Intestinal Nematodes and Eosinophilia Patricia F Walker, MD, DTM&H Medical Director, HealthPartners Center for International Health Associate Professor, Division of Infectious Disease and International Medicine University of Minnesota Healthcare in the Global Village: Serving Refugees in Indiana Indianapolis, Indiana September 25, 2009
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Intestinal Nematodes and Eosinophilia Patricia F Walker, MD, DTM&H Medical Director, HealthPartners Center for International Health Associate Professor,
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Intestinal Nematodesand Eosinophilia
Patricia F Walker, MD, DTM&HMedical Director, HealthPartners Center for International Health
Associate Professor, Division of Infectious Disease and International Medicine
University of MinnesotaHealthcare in the Global Village: Serving Refugees in Indiana
• Strongyloides, C. philippinensis: autoinfection• Pinworm: self-reinfection
Soil Transmitted Helminths (STH) = Geohelminths
• Part of development occurs in the soil
• Average 3 – 4 weeks in soil until infective
• Infection via eggs in contaminated soil (Ascaris, Trichuris) or skin penetration (hookworm)
Soil Transmitted Helminths (STH)
• Infection rates and burden of disease greatest among conditions of poverty, poor sanitation
Guatemalan Children With Soil–Transmitted Helminth Infections
• Stunting, anemia, loss of IQ, diminished school performance
• Many years of lost primary schooling attributable to STH
Parasite Prevalence in Village of Paquila, Guatemala
100
80
60
40
20
00 – 3 4 – 7 8 – 12
Pre
vale
nce
(%
)
Age Class (y)
Ascaris Trichuris Hookworm Strongyloides
Highest Worm Burdens in School-aged Children
Mean Age (years)
Mea
n W
orm
Bur
den
100 20 30 40
Growth Curve of Child With Soil-transmitted Infection
97
75
50
25
3
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
20 3 6 9 12 15 18 21 24 27
Weight (kg)
Thiabenazole for 2 days
90
Age (months)
Percentiles
10
Ascaris lumbricoides
• 1/8th the world’s population infected• Largest of nematodes infecting humans• Adult habitat: small intestine (jejunum)• Obligatory extra-intestinal migration
(eosinophilia)• Lifespan: 1 – 2 years• Intensity of infection greatest in children,
ages 5 – 10 years
Ascaris infection in Haiti and Paraguay
Ascaris Lumbricoides
Eighty-nine hookworms and 81 Ascaris. This demonstration induced many to apply for treatment (Brazil).
Ascaris
Geographic prevalence highest in warm, wet climates
1 adult female = 200,000 eggs/day
Pre-patency: 2 months
Pneumonitis: 4 – 16 days after infection, short duration (~3 wks)
Löeffler Syndrome (Pneumonitis)
Transverse sections of Ascaris larvae in pulmonary alveoli
obstruction (in children, few as 60 worms)• Wandering ascaris: biliary tract obstruction,
cholangitis, pancreatitis, liver abscess
• Treatment: Albendazole x 1 dose
Adult Ascaris worms migrating in liver
Ascaris causing intestinal obstruction.
Acute G.I. Obstruction from Ascaris
Interesting e mails…
Sent: Monday, April 04, 2005 4:32 PMTo: [email protected]: health needsI got your email address from my mother- Linda A.I am an ELL teacher and have many students from Liberia. I had a student complain about coughing up a long white worm as he was eating a lemon at lunch. I sent him to the nurse at school, as he said this was the second time it has happened to him. She sent him back to class saying there wasn't enough to tell anything at this point. Is there anything you can suggest, or anywhere I can direct his parents?Thanks for your help!Michelle R
Ascaris (roundworm):
The only nematode ever coughed or vomited up
Whipworm:Trichuris trichiuria
• Adult habitat: caecum, colorectum• No extra-intestinal phase• Lifespan: 1 - 3 years• 90% infections are asymptomatic• Symptoms with heavy infections
Hookworm:Necator americanus & Ancylostoma duodenale
• One – tenth the world’s population infected• Significant cause of anemia & protein malnutrition
• Adult habitat: small intestine• Lifespan:
~ 1 year (A. duodenale)~ 3 - 5 years (N. americanus)
• Worm burdens do not decline in adult years
Typical Age and Intensity of Infection Relationship
Mean Age (y)
Mea
n W
orm
Bu
rde n
(%
)
10
10
20
30
40
50
60
70
80
90
100
Trichuris
Ascaris
Hookworm
0 20 30 400
Human Hookworm Infection
~600 million cases worldwide (rural poverty >>> urban slums)44 million pregnant women infectedIron-deficiency anemia: Physical & Intellectual RetardationNecator americanus is the predominant hookworm species
Life Cycle of Hookworm
Pre-patency: months - year
Hookworm-Blood Loss
Adult worms injure their host by causing intestinal blood loss:
• Anticoagulants, Hemolysins, and Hemoglobinases• 30 to 200 μL blood per day per hookworm• Intestinal blood loss and Iron Deficiency Anemia
• In 2001, (WHO) adopted a resolution aimed at the “deworming” of 75 percent of all at-risk school-age children by 2010, Prevention and • Improvements in iron, Hgb status• Improved Cognition, Educational Achievement• Reduction in school absenteeism• Reduction in community helminth transmission of
ascariasis & trichuriasis
Control
• Anti-helminthic drugs:• 50 million tablets of mebendazole donated per year
by Johnson & Johnson • Albendazole available from GlaxoSmithKline for 2¢
per pill
• Currently no vaccine exists for ascariasis or trichuriasis
• Human Hookworm Vaccine Initiative (HHVI): Phase I trials
Strongyloidiasis:Strongyloides stercoralis
• Worldwide prevalence: ~100 million
• Adult habitat: duodenum, jejunum
• Lifespan: unknown. Ongoing autoinfection.
Strongyloidiasis - Clinical Presentation
• Asymptomatic eosinophilia
• Abdominal pain
• Dermatitis - larva currens
• Pulmonary infiltrates with eosinophilia
• Dissemination with sepsis
Strongyloides* by ethnicityRegions Hospital, St. Paul, MN1/1/88 - 9/1/98
• Hyper-Infection: • intestinal perforation• hemorrhagic pneumonia• shock, sepsis, gram-negative meningitis• eosinophilia may be limited
Vietnamese male, in US for 8 years, developed fever, rash and pneumonia after being placed on steroids for uveitis.
Good news:Pre-departure treatment for intestinal parasites in US bound refugees
Since May, 1999 CDC has implemented empiric treatment with single dose albendazole 600 mg for all refugees departing from sub Saharan Africa, and for selected groups, such as Hmong arriving from Thailand in 2005
Prevalence of Intestinal Parasites Among Refugees Arriving in Minnesota, pre-May 1999 (n = 4,584)
0
5
10
15
20
25
Pre Post Pre Post Pre Post Pre Post Pre Post Pre Post Pre Post
Infectious DiseasesTable 4.10. Drugs for Parasitic Infections
Acknowledgements for Slides
Stephen Swanson, MD, DTM&H, Hennepin County Medical Center, Minneapolis
Peter Hotez, MD, PhD, FAAPPresident, Sabin Vaccine InstituteMicrobiology, Immunol, & Tropical MedicineThe George Washington University School of Medicine
Post test with answers
What is the most likely worm to be coughed or vomited up?