Post on 01-Dec-2021
transcript
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LYNNE S. GARCIA, MS, CLS, FAAM
Lynnegarcia2@verizon.net
SCACM
Medical Parasitology: Neglected Tropical Diseases
SPONSOR: MEDICAL CHEMICAL CORPORATION
www.med-chem.com
Consultant for: Medical Chemical, Meridian Biosciences, Savyon, AAB, CAP, Genetic Signatures, BioMérieux,
TechLab, Nanosphere 1
“TROPICAL” DISEASES ?THE MALARIA CAPERS, THE THORN IN THE STARFISH
NEW GUINEA TAPEWORMS AND JEWISH GRANDMOTHERS
“Tropical diseases are as American as the heart attack; yellow fever lived happily for centuries in Philadelphia; malaria liked it fine in Washington, not to mention in the Carolinas. The Ebola virus stopped over in Baltimore and Taenia solium settled in Brooklyn.” Most tropical diseases are now considered cosmopolitan.
Dr. Peter Hotez
Baylor College of
Medicine
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TROPICAL PARASITOLOGY ?
IN THE PAST to NOW …….
Malaria: California, North Carolina, Holland, marshlands of London
Hookworms: U.S. southerners, California miners, Alpine Swiss tunnel workers
Filariasis/elephantiasis: Charleston, North Carolina
American Trypanosomiasis: Texas to Detroit and Canada; triatomid bugs - other states; >300,000 cases suspected; serologic evidence of exposure
Leishmaniasis: American integumentary: South U.S. to North Argentina 3
WHAT CAN WE EXPECT IN THE
21ST CENTURY ?
Cataclysmic hot and cold storms; hot summers; more drought, floods, disease
World population 9 billion by 2025
Political turmoil and terrorism
People moving to U.S. and other industrialized nations
CO2 level double by 2100
10-20% of coastal land inundated
Wonderful world for insects and diseases they carry!
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MAJOR NEGLECTED TROPICAL
DISEASES (Ranked by Prevalence)
NTD Global Prevalence Population at risk
Ascariasis 807 million 4.2 billion
Trichuriasis 604 million 3.2 billion
Hookworm 576 million 3.2 billion
Schistosomiasis 207 million 779 million
Lymphatic Filariasis 120 million 1.3 billion
Trachoma 84 million 590 million
Onchocerciasis 37 million 90 million
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MAJOR NEGLECTED TROPICAL
DISEASES (Ranked by Prevalence)
NTD Global
Prevalence
Population at
risk
Leishmaniasis 12 million 350 million
Chagas’ disease 8-9 million 25 million
Leprosy 0.4 million Not Known
African Trypanosomiasis
0.3 million 60 million
Buruli ulcer (M. ulcerans) 0.05 million Not Known
Dracunculiasis 0.1 million Not Known6
Disability Adjusted Life
Years
DALY = YLL + YLD
Disability Adjusted Life Years
Time is used as the common metric for
mortality and health states
YLL Years of life lost due to mortality
YLD Equivalent years of healthy life
lost due to disability 7
KEY POINTS NEGLECTED TROPICAL DISEASES
Among most common infections of the poorest people
Nonemerging, ancient conditions
Chronic and disabling, profound stigma in society
High morbidity, low mortality
Disability-adjusted life years (DALYs) NTD = to those of HIV/AIDS, malaria, and tuberculosis
Coendemicity with HIV/AIDS and malaria
Ranking of the “gang of four” for death, DALYs– HIV/AIDS
– NTDs
– Malaria
– Tuberculosis 8
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Entamoeba
histolytica
Clinical Symptoms
▪ Intestinal: diarrhea, dysentery
▪ Extraintestinal: right upper quadrant pain, fever
Clinical specimens
▪ Intestinal: stool, sigmoidoscopy
▪ Extraintestinal: liver aspirate, biopsy, serology
Therapy
▪ Intestinal: Iodoquinol, Diloxanide furoate (cysts)
▪ Symptomatic: Metronidazole (trophozoites)9
ENTAMOEBA HISTOLYTICA
ENTAMOEBA DISPAR
Note: Ingested RBCs
Entamoeba histolytica (pathogen)
Entamoeba dispar (non-pathogen)
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REPORTING
Entamoeba histolytica Complex
If cysts or no ingested RBCs (trophs) are seen or immunoassay is not available:
▪ Entamoeba histolytica/E. dispar/E. moshkovskii, E. bangladeshi, Entamoeba histolytica COMPLEX
NOTE: Entamoeba moshkovskii (nonpathogen)
looks like Entamoeba histolytica/E. dispar; the
name is currently not added to the overall report.
