Global Health Pre-Trip Session

Helminthic infections seen in developing nations:

Neglected Tropical Diseases!

Paul M Southern, MD, DTM&H

2013 Diseases to be covered

:

(cystic hydatid): granulosus

: duodenale,

Lymphatic : , , B. timori

:

: mansoni, S. haematobium, S. japonicum, S. intercalatum, S. mekongi

: Stongyloides stercoralis

: , T. saginata,

: Diseases NOT covered

Enterobiasis (): Enterobius vermicularis

Filaria (others): , ozzardi, M. perstans, M. streptocerca, Dirofilaria spp.

Intestinal cestodes (rarer): , H. diminuta, Dipyllidium caninum, latum, agents of

Intestinal (rarer): Capillaria philippinensis, spp.

Other trematodes: intestinal, , lung

Tissue nematodes: many

Not covering ANY protozoa, despite their great importance Global Estimates of number of soil- transmitted helminths (millions), WHO

Ascariasis: 1,222

Trichuriasis: 795

Hookworm: 740

Strongyloidiasis: ~500*

* = incomplete data Estimated number of DALYs lost (thousands) by cause [helminths only]*

Schistosomiasis: 1,707 worldwide, 1,502 Africa

: 5,941 worldwide, 2,263 Africa, 3,525 SE Asia

Onchocerciasis: 389 worldwide, 375 Africa

Ascariasis: 1,851 worldwide, 915 Africa, 404 SE Asia

Hookworm: 1,092 worldwide, 377 Africa, 286 SE Asia

* WHO data; DALY = disability-adjusted life years Cost-effectiveness of controlling neglected tropical diseases (Cost per DALY averted in $US)

Lymphatic filariasis: 35 – 370 (depends on region)

Schistosomiasis: 10-23, or as much as 844 (depends on strategy)

Onchocerciasis: 9

Soil-transmitted helminths: 2-11 (mass school treatment) (Includes hookworm, ascariasis, whipworm)

WHO-recommended anthelminthic drugs for treatment or prevention

Disease Albend- Mebend- Diethyl- Ivermectin Prazi- Levam- Pyrantel azole azole carbam- quantel isole ezine Ascariasis + + - (+) - + + Hookworm + + - - - + + Lymphati + - + + - - - c filariasis Oncho- cerciasis - - - + - - - Schisto- - - - - + - - somiasis Trichuriasis + + - (+) - (?) (?) Other - - - - + - - flukes Strongyloid- iasis + (+) - + - - - Taeniasis - - - - + - - Morbidity associated with soil- transmitted helminths*

Intestinal bleeding: Hookworm

Malabsorption syndromes: Ascariasis

Competition for micronutrients: Ascariasis

Impaired growth: Ascariasis

Anorexia, reduced food intake: Ascariasis

Diarrhea or dysentery: Trichuriasis

Cognitive impairment: Trichuriasis

Intestinal obstruction: Ascariasis

Rectal prolapse: Trichuriasis

* Montresor, et al.TRSTMH.2010;104:129-32 Taenia Taenia solium

T. solium T. saginata

CLASSIFICATION OF PATHOGENIC AND COMMENSAL HUMAN PARASITES

B. TISSUE CESTODES (Larval) 1. Taenia solium (cysticercoisis) 2. (hydatid ) 3. Echinococcus multilocularis (alveolar hydatid) 4. Multiceps spp. (Taenia multiceps) “Coenurosis”, “Coenuriasis” 5. mansoni, Spirometra mansonoides, others (Sparganosis)

ECHINOCOCCOSIS (Hydatid Disease)

Causative Agents: Echinococcus granulosus Unilocular, simple cysts, cystic hydatid Echinococcus multilocularis Alveolar, complex cysts Echinococcus oligarthrus} Polycystic hydatid Echinococcus vogeli } Manifestations: Cysts in liver, spleen, lung, bone, kidney, muscles, brain, myocardium Diagnosis: Clinical history and examination, imaging techniques, serological tests (ELISA, CF, IHA, arc-5 double-diffusion assay, enzyme-linked immunotransfer blot), hydatid sand in at surgery Treatment: Surgery, pre-and postoperative with or without (scolicidal); albendazole dosage 400 mg BID X 28 days, repeat if necessary; PAIR Echinoccosis granulosus CT Scan of Abdomen,transverse

CT Scan of Abdomen, vertical

View at Surgery Surgical specimen from prior patient

Intestinal obstruction due to Ascaris lumbricoides

Hookworm Life Cycle

Larva currens

Rhabditiform of Strongyloides stercoralis Strongyloides stercoralis on stool culture plate

P A

Taken from:

Wuchereria bancrofti microfilaria in peripheral blood tip nuclei sheath

Brugia malayi microfilaria Brugia malayi, separation of last nuclei Onchocerca volvulus, life cycle

Geography of epidemiology Black fly, (Simulium damnosum)

Schistosome Map, 2006 Major Schistosomes, life cycle Egg Schistosoma intercalatum Schistosoma spp. epidemiology Epidemiology of S. mansoni and S. haematobium in Africa

Cote d’Ivoire Senegal Epidemiology of S. mansoni and S. haematobium in Africa

Beautiful Lake Malawi: notorious as a prime site for of schistosomiasis S. japonicum, mekongi

Similar pathogenesis as S. mansoni More CNS lesions in S. japonicum Salmonella bacteremic infections may occur with most species of Schistosoma S. Japonicum Asia S. japonicum, Asia Transmission of S. japonicum in China

Agricultural irrigation ditch S. japonicum, S. mekongi The End