazid & rifapentine (3HP) PO once a week x 12 weeks.
Rifampin PO QD x 16 weeks
Isoniazid PO QD for 6-9 months, plus Pyridoxine PO QD for 6-9 months to mitigate peripheral neuropathies
The provider must rule-out active TB before started the treatment for LTBI via:
Labs and Chest X-ray
LTBI
Who should you consult for preferred treatment regimen and the likelihood of drug-resistant strains in the region?
Local NEPMU/MTF
LTBI
Monthly follow up is required and will be documented on which form?
NAVMED 6224/9
Where do you document successful completion of LTBI?
Medical Record
Active TB is denoted from which three terms?
Post-primary TB
Reactivation TB
Active TB
Prolonged & productive cough with or without hemoptysis, chest discomfort & pain, low-grade fever, decreased appetite & anorexia, unexplained weight loss, night sweats
Active TB infection (pulmonary)
TB
Most common in adults (60%–80%). Can occur years to decades after primary infection after immunological impairment.
Post-primary Re-activation TB
Lab test
Measures immune response to TB antigens
Does not differentiate LTBI & ATB
IGRA-TB
TB
Screening and provisional testing, not confirmatory
Does not differentiate between active LTBI and ATB
Tuberculin Skin Test (TST)
Gold standard for confirmatory TB diagnosis
Can differentiate between LTBI and ATB
Sputum Test - Acid-Fast Bascillus (AFB) with NAAT
What might you find on a CXR for a patient with Post-primary Re-Activation TB:
Fibrosis/scarring, cavitations
Enlargement of hilar and mediastinal lymph nodes
Patients with suspected/known active TB immediately get _______ to minimize aerosolization of respiratory secretions and spread
Surgical masks
Active TB
Medical department must wear:
Particulate respirators (N95)
TB
Medical event report must be submitted within:
24 hours
Suspected or confirmed case of active TB, the SMDR notifies _______ as soon as possible
Cognizant NEPMU
TB
Follow routine testing and screening guidelines from which instruction?
BUMEDINST 6224.8C
TB Prevention
Ensured TST/PPD is conducted during which timeframes?
Pre-deployment and Post-deployment
Anthrax scientific name
Bacillus anthracis
Predisposing factors for Anthrax
Working with any unvaccinated animal that is a common reservoir
More common in ranchers, leather workers, veterinarians, wildlife researchers
Incubation period for Anthrax
Cutaneous anthrax 1-7 days; 17 days in rare cases
Zoonotic disease primarily affecting ruminant herbivores such as cattle, sheep, goats, antelope, and deer that become infected by ingesting contaminated vegetation, water, or soil
Anthrax
Four main clinical presentations of Anthrax
Cutaneous
Ingestion
Injection
Inhalation
Most common form of anthrax in humans (95-99%)
Cutaneous
Hallmark of cutaneous anthrax
Eschar with extensive surrounding edema
Small, painless, pruritic papules emerge anywhere from 1 – 12 days after exposure
Papules enlarge rapidly to vesicles or bulla (blisters)
Vesicle or bulla start to erode and leave painless black necrotic ulcer
Cutaneous Anthrax
Treatment for Anthrax
Refer to an infectious disease specialist
Antibiotics
- Ciprofloxacin
- Levofloxacin
- Doxycycline
If untreated, cutaneous anthrax may result in:
Sepsis
Meningitis
Scientific name for Chlamydia
Chlamydia trachomatis
Most frequently reported bacterial STI in the U.S
Chlamydia
Chlamydia transferred from mother to child can cause:
Infant blindness “trachoma”
Known as a ‘silent’ infection because most infected people are asymptomatic & lack abnormal physical examination findings.
