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Strongyloidiasis (Hyperinfection)
Cardiovascular Presentations
Abdominal aortic aneurysm
Acute coronary syndrome (NSTEMI)
Acute coronary syndrome (STEMI)
Acute decompensated heart failure
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Acute mesenteric ischemia
Aortic dissection
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Atrial fibrillation and flutter
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Deep vein thrombosis
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Stable angina
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Superior vena cava syndrome
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Syncope (cardiogenic)
Unstable angina
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Respiratory Presentations
Acute bronchitis
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Aspiration pneumonia
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Croup
Croup (laryngotracheobronchitis)
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Neurological Presentations
Bell's palsy
Benign paroxysmal positional vertigo
Brain abscess
Cauda equina syndrome
Cervical radiculopathy
Concussion (mild traumatic brain injury)
Encephalitis
Guillain-Barré syndrome
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Lumbar radiculopathy
Malignant spinal cord compression
Migraine
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Retropharyngeal abscess
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Spinal cord injury
Status epilepticus
Subarachnoid hemorrhage
Tension headache
Transient ischemic attack
Traumatic brain injury (moderate-severe)
Vestibular neuritis
Viral meningitis
Gastrointestinal Presentations
Acute appendicitis
Acute cholecystitis
Acute diverticulitis
Acute pancreatitis
Anal fissure
Choledocholithiasis and cholangitis
Clostridioides difficile colitis
Gastritis
Gastroenteritis (viral and bacterial)
Gastroesophageal reflux disease
Incarcerated or strangulated hernia
Inflammatory bowel disease flare
Large bowel obstruction
Lower GI hemorrhage
Peptic ulcer disease
Perforated viscus
Small bowel obstruction
Upper GI hemorrhage
Genitourinary and Reproductive Presentations
Acute prostatitis
Acute urinary retention
Ectopic pregnancy
Epididymitis
Orchitis
Ovarian torsion
Paraphimosis
Pelvic inflammatory disease
Priapism
Pyelonephritis
Renal laceration
Ruptured ovarian cyst
Testicular torsion
Tubo-ovarian abscess
Urinary tract infection (uncomplicated)
Urolithiasis (renal colic)
Vaginal bleeding (non-pregnant)
Infectious Disease Presentations
Acute sinusitis
Acute tonsillitis
Acute upper respiratory infection
Animal bite
Bacterial meningitis
Cellulitis
Conjunctivitis (bacterial)
Dental abscess
Endocarditis
Febrile neutropenia
Fournier gangrene
Hand-foot-mouth disease
Hepatitis (acute)
Herpes zoster
HIV-related illness
Human bite
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Infectious mononucleosis
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Osteomyelitis
Otitis externa
Parasitic infection
Periorbital cellulitis
Peritonsillar abscess
Scabies
Sepsis
Septic arthritis
Spontaneous bacterial peritonitis
Tick-borne illness (Lyme disease)
Tinea infection
Tuberculosis
Viral exanthem
Wound infection
Trauma Presentations
Achilles tendon rupture
ACL and mceniscus tear
Ankle fracture
Ankle sprain
Burn
Calcaneus fracture
Cervical spine fracture
Clavicle fracture
Dental avulsion
Distal radius fracture
Drowning
Elbow fracture and dislocation
Electrical injury
Facial bone fracture
Facial laceration
Femur fracture
Fingertip amputation
Forearm fracture (radius and ulna)
Frostbite
Hand:finger laceration
Heat exhaustion
Heat stroke
Hip fracture
Humeral shaft fracture
Knee dislocation
Knee sprain
Lightning injury
Mandible fracture
Metacarpal fracture
Metatarsal fracture
Muscle strain
Nasal fracture
Non-accidental trauma
Orbital fracture
Patella fracture
Phalanx fracture (finger)
Proximal humerus fracture
Pulmonary contusion
Rib fracture
Rotator cuff tear (acute traumatic)
Scalp laceration
Scaphoid fracture
Shoulder dislocation
Skull fracture
Splenic laceration
Sternal fracture
Supracondylar pediatric fracture
Tendon laceration (hand:wrist)
Thoracic and lumbar spine fracture
Tibia:fibula fracture
Tibial plateau fracture
Toe fracture
Traumatic epistaxis
Traumatic hyphema
Toxicologic Presentations
Acetaminophen toxicity
Alcohol intoxication
Alcohol withdrawal
Anticholinergic toxicity
Anticoagulant overdose
Benzodiazepine overdose
Benzodiazepine:sedative overdose
Beta-blocker and calcium channel blocker toxicity
Carbon monoxide poisoning
Caustic ingestion
Digoxin toxicity
Drug eruption
Foreign body ingestion
Opioid intoxication
Opioid overdose
Opioid withdrawal
Organophosphate
Salicylate toxicity
Serotonin syndrome
Stimulant intoxication (cocaine, methamphetamine)
Tricyclic antidepressant overdose
Psychiatric Presentations
Acute anxiety
Acute psychosis
Agitation:behavioral emergency
Bipolar disorder
Conversion disorder
Major depressive episode
Neuroleptic malignant syndrome
Suicidal ideation and attempt
Musculoskeletal and Rheumatologic Presentations
Acute low back pain (mechanical)
Bursitis
Cervical radiculopathy
Costochondritis
Gout (acute)
Lumbar radiculopathy
Pseudogout
Tendinitis
Dermatology Presentations
Acute eczema (Eczema acute flare)
Allergic contact dermatitis
Erythema multiforme
Henoch-Schönlein purpura
Pressure injury
Psoriasis (acute flare)
Stevens-Johnson syndrome
Toxic epidermal necrolysis
Urticaria (acute)