It is more rare and controversy per pathogenicity
(Australia indicates some symptomatic patients)11
Blastocystis spp. (Stramenopile)
Pathogenic
• Central body form, large size range, quantitate
• Multiple nuclei around central body area
• 9/17 subtypes human, HALF PATHOGENIC, rare dissemination (IC)
• Associated with Irritable Bowel Syndrome (4 ST), urticaria; troph
adhesion to epithelium, release of cysteine proteases
• Mucosal sloughing, ↑intestinal permeability, pro-inflammatory cytokine response; subtype variations in pathogenicity
• Common: 1 (Giardia/Dientamoeba 2, 3)
• Prevalence 2016 Lebanon: Blastocystis, 63%; D. fragilis, 60.6%; Giardia,
28.5%; Cryptosporidium, 10.4% 12
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Giardia lamblia
(duodenalis, intestinalis)
Pathogen
• Teardrop shape, spoon
• Two nuclei, stain pale
• Curved median bodies
• Linear axonemes
• Pathogen, 19,733 in 2005
• Water, food borne
• Typical motility, but caught in
mucus
•Fecal immunoassays may
require 2 stools for POS13
Dientamoeba fragilis: Pathogen
• Very pleomorphic, 1 or 2 nuclei
• Nuclei fragmented chromatin or solid
• Pathogenic, transmitted via helminth eggs
• Cyst: animal reservoir, permanent stain
• As common or more common than Giardia
Cyst
~1%
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Pentatrichomonas hominis (NP)
Trichomonas vaginalis (P)
• No cyst forms
• Note different position of undulating membrane
• Nonpathogen (GI tract) and pathogen
(urinary/genital tract) (possible urine
contamination with stool – sexual abuse!!)
NP
P
P. hominis
T. vaginalis
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Cryptosporidium spp. – Clinical
10,500 Cases Reported in 2010
C. hominis (human), C. parvum (animals/humans) C. ubiquitum (zoonotic)
Immunocompetent – GI tract
▪ Self-limiting, profuse watery diarrhea
▪ Cramping pain, nausea, anorexia
Immunocompromised - Disseminated
▪ Severe diarrhea (3-6 liters/day), weeks
▪ HIV patients, CD4 cell count marker
▪ 180-200 cells/mm3 or higher, good
▪ Transplants, water outbreaks 16
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CRYPTOSPORIDIUM SPP.
C. hominis, C. parvum
Modified acid-fast:
stool specimen;
note
sporozoites, 4-6 µm
FA combo reagent
for
Cryptosporidium
and Giardia
Cyclospora 8-10
µm; Crypto 4-6
µm; Artifact ~1
µm; Mod acid-fast
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Cyclospora cayetanensis (Lab confirmed) 1,110 Cases (1997-2008)*
*Does not include year of big outbreaks, 1996 – U.S.
Immunocompetent – GI tract
▪ Malaise, fever, watery diarrhea
▪ Fatigue, anorexia, vomiting, weight loss
Immunocompromised – May disseminate
▪ Relapses for many weeks – in sputum
▪ Up to 12 weeks, biliary disease – AIDS
▪ TMP-SMX effective
BioFire FilmArray (Crypto, Cyclo, E. histo)
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North American Cyclospora
cayetanensis Outbreaks
1990 Tap water 1995, 1996 Fresh Guatemalan raspberries 1996 Basil-Pesto pasta salad, fresh basil 1997 US, Canada raspberries, mesclun 1997 Import voluntarily suspended 1998 US, Canada, fruit salad, raspberries 1999 US, chicken pasta, tomato basil salad 2000 Imported raspberries 2001 Canada, Thai basil 2004 Guatemalan snow peas 2005 US, fresh basil 2009 Cruise ship – multiple countries 2013 US, primarily cilantro, salad mix 2015 US, 29 states, 476 cases, Aug 17, ‘15
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MICROSPORIDIA
Pathogen (now Fungi)
Group of obligate intracellular, sporesfungi: 10 cases up to 1985
Phylum Microspora, 160 genera, 1,300 spp
Genera (8), 14 species = human pathogens
Possibilities include person-to-person and animal-to-person – Insects??? (water & foodborne; widespread antibodies)
Questions remain (reservoir hosts, congenital infections): as of 2015 20
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Microsporidia Diagnosis
Order: Stool & Urine
Modified trichrome stains (chromotrope)
10X amount of chromotrope 2R, dye in routine Wheatley’s trichrome (O&P)
Tissue Gram stains recommended
PAS, silver stains acceptable, H&E NO
Calcofluor, but non specific (stool)
