Micro Block 4 Flashcards
What does Treponema pallidum cause?
Syphilis
How is Treponema pallidum transmitted?
Direct contact w/ infectious chancre/lesion
What happens during Primary, Secondary and Tertiary Syphilis?
Primary: 10-90 days later, Avg 21 days
Painless chancre, small and firm
Lasts 3-6 weeks and “heals”
Secondary: 1-6mon later, rash
Tertiary: Multi-organ infection
What does Borrelia burgdorferi cause?
Lyme disease
What is Borrelia burgdorferis transmission vector?
Prolonged bite from Deer Tick
What are the clinical S/Sx of Borrelia burgdorferi?
Early stages are asymptomatic
Skin- red macula/papula > 5cm
erythema migrans
Neuro/Cardio- Encephalitis, facial palsy
What is the transmission method of Leptospira interrogans?
Contact w/ contaminated urine, water or soil
What animals can carry Leptospira interrogans?
Rats Swine Badgers Rodents Deer Fox
What are the clinical S/Sx of Leptospira interrogans?
Headache Myalgia Chills Conjunctival stuff Renal/liver failure
What is the Gram stain and cell shape of Burkholderi spp?
GNB
Where is B. pseudomallei an endemic?
Southeast Asia
N. Australia
South Pacific
How is B. pseudomallei transmitted?
Contaminated soil and surface water
What clinical S/Sx does B. pseudomallei cause?
Acute pulmonary infection
Acute localized infection (ulcer, nodule, abscess)
Septicemia
Multiple organ involvement
B. pseudomallei symptoms may lay dormant for how long? B. pseudomallei symptoms may show as early as?
Years
2-4wks
Burkholderia mallei is closely related to what microbe?
B. pseudomallei
What does B. mallei cause?
Glanders disease in horses
Where is B. mallei an endemic?
Africa Asia Middle East S America Eradicated from N America and Europe
Transmission of B. mallei to humans is rare but can occur through what transmission?
Contact w/ blood/body fluids into abrasion
What does B. mallei effect in humans?
What is it’s mortality rate?
Lungs, airway Septicemia Cutaneous lesions Liver Spleen Fever 95% untreated, 50% treated
What does B. cepacia cause?
Infrequent
Pneumonia in compromised/CF pts
What is the Gram stain, cell shape and air requirement of Peptostreptococcus?
GPC chains anaerobe
What does Peptostreptococcus cause if translocated?
Necrotizing soft tissue infections
PID
Bone/joint infections
What is the Gram stain, cell shape and air requirement of Fusobacterium?
GNB anaerobic
What kind of infections does Fusobacterium cause?
Peridontal
Skin
What is the Gram stain, cell shape and air requirement of Faecalibacterium?
GPB NSF Anaerobe
What microbe is an important component of probiotics?
Bifidobacterium
What is the Gram stain, cell shape and air requirement of Bifidobacterium?
GPB branch NSF anaerobe
Where is Bifidobacterium considered to be normal bacterium?
Gut
Vagina
Mouth
Myxovirus is an etiologic agent of what?
Influenza
What is the incubation and symptom times for Myxovirus?
Incubation: 1-2
Symptoms: 5-7 days (cough: 7-14 days)
Myxovirus cause what percentage of viral pneumonia admissions?
10% w/ high mortality
Secondary Bacterial Pneumonia can sometimes follow what type of infection?
Viral URT infection
How is Myxovirus transmitted?
Droplets
Contact
Inhalation of droplets
What is the structure of the Myxovirus?
Enveloped RNA w/ 8 strands Lipid bilayer from previous host Hemagglutinin Neuraminidase- for attachment/virulence Matrix protein- capsid
What are the antigenic types of Myxovirus?
A B C
Animal strains of Myxovirus are based on what?
Original source of viral envelope
What is Type A Myxovirus?
Human: H3N2, H1N1
Swine: H1N1
What is a characteristic of Myxovirus Antigen Types B and C
Antigenically stable
What are the virulence factors of Myxovirus?
