Vector-borne InfectionsVector-borne Infections

Allison Liddell, M.D.Allison Liddell, M.D.Infectious DiseasesInfectious Diseases

September 25September 25thth, 2006, 2006

Clinical Vignette

28yo FBI agent on temporary assignment in the Nantahala forest in Western North Carolina presents with acute onset fever, chills, headache 3 days after Memorial Day.

Exam: confused, ill appearing, a few petechiae present on wrists and ankles

Labs: platelets=75K, mild leukocytosis, mildly elevated transaminase

LP with 75 WBC, mostly lymphocyes with protein=154

Tick-Borne Infections in Tick-Borne Infections in the U.S.the U.S.

Lyme diseaseLyme disease Rocky Mountain spotted Rocky Mountain spotted

feverfever EhrlichiosisEhrlichiosis TularemiaTularemia BabesiosisBabesiosis Colorado tick feverColorado tick fever Tick-borne relapsing Tick-borne relapsing

feverfever Tick-borne encephalitisTick-borne encephalitis Tick paralysisTick paralysis Q FeverQ Fever

Ticks as Effective Disease Vectors:

Feed on blood Wide host range Persistent attachment

(painless)- wide dispersal Longevity Transovarial transmission

(RMSF, tularemia, Babesia) Few natural enemies Resistant to environmental

stresses High reproductive potential

Questing tick

Rocky Mountain Rocky Mountain Spotted FeverSpotted Fever

Described in late 1900’s in Bitter Described in late 1900’s in Bitter Root ValleyRoot Valley

Caused by infection with Caused by infection with Rickettsia Rickettsia rickettsiirickettsii

Obligate intracellular, requires cell Obligate intracellular, requires cell culture to cultivateculture to cultivate

RMSFtransmission

Maintained transovarially in Maintained transovarially in ticksticks

Tick vectors are hard ticks:Tick vectors are hard ticks: Dermacentor variabilisDermacentor variabilis

(eastern US)(eastern US) D. andersoniD. andersoni (western US) (western US) A. americanumA. americanum (south- (south-

southwestern US)southwestern US)

Parola, Clin Infect Dis 2001 Mar 15;32(6):897-928

RMSFepidemiology

Most cases occur Most cases occur May – SeptemberMay – September

Highest rate in Highest rate in children 5 - 9 yearschildren 5 - 9 years

Exposure to dogs, Exposure to dogs, grassy areas risk grassy areas risk factorfactor

8.5% mortality (Billings et al)

TDH Website

TDH Website

RMSF Clinical ManifestationsClinical Manifestations

Incubation period 2 - 14 daysIncubation period 2 - 14 days Onset with fever, myalgias, headacheOnset with fever, myalgias, headache GI findings may mimic an acute abdomenGI findings may mimic an acute abdomen Rash appears 3 - 5 days after onset of feverRash appears 3 - 5 days after onset of fever Meningismus and CSF pleocytosis may occurMeningismus and CSF pleocytosis may occur WBC usually normal, platelets often WBC usually normal, platelets often

decreaseddecreased Hyponatremia occurs in 50%Hyponatremia occurs in 50%

RMSFDiagnosis

Serology IF staining of tissue

specimen PCR under

development

RMSFOutcome

N=6388 over 1981-1998 Annual case-fatality rate 3.3% Risk factors for mortality:

Old age Chloramphenicol only Tetracycline not primary therapy Treatment delayed > 5 days

Holman et al JID 2001

Clinical Vignette

54 yo WM farmer in Missouri presents with 3 day h/o high fevers, chills, headache and marked malaise in June

Exam notes a confused, ill-appearing man but is otherwise unremarkable

Labs note transaminases 3 x normal, platelets 115K, WBC 2.1, CSF 32WBC, protein 127

History of History of EhrlichiosisEhrlichiosis

1935 - 1935 - E. canisE. canis-hemorrhagic -hemorrhagic illness in Algerian dogsillness in Algerian dogs

1950s – 1950s – E. sennetsuE. sennetsu--mononucleosis-like illness in mononucleosis-like illness in JapanJapan

1986 – Ehrlichiosis-patient in 1986 – Ehrlichiosis-patient in Detroit after tick bites in Detroit after tick bites in ArkansasArkansas

1991 - 1991 - E. chaffeensisE. chaffeensis cultured cultured from patient at Fort Chaffee in from patient at Fort Chaffee in ArkansasArkansas

