Presentation is loading. Please wait.

Presentation is loading. Please wait.

Intestinal Nematodes and Eosinophilia Patricia F Walker, MD, DTM&H Medical Director, HealthPartners Center for International Health Associate Professor,

Similar presentations

Presentation on theme: "Intestinal Nematodes and Eosinophilia Patricia F Walker, MD, DTM&H Medical Director, HealthPartners Center for International Health Associate Professor,"— Presentation transcript:

1 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

2 Parasitic Helminths Trematodes (flukes) Venous system: Schistosoma Biliary tract: Clonorchis, Fasciola Lung: Paragonimus Cestodes (tapeworms) Taenia saginata, Taenia solium, H. nana Nematodes (roundworm) Intestinal Blood, lymphatic, subcutaneous

3 Lecture Overview 1.General Facts about Intestinal Nematodes 2.4 major intestinal nematodes: Ascaris, Trichuris, hookworm and Strongyloides Public Health Implications Lifecycle Clinical presentation Treatment 3.Trends in Intestinal Parasitism among Refugees

4 General Facts about Intestinal Nematodes Frequently nonspecific symptoms Often asymptomatic until worm burden becomes large Weight loss, GI discomfort Diarrhea or fever from nematodes is uncommon Polyparasitism Burden is greatest in children

5 General Facts about Intestinal Nematodes Tropical and subtropical predominance Dont multiply in host 2 exceptions Infection limited to life span of worm unless reinfection occurs Lifespan: 2 months – 5 years Rare Exceptions: Strongyloides, C. philippinensis: autoinfection Pinworm: self-reinfection

6 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)

7 Soil Transmitted Helminths (STH) Infection rates and burden of disease greatest among conditions of poverty, poor sanitation

8 Guatemalan Children With Soil–Transmitted Helminth Infections Stunting, anemia, loss of IQ, diminished school performance Many years of lost primary schooling attributable to STH

9 Parasite Prevalence in Village of Paquila, Guatemala – 34 – 78 – 12 Prevalence (%) Age Class (y) AscarisTrichurisHookwormStrongyloides

10 Highest Worm Burdens in School-aged Children

11 Growth Curve of Child With Soil-transmitted Infection

12 Ascaris lumbricoides 1/8 th the worlds 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

13 Ascaris infection in Haiti and Paraguay

14 Ascaris Lumbricoides Eighty-nine hookworms and 81 Ascaris. This demonstration induced many to apply for treatment (Brazil).

15 Ascaris Geographic prevalence highest in warm, wet climates 1 adult female = 200,000 eggs/day

16 Pre-patency: 2 months Pneumonitis: 4 – 16 days after infection, short duration (~3 wks)

17 Löeffler Syndrome (Pneumonitis) Transverse sections of Ascaris larvae in pulmonary alveoli

18 Ascaris lumbricoides Larval phase: eosinophilia, pneumonitis Adult phase: Malnutrition, Impaired Physical Growth Mild abdominal discomfort Small bowel obstruction (in children, few as 60 worms) Wandering ascaris: biliary tract obstruction, cholangitis, pancreatitis, liver abscess Treatment: Albendazole x 1 dose

19 Adult Ascaris worms migrating in liver

20 Ascaris causing intestinal obstruction.

21 Acute G.I. Obstruction from Ascaris

22 Interesting e mails… Sent: Monday, April 04, :32 PM To: Subject: health needs I got your 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

23 Ascaris (roundworm): The only nematode ever coughed or vomited up

24 Whipworm: Trichuris trichiuria Adult habitat: caecum, colorectum No extra-intestinal phase Lifespan: years 90% infections are asymptomatic Symptoms with heavy infections Intensity of infection peaks by age 10

25 Pre-patency: 2 months

26 Whipworm: Trichuris trichiuria Clinical Features: Asymptomatic Physical Weakness, Anemia Stunted Growth, Cognitive Deficits Stool frequency (12+/day), nocturnal stooling Trichuris dysentery syndrome Trichuris colitis Rectal prolapse Treatment: Albendazole x 3 days.

27 Whipworm: Trichuriasis Colitis

28 Rectal Prolapse from Trichiuriasis

29 Whipworm Egg: 2 polar plugs

30 The Human Hookworms Necator americanus Ancylostoma duodenale

31 Hookworm: Necator americanus & Ancylostoma duodenale One – tenth the worlds population infected Significant cause of anemia & protein malnutrition Adult habitat: small intestine Lifespan: ~ 1 year ( A. duodenale ) ~ years ( N. americanus ) Worm burdens do not decline in adult years

32 Typical Age and Intensity of Infection Relationship Mean Age (y) Mean Worm Burden (%) Trichuris Ascaris Hookworm

33 Human Hookworm Infection ~600 million cases worldwide (rural poverty >>> urban slums) 44 million pregnant women infected Iron-deficiency anemia: Physical & Intellectual Retardation Necator americanus is the predominant hookworm species

34 Life Cycle of Hookworm Pre-patency: months - year

35 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

36 Adult Hookworms in Situ (1 cm) Adult size: cm Daily eggs per worm: 5 20,000

37 Hookworm: Clinical Features: Ground-itch –> Dry cough, wheezing (1-2 wks later) in primary infection Abdominal discomfort Progressive iron-deficiency anemia 40 – 160 worms associated with Hgb < 11 g/dL Failure to thrive, extreme fatigue IQ loss Treatment: Albendazole x 1 dose

38 Hookworm Disease Pallor and Facial Edema Anasarca

39 At-Risk Populations for Hookworm Disease Women and Children: Low Iron Stores Children: Physical growth stunting Cognitive deficits and intellectual retardation Women of Child-bearing age Puberty Menstruation Pregnancy Increased Maternal Mortality (anemia) Low Birthweight Infant Mortality

40 School Based Deworming 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

41 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

42 Strongyloidiasis: Strongyloides stercoralis Worldwide prevalence: ~100 million Adult habitat: duodenum, jejunum Lifespan: unknown. Ongoing autoinfection.