Chlamydia
Male presentation for chlamydia
Urethritis
- CLEAR WATERY discharge
- Dysuria is most common complaint
- Scant discharge on underwear usually presents in the morning
Urethritis
- Dysuria
- Pyuria
- Increased urinary frequency
Cervicitis
- Increased vaginal discharge
- Intermenstrual vaginal bleeding
- Dyspareunia
Female presentation for chlamydia
___% of chlamydia and gonorrhoeae co-infections
> 50%
Gold standard for laboratory diagnosis for Chlamydia
Nucleic Acid Amplification Testing (NAAT)
-UA or discharge swab
Preferred treatment for Chlamydia
Doxycycline 100mg PO BID for 7 days
Antibiotic of choice for chlamydia if concerned for coinfection with gonorrhea
Ceftriaxone
Untreated chlamydia can cause:
- Pelvic Inflammatory Disease
- Pre-term delivery in women who are pregnant
- Reactive Arthritis
Gonorrhea scientific name
Neisseria gonorrhoeae
Incubation period for Gonorrhea
1-14 days, can be as short as 2-4
Male presentation for gonorrhea
Dysuria
-White/yellow/green urethral discharge
Female presentation for gonorrhea
- Dysuria, increased vaginal discharge, or vaginal bleeding
- Lower abdominal discomfort
- Dyspareunia
Diagnostic lab tests for Gonorrhea
GC/NAAT
Culture (important due to antibiotic resistant strains)
__% of gonorrhea infections are resistant to at least one antibiotic
50%
Emergence of fluoroquinolone-resistant N. gonorrhoeae left _________ as the sole remaining class available for treatment of gonorrhea in the U.S.
Cephalosporins
Treatment for Gonorrhea
Ceftriaxone 500mg IM single dose
AND
Doxycycline 100mg PO BID x 7 days
STI screening includes:
Gonorrhea
Chlamydia
HIV
RPR for syphilis
HPV vaccination counseling
Scientific name for syphilis
Treponema pallidum
Incubation period for Syphilis
10-90 days; average is 21 days
Stages of Syphilis
Primary Syphilis
Secondary Syphilis
Latent Stage
Tertiary Syphilis
Begins as a painless papule that proceeds to ulcerate. Ends as a to 1-2cm painless ulcer with raised margins. This is called a chancre.
Lymphadenopathy is typically in the inguinal lymph nodes.
Chancre lasts 3 to 6 weeks and heals.
Primary Syphilis
Skin rashes and/or mucous membrane lesions (sores in the mouth, vagina, or anus)
Syphilitic rash is characterized by diffuse non-pruritic maculopapular eruption on the trunk and extremities that includes the palms and soles.
Additional symptoms may include fever, swollen lymph glands, sore throat, patchy hair loss, headaches, weight loss, muscle aches, and fatigue.
Secondary Syphilis
Stage is a period of no visible signs or symptoms of syphilis.
Without treatment, the patient will continue to be infected but will not realize it.
Latent Stage
Rare and develops in a subset of untreated syphilis infections that appear 10–30 years after infection and can be fatal.
Cardiovascular syphilis
Neurosyphilis
- General paresis
- Tabes dorsalis
Gummatous syphilis
Tertiary syphilis
Diagnostic tests for Syphilis
Serologic test (the standard)
Nontreponemal tests (RPR)
Treponemal test (FTA-ABS) (confirmatory test)
Nonspecific Syphilis test, not definitive
Can be falsely positive (Lupus, mononucleosis, pregnancy)
Need to be confirmed with treponemal test
RPR
Standard treatment for all stages of syphilis
Penicillin G
Treatment for Primary Syphilis
Penicillin G 2.4 million units IM once
PCN allergy: Doxycycline 100mg PO BID x 14 days
Treatment for secondary syphilis
Penicillin G 2.4 million units IM once weekly for 3 weeks
Doxycycline 100mg PO BID x 4 weeks
An acute febrile reaction frequently accompanied by headache, myalgia, fever, that can occur within 24 hours after initiation of therapy for syphilis.
Reaction occurs most frequently among persons who have early syphilis, presumably because bacterial burdens are higher during these stages.