Genus Genus EhrlichiaEhrlichia

Small gram-negative bacteria Small gram-negative bacteria closely related to closely related to RickettsiaeRickettsiae Obligate intracellular Obligate intracellular

parasitesparasites Infect circulating blood Infect circulating blood

elementselements Reside and replicate within Reside and replicate within

membrane-bound membrane-bound cytoplasmic vacuolescytoplasmic vacuoles

Vertebrate reservoirs and Vertebrate reservoirs and arthropod vectorsarthropod vectors

EHRLICHIA CASES BY AGE, ST. LOUIS, 1994-2000

02468

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0-10 11-20 21-30 31-40 41-50 51-60 61-70 71-80 >80

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EHRLICHIA CASES BY MONTH, ST. LOUIS 1994-2000

0

5

10

15

20

25

30

35

40

45

Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec

Nu

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ases

Ehrlichia ewingiiEhrlichia ewingii First discovered in dogs with First discovered in dogs with

granulocytic ehrlichiosis, 1992granulocytic ehrlichiosis, 1992 Disease is milder than Disease is milder than E. canisE. canis

infectioninfection Manifestations include fever, Manifestations include fever,

lethargy and polyarthritislethargy and polyarthritis Found to date in dogs in Found to date in dogs in

Missouri, Arkansas, Missouri, Arkansas, Oklahoma and N. CarolinaOklahoma and N. Carolina

Member of Member of E. canisE. canis genogroup genogroup (cross-reactivity)(cross-reactivity)

Experimental transmission by Experimental transmission by A. americanumA. americanum

Ehrlichiae Causing Human & Ehrlichiae Causing Human & Veterinary DiseaseVeterinary Disease

Day of Treatment & Risk of Day of Treatment & Risk of Complications/DeathComplications/Death

EhrlichiosisEhrlichiosis

Day of Rx Odds Ratio P

1 – 3 1.0 -

4 – 7 2.50 0.114

> 7 4.48 0.014

Fishbein DB et al, Annals Intern Med, 1994

Human Ehrlichiosis Symptoms

HME HGE

Fever 97 94-100

Headache 81 61-85

Myalgia 68 78-98

Malaise 84 98

Rash 36 2-11

Confusion 20 17

Dumler et al, Annu. Rev. Med. 1998. 49:201-213

Human EhrlichiosisHuman EhrlichiosisClinical SpectrumClinical Spectrum

DICDIC PancytopeniaPancytopenia Encephalitis/MeningitisEncephalitis/Meningitis Pulmonary Pulmonary

infiltrates/Respiratory infiltrates/Respiratory failurefailure

Gastrointestinal Gastrointestinal bleedingbleeding

Renal FailureRenal Failure

Human Ehrlichiosis Human Ehrlichiosis LaboratoryLaboratory FindingsFindings

LeukopeniaLeukopenia

ThrombocytopeniaThrombocytopenia

Elevated transaminasesElevated transaminases

HyponatremiaHyponatremia

>>4-fold elevation in IFA4-fold elevation in IFA

PCRPCR

RMSF/EhrlichiosisRMSF/EhrlichiosisTreatmentTreatment

Adults:Adults: Doxycycline 100 mg Doxycycline 100 mg bidbid

Children:Children: Doxycycline 3 mg/kg/day in Doxycycline 3 mg/kg/day in 2 divided doses2 divided doses

Duration: 3 days after defervescence, Duration: 3 days after defervescence, minimum 5-7 daysminimum 5-7 days

Clinical Vignette

34 yo WF owner of a campground presents with a nonhealing lesion on the right index finger for 2 weeks, adjacent to the nail bed.

Failed Augmentin and acyclovir by PCP for “infected paronychia”

Exam notes an ulcerated lesion and regional adenopathy

TularemiaHistory

McCoy & Chapin 1910 “plague-like disease”

of rodents in Tulare Co. CA

Bacterium Tularense Edwards Francis

1928 - 800 cases isolated organism proved vector

named the diseasedeveloped culture and serology methodsnoted risk to workers

Parola, Clin Infect Dis 2001 Mar 15;32(6):897-928

TularemiaTularemiaEpidemiologyEpidemiology

1368 cases 1990-20001368 cases 1990-2000 All states except Hawaii, All states except Hawaii,

but predominately MO, but predominately MO, AK, OK & SDAK, OK & SD

Reinstated on nationally Reinstated on nationally notifiable list 2000 notifiable list 2000 (n=142)(n=142)

