CC March 2016 Chagus Disease

echoecho's version from 2016-04-21 06:11


Question Answer
Chagus disease (CD) is a ______ infestation with acute and chronic implications?parasitic
It is the most common parasitic disease of the ______ hemisphere, and evidence of its presence in the prehistoric Andean populations has been found in archaeological studies?Western
The highest prevalence is in the _____ and _____ America, where the insect vectors and impoverished rural populations have contributed to its persistence?Central; South
Recently, the infection has spread to North America due to patterns of ______ to the US and Canada?emigration
It is well suited to a slow and steady penetration into the population due to the nature of its _____ _____?clinical course
As many as _______ infected individuals reside in the US, with up to _____% likely to develop significant, life-threatening complications?300,000; 30%
Chagus disease is also called what?American trypanosomiasis
CD is caused by what protozoan parasite?Trypanosoma cruzi
CD is most commonly spread through insect vectors in what group?triatomine group (e.g.: kissing bugs, assassin bugs)
These bugs have been reported in more than half of the _____ 48 states?lower
How is the organism inoculated?it is inoculated into an individual by the bite of the insect or ingestion of insect fecal material in contaminated food and water and can be transmitted vertically during pregnancy, as well as through blood and organ donation from an infected individual
CD has an incubation period of ___ to ___ weeks followed by a mild illness with what s/s?1) one to two 2) low-grade fever, fatigue, malaise and hepatosplenomegaly
What 2 s/s are infrequently seen?1) painless swelling of the eyelids (Romana's sign) 2) nodular skin lesions
Untreated, the acute illness usually resolves in a few ____?weeks
Complications in the acute phases are rare but may be life-threatening. List two examples?1) meningoencephalitis 2) myocarditis
A healthy immune response clears the parasitemia in ___ to ___ weeks, but does not cure the infection?4 to 8
Unless treated, a _____ phase develops with lifelong asymptomatic infection, though as noted previously, complications may develop in up to ___% of chronically infected individuals?chronic; 30%
List the chronic cardiac complications?1) cardiomyopathy 2) arrhythmias 3) conduction system defects 4) congestive heart failure
List the gastrointestinal symptoms?affect the esophagus (e.g. motility disorders, achalasia and megaesophagus) or the colon (megacolon)
These alimentary problems result from damage to what?intramural neurons
Persistent, unrecognized infection raises concerns for what 2 medical procedures and has resulted in additional screening performed by the Red Cross since 2007?blood banking; organ transplantation
How is acute infection detected?1) blood smear identification of the parasite confirmed by PCR (polymerase chain reaction)
Most acute infections are not identified, why?due to the mildness and spontaneous resolutions of symptoms
Chronic infection is confirmed by what?positive PCR and/or serology detecting IgG
Why are making decisions regarding treatment of adults difficult?the mildness of initial infection and the apparent resolution making decisions
If detected in the acute phase, infection should be treated what 2 options?1) benznidazole 2) nifurtimax
Neither of the 2 above drugs is approved by the FDA, however, but are available through what institution?CDC under investigational protocols related to the Neglected Parasitic Infections program.
Is treatment with antimalarial drugs appropriate treatment for CD?no
Why are studies of incidence, prevalence and clinical progression lacking?because the number of identified infected individuals in this country is small
Many thousands of cases of _______ are likely to emerge from this group over the next decade?cardiomyopathy
***It is also unclear how effective treatment of CD will affect the ______ of its complications?prevalence
Why is congenital infection with CD now felt to be the most common mode of acquisition? as insect vector control and public health initiatives have reduced the primary source
What is the mode of transmission of congenital infection with CD?transmission occurs transplacentally through breaches in placental vessels
True or false? First trimester transmission is less likely than during the second and third trimesters or perinatally?true
*** List two factors that influence the maternal immune response?1) downregulation of tissue necrosis factor (TNF) OR 2) coinfection with HIV make transplacental infection more likely
CD infection during pregnancy may result in a slightly higher rate of what medical conditions?1) spontaneous abortion 2) premature rupture of membranes 3) low birth weights
Screening of pregnant women is widely performed in the endemic areas of _____ _____ and _____ ______ and is becoming more common in the US?Central America; South America
Congenital CD is often _______ (asymptomatic vs. symptomatic), but when acute disease occurs, it may present how?1) asymptomatic 2) with a variety of nonspecific symptoms or progress to devastating complications of meningitis and myocarditis
Suspected congenital infection is detected in the same method as _____ infection?acute
Where maternal or congenital infection is suspected, testing of any children at home is recommended, why?because they may harbor chronic asymptomatic infection
Treatment of infected newborns and young children is associated with fewer ____ _____ than treatment of adults and has been demonstrated to lessen the risk of chronic infection and cardiomyopathy?side effects
What is the preferred choice of medication? another medication which can also be used?1) benznidazole 2) nifurtimox
Treatment of the infected pregnant women is generally delayed until what?after pregnancy and conclusion of breastfeeding
Exceptions are made when what 2 complications are present (a few case reports have revealed no fetal injury)?1) cardiomyopathy 2) CNS complications
*** SUMMARY = Acute illness is usually mild and resolves even if _____?untreated
*** SUMMARY = Without treatment, a ____ phase occurs; most patients remain _____ (asymptomatic vs symptomatic) but ____% will develop complications?chronic; asymptomatic; 30
*** SUMMARY = _______ infection with CD is no felt to be the most common mode of acquisition?congenital