Fecal immunoassays under development; available in Europe 21
Microsporidia – Polar Tubule
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MICROSPORIDIA
Intestinal Tissue Urine: Calcofluor White
Spores in NA aspirate
Spores, muscle Corneal button Corneal stroma
Eye Infections Cytospin
Gram stain
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Microsporidia Genera – Clinical(Eye infections mimic herpes virus stromal
keratitis)
Enterocytozoon bieneusi - IMPORTANT• Enteritis, cholangitis, cholecystitis,
pneumonia, bronchitis, sinusitis, rhinitis
Encephalitozoon intestinalis - IMPORTANT• Enteritis, cholangitis, cholecystitis, nephritis, urinary
tract infection, sinusitis, rhinitis, bronchitis, keratoconjunctivitis, disseminated
Pleistophora, Trachipleistophora, Vittaforma, Anncaliia, Microsporidium, Brachiola, Tubulinosema
• Hepatitis, peritonitis, encephalitis, urinary tract, intestinal, keratoconjunctivitis, sinusitis, rhinitis, disseminated infection 24
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Naegleria fowleriPrimary Amebic Meningoencephalitis
(PAM) – Neti pot sinus irrigation
28-year-old male developed PAM after a history of
irrigating sinuses daily with tap water and Neti pot
Admitted with severe headache, vomiting, fever, neck and back pain; CSF = bacterial meningitis; antibiotics
Wet mount of CSF = amebae; patient expired
51-year-old female PAM after 3 days of altered mental status, nausea, vomiting, high fever
Died 4 days later; Neti pot use; faucets PCR +
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PATHOGENIC FREE-LIVING
AMEBAE: Acanthamoeba
Environment Soil, air, fresh water, salt water, sewage
Washing the face in pond water, sand/dust
in eye, inhalation, traumatic injection, entry
through existing wounds or lesions
Disseminated InfectionsSkin, brain, bones
Rhinosinusitis, keratitis, otitis, vasculitis, endophthalmitis reported in HIV infected persons
Skin lesions present in absence of CNS involvement
ImmunocompromisedAIDS, lung, kidney, or liver transplants
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PATHOGENIC FREE-LIVING AMEBAE
AGAR PLATE CULTURE
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NEGLECTED TROPICAL DISEASES
Arctic Canada, Alaska
Trichinosis (Trichinella spiralis nativa)
– Inuit, 150,000 indigenous people (rely on hunting, fishing); Europe – horse meat
– Absence of fruits, vegetables (sea mammals, polar bears)
– 60% polar bears infected, walrus often the cause
Toxoplasmosis: 60% pos (seal, caribou)
Echinococcosis
– Cystic: (E. granulosus) (wolves, sled dogs), 12,000 Inuit
– Alveolar: (E. multilocularis) now moving into Canada, Dakotas, Montana, Wyoming
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ECHINOCOCCUS
MULTILOCULARIS
(Alveolar Hydatid Disease)
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ECHINOCOCCOSIS
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MAJOR NTDS – U.S., Canada
(Ranked by Prevalence) * No data: Dientamoeba
Blastocystis
NTD Estimated No. of Cases
Giardiasis* 424,120 - 2,120,600
Toxocariasis 323,000 - 500,000
Chagas’ Disease 150,000
Strongyloidiasis 68,000
Cysticercosis 2,800 – 41,400
Cystic Echinococcosis 12,000
Congenital Toxoplasmosis 400 – 4,000 per year
Trichinellosis 1,500
Alveolar Echinococcosis <10032
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NEGLECTED TROPICAL DISEASES
Mexico and the Caribbean
Onchocerciasis: (Onchocerca volvulus) southern states
of Chiapas, Oaxaca
– Use of ivermectin widely used, no new cases of blindness
Hookworm, other soil transmitted helminths
Cutaneous leishmaniasis cases on the increase
Chagas’ disease: >1,500 new cases (1990-2005)
Amebiasis (Entamoeba histolytica)
Caribbean: Lymphatic filariasis, schistosomiasis,
hookworm33
NEGLECTED TROPICAL DISEASES – U.S.
Soil Transmitted Helminths (1)
Toxocariasis
Toxocariasis (ingestion of Toxocara eggs – dog ascarid parasite)
– Visceral Larva Migrans
– Ocular Larva Migrans (retinoblastoma)
– Covert Toxocariasis (asthma); link in Europe
1970’s: 4.6-7.3% children (African-Americans –30%), various areas within U.S.
