what bacteria cause the most TB in the US? what are 4 other bacteria that can cause it?
what are the two populations of people that TB can be divided by?
hight risk for becoming INFECTED with TB
high risk for DEVELOPING TB DISEASE
what are 7 things that can put someone at high risk for TB INFECTION (not disease)
1. close contact
2. foreign born
3. low income and homeless
4. health care workers in high risk groups
5. racial and ethnic minorities
6. infants, children and adolescents
7. IV drug users
name five areas of the world where TB is common?
4. eastern europe
5. latin america
what groups of people are at risk for developing TB disease!? (7)
1. people with HIV (thats why prevalence increased in the 80s)
2. infection of TB within last two years (5% risk, and 10% lifetime)
3. infants and children
4. prolonged therapy with corticosteroids
5. IV drug use
what is the greatest risk factor for devloping TB?
HIV!!! 7-10% risk for devloping TB disease each year when infected with both TB and HIV
are people with LTBI infectious? what percent of these people will go on to develope the disease?
no they aren't infectious!!
10% will go on to develope disease!
Explain the pathogenisis steps for TB (5 steps)
1. tubercle bacilli are inhaled and travel to alveoli
2. multiple in alveoli, infection begins
3. small number of tubercle bacilli enter bloodstream and spread throughout body
4. within 2-4 weeks macrophages survive bacilli, form a barrier shell that keeps the bacilli contained and under control know as LBTI
5. if the immune system can't keep tubercle bacilli under control, they multiple rapidly and cause TB DISEASE *it can occur in other places in the body too*
Is LTBI treated with medication?
YES IT IS
you want to prevent these patients from getting it in the future!!!
who is high priority treatment for LTBI with a TST >5 mm or postitive IGRA? (5 things)
1. close contacts of those with infectious TB disease
3. chest xrays indicating previous TB
4. organ donor transplants
5. immunocomprimised patients
who is high priority for LTBI treatment >10 mm or positive IGRA test? (5 things)
1. people who came to US within last 5 years where TB is common
2. IV drug users
3. live or work in high risk facilities
4. micro labatories
what are the two ways HIV can influence the path of TB?
1. person with LTBI becomes infected with HIV and then developes TB disease as the immune system is weakened
2. a person with HIV becomes infected with TB and rapidly developes the disease
multi-drug resistant TB is resistant to which drugs?
isoniazid and rifampin (2 first line drugs avaliable)
extensively drug resistant (XDR-TB), what drugs are they resistant to?
isoniazid and rifampin, PLUS fluoroquinolones and at least 1 of the 3 second line drugs
**this is a major issue around the world**
how long should a patient be treated for TB?
what if this person has pos sputum after 2 months of treatment?
at least 6 months
if cavities on chest xray and postitive sputum cultures at 2 motnhs then treatment should be extended for 9 months
what are the three phases of TB infection treatment?
1.initial phase: first 8 weeks of treatment, four drugs are used
isoniazid, rifampin, pyrazinamide, ethambutol
2. continuation phase: after first 8 weeks of treatment, bacilli remaining after initial phase are treated with at least two drugs
3. relapse phase: occurs when treatment is not continued for long enough, surviving bacilli may cause TB disease at a later time
in order to prevent drug resistance, TB disease must be treated with at least how many drugs?
2 ones the organism is suseptible to
what are the classic symptoms assosicated with TB (clinical and xray)?
coughing >3 weeks
pleuritic chest pain
infiltrates (collection of fluid and cells in lung tissues)
cavities (hollow spaces within lung usually in the upper lobe)
caseating granuloms on biopsy (necrotizing granulomas)
what tests do you use to diagnose TB?