Environmental and Exposure Presentations
Envenomation (snake, spider, insect)
High-altitude illness
Hypothermia
Hematologic and Oncologic Presentations
Acute chest syndrome
Coagulopathy
Hyperviscosity syndrome
Sickle cell crisis (vaso-occlusive)
Symptomatic anemia
Thrombocytopenia (severe)
Tumor lysis syndrome
Pediatric-Specific Presentations
Bronchiolitis
Croup
Emergency delivery
Febrile seizure
Kawasaki disease
Neonatal jaundice
Neonatal sepsis
Nursemaid's elbow
Pediatric fever 0 to 28 days
Pediatric fever 29 to 60 days
Pediatric fever 61 to 90 days
Pyloric stenosis
Slipped capital femoral epiphysis
Intussusception
Endocrine and Metabolic Presentations
Adrenal crisis
Diabetic ketoacidosis
Hypercalcemia
Hyperosmolar hyperglycemic state
Hypertensive emergency
Hypertensive urgency
Hypoglycemia
Myasthenia gravis crisis
Myxedema coma
Severe hyperkalemia
Severe hyponatremia
Thyroid storm
ENT and Maxillofacial Presentations
Acute laryngitis
Acute otitis media
Acute pharyngitis
Cerumen impaction
Epistaxis (anterior)
Nasal foreign body
Otitis externa
Tympanic membrane perforation
Ophthalmologic Presentations
Acute angle-closure glaucoma
Central retinal artery occlusion
Chemical eye injury
Corneal abrasion
Corneal ulcer
Globe rupture
Ocular foreign body
Orbital cellulitis
Retinal detachment
Obstetric Presentations
Hyperemesis gravidarum
Painful vaginal bleeding in pregnancy
Placenta previa
Placental abruption
Preeclampsia:eclampsia
Preterm labor
Threatened:inevitable:incomplete abortion
Systemic and Miscellaneous Presentations
Anaphylaxis
Angioedema
Cannabis-induced hyperemesis
Strongyloidiasis (Hyperinfection)
POCUS
Procedures
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ECG Guide
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Clinical Assessment Checklist
Browse categories and answer follow-up questions to refine your symptom profile.
Approach to the Critical Patient
Immediate priorities
Airway and breathing threats
▶
Respiratory failure from pulmonary hyperinfection
▶
SpO2 < 90% on room air
PaO2 < 60 mmHg
ARDS pattern infiltrates
▶
Diffuse bilateral ground-glass opacities
Larval migration through pulmonary vasculature
If respiratory failure, early intubation planning
▶
Avoid delay in hypoxemic patient
Lung-protective ventilation for ARDS
Circulation and sepsis threats
▶
Septic shock from enteric bacterial translocation
▶
SBP < 90 mmHg
MAP < 65 mmHg
Gram-negative bacteremia in 40% of hyperinfection cases
▶
Enteric organisms breach bowel wall with larvae
Lactate >= 2 mmol/l indicates tissue hypoperfusion
If septic shock, broad-spectrum antibiotics within 1 hour
▶
Cover enteric Gram-negatives and anaerobes
Piperacillin-tazobactam or meropenem first-line
Neurologic threats
▶
CNS dissemination with meningitis or brain abscess
▶
Altered mental status in hyperinfection
Neck stiffness or photophobia
Enteric bacterial meningitis carrying extremely high mortality
▶
Larvae carry gut flora through meninges
LP after imaging if clinically stable
Key decision points
Recognize hyperinfection vs chronic strongyloidiasis
▶
Hyperinfection: massive larval burden + systemic spread
▶
Larvae in stool, sputum, BAL, blood, CSF
Mortality 60-87% even with treatment
Chronic: low-level autoinfection without dissemination
▶
Eosinophilia often present
Outpatient manageable
Disseminated disease: larvae beyond GI tract and lungs
▶
Liver, CNS, heart, kidneys involved
Worst prognosis
Trigger identification
▶
Corticosteroid use — single strongest precipitant
▶
Even brief or low-dose courses capable of triggering
COVID-19 dexamethasone-associated cases documented
HTLV-1 coinfection — second most important trigger
▶
Impairs Th2 immune response
Promotes uncontrolled autoinfection
Post-transplant immunosuppression
▶
Median onset 13 weeks post-transplant
Donor-derived transmission well-documented
Monitoring and resuscitation targets
Hemodynamic targets
▶
MAP >= 65 mmHg
▶
Norepinephrine if refractory to fluid resuscitation
Vasopressin as adjunct for refractory shock
Lactate clearance target
▶
Repeat lactate at 2 hours
Target < 2 mmol/l
Anthelmintic urgency
▶
Ivermectin initiation within hours of diagnosis
▶
Every hour of delay increases larval burden
Oral route preferred if GI absorption intact
If ileus or malabsorption, use subcutaneous or rectal route
▶
Off-label but necessary in critically ill
Confirmed in transplant case series
Immediate consults
Mandatory consultation triggers
▶
Infectious disease — all hyperinfection cases
▶
Mandatory per AST-IDCOP guidelines
Guide anthelmintic duration and monitoring
ICU team — all hyperinfection cases
▶
High mortality requires intensive monitoring
Ventilatory support may be needed
Tropical medicine or parasitology specialist
▶
If available, for complex cases
Optimize stool and specimen monitoring strategy
Transplant team if post-transplant
▶
Immunosuppression reduction decision
Donor-derived infection evaluation
History
Presenting symptoms
Gastrointestinal symptoms
▶
Diarrhea — often bloody or watery
▶
May be profuse in hyperinfection
Alternating with constipation in chronic disease
Abdominal pain
▶
Diffuse or periumbilical
Mimics acute abdomen with ileus or obstruction
Nausea, vomiting, anorexia, weight loss
▶
Malnutrition is both risk factor and consequence
Malabsorption from mucosal invasion
Pulmonary symptoms
▶
Cough
▶
May be productive with larvae-laden sputum
Hemoptysis in severe pulmonary hyperinfection
Dyspnea and wheezing
▶
Löffler-like syndrome from larval migration
ARDS pattern in severe cases
