TWO CLUSTERS OF HANTAVIRUS INFECTION IN TEXAS

Diseases in Nature Transmissible to ManJune 12, 2007

JL Alexander, TDSHS, Zoonosis Control DivisionMN Rivers, Texas Tech University Health Sciences Center, AmarilloRE Rohde, Clinical Laboratory Science, Texas State UniversityJR Pierce Jr, Amarillo Bi-City-County Health District & Texas Tech University Health Sciences Center, Amarillo

Outline

General review of hantavirus

Report of two clusters in Texas

Review of Texas data Implications of this

report

Chronically infected Chronically infected rodentrodent

Virus is present in Virus is present in aerosolized excreta, aerosolized excreta,

particularly urineparticularly urine

Horizontal transmission of Horizontal transmission of infection by intraspecific infection by intraspecific

aggressive behavioraggressive behavior

Virus also present in Virus also present in throat swab and fecesthroat swab and feces

Secondary aerosols, mucous Secondary aerosols, mucous membrane contact, and skin membrane contact, and skin breaches are also sources of breaches are also sources of

infectioninfection

Transmission of HantavirusesTransmission of Hantaviruses

Peromyscus maniculatusDeer mouse

Sigmodon hispidusCotton rat

Subfamily Sigmodontinae associated virusesSubfamily Sigmodontinae associated viruses

VirusVirus HostHost LocationLocation

Sin nombreSin nombre Peromyscus maniculatusPeromyscus maniculatus West & Central West & Central

U.S. & CanadaU.S. & Canada

Monongahela Monongahela Peromyscus maniculatusPeromyscus maniculatus Eastern U.S. & Eastern U.S. &

Canada Canada

New YorkNew York Peromyscus leucopusPeromyscus leucopus Eastern U.S. Eastern U.S.

BayouBayou Oryzomys palustrisOryzomys palustris Southeastern U.S. Southeastern U.S.

Black Creek Canal Black Creek Canal Sigmodon hispidusSigmodon hispidus Florida Florida

Numerous other hantaviruses have been identified but not linked to human Numerous other hantaviruses have been identified but not linked to human diseasedisease

Hantaviruses in the New WorldHantaviruses in the New World

Subfamily Sigmodontinae associated virusesSubfamily Sigmodontinae associated viruses

VirusVirus HostHost LocationLocation

AndesAndes Oligoryzomys longicaudatusOligoryzomys longicaudatus Argentina & ChileArgentina & Chile

OranOran Oligorozomys longicaudatusOligorozomys longicaudatus Northwest ArgentinaNorthwest Argentina

LechiguanasLechiguanas Oligoryzomys flavescensOligoryzomys flavescens Central ArgentinaCentral Argentina

Hu39694Hu39694 UnknownUnknown Central ArgentinaCentral Argentina

Laguna NegraLaguna Negra Calomys lauchaCalomys laucha Paraguay &Paraguay &BoliviaBolivia

BermejoBermejo Oligoryzomys chacoensisOligoryzomys chacoensis Northwest ArgentinaNorthwest Argentina

JuquitibaJuquitiba UnknownUnknown BrazilBrazil

ChocloChoclo Oligoryzomys fulvescensOligoryzomys fulvescens PanamaPanama

Numerous other hantaviruses have been identified but not linked to human Numerous other hantaviruses have been identified but not linked to human diseasedisease

Hantaviruses in the New WorldHantaviruses in the New World

Most FrequentMost Frequent OtherOther RareRare

FeverFever DizzinessDizziness RhinorrheaRhinorrhea

MyalgiaMyalgia ArthralgiaArthralgia Sore ThroatSore Throat

Nausea/VomitingNausea/Vomiting

CoughCough

Shortness ofShortness ofBreath Breath (late in (late in the course of the course of

disease)disease)

HPS - Clinical PresentationHPS - Clinical Presentation

Number of Casesof Hantavirus Pulmonary Syndrome (HPS)

(Region of the Americas, 1993–2004*) 321

331

592

362

48

99

88

35Panama Brazil

Paraguay

UruguayArgentin

a

Chile

36 Bolivia

USA

Canada

= No. of cases

* 2004 using preliminary data.