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NEGLECTED TROPICAL DISEASES – U.S.
Soil Transmitted Helminths (2)
Toxocariasis
1990’s: Connecticut rural, urban areas – 10%
serology pos; poor Hispanic children (up to 50%
in Bridgeport), 27.5% playgrounds in Wallingford
contaminated with Toxocara eggs (2005)
New York City: 5% children tested for lead were
positive for previous T. canis infection (1987)
Possibility of 500,000 inner city American
children have/had toxocariasis (major East Coast
and Southern cities)35
TOXOCARIASIS
VLM, OLM, NLM
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NEGLECTED TROPICAL DISEASES – U.S.Soil Transmitted Helminths (3)
Strongyloidiasis
Strongyloidiasis (enteritis and diarrhea; fatal disseminated disease in immunocompromised)
Chronic >40 yrs, steroids, transplants
Endemic rural Appalachian region of U.S. (6.8 mil); estimated 68,000 cases (Strongyloides stercoralis)
Eastern Kentucky and Tennessee: 1-4% infection
Worldwide: 30 million in Asia, Africa, Americas
Sputum Stool
Colon
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Strongyloides stercoralisCulture good sensitivity (serology fair) – results vary
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DIROFILARIA SPP.
IN U.S.
Dog heartworm, mosquitoes
Human subcutaneous nodules, lung parenchyma “coin lesions” –x ray
Ocular, inflammation, pain, blurring
No microfilariae in blood, serologies poor
Surgical/autopsy worm ID
Often misdiagnosed, harmful interventions
Emerging zoonosis in US, many dogs positive
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RARE INFECTIONS in U.S.
Baylisascaris procyonis – Raccoon
Serology: CDC
Raccoon ascarid, zoonotic disease; eggs/juveniles
Human: egg/dirt ingestion; not reportable disease
–Young children, VLM, NLM
–Lethargy, coma, blindness, death
–Larval growth (2 mm); very vigorous
Diagnosis: (larvae in tissues); raccoon latrines, many extremely resistant eggs; not killed 44ºC
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LIVER AND LUNG TREMATODES
(Flukes)
>50 million people infected, >1.1 billion exposed
Aquaculture: 48.2% (2012), water/snail exchange
Life cycles tend to be complex with one or more intermediate hosts as well as definitive hosts (require freshwater snail in life cycle)
Humans serve as the definitive host - immigrants
Ingestion of metacercariae encysted on plant material or within fish, crabs, crayfish, etc.
Most well known infections: Clonorchis sinensis, Opisthorchis, Fasciola, and Paragonimus spp.
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CLONORCHIS SINENSIS (Chinese Liver
Fluke)
Pathogenic: Yes, worm burden, cholangiocarcinoma
Acquired: Ingestion of infective metacercariae encysted in raw or poorly cooked freshwater fish (aquaculture)
Body site: Bile ducts and liver
Symptoms: None to acute pancreatitis, biliary tract obstruction
Clinical specimen: Stool
Epidemiology: China, Japan, Korea, Malaysia, Singapore, Taiwan, Vietnam, human to human; animal to human (dogs, cats, fish-eating mammals)
Control: Improved hygiene, fecal waste disposal, adequate cooking of freshwater fish 43
BLOOD TREMATODES
(Flukes)
200 – 300 million people in 77 countries
Rounded with separate sexes, blood vessels, non-operculated eggs, no encysted metacercariae
Life cycles tend to be complex, requiring freshwater snail in life cycle
Humans serve as the definitive host
Skin penetration by cercariae released from the freshwater snail.
Most well known infections: Schistosoma mansoni, S. haematobium, S. japonicum 44
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SCHISTOSOMA SPP.
(Blood Flukes)
Potential diagnostic problem: premature hatching
Concentration: use saline, not water (stool, urine)
Note expansion of miracidium larva once
released from shell.
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BABESIA SPP.
Babesia divergens: Europe
– Rare, but 42% mortality
Babesia microti: US, parts of Europe, Japan
– Northeast, south to New Jersey; 5% mortality
– Most cases mild; more severe in immunosuppressed
WA1, CA1, MO1 (Babesia divergens-like), states
– Very serious in splenectomized patients
– Related to canine pathogen, B. gibsoni
WA1, CA5: Now Babesia duncani
– More pathogenic than B. microti
Ixodes
scapularis
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Other blood parasites: Babesia spp.