Dermatologic symptoms
▶
Larva currens — pathognomonic migratory serpiginous urticaria
▶
Perianal, buttocks, and lower abdomen distribution
Moves rapidly (centimeters per hour) unlike cutaneous larva migrans
Pruritus ani
▶
Perianal pruritus from larval migration
Epidemiologic history
Geographic exposure
▶
Tropics and subtropics — highest endemicity
▶
Sub-Saharan Africa, Southeast Asia, Latin America
Rural southeastern United States and Appalachia
Immigration or refugee status
▶
Infection can persist asymptomatically for decades
Remote exposure remains relevant
Barefoot soil contact, agricultural work, or mining
▶
Filariform larvae penetrate intact skin
Occupational exposure underrecognized
Immunosuppression history
▶
Corticosteroid use — any dose, any duration
▶
Even short courses can precipitate hyperinfection
COVID-19 dexamethasone treatment — documented cases
Transplant history
▶
Solid organ or hematopoietic stem cell
Donor-derived infection possible (onset ~13 weeks)
Chemotherapy or biologic agents
▶
Anti-TNF agents, vincristine, mycophenolate, tacrolimus
Hematologic malignancy treatment
Risk factors
Host risk factors
▶
HTLV-1 coinfection
▶
Strongest immune predictor of hyperinfection
Impairs Th2 response and eosinophil activity
Hematologic malignancy
▶
Lymphoma and leukemia at high risk
Chemotherapy-related immunosuppression
Alcohol use disorder
▶
Independently associated with severe disease
Nutritional compromise compounds risk
HIV/AIDS
▶
Particularly when CD4 < 200 cells/mm3
Less common trigger than corticosteroids
Prior infection history
▶
Known prior Strongyloides infection
▶
Untreated chronic infection can persist decades
Previous eosinophilia workup results
Family or household contacts with similar symptoms
▶
Shared soil exposure assessment
Travel history of household members
Alarm features in history
High-risk presentation triggers
▶
Gram-negative bacteremia or meningitis + GI symptoms
▶
Near-pathognomonic for hyperinfection
Enteric organisms on blood or CSF culture
Septic shock in returning traveler or immigrant
▶
No obvious source despite workup
Concurrent GI and pulmonary symptoms
Absence of eosinophilia in at-risk patient
▶
70-100% of hyperinfection patients have normal eosinophil count
Eosinophilia actually protective — associated with lower mortality
Physical Exam
Vital signs and general
Vital sign patterns
▶
Fever
▶
Present in 50-70% of hyperinfection cases
Hypothermia in severe septic shock
Tachycardia and hypotension
▶
Septic shock physiology
HR > 100 bpm as early sepsis sign
Tachypnea and hypoxia
▶
SpO2 monitoring
Respiratory rate as marker of severity
General appearance
▶
Degree of distress and toxicity
▶
Diaphoresis, pallor, altered mentation
Cachexia and malnutrition signs
Abdominal exam
Abdominal findings
▶
Diffuse tenderness
▶
Peritoneal signs if bowel perforation
Rigidity indicating surgical emergency
Bowel sounds
▶
Absent sounds suggesting ileus
High-pitched sounds with obstruction
Hepatomegaly
▶
Hepatic involvement in disseminated disease
Liver tenderness on palpation
Rectal exam
▶
Perianal erythema and excoriation
▶
From larva currens migration
Blood on rectal exam with colitis
Pulmonary exam
Auscultatory findings
▶
Diffuse crackles
▶
Bilateral in pulmonary hyperinfection
Basilar predominance early
Wheezing
▶
Bronchospasm from larval migration
May mimic asthma exacerbation
Decreased breath sounds
▶
Pleural effusion
Consolidation from secondary pneumonia
Neurologic exam
CNS findings
▶
Altered mental status
▶
Confusion to coma in CNS dissemination
Encephalopathy from sepsis and/or meningitis
Meningismus
▶
Neck stiffness
Kernig and Brudzinski signs
Focal neurologic deficits
▶
Brain abscess in disseminated disease
Cranial nerve palsies reported
Dermatologic exam
Skin findings
▶
Larva currens
▶
Serpiginous urticarial tracks
Perianal, trunk, and extremity distribution
Transient — resolves in hours at each site
Petechiae or purpura
▶
DIC complication
Thrombocytopenia in severe disease
Jaundice
▶
Hepatic involvement
Sepsis-related cholestasis
Differential Diagnosis
Life-threatening mimics
Sepsis and bacteremia from other sources
▶
ICD-10: A41.9 — Sepsis, unspecified organism
▶
Distinguish by larvae on stool/sputum exam
Eosinophilia suggests parasitic etiology if present
Spontaneous bacterial peritonitis
▶
Ascites with fever and peritoneal signs
Paracentesis distinguishes
Bacterial meningitis from other causes
▶
ICD-10: G00.9 — Bacterial meningitis, unspecified
▶
CSF larvae diagnostic for Strongyloides
Enteric organisms on CSF culture should raise suspicion
ARDS from other causes
▶
ICD-10: J80 — Acute respiratory distress syndrome
▶
BAL larvae distinguish pulmonary hyperinfection
Consider alongside pneumonia and aspiration
Gastrointestinal mimics
Inflammatory bowel disease
▶
ICD-10: K51.9 — Ulcerative colitis, unspecified
▶
Bloody diarrhea overlap
Biopsy may reveal larvae in mucosa
ICD-10: K50.9 — Crohn's disease, unspecified
▶
Transmural involvement mimics
Immunosuppression for IBD can trigger hyperinfection
Intestinal obstruction
▶
ICD-10: K56.60 — Unspecified intestinal obstruction
▶
Ileus from bowel wall invasion
Imaging may show thickened bowel wall
Eosinophilic gastroenteritis
▶
ICD-10: K52.81 — Eosinophilic gastritis and gastroenteritis
▶
Eosinophil infiltration overlaps
Stool exam distinguishes
Pulmonary mimics
Community-acquired pneumonia
▶
ICD-10: J18.9 — Pneumonia, unspecified
▶
Fever and infiltrates overlap
Sputum larvae absent in CAP
Loeffler syndrome from other parasites
▶