1. tuberculin skin test (TST)
2. interferon gamma assays (IGRAS)-measures immune response to m. tuberculosis, less likely to be incorrect compared to TST
3. culture with AFB staining
-need 3 specimens, 8-24 hour collection intervals, can induce with inhaling saline mist spray
4. chest x-ray (infiltrates and cavities)
5. nucleic acid amplification test
6. bronchoscopy or gastric wash if having hard time getting sample
explain the tuberculin skin test? what can't this test do? what are positive test results for the three groups of people?
in lastent infection positive 2-4 weeks after infection
-injected with inactive tubercle bacilli, read within 48-72 hours
**this test can't differentiate between latent and active TB, just that a person has been infected at some point**
Positive test results:
15 mm in normal patients
10 mm in immigrants, children
5 mm in HIV, immunsuppressed, positive chest xray, primary TB exposure
explain the difference on chest xray between primary and reactivated TB?
primary: homogeous infiltrates, hilar/paratracheal lymph node englargement, middle/lower lobe consolidation
reactivation: fibrocavity apical disease, nodules, infiltrates **TB reactivation presents at the top of the lungs instead of wher eit happened originally**
what is the gold standard for TB testing?
acid fast bacilli tests
3 negative tests are considered negative!!
how long should a person be isolated and on treatment before being allowed in public when they have TB?
need to be isolated for a minimum of 2 weeks
what are the four drugs you use during the initial treatment phase for TB? what are their side effects? how do you treat someone if they have been exposed to someone with active TB? what is the treatment regiment for LBTI?
1. rifampin (hepatitis, flu, orange body secretions)
2. isoniazid (hepatitis, periphreal neuropathy, give B6 to prevent risk)
4. ethambutol (optic neuritis)
**for LBTI: treat with isoniazid and pyrazinamide for 9 months, or 12 months if HIV pos or granulomas present on CXR**
**if someone is exposed to patient with active TB, then treat them emipircally for 12 weeks until negative TB can be obtained**
In TB, explain the differences between LTBI and TB disease in these characteristic:
1. active/inactive bacilli
2. chest xray findings
3. sputum smears
6. a case of TB or not
what should you connect Ghon complexes and Ranke complexes? what are they?
ghon complexes: calcified primary focus
ranke complexes: calcified primary focus and hilar lymph nodes
**these represent healed primary infection**
**what is the highest risk group for HIV infection***
men having sex with men
what are the two receptors HIV uses to get into the cell?
CCR5 and CXCR4
explain the structure of the HIV virus? why does it mutate quickly?
1. RNA virus
2. glycoprotein 120 and stem gp14
3. viral protein p24 core antigen
4. CCR5 or CXCR4 receptors
****MUTATIONS OCCUR QUICKLY SINCE THE RNA POLYMERASE USED TO MAKE THE DNA TO INSERT INTO THE HUMAN DNA ISN'T GOOD AT ITS JOB AND OFTEN THERE ARE COPYING ERROS LEADING TO MUTATIONS***
what are the two strains of HIV and where are they found?
HIV1: most common in the US "M strain"
HIV2: Africa, less aggressive
what cells does HIV infection?
CD4 Helper T cells
also monocytes and macrophages because they have the CD4 receptor
briefly explain the differences between HIV and AIDS?
HIV is in the infection
patient is usually asymptomatic or minimally symptomatic and the infection hasn't yet effected the persons immune system yet
HAVING HIV DOESN"T MEAN YOU HAVE AIDS
when the persons immune system has become compromised and the CD4 cells have become significantly diminished
***Acquired immunodeficiency syndrome (AIDS)***
what are the 3 options the CDC defines this?
1. clinically: opprtunistic infections effect patient that wouldn't otherwise if the pt wasn't immunocomprimised
2. biomedically: CD4 count less than 200
3. historically: at some potin in the past ever had opportunistic infections or a CD4 count lower than 200
**must have one of these qualifications but you don' thave to have all of them***
what is the percent chance of contracting HIV from a needle stick?
how is HIV transmitted?
vertical- mother to child
parenteral- injection drug users
what racial group have the highest burden of HIV/AIDS?
what are the four stages of HIV infection?
stage 1 primary
stage 2 asymptomatic
stage 3 symptomatic with viral replication
stage 4 AIDS
stage 1 HIV
when does this occur?