Total cases = 1910

RI5

11

0

51

41 53

1

13

2

5

14

1

27

721

73

1

2

10

3

8

14

33

30

1

1

35

1

1

7

Hantavirus Pulmonary Syndrome Casesby Reporting State United States – March 26, 2007

Total Cases (N=465 in 31 States)

0 Cases

>=10 Cases5-9 Cases1-4 Cases

Hantavirus Pulmonary Syndrome, United StatesDescriptive Demographic Statistics

March 26, 2007

Gender

Characteristics Total

Ethnicity

Case Fatality

Race

Mean=38 [1-83]

N

MaleFemale

465 (100%)

292 (64%)173 (37%)

White 355 (78%)American Indian 87 (19%)

BlackAsian 3 ( 1%)

Hispanic 65 (14%)

Dead 165 (35%)

Age (years)

7 ( 2%)

Hantavirus in North America Usually sporadic, few clusters reported CDC review (Emerg Inf Dis 1997;3:361) in 1997 of

160 cases determined that few (7%) occurred in clusters

As opposed to South American hantaviruses, no human-to-human transmission has been described in North America

Sin nombre most common type Typically HPS but may have infection without

pneumonia

Cluster #1 – Randall county 07/03 50 year old plumber’s assistant previously

healthy. Smokes. Daily alcohol consumption. Seen in ED with four days of chills, myalgias,

vomiting, cough, and shortness of breath. Thought to have cold and sent home on symptomatic treatment

Cluster #1 – contd Returns to ED two days later with worsening

shortness of breath WBC=9100 (73% segs, 12% bands);

H/H=17.5/52.3; plts=92,000. CXR=RML/RLL interstitial infiltrates

Rapidly deteriorates and dies 48 hours later Autopsy = diffuse bilateral pulmonary edema

with sparse interstitial inflammation Serum IgM & IgG positive for Sin Nombre virus Epidemiologic investigation significant

peridomestic exposure to mice

Cluster #1 – contd

42 year old common law wife also ill with cold, vomiting and fever. Goes to ED, signs out AMA

IgG and IgM positive for SNV Manager of trailer park had been ill one year

previously, admitted to hospital with undiagnosed bilateral pneumonia and eventually recovered. IgG positive for SNV one year later.

Cluster #2 – Crosby county 04/02

Elderly mother expired on 4th day post-admission due

to “pneumonia”

Middle-aged daughter expired with ARD within 24 hours of

admittance 4 days later

Cluster #2 – contd During mother’s illness, case’s younger

brother and family from out of state had visited residence, opened a cabinet and received a “face full of dust”

Approximately two weeks later brother began exhibiting malaise, fever, myalgia; seen in ED and released

1 week later, brother readmitted with respiratory symptoms, tested positive for SNV IgG and IgM

Recovered uneventfully

April/May 2002

Younger brother had visited home during the mother’s

illness and became ill within 4 weeks after returning to AZ

Middle-aged daughter expired with ARD within 24 hours of

admittance 4 days later

Elderly mother expired on 4th day post-admission due

to “pneumonia”

Texas HPS cases 1993 - 2006 32 cases SNV =26, Bayou virus = 4, Unknown = 2 All cases were hospitalized. BV cases were restricted to coastal counties. 19/26

(73%) of SNV cases occurred in Panhandle Plains counties.

Mortality was 40% (46% for SNV vs. 0% for BV) Those aged 20-64 years were overrepresented

(63% of cases vs. 49% of pop)

High Plains Ecoregion

62.5% (20/32) of Texas HPS cases

4.7% Texas Pop

Texas HPS – age and gender

Aged 20-64Male Gender

Texas Population

Case Population

00.10.2

0.30.4

0.5

0.6

0.7

0.8

0.9

Texas HPS cases 1993 – 2006 (cont) Common clinical characteristics included:

fever ≥101°F (83%) nausea and/or vomiting (94%), diarrhea (67%), headache

(86%), hematocrit ≥55% (30%), platelets ≤100,000 (93%),

creatinine ≥1.5 (60%), leukocyte count ≥20,000 (48%), bands ≥10% (85%).

85% of HPS cases reported seeing peridomestic rodents or rodent excreta.

85% of HPS cases were initially seen by a physician and dismissed to home, later to be admitted to the hospital

Texas HPS – clinical characteristics

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Clinical Characteristics

Thrombocytopenia

Bandemia

Hematocrit ≥ 55%

Nausea and/orVomiting

Diarrhea

Hantavirus Texas clusters - conclusions We described two Texas clusters of Hantavirus

infection Both clusters involved Sin nombre virus and occurred

in the Texas Panhandle. 6 people were infected. Five developed an illness

consistent with HPS; one person developed evidence of Hantavirus infection without HPS.

Overall mortality was 50% The diagnosis was initially overlooked in 4/6 patients

and was only suspected when HPS was diagnosed in an epidemiologically related case

Acknowledgements

James Schuermann, BS, TDSHS Zoonosis Branch

Thomas Gerald, TTUHSC Research Associate

Fellow Investigators Megan Rivers, TTUHSC Medical Student Dr. James Alexander, TDSHS Rodney Rohde, Texas State University