Type A (biogroup Type A (biogroup tularensis)tularensis)

Multiple vectors (tick, Multiple vectors (tick, deerfly)deerfly)

>250 animal species>250 animal species rabbitsrabbits hareshares muskratsmuskrats

Other transmissionOther transmission carnivorescarnivores direct contactdirect contact inhalation/ingestioninhalation/ingestion

Peak incidence 1939Peak incidence 1939

Outbreak 2001 Pneumonic Tularemia

15 patients 11 primary pulmonary 1 death

Outbreak 2001 Pneumonic Tularemia

Figure 1. Cases of Primary Pneumonic Tularemia, Tularemia with No Localizing Signs, and Ulceroglandular Tularemia on Martha's Vineyard, May 21 through October 28, 2000, According to the Week of Onset of Illness.

Feldman et al, N Engl J Med 2001 Nov 29;345(22):1601-6

TularemiaTularemiaClinical ManifestationsClinical Manifestations

UlceroglandularUlceroglandular

black based ulcerblack based ulcer

tender regional tender regional

lymphadenopathy lymphadenopathy

bubobubo

TyphoidalTyphoidal

OculoglandularOculoglandular

Primary pulmonaryPrimary pulmonary

TularemiaTularemiaDiagnosisDiagnosis

TitersTiters

4-fold increase4-fold increase

single > 1:160single > 1:160

Skin testSkin test

Culture – notify Culture – notify

laboratorylaboratory

TularemiaTularemiaTreatmentTreatment

Streptomycin 1 gm iv q12h for 10 daysStreptomycin 1 gm iv q12h for 10 days

Gentamicin 5 mg/kg/d for 10 daysGentamicin 5 mg/kg/d for 10 days

Tetracycline/chloramphenicolTetracycline/chloramphenicol associated with 15-20% relapseassociated with 15-20% relapse

QuinolonesQuinolones Excellent in vitro activityExcellent in vitro activity Limited data, anecdotal experience suggests efficacyLimited data, anecdotal experience suggests efficacy

Live attenuated vaccine for high risk groupsLive attenuated vaccine for high risk groups

TularemiaTularemiaComplicationsComplications

Pneumonia Pneumonia

abscess, effusionabscess, effusion

RhabdomyolysisRhabdomyolysis

Acute renal failureAcute renal failure

MeningitisMeningitis

PericarditisPericarditis

Clinical vignette

27yo WM hiker spends a week in the Rocky Mtns in a cabin.

Last day of trip develops fever, chills, HA, myalgias

Resolves in 3 days, then recurs 7 days later

Tick-borne Relapsing Fever

Dutton et al- Described tick relapsing fever, caused by Borrelia duttonii and transmitted by Ornithodoros moubata in W. Africa

13 species of Borrelia genus Ornithodoros

Noctural feeder Short attachment Usual hosts small mammals

Worldwide, but only Western US Occurs in cabin-dwellers

Parola, Clin Infect Dis 2001 Mar 15;32(6):897-928

Tick-borne Relapsing Fever

acute onset of high fever with chills, headache, myalgia, arthralgia, and coughing

Hemorrhage, iritis or iridocyclitis, hepatomegaly, or splenomegaly

rash at the end of the first febrile episode

•neurological findings

•B. turicatae (U.S.)

•B. duttonii (Africa)

•Jaundice ( 7%)

•case-fatality rate 2%-5%

•Primary episode 3 days

•Mean period between episodes 8 days

Tick-borne Relapsing Fever

Borreliae in peripheral

blood of febrile patients.

Sensitivity 70% (darkfield microscopy or Giemsa or Wright's

stain). Quantitative buffy coat Serology not useful PCR

Jarisch-Herxheimer reaction

•doxycycline (Penicillin, erythromycin, or

ceftriaxone)

Clinical vignette

23 yo WF vacationer on Long Island develops fever, malaise, and circular rash on her arm

Lyme

Most commonly reported tick-borne infection in U.S.

1993-1997, mean 12,451 annual cases (CDC)

LymeHistory

Cluster of cases near Lyme, CT 1975

Johnson RC, Schmid GP, Hyde FW, Steigerwalt AG, Brenner DJ. Borrelia burgdorferi sp. nov.: etiological agent of Lyme disease. Int J Syst Bacteriol 1984; 34:496 7.