Gene recombination/mutation Hemagglutinin Neruaminidase Animal specific envelope Surface Ag changes Viral Envelope adaptations to enter and replicate in human cells
What are the treatment/vaccine options for Myxovirus?
Antiviral meds avail and effective in first 48hrs
Vaccine for most common 3 Ags
Vaccine predicted by WHO, DoD and CDC
Rhino/Resp Syncytial Virus/Corona virus are all what type of nucleic acid virus?
RNA enveloped
What is the most primary cause of the common cold?
1 in infants- Syncytial Virus
#1- Rhino Virus #2- Corona
Rhino virus has ___ Ag types?
Corona virus has __ Ag types?
160+
30
What does the Corona virus cause?
SARS- 30% mortality
MERS CoV- Middle East Resp Syndrome Corona Virus
Where is MERS-CoV predominantly located?
What animal is the carrier?
Jordan
Saudia Arabia
Camels
Respiratory Syncytial Virus is AKA ?
Human Orthopneumovirus- primary agent in infants/young children
How is the Resp Syncytial Virus transmitted?
Contact
Droplets
Inhalation of droplets
What type of viral particle is the Parainfluenza virus?
Enveloped RNA
What does Parainfluenza virus cause?
Croup
Bronchitis
Cold-like S/Sx
Especially in children
What is the virus type of the Human Metapneumovirus (hMPV)?
Enveloped RNA
What does Human Metapneumovirus (hMPV) cause?
Common cold
Bronchiolitis
Pneumonia
Croup
When do Human Metapneumovirus (hMPV) outbreaks usually occur throughout the year?
Late winter-early spring
What is the incubation/shedding period for Human Metapneumovirus (hMPV)?
Incubation: 3-5
Shedding: weeks
What PT population is Human Metapneumovirus (hMPV) more predominant in?
Young children
Human Metapneumovirus (hMPV) S/Sx are similar to what other virus? Why is there a similarity?
RSV, same taxonomic family
What type of virus is Adenovirus?
Non-enveloped DNA
What is Adenovirus an etiologic agent of?
5-10% of all viral infections
50% of all infections before 5y/o
What patient population is hit heavily by Adenovirus?
Military recruits
Acute Respiratory Disease
What is Adenovirus an etiologic agent of?
Acute Respiratory Disease Conjunctivitis Atypical Pneumonia Cold-like disease GI disease Croup/bronchitis Cystitis
What Ag types is the Adenovirus vaccine good for?
Types 4 and 7
What kind of virus is Herpes Virus?
Large Enveloped DNA
What are the S/Sx of Herpes simples Types 1 and 2
Fever Blisters Cold Sores Gingivostomatitis Keratoconjunctivitis- neonate/contact lens Genital lesions Meningitis
What is Herpes Zoster?
HZV, chicken pox and shingles
How is chicken pox acquired?
Respiratory tract
What is the difference in lesions between chicken pox and shingles?
CP- vesicle-type lesions, large
S- small, closely spaced
What does Epstein-Barr Virus cause?
How does it do this?
Mononucleosis
Transmitted by oral secretions and infects B cells
How is Epstein-Barr virus brought out of latency?
Reactivated (switched to lytic cycle) upon B cell stimulation for other, non-related infection
What does Cytomegalovirus cause?
Congenital Cytomegalic Inclusion Disease in children
Occasionally: CMV mononucleosis w/ microcephaly, jaundice and multiple organ involvement
CNS impairment= growth/mental retardation
CMV is a latent viral infection within what type of patient population?
Immunosuppressed
Immunocompromised
Transplant/cancer/AIDS
S/Sx of CMV infection in immunocompromised PT?
Febrile mononucleosis Pneumonitis Hepatitis GI ulcers Encephalopathy
Severity of a CMV infection is directly related to what?
Strength of CMI
What type of virus is the Rotavirus?
RNA w/ 8 species (A-H)
Rotavirus is the most common cause of what illness in what population?
Severe epidemic diarrhea in infants/young children
Rotavirus A=90%
How is Rotavirus transmitted?
Fecal-oral
What kind of virus is the Norwalk virus?
Non-enveloped RNA virus
Norwalk virus is the only species within what genus?