43 Strongyloidiasis - Clinical Presentation Asymptomatic eosinophilia Abdominal pain Dermatitis - larva currens Pulmonary infiltrates with eosinophilia Dissemination with sepsis

44 Strongyloides* by ethnicity Regions Hospital, St. Paul, MN 1/1/88 - 9/1/98 Ethnicity N % Cambodian Hmong Vietnamese African85.0 Hispanic42.5 Laotian21.2 Unknown % Microbiology Lab Regions Hospital * Positive stool specimens

45 Documented length of infections in years Adapted from Hospital for Tropical Disease London, 1997

46 Pruritic Larva Currens from Strongyloides Larva currens = autoinfection with Strongyloides filariform larvae Moves rapidly (2 10 cm/hr), lasts shorter than CLM

47 Copyright © 2006, 1999 by Elsevier Inc. Strongyloides Rhabditiform Larvae may transform to Filariform Larvae… penetrating perianal skin and bowel mucosa Adult Filariform Larvae (penetrating) Rhabditiform Larvae

48 Strongyloidiasis Hyperinfection: Strongyloides stercoralis Hyper-Infection: intestinal perforation hemorrhagic pneumonia shock, sepsis, gram-negative meningitis eosinophilia may be limited

49 Vietnamese male, in US for 8 years, developed fever, rash and pneumonia after being placed on steroids for uveitis.



52 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

53 Prevalence of Intestinal Parasites Among Refugees Arriving in Minnesota, pre-May 1999 (n = 4,584) PrePostPrePostPrePostPrePostPrePostPrePostPrePost GiardiaHookwormTrichurisAscarisStrongy - loides Any helminth Multiple helminths 10.2% 8.7% 8.2% 3.7% 2.3% 21.5% 3.1% Giardia Hookworm Trichuris Ascaris Strongyloides Any helminth Multiple helminths Percentage

54 Prevalence of Intestinal Parasites Among Refugees Arriving in Minnesota, pre/post-May 1999 (n = 18,015) PrePostPrePostPrePostPrePostPrePostPrePostPrePost Any helminth Multiple helminths 10.2% 8.7% 8.2% 4.6% 0.3%0.6% 8.5% 3.7% 2.3% 21.5% 3.1% Hookworm Giardia Hookworm Trichuris Ascaris Strongyloides Any helminth Multiple helminths GiardiaTrichurisAscarisStrongy - loides Percentage 8.4% 0.5%

55 To Review… General Truths about Nematodes Polyparasitism Burden greatest in children except hookworm, ? Strongyloides Dont Multiply in Host (2 exceptions) Eosinophilia = tissue invasion Larval stages or Strongyloides

56 Recommended References TROPICAL INFECTIOUS DISEASES Principles, Pathogens, & Practice, Second Edition, 2006 Guerrant, Walker, Weller Churchill Livingstone MANSONS TROPICAL DISEASES Twenty-first Edition, 2003 Cook & Zumla W.B. Saunders ATLAS OF TROPICAL MEDICINE & PARASITOLOGY Sixth Edition, 2007 Peters & Pasvol Mosby Elsevier RED BOOK 2006 Report of the Committee on Infectious Diseases Table Drugs for Parasitic Infections

57 Acknowledgements for Slides Stephen Swanson, MD, DTM&H, Hennepin County Medical Center, Minneapolis Peter Hotez, MD, PhD, FAAP President, Sabin Vaccine Institute Microbiology, Immunol, & Tropical Medicine The George Washington University School of Medicine

58 Post test with answers What is the most likely worm to be coughed or vomited up? Trichuris Hookworm Strongyloides Tapeworm Ascaris

59 Which worm infection do you ALWAYS want to treat? Ascaris Trichuris Strongyloides Pinworm Hookworm

60 Which worms burden of illness increases through your late childhood and early adulthood years? Strongyloides Hookworm Ascaris Trichuris Pinworm

61 Which worm infection is most likely to mimic colitis? Trichuris Ascaris Strongyloides Pinworm Hookworm

62 Which Nematode is the most likely to be the cause of eosinophilia in an immigrant/refugee from Africa who has been in America x 9 months? Trichuris Strongyloides Pinworm Hookworm Ascaris

63 When is the ideal time to check Stool O & P in Returning Traveler? IMMEDIATELY upon landing Within 1 week 1 month 2 month 6 months 1 year

Download ppt "Intestinal Nematodes and Eosinophilia Patricia F Walker, MD, DTM&H Medical Director, HealthPartners Center for International Health Associate Professor,"

Similar presentations

Ads by Google