Lymeepidemiology

B. burgdorferi sensu lato

Tick vector Black-footed mouse

reservoir White-tailed deer host Birds and mammals

implicated in Europe

Lyme DiseaseLyme DiseaseEarly ManifestationsEarly Manifestations

Erythema migrans Erythema migrans (90%)(90%) Occurs 8-14 days after Occurs 8-14 days after

bitebite Single lesion, average Single lesion, average

size 15cmsize 15cm Systemic symptoms Systemic symptoms

may be presentmay be present Secondary lesions may Secondary lesions may

occuroccur

CarditisCarditis Aseptic meningitisAseptic meningitis Bell’s palsyBell’s palsy

Lyme DiseaseLyme DiseaseLate ManifestationsLate Manifestations

ArthritisArthritis Knees involved in 90%Knees involved in 90% Usually resolves, 1-2 weeksUsually resolves, 1-2 weeks May recurMay recur

CNS disease (rare in children)CNS disease (rare in children)

Lyme DiseaseLyme DiseaseDiagnosisDiagnosis

SerologySerology ELISAELISA Western blotWestern blot

Culture on BSK-II Culture on BSK-II mediamedia 57-85% sensitive skin57-85% sensitive skin Blood, CSF, synovial Blood, CSF, synovial

fluidfluid

Warthin-Starry stainWarthin-Starry stain

PCRPCR

Lyme DiseaseLyme DiseaseTreatment of Early DiseaseTreatment of Early Disease

Doxycycline ( Doxycycline ( 8 years of age) 8 years of age)

AmpicillinAmpicillin

Penicillin allergic: cefuroxime axetil or Penicillin allergic: cefuroxime axetil or

erythromycinerythromycin

Duration 14 - 21 daysDuration 14 - 21 days

Lyme DiseaseLyme DiseaseTreatment-Disseminated & Late DiseaseTreatment-Disseminated & Late Disease

Multiple skin lesionsMultiple skin lesions Oral, 21 daysOral, 21 days

Isolated facial palsyIsolated facial palsy Oral, 21 -28 daysOral, 21 -28 days

ArthritisArthritis Oral, 28 daysOral, 28 days

Persistent arthritisPersistent arthritis Parenteral, 14 - 21 daysParenteral, 14 - 21 days

CarditisCarditis Parenteral, 14 - 21 daysParenteral, 14 - 21 days

CNSCNS Parenteral, 14 - 21 daysParenteral, 14 - 21 days

Does Lyme Disease Exist Does Lyme Disease Exist in Texas?in Texas?

Southern Tick-Associated Rash Illness (STARI)

Similar EM rash Long-term and serious

complications not reported

Responds to doxycycline Organism by PCR B.

lonestari No culture 639 cases in Texas 1986-

1996

Lyme-Like Disease in MissouriLyme-Like Disease in Missouri

ECM - YesECM - Yes Serology - usually Serology - usually

negativenegative Complications - RareComplications - Rare Vector - Lone star tickVector - Lone star tick Etiologic agent - variant Etiologic agent - variant

Borrelia species (?)Borrelia species (?) Protection from vaccine - Protection from vaccine -

UnknownUnknown

Tick-Transmitted DiseasesTick-Transmitted DiseasesPreventionPrevention

Avoid tick-infested areasAvoid tick-infested areas

Wear protective clothing that covers exposed areasWear protective clothing that covers exposed areas

Use DEET - containing insect repellantsUse DEET - containing insect repellants

Spray permethrin on clothesSpray permethrin on clothes

Remove attached ticks promptly Remove attached ticks promptly Do not squeezeDo not squeeze

Clinical Vignette

47yo outdoor construction worker in Massachusetts presents with 1 week of fever, chills, DOE in June.

PMH is significant for splenectomy due to trauma.

Lab calls reporting strange finding on blood smear.

Babesiosis

Babesia microti (Europe B. divergens) Worldwide distribution Primary host white-footed mouse

Peromyscus leucopus

Usually tick-borne Can be transfusion-related

Babesiosis

Clinical Features: Most infections asymptomatic fever, chills, sweating, myalgias, fatigue, hepatosplenomegaly, and

hemolytic anemia.  incubation period of 1 to 4 weeks more severe in immunosuppressed, splenectomized, and/or elderly.  B. divergens tend to be more severe usually occurs.

Laboratory Diagnosis: thick and thin blood smears (Giemsa) 

Treatment: clindamycin plus quinine or atovaquone plus azithromycin exchange transfusion has been used in severely ill patients with high

parasitemias.