Ascaris, hookworm, Toxocara
Serology and exposure history differentiate
Pulmonary embolism
▶
ICD-10: I26.99 — Other pulmonary embolism without acute cor pulmonale
▶
Dyspnea and hypoxia overlap
CTPA distinguishes
Other parasitic infections
Other soil-transmitted helminths
▶
ICD-10: B76.0 — Ancylostomiasis (hookworm)
▶
Stool ova and parasite exam distinguishes
Geographic exposure overlap
ICD-10: B77.0 — Ascariasis with intestinal complications
▶
Can also cause Loeffler syndrome
Stool microscopy distinguishes
Strongyloides stercoralis chronic infection
▶
ICD-10: B78.0 — Intestinal strongyloidiasis
▶
Low-level asymptomatic autoinfection
Distinguish from hyperinfection B78.7 (disseminated)
ICD-10: B78.7 — Disseminated strongyloidiasis
▶
Larvae beyond GI tract and lungs
Highest mortality subgroup
Laboratory Tests
Complete blood count
White blood cell count
▶
Leukocytosis typical in hyperinfection
▶
Left shift indicating bacterial co-infection
Leukopenia in overwhelming sepsis — poor prognostic sign
Eosinophil count — critical pitfall
▶
Eosinophilia absent in 70-100% of hyperinfection
Normal eosinophil count does NOT rule out disease
Eosinophilia when present is protective (lower mortality)
Hemoglobin and platelets
▶
Anemia from GI blood loss
▶
Iron deficiency pattern with chronic disease
Normocytic in acute blood loss
Thrombocytopenia
▶
DIC complication
Sepsis-related consumptive process
Metabolic and organ function panels
Comprehensive metabolic panel
▶
Hypoalbuminemia
▶
Protein-losing enteropathy
Marker of malnutrition severity
Elevated transaminases
▶
Hepatic involvement in disseminated disease
Sepsis-related hepatic dysfunction
Electrolyte abnormalities
▶
Hyponatremia with SIADH from CNS disease
Hypokalemia from diarrhea losses
Renal function
▶
Creatinine and BUN for AKI
▶
Sepsis-associated renal failure
Contrast consideration for imaging
Urinalysis
▶
Larvae in urine in disseminated disease (rare)
Hematuria and pyuria in renal involvement
Inflammatory and sepsis markers
Lactate
▶
Serum lactate for tissue perfusion
▶
>= 2 mmol/l — sepsis concern
>= 4 mmol/l — septic shock threshold
Serial lactate clearance
▶
Repeat at 2 hours after resuscitation
Failure to clear portends poor prognosis
Procalcitonin and CRP
▶
Procalcitonin elevation with bacterial co-infection
▶
Guides antibiotic duration
High levels with Gram-negative bacteremia
CRP — nonspecific but markers disease activity
▶
Useful for treatment response monitoring
Coagulation panel
DIC screen
▶
PT, PTT, INR
▶
Prolonged in coagulopathy
Fibrinogen consumption in DIC
D-dimer
▶
Elevated in DIC and PE
Context-dependent interpretation
Fibrinogen
▶
Low fibrinogen confirms consumptive DIC
Replace with cryoprecipitate if bleeding
Microbiological workup
Blood cultures
▶
Two sets before antibiotics
▶
Enteric organisms — E. coli, Klebsiella, Enterococcus
Gram-negative bacteremia in ~40% of hyperinfection
Follow to clearance with serial cultures
▶
Duration of bacteremia guides antibiotic course
Stool examination
▶
Stool ova and parasites — look for filariform larvae
▶
Single stool sensitivity low (~30%)
Serial exams x3-7 improve yield significantly
Agar plate culture — most sensitive stool method
▶
Sensitivity ~89%
Requires fresh stool and 48-72 hours incubation
Baermann concentration technique
▶
Improved sensitivity over direct smear
Better for larvae with low motility
Serology
▶
Strongyloides IgG ELISA
▶
Sensitivity 75-94% in immunocompetent hosts
Reduced to 43-68% in immunocompromised — major limitation
Cannot be used alone to rule out disease
HTLV-1 serology
▶
Essential in all hyperinfection cases
Guides prognosis and secondary prophylaxis planning
Other specimens
▶
Sputum examination
▶
Larvae identifiable in respiratory secretions
Induced sputum increases yield
CSF analysis
▶
If meningitis suspected — LP after imaging
Larvae and enteric organisms may be identified
Stool PCR
▶
Available in specialized centers
Sensitivity ~62%, specificity ~95%
Useful when other methods negative
Diagnostic Tests
Scoring Systems
Severity stratification
▶
No validated scoring system specific to Strongyloides hyperinfection
▶
SOFA score for organ dysfunction in septic hyperinfection
APACHE II for ICU prognostication
WHO classification of strongyloidiasis
▶
Chronic uncomplicated: eosinophilia, minor GI symptoms
Hyperinfection: massive larval burden, systemic spread
Disseminated: larvae beyond GI tract and lungs
Severity predictors from meta-analysis data
▶
Corticosteroid use — strongest predictor of severe disease
Absence of eosinophilia — associated with increased mortality
Septic shock — mortality approaches 100% without treatment
ICD-10 coding
▶
B78.0 — Intestinal strongyloidiasis
▶
Chronic or limited GI disease
B78.1 — Cutaneous strongyloidiasis
▶
Larva currens predominant presentation
B78.7 — Disseminated strongyloidiasis
▶
Larvae beyond GI tract and lungs
B78.9 — Strongyloidiasis, unspecified
▶
Use when syndrome not fully characterized
MRI
Brain MRI indications
▶
CNS dissemination evaluation
▶
Altered mental status in hyperinfection
Suspected brain abscess or meningitis
Findings in CNS strongyloidiasis
▶
Multiple enhancing lesions on contrast T1
Leptomeningeal enhancement in meningitis
Abscess formation with rim enhancement
Abdominal MRI
▶
Bowel wall assessment
▶
Thickening from mucosal invasion
Superior soft tissue contrast vs CT
Used when CT contrast contraindicated
Hepatic involvement
▶
Focal hepatic lesions in disseminated disease
MRI superior for characterization
CT
CT chest indications and findings
