Cryptosporidiosis Flashcards
What is cryptosporidiosis caused by?
Various species of the protozoan parasite Cryptosporidium
The three species that most commonly infect humans are C. hominis, C. parvum, and C. meleagridis.
What is the primary symptom of cryptosporidiosis?
Diarrhea
Infection typically causes diarrhea, especially in immunocompromised individuals.
What CD4 T lymphocyte cell count is associated with the greatest risk for severe cryptosporidiosis?
CD4 cell counts <100 cells/mm3
How does the incidence of cryptosporidiosis in people with HIV in high-income countries compare to low-income countries?
The incidence has decreased in high-income countries, now <1 case per 1,000 person-years.
How is cryptosporidiosis transmitted?
Through ingestion of Cryptosporidium oocysts
Viable oocysts can be transmitted from infected humans or animals.
What are common clinical manifestations of cryptosporidiosis?
Watery diarrhea, nausea, vomiting, lower abdominal cramping
Disease severity can range from asymptomatic to profuse diarrhea.
What diagnostic method is traditionally used to identify cryptosporidiosis?
Microscopic identification of oocysts in stool with acid-fast staining
What newer diagnostic methods are being increasingly used for cryptosporidiosis?
Antigen detection and polymerase chain reaction
These methods can identify more cases than traditional microscopic methods.
What is the recommended approach for preventing exposure to Cryptosporidium for people with HIV?
Education on transmission methods, handwashing, avoiding contaminated water or food
True or False: Cryptosporidium oocysts are resistant to chlorine.
True
What should people with HIV do to minimize the risk of cryptosporidiosis while swimming?
Avoid swallowing water and swimming in potentially contaminated water
What is the recommended action during municipal water supply outbreaks?
Boil water for at least 1 minute
Fill in the blank: The preferred management strategy for cryptosporidiosis includes aggressive _______ and electrolyte replacement.
rehydration
What is the role of antiretroviral therapy (ART) in managing cryptosporidiosis?
Initiating ART helps achieve immune restoration and resolve clinical cryptosporidiosis
What is the recommended treatment regimen for cryptosporidiosis in adults?
Nitazoxanide 500 mg to 1,000 mg PO twice daily for at least 14 days
This should be combined with optimized ART and symptomatic treatment.
What should be avoided in late pregnancy when treating cryptosporidiosis?
Tincture of opium
What dietary restriction is recommended for individuals with cryptosporidiosis?
Avoid milk products
Diarrhea can cause lactase deficiency.
What is the response rate of paromomycin in treating cryptosporidiosis?
67%
However, few cures were reported, and relapses were common.
What should people with HIV traveling to low-income countries avoid?
Drinking tap water or using it to brush teeth
What is the effect of rifabutin and clarithromycin in relation to cryptosporidiosis?
They have been found to protect against cryptosporidiosis
What was the response rate of paromomycin in a meta-analysis of 11 published studies in humans?
67%
However, there were few cures and long-term success rates were only 33%
What common issue was reported in patients treated with paromomycin?
Relapses were common
Long-term success rates were only 33%
What is the effectiveness of paromomycin compared to placebo in patients with AIDS and cryptosporidiosis?
Limited effectiveness
Demonstrated in two randomized trials
What may improve the response rate in patients receiving paromomycin?
ART (antiretroviral therapy)
Suggested by one case series
Should paromomycin be used instead of nitazoxanide?
Yes, in conjunction with ART but never instead of ART
Classified as CIII recommendation
What should patients with cryptosporidiosis be offered as part of initial management?
ART
Classified as AII recommendation
Can HIV protease inhibitors inhibit Cryptosporidium in animal and in vitro models?
Yes
No clinical evidence supports PI-based ART as preferable in patients with documented cryptosporidiosis
What should patients be monitored for during therapy?
Signs of volume depletion, electrolyte imbalance, weight loss, and malnutrition
Monitoring for IRIS is also important
What has been described in association with extraintestinal cryptosporidiosis?
Immune reconstitution inflammatory syndrome (IRIS)
Observed in three cases
What are the main approaches to managing treatment failure in cryptosporidiosis?
Supportive treatment and optimization of ART
Achieving full virologic suppression is key
What should guide the response to therapy in treatment failure?
Clinical response rather than stool test results
Some advocate adding antiparasitic drugs
Are there any known pharmacologic interventions effective in preventing the recurrence of cryptosporidiosis?
No
No known effective pharmacologic interventions
What are the mainstays of initial treatment of cryptosporidiosis during pregnancy?
Rehydration and initiation of ART
Same as for nonpregnant individuals
Is pregnancy an indication for ART?
Yes
Pregnancy should not preclude the use of ART
Is nitazoxanide teratogenic in animals?
No
However, no data on use in human pregnancy are available
When can nitazoxanide be used in pregnancy?
After the first trimester in people with severe symptoms
Classified as CIII recommendation
What is the absorption and associated risk of paromomycin in pregnancy?
Minimal systemic absorption
Limited information about teratogenic potential
When can paromomycin be used in pregnancy?
After the first trimester in people with severe symptoms
Classified as CIII recommendation
What is the status of loperamide in terms of absorption and birth defects?
Poorly absorbed and not associated with birth defects in animal studies
One study noted increased risk of congenital malformations
When should loperamide be avoided during pregnancy?
In the first trimester
Unless benefits outweigh potential risks
What is the preferred antimotility agent in late pregnancy?
Loperamide
Classified as CIII recommendation
What risk is associated with opiate exposure in late pregnancy?
Neonatal respiratory depression and withdrawal
Tincture of opium is not recommended in late pregnancy