Infection with Babesia.  Giemsa-stained thin smears.  Note in B the tetrad (left side of the image), a dividing form pathognomonic for Babesia.  Note also the variation in size and shape of the ring stage parasites and the

absence of pigment. 

Babesia microti infection, Giemsa-stained thin smear.  The organisms resemble Plasmodium falciparum; however Babesia parasites present several distinguishing features: they vary more in shape and in size; and

they do not produce pigment. 

Clinical Vignette

48 yo male presents with acute onset episodic fever abdominal pain, headache, myalgias and nausea/vomiting, then profuse sweats.

Recent trip to Thailand looking for exotic bird species.

Exam notes tender right and left upper quadrant and splenomegaly

Labs note pancytopenia

Malaria

300–500 million infections worldwide and approximately 1 million deaths annually (CDC)

Plasmodium falciparum, P. vivax, P. ovale, or P. malariae

infected female Anopheles mosquito

blood transfusion or congenital

Fatal cases are due to falciparum (“knobs”)

P. vivax and P. ovale parasites can persist in the liver (natural infection only)

P. malariae acute illness rare in normal hosts, causes chronic infection (GN)

Malaria

Chloroquine-susc Dominican Republic,

Haiti Central America west

of the former Panama Canal Zone

Egypt some countries in the

Middle East

mefloquine resistance borders of Thailand with

Burma (Myanmar) and Cambodia

western provinces of Cambodia eastern states of Burma

(Myanmar) Fansidar resistance

Amazon River Basin area of South America,

Southeast Asia other parts of Asia large parts of Africa

Malaria

fever and influenzalike symptoms chills, headache,

myalgias, and malaise Classic paroxysm

Chill Spike Sweat

can occur at intervals Falciparum less exact Vivax/ovale tertian Malariae quartian

anemia and jaundice, seizures, mental confusion kidney failure, coma, and

death 6 days after initial exposure

to several months after chemoprophylaxis

MalariaDiagnosis

Peripheral smear Vivax/ovale Falciparum

No mature forms High parasitemia

(directly related to mortality in nonimmune)

Multiple ring forms/cell Infects all ages

Hypoglycemia Lactic acidosis Hemolysis Acute renal failure Pancytopenia

MalariaTreatment

Hospitalize if nonimmune and suspect falciparum

Different drug than prophylaxis

Halofantine cross resistant w/mefloquine

Start 2nd drug later

If vivax/ovale need Primaquine

Artemisin if mefloquin/cholorquine resistance

Exchange transfusion if parasitemia >15% in nonimmune

Malaria Prevention

transmission occurs primarily between dusk and dawn

well-screened areas, mosquito nets, clothes that cover

DEET (N,N-diethylmetatoluamide)

pyrethroid-containing flying-insect spray in living and sleeping areas

Chemoprophylaxis

mefloquine or chloroquine 1–2 weeks before doxycycline and atovaquone/proguanil 1–2 days

before continuously while in malaria-endemic areas 4 weeks (chloroquine, doxycycline, or mefloquine)

after 7 days (atovaquone/proguanil) after Terminal prophylaxis with Primaquine final 14 days

fatal hemolysis in those who are G6PD deficient

Chemoprophylaxispregnancy

Long history of chloroquine and quinine use Data supports safety of mefloquine in 2nd an

3rd trimester Data in first trimester sketchy, patient must

weigh risks No Doxycycline or Primaquine No data for Malarone

Malaria

Persons who have been in a malaria risk area, either during daytime or nighttime hours, are not allowed to donate blood for a period of time after returning from the malarious area. Residents of nonmalarious countries are not allowed to donate

blood for 1 year after they have returned from a malarious area. Persons who are residents of malarious countries are not

allowed to donate blood for 3 years after leaving a malarious area.

Persons who have had malaria are not allowed to donate blood for 3 years after treatment for malaria.

Malaria Information

http://www.cdc.gov/travel Voice information service 1-877-FYI-TRIP CDC Malaria Hotline (770-488-7788) from 8:00

a.m. to 4:30 p.m. Eastern time CDC Emergency Operation Center at 770-488-7100

page person on call for the Malaria Epidemiology Branch.