▶
Pulmonary hyperinfection pattern
▶
Diffuse bilateral ground-glass opacities
Consolidation in secondary bacterial pneumonia
Centrilobular nodules from larval migration
ARDS pattern
▶
Bilateral airspace disease
Pleural effusions
Sensitivity for pulmonary involvement
▶
High sensitivity for detecting infiltrates
Not specific — cannot distinguish from other causes
CT abdomen and pelvis
▶
Bowel findings
▶
Bowel wall thickening — duodenum and jejunum predominant
Ileus pattern with air-fluid levels
Pneumatosis intestinalis in severe mucosal injury
Mesenteric changes
▶
Mesenteric lymphadenopathy
Ascites from protein loss or peritonitis
Hepatosplenic findings
▶
Hepatomegaly
Splenomegaly in HTLV-1 co-infected patients
CT head
▶
CNS dissemination evaluation
▶
Initial imaging before LP if meningismus
Abscess or edema pattern
Findings
▶
Hypodense lesions in brain abscess
Cerebral edema in severe meningitis
Ultrasound
Abdominal ultrasound
▶
Hepatic assessment
▶
Hepatomegaly with echogenic changes
Periportal thickening in hepatic involvement
Ascites detection
▶
Free fluid in peritoneum
Guide diagnostic paracentesis if needed
Bowel wall thickening
▶
Limited by ileus and bowel gas
CT preferred for full abdominal assessment
Point-of-care ultrasound
▶
Focused cardiac assessment
▶
IVC collapsibility for volume status
Sepsis-associated cardiomyopathy
Pleural assessment
▶
Pleural effusion detection
Guide thoracentesis if indicated
Transcranial Doppler
▶
Not routinely indicated
▶
MRI preferred for CNS assessment
Consider in comatose patient if MRI unavailable
Disposition
ICU admission criteria
All hyperinfection cases require ICU admission
▶
High mortality mandates intensive monitoring
▶
Case fatality rate 60-87% even with treatment
Approaches 100% without treatment
Hemodynamic monitoring requirements
▶
Arterial line for continuous blood pressure
Central venous access for vasopressors
Respiratory monitoring
▶
Serial ABGs and chest imaging
Intubation readiness
Mandatory consultations before admission
▶
Infectious disease consultation
▶
Treatment duration and monitoring guidance
AST-IDCOP guideline adherence
Critical care team for ICU management
▶
Ventilator management if ARDS develops
Vasopressor titration
Transfer criteria
Transfer triggers
▶
Lack of infectious disease specialist on-site
▶
Tropical medicine center preferred
Parasitology specialist availability
Surgical emergency requiring higher-level care
▶
Bowel perforation with peritonitis
GI bleeding requiring endoscopic or surgical intervention
CNS dissemination requiring neurosurgical consultation
▶
Brain abscess drainage
ICP monitoring
Discharge criteria for chronic strongyloidiasis
Copy
Uncomplicated chronic strongyloidiasis
▶
Hemodynamically stable
▶
No systemic complications
Tolerating oral medications
Outpatient treatment with ivermectin
▶
Single oral dose with documented follow-up
Stool exam at 2 and 4 weeks to confirm clearance
Close infectious disease follow-up arranged
▶
Repeat serology at 6 months
Monitoring for treatment failure
Follow-up planning
Copy
Post-hyperinfection monitoring
▶
Serial stool exams every 2 weeks for 4-6 weeks
▶
Autoinfection cycle is approximately 2 weeks
Confirm larval clearance from all body fluids
Serology follow-up
▶
IgG may take 12-18 months to serorevert
Not useful for acute treatment monitoring
Secondary prophylaxis if immunosuppression continues
▶
Ivermectin two doses every 2 weeks for 6 weeks
Pre-treatment before any immunosuppression initiation
Treatment
Anthelmintic therapy
Ivermectin — drug of choice
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Chronic strongyloidiasis dosing
▶
200 mcg/kg oral single dose
Repeat at 2 weeks for increased efficacy
Hyperinfection dosing
▶
200 mcg/kg orally once daily
Continue until larvae cleared from all body fluids
Then continue for minimum 7-14 additional days after clearance
Route alternatives when oral absorption compromised
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Subcutaneous ivermectin — veterinary formulation, off-label
Per-rectum ivermectin — off-label, used in ileus cases
Transplant case series support non-oral routes
Mechanism of action
▶
Glutamate-gated chloride channel agonist
Causes paralysis and death of larvae and adult worms
Does not reliably kill eggs — treatment must continue through cycles
Albendazole — alternative or combination therapy
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Dosing
▶
400 mg orally twice daily for 10-14 days
Can be combined with ivermectin for severe cases
Role
▶
Second-line when ivermectin unavailable
Combination therapy in refractory hyperinfection
Less effective than ivermectin per Cochrane review
Thiabendazole — historical alternative
▶
25 mg/kg twice daily for 5 days
Higher toxicity profile — rarely used now
Superseded by ivermectin and albendazole
Emodepside — emerging agent
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Phase 2a trial data (2025) — promising efficacy
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Dose-ranging study vs ivermectin in Laos
May offer alternative for ivermectin-resistant cases
Not yet approved for human strongyloidiasis
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Investigational use only
Antibiotic therapy for bacterial co-infection
Empiric broad-spectrum coverage
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First-line for septic shock
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Meropenem 1 g IV every 8 hours
Covers enteric Gram-negatives, anaerobes, and ESBL producers