6 weeks after infection
stage 2 asymptomatic
how llong does this last?
what might they have?
lasts 10 years
free of symptoms
possible swollen glands
levels of HIV in blood drop to low levels
HIV antibodies are detectable in the blood
stage 3 HIV
symptomatic with viral replication
when odes this occur?
what are theu suspectible to?
at what CD4 level are HIV patients susceptible to opportunistic infection??
after 10 years viral replication is triggered at a high rate
CD4 cells destroyed in the process and the loss is significant
cause increase symptoms of HIV and increased susceptibility to opportunistic infections, disease and malignancy
**CD4 below 500 HIV infected pt is at risk for opportunistic infection**
in stage 3 HIV what are 4 diseases that can suggest the patient may progress to AIDS?
1. persistent herpes-zoster infection (shingles)
2. oral candidiasis
3. oral hairy leukoplakia
4. kaposi sarcoma
stage 4 HIV/AIDs
what is this characterzied by?
what 2 CD4 levels suggest progression to stage 4?
what are disease that a person can be susceptible for both?
immune system significantly weakened
1. CD4 less than 500
2. CD4 less than 200
what is the order of tests you order if suspecting HIV in patient??
what do they tell us?
what test don't we use anymore?
1. TOC #1: 4th Gen
HIV-1 and HIV-2 IgG
and IgM plus HIV-1 p24 Antigen
**tests antigen so can be detected earlier, 2-3 weeks after infection**
*if postitive then move onto next!!!!
TOC #2 if previous postivie: Multispot Or RNA PCR
**distinguishes between presence of HIV1 or HIV2**
***this testing algorithm is more accurate, faster, and less expensive than previous so not longer use western blot**
are there at home HIV tests?
HIV-1 test system
(prick finger, mail it in..wait a week)
what should you do if someones at home screening test is positive?
1. order 4th gen HIV1/2 IgG/IgM/p24Ag
2. multispot HIV1
3. order quantitative HIV-1 PCR to get viral load!!!
what should you continue to monitor in HIV/Aids patients every 3-6 months?
1. viral load
2. CD4 levels
what are the 5 tx options reccomended to HIV?
4 integrase strand transfer inhibitor (INSTI)-based regimens
1 ritonavir-boosted protease inhibitor-based regiment
Years ago, some patients and providers made the decision to delay initiation of HIV therapy with the thought that later treatment would reduce total medication exposure and decrease adverse effects.
Do we still follow these guidlines or suggestions?
data suggesting that earlier therapy improves long-term immune function
what is the HAART tx for HIV?
4 drug classes
highly active anti-retroviral tx
1. Fusion inhibitors
2. nucleoside/nucleotide reverse transcriptase inhibitors
3. non-nucleoside reverse transcriptase inhibitors
4. protease inhibitors
*****combination of 3 active anti-retrovirals****
what are the goals of HIV treatment? (4)
1. supress HIV viral load
2. reconstitiute the immune system and get CD4 levels back
3. prevent reistance
4. prevent future infections
what is the post-exposure DOC for HIV?
when do you give it?
truvada plus raltegravir
started ideally 1-2 hours after exposure but must be within a minimum of 72 hours for best results
tx for 28 days, but high risk groups can start up to 2 weeks post exposure
***goal: prevent initial infection with antivirals!!!***
***pre-exposure HIV prophlaxsis***
who is this given in?
what does it do?
name of the drug?
how many times must you take it for it to be effective?
given to someone with partner who has HIV or someone who plans to participate in sexual activity with someone with HIV and wants to protec thtemself
PrEP is generally well-tolerated and can be dramatically successful
that early HIV treatment can reduce the risk of transmitting HIV to the uninfected partner by 96%.1
TRUVADA can prevent transmission!!!! must be take more than or equal to 4 times a week!!!!!
