bacterial infection (S-Y) Flashcards
how are Salmonella serotypes be categorized?
-typhoidal (typhoid & paratyphoid fever) - Typhi, Paratyphi A, tartrate negative Paratyphi B, Paratyphi C
-nontyphoidal (acute diarrhea)
how are the Salmonella (nontyphoidal) transmitted?
animal reservoirs (domestic and wild)
- eating contaminated foods (dairy, eggs, meat, raw produce)
- drinking contaminated water
- contact with people who have a diarrheal illness
what increases the risk of nontyphoidal salmonella infection after exposure?
taking AB or antacid medication
what are the symptoms of nontyphoidal salmonella infection?
acute diarrhea (incubation 12-96 hours, but it can be more than 7 days)
abdominal cramps, fever, usually resolves without treatment after 1-7 days
what % of people develop bacteremia or focal invasive infection (osteomyelitis, meningitis, endovascular infection, septic arthritis) from nontyphoidal salmonella infection?
5% (higher among infants, older adults, immunocompromised)
ppl with atherosclerosis, hemoglobinopathies, or maligantn neoplasms - increased risk for extraintestinal infection
how to diagnose nontyph salmonella infection?
culture (routine stool culture, abscesses, blood, CSF, urine)
how to treat salmonellosis?
- most just supportive care - rehydration therapy
- AB not recommended for most with uncomplicated salmonellosis (does not shorten the duration of illness and can prolong bacterial shedding)
who should get AB treatment for salmonellosis?
Consider antibiotic therapy for patients with suspected invasive disease (e.g., patients with severe diarrhea, high fever, manifestations of extraintestinal infection) and for patients at increased risk for invasive disease (e.g., infants, older adults, people who are immunocompromised, patients with known atherosclerosis). For these populations, treat infections empirically until susceptibility results are available.
which empiric AB drug should be used for salmonellosis?
fluoroquinolones in adult travelers (resistance rising globally)
ceftriaxone - children and adults with invasive disease (resistance rare)
azithromycin can be used for children and is an alternative agent for adults
what causes tetanus?
Clostridium tetani - spore-forming, anaerobic, gram positive
tetanus is more common in which area?
in rural and agricultural regions; areas where contact with soil or animal excreta is likely; warm and moist environments; and areas where immunization against tetanus is inadequate.
which countries have not achieved maternal and neonatal tetanus elimination?
Afghanistan, Angola, Central African Republic, Guinea, Mali, Nigeria, Pakistan, Papua New Guinea, Somalia, Sudan, South Sudan, Yemen
what is average incubation period for tetanus?
- incuation on average 10 days (3-21 days)
- duration of the incubatino period is inversely related to the severity of symptoms –> shorter incuation = riskier
how do you classify tetanus symptoms?
generalized, localized, and cephalic
generalized: >80%, lockjaw, generalized spasms, risus sardonicus, opisthotonus
localized: muscle spasms confined to the injury site
cephalic: head or face wound and flaccid cranial nerve palsies
how does neonatal tetanus occur?
contaminated umbilical stumps and whose mothers are unimmunized or inadequately immunized
long term sequelae - behavioral, intellectual, and neurologic abnormalities
what is case-fatality ratios for generalized tetanus? localized tetanus?
25~100%
<1%
how to dianose tetanus?
clinical findings with epidemiologic support only
how to treat tetanus?
- tetanus immune globulin (TIG)
- aggressive wound care and debridement
- supportive care
- AB 7-10 days: metronidazole; alternative is IV penicillin G
- must be hospitalized in a quiet, dim room to minimize spasms
Under 7 years, which tetanus vaccine is available? how many doses for children?
DTaP (diphtheria-tetanus-acellular pertussis)
DT (diphtheria-tetanus)
Infants/children - 5 doses of DTaP at 2, 4, 6, 15-18 months, 4-6 years
from 10 years old, which tetanus vaccine is avaialbe?
-Tdap (tetanus-diphtheria-acellular pertussis)
-adolescent shoudl receive 1 dose of Tdap at 11-12 years of age
-Children 7 and up can receive Tdap for catch-up vaccination
for pregnancy what is the indication of tetanus vaccination?
27-36 weeks’ gestation
unvaccinated pregnant people should receive 2 doses of TTCV during their pregnancy
what is contraindication & precaution of tetanus vaccination?
- encephalopathy without an identifiable cause occurring within 7 days of a previous dose of DTP, DTaP or Tdap - for the pertussis component of the vaccines; can receive either DT or Td
- progressive or neurolgic disorder due to pertussis component
when do you get tetanus vaccination for wound management?
when do you get tetanus TIG for wound management?
TTCV: history of tetnus vaccine unknown or less than 3 previous doses
TIG: history of tetanus vaccine unknown or less than 3 previous doses and the wound is not clean/minor wound.
what is the causing agent of tuberculosis?
Mycobacterium tuberculosis complex - rod-shaped, nonmotile, slow-growing, acid-fast bacteria including M. bovis and M. tuberculosis hominis
how is the TB transmited?
- coughs, through the air
- unpasteurized dairy products from infected cattle (bovine TB - caused by M. bovis)
what is multidrug-resistant TB resistant to?
at least the 2 most effective drugs - isoniazid and rifampin
how to diagnose TB?
8-10 weeks after exposure, do tuberculin skin test (TST) or interferon-gamma release assay (IGRA)
how much % of people who are infected with TB progress to TB disease?
If not progress to TB disease, what happens?
5-10%
-if not progress, it remains inactive (latent TB infection) – no symptoms, cannot spread the infection to others