Alternative
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Piperacillin-tazobactam 4.5 g IV every 6 hours
Adequate coverage for most enteric pathogens
De-escalation based on cultures
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Narrow spectrum once susceptibilities known
Duration guided by source control and clinical response
CNS bacterial meningitis coverage
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Ceftriaxone 2 g IV every 12 hours
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Gram-negative meningitis coverage
Adjust based on CSF culture and susceptibilities
Add metronidazole if enteric anaerobes suspected
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500 mg IV every 8 hours
CNS penetration adequate
Dexamethasone for bacterial meningitis — use with extreme caution
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May worsen Strongyloides hyperinfection
Weigh benefit vs harm individually
Immunosuppression management
Reduce or discontinue immunosuppression
▶
Corticosteroids — taper and discontinue if possible
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Critical step — reduces larval burden amplification
Discuss with primary team managing underlying condition
Transplant immunosuppression
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Balance rejection risk vs hyperinfection mortality
Transplant team involvement mandatory
Tacrolimus and mycophenolate dose reduction considered
IRIS monitoring if rapid immunosuppression withdrawal
▶
Immune reconstitution inflammatory syndrome
May paradoxically worsen symptoms transiently
Supportive care
Fluid resuscitation
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Crystalloid bolus for sepsis and hypotension
▶
30 ml/kg initial bolus per Surviving Sepsis Campaign
Reassess volume status after each bolus
Vasopressor therapy for refractory hypotension
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Norepinephrine 0.01-3 mcg/kg/min — first-line vasopressor
Vasopressin 0.03-0.04 units/min as second agent
Respiratory support
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Supplemental oxygen titration
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Target SpO2 92-96%
High-flow nasal cannula for moderate hypoxemia
Mechanical ventilation for ARDS
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Lung-protective ventilation strategy
Tidal volume 6 ml/kg ideal body weight
PEEP titration per ARDSnet protocol
Nutritional support
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NPO if ileus, obstruction, or hemodynamic instability
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Parenteral nutrition for disseminated disease with malabsorption
Early enteral nutrition when gut function returns
High protein, high calorie targets
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25-30 kcal/kg/day
1.2-1.5 g protein/kg/day
Pre-treatment prophylaxis
Screen at-risk patients before immunosuppression
▶
Stool exam and serology before corticosteroids or transplant
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All endemic region exposures require screening
Empiric ivermectin if testing unavailable and urgency high
WHO preventive chemotherapy recommendation
▶
Treatment of at-risk populations in endemic areas
Pre-transplant screening mandatory per AST-IDCOP guidelines
Post-COVID corticosteroid protocol
▶
Empiric ivermectin protocol implemented at some centers
Demonstrated safety and efficacy in COVID-19 dexamethasone cohort
Special Populations
Pregnancy
Pregnancy considerations
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Ivermectin safety in pregnancy
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FDA Category C — limited human data
Animal studies show embryotoxicity at high doses
Generally avoided in first trimester if possible
Risk-benefit in hyperinfection
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Maternal mortality from untreated hyperinfection is extremely high
Ivermectin use justified when hyperinfection is life-threatening
Consult maternal-fetal medicine and infectious disease
Albendazole in pregnancy
▶
Teratogenic in animal studies
Avoid in first trimester
Use only if ivermectin unavailable and disease life-threatening
Obstetric complications
▶
Vertical transmission rare but reported
▶
Larvae can cross placenta
Neonatal strongyloidiasis documented
Preterm labor risk with systemic illness
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Monitoring with obstetric team
Fetal monitoring for compromised pregnancies
Breastfeeding
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Ivermectin excreted in breast milk
Pause breastfeeding during treatment if possible
Geriatric
Age-related risk factors
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Higher prevalence of undiagnosed chronic infection
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Remote endemic area exposure decades prior
Low clinical suspicion in primary care
More frequent corticosteroid prescriptions
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COPD, arthritis, polymyalgia rheumatica
Each prescription a potential hyperinfection trigger
Nutritional deficiency and immune senescence
▶
Impaired Th2 responses with aging
Malnutrition compounding immune deficiency
Modified management approach
▶
Renal function monitoring with ivermectin
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CrCl monitoring for drug accumulation risk
No dose adjustment required but monitor closely