Maltese Cross varies
Artifacts Plasmodium falciparum
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LEISHMANIASIS – KEY FACTS~350 Million in 88 countries at risk
Cutaneous: macrophages of skin
Old World: L. tropica, L. major, L. aethiopica
New World: L. mexicana, L. braziliensis
Mucocutaneous: macrophages of skin and buccal cavity or nasopharynx
L. braziliensis
Visceral: macrophages of spleen, liver, bone marrow (reticuloendothelial system)
L. donovani, L. infantum
American integumentary: cut/mucocut presentations on American continent
South U.S. to North Argentina
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CUTANEOUS LEISHMANIASIS
: CLINICAL PRESENTATION
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INTEGUMENTARY LEISHMANIASIS
L. mexicana Complex
Common throughout Mexico, Belize, Guatemala and southern United States (Arizona, Texas)
Forest rodents (wood rats) are important hosts
Prolonged exposure = “chicleros” live in forest collecting chewing gum latex (30% infected in first year), timber cutters, road builders, farm workers
Two culture-positive and four PCR-pos rodents Leishmania-positive. Isolates extend geographic and ecologic range of enzootic leishmaniasis in the United States and represent a new host record. Now in Tucson, Arizona. South US to North Argentina.
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MUCOCUTANEOUS/INTEGUMENTARY
LEISHMANIASIS
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CUT/MUCOCUT LEISHMANIASIS:
DIAGNOSIS
Organism isolation by smear or culture; histology
Lesion sampling: dental broach, slit scrape method, aspiration of lesion edge (multiple samples required), biopsy
Tissue sampling better than other smearing techniques; culture positive in 80% of cases
LD bodies seen in about 30% of patients; many lymphocytes/plasma cells in wet ulcerative lesions; dry lesions = granulomas / fewer cells
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AMERICAN TRYPANOSOMIASIS
(No longer South American)
Chagas’ Disease – Trypanosoma cruzi, MD suspicion
Transmission –feces of triatomid bugs (kissing bugs,
reduviid bugs); U.S. bugs infected; POTENTIAL; possible
anaphylaxis; Chagas Detect Plus Rapid (InBios) POC
Bug’s feces contact site of bug bite or mucus membranes;
transfusions, congenital infections
Mexico, Central, South, and North America (Texas, LA,
Georgia, California); rural areas; dogs, cats, opossums,
rodents, armadillos important reservoir hosts
Latin America: #1 impact on health, social systems; dogs
sentinel animals for organism reintroduction 53
CONFIRMED BLOOD DONATIONS:
CHAGAS’ DISEASE
Spread of Triatomid Bugs
>300,000 infected with T. cruzi in US; 300 new
congenital infections in US/yr; Canada also high
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AMERICAN TRYPANOSOMIASIS–
CLINICAL DISEASE
Initial infection often asymptomatic –years later chronic
form of disease; acute disease, children
Unilateral periorbital edema (Romaña’s sign)
Lesion, fever, lymphadenopathy, myocarditis,
hepatosplenomegaly, meningoencephalitis
Chronic disease = cardiomyopathy, congestive heart
failure or arrhythmias; dilation of esophagus or colon;
“MEGASYNDROME”
xenodiagnosis
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TOXOPLASMA
GONDII
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INFECTIONS IN HIV+ INDIVIDUALS
Toxoplasmosis
Toxoplasmosis; enhance HIV-1 replication
15.8% US positive for IgG antibodies; at risk for reactivation of latent infection
–Oocysts in cat feces, rare/raw meats,
in utero, transfusions, transplantation
–Most infections asymptomatic
–Severe CNS problems in compromised
Diagnosis problems: serologies
Tissue isolation hard to interpret57
SUMMARY
“Tropical Parasitology” may be somewhat misleading, since these diseases do not seem to be confined to particular areas of the world.
The world is not as compartmentalized as we may think.
Potential changes in the 21st century will support the spread of these diseases in many areas of the world.
The Neglected Tropical Diseases (NTDs) and their impact on global health will become more widely recognized and more important.
The expansion of mass drug delivery systems and vaccine development will continue to be supported by the need to control and eliminate these infections.
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10 LEADING CAUSES OF GLOBAL DALYs*DALYs (the number of healthy life years lost from
disability or premature death) lost annually.
Lower respiratory infections 91.4 million
HIV/AIDS 84.5 million
Unipolar depression 67.3 million
Diarrheal diseases 62 million
Ischemic heart disease 58.6 million
NEGLECTED TROPICAL DISEASES 56.6 million
Cerebrovascular diseases 49.2 million
MALARIA 46.5 million
Road traffic accidents 38.7 million
Tuberculosis 34.7 million59
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