What is the appropriate nomenclature for this virus?
Genus Norovirus
Norwalk virus is preferred
What is Norwalk virus the major worldwide cause of?
Epidemic/sporadic viral gastroenteritis
Causes 90% of epidemic non-virall gastroenteritis
What populations/areas are susceptible to Norwalk virus?
Schools
Camps
Cruise ships
What is the incubation time for Norwalk?
How long do the S/Sx last?
Incubation= 18-48hrs S/Sx= 12-60hrs
How is Norwalk transmitted?
Food
Water
Vomit
What geographical locations are hot spots for HIV?
Southern Africa
South/SE Asia
What viral group does HIV belong too?
What kind of virus is it?
Retrovirus
Medium enveloped RNA
What are the characteristics/make up of the HIV envelope?
Glycoprotein 41
Glycoprotein 120
Ag variable
What kind of protein makes up the HIV capsid?
Protein 24
What is the core make up of the HIV particle?
2 RNA strands
Reverse transcriptase
What are the two Ag types of HIV?
What geographical locations are they predominantly found?
HIV 1- worldwide
HIV 2- West Africa
What are the steps of infection for HIV->cell?
1- GP120 attaches to CD4 marker, GP41 attaches to CXCR4
2- RNA enters host cell
3- Reverse transcriptase
4- New DNA incorporates with host DNA and alters CD$ ability to produce cytokinase
5- New virons released kill CD4 cells
How does HIV infect a cell if there are no CD4 markers present?
Co-infect w/ another retrovirus
What types of cells are infected by HIV?
CD4 helper T cells
Monocytes- macrophages
HIV virons have been isolated from what types of cells?
Sperm
Blood
Perinatally
What is Stage I of HIV infection?
Primary HIV infection, lasts 1-4mon Virus is replicated and shed P24 Ag detectable, Abs for P24 present Mononucleoside/flu-like S/Sx Asymptomatic after 1-3wks
What is Stage II of HIV infection?
Latent/Asymptomatic Period
Virus replication/shed at low rate
HIV Abs detectable, CD4 levels decrease
What is Stage III of HIV infection?
Persistent Generalized Lymphadenopaty/AIDS related Complex Virus replication/shedding a high rate Lymphodenopathy Kaposis Sarcoma Opportunistic infections
What is Stage IV of HIV infection?
AIDS symptomatic period
Decreased CD4, moderate decrease in CD8 cells
Ag P24 appears, viral replication overwhelms CMI
What are the opportunistic infections seen during Stage IV of HIV infections?
TB Pneumocystitis carini Fungal infections Toxoplasmosis gondii Herpes simplex Cryptosporidium Cytomegalovirus Mycobacterium avian complex CNS involvement- dementia
What are the S/Sx of a hepatitis infection?
Anorexia Weight loss Hepatic tenderness Jaundice Dark urine
What is the viral structure of Hepatitis B Virus (HBV)?
Enveloped DNA
Core- DNA and DNA polymerase
Which HBV Ag presence is associated with relatively high infectivity?
HBeAg
“e” antigen of the core
How is HBV transmitted?
Parenteral route is most predominant
Contact w/ blood
Needles/syringes
What PT population is at high risk for HBV?
IV drug users
Prison populations
What is the incubation time frame for HBV?
45-180 days
Define seroconversion
Immune response of convsersion from absence of a specific Ab to presence of specific Ab
What is the earliest marker of an acute/infectious state of HBV?
HBsAg
Hepatitis B surface Ag
Persistence of HBsAg over __ months implies chronic disease/failure to seroconvert?
6mon
What does HBeAg in HBV indicate?
Early indicator of acute infection
Active virus replication
Most infectious period
Persistence +10wks indicative of chronic carrier state/chronic liver damage
What does Anti-HBs surface Ag indicate?
Convalescence- recovery and immunity
Failure to seroconvert indicative of chronic infection
What type Ag in HBV PTs indicates recovery and immunity?
Anti-HBs
Antibody to Hepatitis B Surface Ag
Major protective Ab against HBV
Develops from Vaccine