Polypharmacy interactions
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Ivermectin P-glycoprotein substrate
Drug interactions with CNS depressants
Nutritional rehabilitation priority
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Protein and caloric supplementation
Micronutrient deficiency correction
Pediatrics
Pediatric dosing
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Ivermectin 200 mcg/kg orally
▶
Same weight-based dosing as adults
Not approved for children < 15 kg due to limited data
Use clinical judgment in life-threatening hyperinfection regardless of weight
Albendazole 400 mg twice daily for children > 2 years
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15 mg/kg/day divided twice daily if < 15 kg
10-14 day course for hyperinfection
Pediatric risk factors
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Lower threshold for severe disease in malnourished children
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Protein-energy malnutrition impairs immunity
Higher parasite burden per body mass
Congenital infection
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Rare but documented vertical transmission
Neonatal presentation with diarrhea and failure to thrive
School-age children in endemic regions
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Barefoot exposure to contaminated soil
WHO preventive chemotherapy mass drug administration programs
Pediatric clinical features
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Growth retardation and failure to thrive
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Chronic malabsorption and protein loss
Nutritional rehabilitation essential
Abdominal pain and diarrhea mimicking other common pediatric conditions
▶
IBD, infectious enteritis, appendicitis
High index of suspicion with endemic exposure
Background
Epidemiology
Global burden
▶
Estimated 30-100 million infected worldwide
▶
Most asymptomatic chronic carriers
Hyperinfection rare but catastrophic
Endemic regions
▶
Tropics and subtropics — highest burden
Sub-Saharan Africa, Southeast Asia, Central and South America
Rural southeastern United States (Appalachia)
US epidemiology
▶
Predominantly imported infection in immigrants and travelers
Veteran populations with historical exposure
Rising incidence with global migration
Hyperinfection incidence
▶
1-2% of infected immunosuppressed patients develop hyperinfection
▶
Underestimated due to diagnostic challenges
Corticosteroid use accounts for majority of cases
Post-transplant incidence
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Highest risk in first 6 months post-transplant
Donor-derived transmission median onset 13 weeks
Mortality
▶
Case fatality rate 60-87% even with treatment
Approaches 100% without anthelmintic therapy
Presence of eosinophilia at presentation associated with lower mortality
Pathophysiology
Life cycle and autoinfection
▶
Strongyloides stercoralis lifecycle
▶
Free-living: rhabditiform larvae in soil develop to filariform
Filariform larvae penetrate intact human skin
Migrate via bloodstream to lungs, then swallowed to GI tract
Autoinfection cycle
▶
Rhabditiform larvae can transform to filariform within host
Penetrate intestinal mucosa or perianal skin
Cycle every approximately 2 weeks — allows indefinite persistence
Normal immune control
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Th2 response and eosinophils contain larval burden
IgE-mediated mechanisms limit autoinfection
Hyperinfection mechanism
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Immunosuppression disrupts Th2 control
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Corticosteroids directly impair eosinophil function
HTLV-1 skews Th1 response, abrogating Th2 protective immunity
Accelerated autoinfection
▶
Massive larval proliferation overwhelms host defenses
Larvae penetrate and disrupt bowel wall integrity
Bacterial translocation
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Larvae carry gut flora through disrupted mucosa
Enteric bacteria enter bloodstream and CSF
Polymicrobial Gram-negative sepsis results
Pulmonary hyperinfection
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Larvae traverse pulmonary vasculature
Hemorrhagic alveolitis and inflammation
Secondary bacterial pneumonia from seeding
Therapeutic Considerations
Ivermectin mechanism and pharmacology
▶
Glutamate-gated chloride channel agonist
▶
Causes paralysis and death of parasites
High affinity for invertebrate chloride channels
Pharmacokinetics
▶
Peak serum concentration 4 hours after oral dose
Half-life 12-16 hours
Hepatic metabolism via CYP3A4
Treatment duration controversy
▶
No RCT-level evidence for optimal hyperinfection duration
Consensus: treat until larvae absent from all body fluids
Minimum 7-14 days post-clearance
Treatment failure and resistance
▶
Treatment failure mechanisms
▶
Impaired oral absorption in ileus — use alternative routes
Inadequate duration — larvae in deep tissues may repopulate
HTLV-1 impairs immune clearance despite drug effect
Emerging resistance
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Anecdotal ivermectin resistance reports in humans
Veterinary ivermectin resistance in animals well-documented
Emodepside as alternative in development
Preventive strategy
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Pre-immunosuppression screening
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Stool exam plus serology for all at-risk patients
Empiric ivermectin if testing not feasible and urgency high