Clinical Vignette

72 yo WM alcoholic with CAD presents with 3 day h/o fever, myalgias, headache followed by acute onset confusion and tremulousness

Works as a nursery sales rep and travels frequently to East Texas

No improvement on levaquin EKG afib CSF notes elevated protein and lymphocytic

pleiocytosis

Viral Encephalitisarthropod-borne

Alphaviridae Eastern Equine Western Equine

BunyaviridaeLaCrosse

FlaviviridaeSt. Louis

Powassan (ticks)

Japanese

Tick-borne (ticks)

West Nile

Culex

SLE Human CasesSLE Human Cases

EEE Equine CasesEEE Equine Cases

EEE Human CasesEEE Human Cases

SLE Avian CasesSLE Avian Cases

EEE Mosquito PoolsEEE Mosquito Pools

WNV Equine CasesWNV Equine Cases

WNV Human CasesWNV Human Cases

WNV Avian CasesWNV Avian Cases

SLE 5 Human CasesSLE 5 Human Cases

Outbreak or Cluster with Human Case(s)

Arboviral ActivityArboviral Activity Louisiana Louisiana

20012001

Eastern Equine

Eastern US Ave. 4

cases/year Togaviridae,

genus Alphavirus

35% mortality 35% permanent

neuro defect

St. Louis Encephalitis

Aseptic meningitis or encephalitis Majority subclinical or mild illness Intermittent epidemic transmission - up to 3,000

cases per year (1975) Culex mosquitoes Elderly - biological risk factor Low SES areas - environmental risk factor Outdoor occupation - exposure risk factor

St. Louis Encephalitis

Largest outbreaks in 15 years occurred in 1990 Urban transmission in west first recognized in 1987 Deterioration of inner cities, global warming may

increase vector abundance and transmission Unpredictable and intermittent occurrences of

outbreaks Multiple environmental, biological and social

factors contributing to disease occurrence Virus maintenance and overwintering cycle

La Crosse Encephalitis

Frank encephalitis progressing to seizures, coma majority subclinical or mild 70 cases/year Case-fatality ratio <1% Social costs from adverse effects on IQ and school performance woodland habitats in treehole mosquito (Aedes triseriatus) and

vertebrate hosts (chipmunks, squirrels); survives winter in mosquito

Vector uses artificial containers (tires, buckets, etc.) in addition to treeholes

La Crosse Encephalitis

Children <16 years old: biological risk factor Residence in woodland habitats environmental risk

factor Containers at residence environmental risk factor Outdoor activities: behavioral risk factor Traditional endemic foci in the great-Lakes states Increased case incidence in mid-Atlantic states Rural poor most affected Disease is considerably under-reported

West Nile Virus

• First isolated from a febrile adult woman in the West Nile District of Uganda in 1937

• Ecology was characterized in Egypt in the 1950s.

• Cause of severe human meningoencephalitis in elderly patients during an outbreak in Israel in 1957

• Equine disease first noted in Egypt and France in early 1960s.

• Outbreak of West Nile-Like Viral Encephalitis -- New York, 1999. MMWR, 1999:48(38);845-9

• Update: West Nile-Like Viral Encephalitis -- New York, 1999. MMWR, 1999:48(39);890-2

West Nile Virus in the U. S. 2005

Clinical Epidemiology

Incubation period 3 - 14 days 20% develop “West Nile fever” 2006 to date: 2171 cases, 74 deaths in U.S. 1 in 150 develop meningoencephalitis

Advanced age primary risk factor for severe neurological disease and death

West Nile Fever: Classic Clinical Description

• Mild dengue-like illness of sudden onset

• Duration 3 - 6 days

• Fever, lymphadenopathy, headache, abdominal pain, vomiting, rash, conjunctivitis, eye pain, anorexia

• Symptoms of West Nile fever in contemporary outbreaks not fully studied

West Nile Fever: Classic Clinical Description

Symptoms of Hospitalized Patients withWest Nile Virus, New York City, 1999

2%Lymphadenopathy

19%Rash

27%Diarrhea

46%Change in mental status

47%Headache

51%Vomiting

53%Nausea

56%Weakness

90%Fever

Neurological Presentations of West Nile Virus Infection

New York City 1999 Encephalitis/meningoencephalitis 62% Meningitis 32% Complete flaccid paralysis 10%

Confused with Guillain-Barre syndrome EMG and nerve conduction velocity-both axonal and demyelinating lesions,

with axonal lesions most prominent

Preliminary data 2002 Complaints of weakness out of proportion to exam Myoclonus nearly a universal finding Some patients have Parkinsonian

Previous series Ataxia, extrapyramidal signs, cranial nerve abnormalities, myelitis, optic

neuritis, seizures

West Nile Virus

489 WNV-viremic donors as of 9/16/03 two cases of blood transfusion-associated

WNV in 2003, (TX and Nebraska). Both encephalitis and are recovering.