***who does the CDC reccomend get tested for HIV***
CDC reccomends everyone age 13-64 to be tested at least once
1. everyone who presents with symptoms of STD should be tested at that visit
2. testing anyone that starts new relationship
****what is the reccomendations for HIV testing in gay or bisexual testing for HIV?****
For individuals who identify as gay or bisexual testing every 3-6 months may be beneficial.
but AT LEAST ANNUALLY
***explain the life expectancy of someone living with HIV?***
life expectancy for those living with HIV has increased to approximately the same as that for HIV negative individuals
***what does HIV treatment regimen consist of?***
regimens must consist of 3 or more active agents from multiple medication classes
many pills have a combination of multiple drugs in them to increase compliance
**when should post exposure prophylaxsis be started***
within a minimum of 72 hours for best results!!!
what does this come from?
who is it common in?
what is the 4 most common causes?
what is the most common?
what are 3 symptoms?
what are 4 tx considerations?
fecally contaminated water and food
more common in younger people
MOST COMON BACTERIA, then parasites
MOST COMMON: E.coli, shigella/salmonella, campylobacter, viral
1. abrupt onset of loose stools
2. abdominal cramping
3. rectal urgency
1. typically self limited
3. fluoroquinolones, short 3 day course
is prophylaxsis reccomended for travelers diarreah?
nope it is not...
but you can consider prophylaxsis in special situations with
what are 5 preventative measures you can take to prevent travelers diarreah?
1.avoid street vendors
3. raw or undercooked meats/seafoods
4. avoid raw fruits, vegetables
5. avoid tap water, ice and dairy products
what is the most common E.coli for what we think of as e. coli?
shigella toxin-producing (STEC) also called "enterohemmorrhagic"
E. COLI0157 is the one that we usually think of when taking about e.coli outbreak!!
what is the most common cause of travelers diarreah?
3 sxs? and duration?
3. assocaited with abdominal cramping
4. 5-10 duration
supportive unless severe
what is the main bacteria that causes this?
what is it most common in?
what does it break out across states?
what are the 3 types?
salmonella typhimurium MC
POULTRY MC!!! can also include leafy greens, beef, dairy, nuts
****MULTISTATE OUTBREAKS COMMON since found in animal flocks and herds***
1. enteric fever, TYPHOID FEVER
enteric fever salmonellosis
"enteric fever/typhoid fever"
where are the 3 places this replicates?
is there a prodrome?
what happens as fever develops? (5)
DX (what to keep in mind)?
Tx: 2 abx and for how long?
replicate in peyer patches, mesenteric lymph nodes, spleen
prodrome: malaise, headache, cough, sore throat
as fever developes: (peaks 7-10 days)
1. abdominal pain/distension
2. pea soup poop
5. rash pink papules primarily on trunk during 2nd week
1. blood sample
+ during first week
- after first week
what is the incubration?
what are the 5 sxs and msot important?
most common form of salmonella infection!!
incubation 8-48 hours after ingestion of infected food or water
bloody diarreah 3-5 days!!!!
what does this cause?
what are 5 sxs associated with this?
what are the 2 ways to dx this and what do you see?
what are 2 tx options?
1. starts abruptly with diarrhea
2. lower abdominal cramps
3. tenesmus with fever chills
4. loose stools with mixed blood and mucous
5. tender abdomen
2. sigmoidoscopy with punctate lesions, ulcers and inflammed mucose
what is the bacterial that causes this?
what does it cause in the body?
what does the pt present with?
what are the 2 tx options?
toxin activates adenylyl cylase in the intestinal epithelial cells in the small intesting causes hyper secretion of water and chloride ions with massive diarreah
"rice water stool" grey turbid diarreah and causes hypovolemia
1. stool culture for vibrio cholerae
`1. replace fluids and electrolytes sugar/salt water, severe use IV replacement
2. abx in severe cases
what are the 3 things you can do to prevent cholera?
1. clean water and food
2. proper waste disposal
3. vaccine but protection is temporary and booster is needed every 6 months