AST-IDCOP guideline recommendation
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Screen all transplant candidates from endemic regions
Treat with ivermectin before transplantation
WHO preventive chemotherapy
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Mass drug administration in highly endemic settings
Preventive chemotherapy review published Lancet Infect Dis 2025
Patient Discharge Instructions
copy discharge instructions
Copy
Your diagnosis and condition
▶
You have been treated for Strongyloides — a parasitic infection
▶
This parasite lives in soil and enters through the skin
In your case, the infection became serious and required hospitalization
Your medication is very important
▶
Take all doses of your antiparasitic medication as prescribed
Do not stop early even if you feel better
Follow-up stool tests are required
▶
Stool samples check that the parasite is gone
You will need tests at 2 weeks and 4 weeks after discharge
Return to emergency department if you experience
▶
Worsening abdominal pain or cramping
▶
Especially if severe or associated with vomiting
If you cannot keep food or water down
Bloody diarrhea or black tarry stools
▶
This can mean GI bleeding
Go to ER immediately
Shortness of breath or new cough
▶
Especially coughing up blood
Chest pain with breathing
Fever above 38.3 degrees Celsius
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Especially with chills or shaking
Severe headache, neck stiffness, or confusion
▶
These can be signs of spread to the brain
Call 911 or go to ER immediately
Skin rash that moves or spreads rapidly
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Especially around abdomen, buttocks, or thighs
Medications to avoid
▶
Do not take prednisone or other steroids unless directed by your doctor
▶
Steroids can make this infection much worse
Always remind any doctor about your Strongyloides infection
Other immunosuppressant medications require specialist approval
▶
Inform all doctors about this infection
Lifestyle and prevention
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Avoid walking barefoot on soil in endemic areas
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Wear shoes when outdoors in tropical regions
Protective clothing when doing yard or garden work
Good hand hygiene after soil contact
▶
Wash hands thoroughly with soap and water
Nutritional recovery
▶
Eat high-protein, well-balanced meals
Your body needs good nutrition to recover
Follow-up appointments
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Infectious disease specialist in 2 weeks
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Bring stool sample for analysis
Medication review at this visit
Primary care follow-up in 4 weeks
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Blood work to check recovery
Ongoing monitoring for recurrence
References
Guidelines and key sources
AST-IDCOP Guidelines — Parasitic infections in transplantation
▶
La Hoz RM, Morris MI et al. Clinical Transplantation 2019
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Strongyloides screening and management in transplant recipients
Mandatory pre-transplant screening recommendation
Abad CLR, Bhaimia E, Schuetz AN, Razonable RR. Clinical Transplantation 2022
▶
Comprehensive review of strongyloidiasis after solid organ and HSCT
Cochrane Systematic Review
▶
Henriquez-Camacho C et al. Cochrane Database Syst Rev 2016
▶
Ivermectin versus albendazole or thiabendazole for S. stercoralis
Ivermectin superior efficacy demonstrated
WHO Guideline Review
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Lo NC, Addiss DG, Buonfrate D et al. Lancet Infect Dis 2025
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Review of WHO preventive chemotherapy for strongyloidiasis control
Mass drug administration evidence base
Landmark studies and reviews
Severe Strongyloidiasis Systematic Review
▶
Rojas OC, Montoya AM, Villanueva-Lozano H et al. Trans R Soc Trop Med Hyg 2023
▶
Meta-analysis of 339 severe cases
Mortality 60-87% even with treatment
Immunocompromised host review
▶
Keiser PB, Nutman TB. Clin Microbiol Rev 2004
▶
Strongyloides in immunocompromised population
Pathophysiology and management review
Czeresnia JM, Weiss LM. Lung 2022
▶
Comprehensive pulmonary and systemic manifestations review
Outcomes data
▶
Henao-Martinez AF et al. Am J Trop Med Hyg 2024
▶
Clinical characteristics and outcomes of disseminated strongyloidiasis in the US
Multicenter network analysis
Chittrakarn S et al. PLoS Negl Trop Dis 2026
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Predictors of severe strongyloidiasis and mortality in hospitalized patients
Eosinophilia protective; corticosteroids increase severity
Pharmacotherapy references
Ivermectin pharmacotherapy
▶
Buonfrate D, Rodari P, Barda B et al. Expert Opin Pharmacother 2022
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Current pharmacotherapeutic strategies for strongyloidiasis
Treatment complications and management
FDA Drug Label — Ivermectin. Updated 2025-01-29
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Approved indications and dosing
Emerging therapies
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Taylor L et al. Lancet Infect Dis 2025
▶
Emodepside Phase 2a dose-ranging randomised controlled trial
Efficacy and safety vs ivermectin in Strongyloides stercoralis
SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.
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Management Protocols
Strongyloidiasis (Hyperinfection)