In 2003, all blood banks started screening for West Nile virus and will not take donations from people w/fever and headache in the week prior

1999 and 2000 Serosurvey Results

Location Participants PositivesSeroprevalence

(%)

NYC 1999

Queens677 19 2.6

NYC 2000

Staten Is.871 4 0.46

NYS 2000

Suffolk Co.834 1 0.12

CT 2000

Fairfield Co.731 0 0.0

Clinical Vignette

59 yo Mexican immigrant admit with 3 month history of progressive shortness of breath, PND, orthopnea, LE edema

Chagas’ Disease

American trypanosomiasis (Trypanosoma cruzi)

16-18 million people are infected 50,000 will die each year. poorly constructed houses found in the

rural areas of the above-mentioned countries are at elevated risk of infection. Houses constructed from mud, adobe, or thatch present the greatest risk.

Chagas’ Disease

Reduviid bugs, or "kissing bugs"

South and Central America

deposits feces on a person's skin at night

rubs the feces into the bite wound, an open cut, the eyes, or mouth.

Transplacental, congenital or breastfeeding.

By blood transfusion By eating uncooked food

contaminated feces of "kissing bugs."

early stage of infection (acute Chagas disease) usually is not severe, but can be fatal in infants.

1/3 chronic after 10-20 years.

average life expectancy decreases 9 years.

Chagas’ Disease

Acute: 1% of cases. Romaña's sign fatigue, fever, enlarged

liver or spleen, and swollen lymph glands.

rash, loss of appetite, diarrhea, and vomiting occur. In

infants and in very young children cerebral edema

symptoms last for 4-8 weeks.

Indeterminate (asymptomatic)

Chronic: Cardiac problems, including

an enlarged heart, altered heart rate or rhythm, heart failure, or cardiac arrest are symptoms of chronic disease.

enlargement of parts of the digestive tract, which result in severe constipation or problems with swallowing.

immune compromised, including persons with HIV/AIDS, Chagas disease can be severe.

Clinical Vignette

September 9, 1981, a 72-year-old male from Edinburg, Texas, developed fever and weakness 16 days after being bitten by tsetse flies during a hunting trip in northwest Tanzania. Several days after onset of fever, he noticed a raised, tender, erythematous nodule (6-8 cm in diameter) on the posterior aspect of his right arm.

East African Trypanosomiasis

six patients have shared several characteristics: exposure to infected tsetse flies while visiting game parks in

eastern or southern Africa, development of acute, febrile illness consistent with

Trypanosoma brucei rhodesiense infection 1-21 days after visiting

detectable typanosomes on peripheral blood smears, and recovery after appropriate therapy. Only two of the five earlier cases showed clear evidence of

central nervous system (CNS) involvement; both patients had elevated CSF protein, increased CSF cell count, and trypanosomes in the CSF.

East African Trypanosomiasis

Suramin is recommended for hemolymphatic stage does not cross the blood-brain barrier, Melarsoprol, (relatively toxic) +/- suramin when infection

involves the CNS trypanosomes are observed in the CSF morula cells of Mott or an elevated CSF IgM is strongly

suggest CNS involvement elevated CSF cell count usually should be monitored for CNS involvement during

treatment and at regular intervals for 1-2 years thereafter

Clinical Vignette

36 yo WF presents with nonhealing lesions on face for several months

Frequent travel to Caribbean and Mexico Recent pregnancy complicated post-partum

by acute cholecystitis

Leishmaniasis

Sand fly vector  factors determining the form : species,

geographic location, and immune response of the host. 

Cutaneous leishmaniasis one or more lesions  raised edge and central crater.  painless or painful.  Regional lymphadenopathy

visceral leishmaniasis fever, weight loss, and an enlarged

spleen and liver (usually the spleen is bigger than the liver). 

lymphadenopathy.  pancytopenia  opportunistic infection in areas where it

coexists with HIV.

Leishmaniasis

Leishmaniasis

Diagnosis: biopsy

Treatment: stibogluconate (per CDC) (see Medical Letter)

Don’t forget

Dengue Plague Yellow fever Onchocerciasis Loaiasis West African

Trypanosomiasis

Typhus Endemic Scrub