Jarisch-Herxheimer reaction
Trichomoniasis organism type
Anaerobic, flagellated protozoan PARASITE
Trichomoniasis scientific name
Trichomoniasis vaginalis
Incubation period for Trichomoniasis
5-28 days
T. vaginalis principally infects ______ epithelium in the urogenital tract
Squamous epithelium
Purulent, malodorous discharge, burning, pruritis, dysuria, dyspareunia
Physical exam: erythematous vulva, green-yellow malodorous discharge
Trichomonas
Trichomonas lab diagnostic tests
Wet mount prep
NAAT
Treatment for trichomonas
Metronidazole 2g PO single dose or 500mg BID x 7 days
No alcohol consumption during treatment and 24 hours after completion
Trichomonas
Abstain from sex until they have been treated and asymptomatic for __ days
7 days
HSV scientific name
Human alphaherpesvirus 1 & 2
Incubation period of HSV
2-12 days; average is 4 days
Severe. painful genital ulcers
Dysuria
Fever
Local inguinal lymphadenopathy
Primary infection HSV
Unilateral small vesicular lesions on erythematous base or ulcerative lesions “dew drops on a rose petal”
May have mild tingling or shooting pains in buttocks and legs prior to recurrent episode
Recurrent HSV infection
Acute treatment for Primary HSV infection
Acyclovir 400 mg orally TID for 7–10 days
Acyclovir 200 mg orally five times a day for 7–10 days
Valacyclovir 1 g orally BID for 7–10 days
Famciclovir 250 mg orally TID for 7–10 days
Reactivation of HSV can be triggered by:
Stress, menstruation, anxiety
Scientific name of HPV
Human papilloma virus
Most common strains of HPV causing anogenital warts
Types 6 & 11
HPV strains that are high-risk subtypes for developing a malignancy
16 & 18
Most common STD in the world
HPV
Incubation period for HPV
2 weeks to 1 year
Anogenital lesions may be found on the penis, vulva, vagina, cervix, perineum, and the anal region.
-Usually appear as raised, skin-colored, fleshy papules that
range in size from 1-5 mm.
-They can be broad and flat, pedicled, or occasionally have a cauliflower-like appearance
HPV
HPV Treatment
Topical therapies
Cryotherapy
Surgical excision
HPV treatment should be pursued if:
Lesions that persist for more than two years if the lesions are symptomatic, or for cosmetic purposes.
HPV topical therapies
Imiquimod cream
Podophyllotoxin Solution
HPV treatment
Inexpensive, minimally painful, and safe during pregnancy
Weekly treatment for 6-10 weeks.
Cryotherapy
HPV therapy that has a clearance rate near 100%
Surgical excision
HPV
Infection is preventable with:
Vaccination (Gardasil)
Who should get vaccinated against HPV?
All females and males 11-26 years of age
9 of every 10 cases of cervical cancer are caused by:
HPV
HPV can cause what types of cancer?
Female: Cervix, Vagina, Vulva
Male: Penis
Scientific name for HIV
Human immunodeficiency virus
Subtypes of HIV
HIV-1 & HIV-2
Incubation period for HIV
2-4 weeks
Untreated survival timeframe for HIV
9 to 11 years
Sex workers have a __x higher infection rate of HIV than the general population
12x
The acute phase of HIV infection is called:
Acute Retroviral Syndrome (ARS)
Fever, maculopapular rash, arthralgia, myalgia, malaise, lymphadenopathy, oral ulcers, pharyngitis, and weight loss.
The presence of fever and rash have the best positive predictive value
Acute Retroviral Syndrome (acute phase of HIV)
HIV laboratory testing
Screening test: OraQuick ADVANCE Rapid HIV-1/2 Antibody test
Confirmatory test: 4th Gen HIV immunoassay
HIV PrEP
Pre-exposure prophylaxis
HIV PrEP Guidelines
DHA IPM 18-020: Guidance for HIV (PrEP) for Persons at High Risk
Initiation of PrEP requires:
Negative 4th gen HIV test within 7 days if infection is not suspected
Negative 4th gen HIV test & Nucleic Acid Test within 7 days if infection is suspected
HIV PEP
Post-exposure Prophylaxis
Medication type that has improved life expectancy for HIV patients
ART
HIV in Military Service Members instruction
DoDI 6485.01
DoDI member with HIV
Clinical evaluations required by military infectious disease physicians at least every ____ months after diagnosis
6-12 months
