Dengue, Region 11, 2013 Brian R Smith, MD, MPH - PowerPoint Presentation

1. Dengue, Region 11, 2013Brian R Smith, MD, MPHRegional Director, HSR 11Harlingen, TX

2. DengueEmerging vector-borne disease Spread by Aedes mosquitoes infected with dengue virus~500,000 hospitalizations/year~25,000 deaths/yearAcute febrile illnessCommon symptoms: fever, headache, myalgia, retro-orbital and joint pain, rashComplications: effusion, hemorrhage, shock, deathCase-fatality rate: 0.5–5%Image (top): “Train-the-Trainer” course material, CDC 2010.Image (bottom): Simmons et al., “Current Concepts: Dengue,” NEJM 2012.

3. Dengue is the most prevalent mosquito-borne viral disease All DENV types can cause full spectrum of diseaseInfection confers lifelong DENV type-specific immunityShort-term cross-immunity (≤2 months)Can have dengue four times in lifeGenetic variation within typesSome genetic variants thought to be more virulentDengue VirusSabin 1959. Viral and Ricketsial Infections of Man. Third Edition Philadelphia: JB Lippincott Company, 361-373.

4. Members of family Flaviviridae, genus FlavivirusLike other flavivirus, DENV can cause neurologic diseaseDengue Virus Selected FlavirusesTick-borne encephalitis virus West Nile VirusMurray Valley Encephalitis VirusJapanese Encephalitis VirusSt. Louis Encephalitis VirusDENV - 1DENV - 3DENV - 2DENV - 4Yellow Fever Virus

5. Transmission of DENVAcutely infected, viremic person gets bitten by mosquito Days70142128Mosquito ingests DENV in blood meal. DENV replicates in its body for 8-12 days before able to transmit DENV to personInfected mosquito bites another person and transmits DENV. DENV replicates in person for 3 to 14 days before symptom onsetExtrinsic Incubation Period Intrinsic Incubation PeriodPossibility of Blood-borne TransmissionMosquito-borne Transmission

6. ~3.6 billion people live in areas with endemic dengue~400 million annual DENV infections~100 million annual symptomatic cases per year~21,000 annual dengue deathsEpidemiology of DengueImage: CDC Yellow Book, 2012. Bhatt, et. al. Nature 2013.

7. Dengue Worldwide, 1955–2010Data source: WHO DengueNet

8. Global Dengue~3.6 billion people live in areas with endemic dengue1~400 million annual DENV infections, 100 million cases21WHO Dengue Guildelines, 2009.2Bhatt et al., Nature, 2013.

9. Dengue in the AmericasAedes mosquitoes nearly eradicated from the Americas by 1970DENV reintroduced into the Americas in 1970’s Declining or lack of effective mosquito control Increased domestic mosquito larval habitatsDHF epidemics beginning in the 1980’sImage: Gubler. Clin Microbiol Rev 1998 . Black = Areas with Aedes mosquitoes

10. Increasing Disease Severity in the AmericasImages: San Martin et al., Am J Trop Med Hyg 2010.4.6-fold increase in dengue cases from 1980 to 200716.4 per 100,000 in 1980s  35.9 in 1990s  71.5 in 2000-20078.3-fold increase in DHF cases0.8 per 100,000 in 1980s  1.2 in 1990s  1.7 in 2000-20071.3% of cases were DHF in 1980s  2.4% in 2000-2007Average dengue incidence per 100,000 by country

11. Travel-associated Dengue in US, 2010 Source: ArboNET dataLead StatesNY178FL133CA36NJ29IL23PA22TX19WA19IL19OH16642 cases reported from 38 states

12. Locally-acquired Dengue in TexasHistorical outbreaks1First outbreak 1885-86: >70% of Austin residents affectedLast 1922: ~500,000 cases throughout the stateOutbreaks with locally-acquired cases in border towns1980: 1 case Brownsville, and 27 cases in border Texas towns1986: 9 cases Brownsville (4), Corpus Christi (3), Laredo (2)1995-6: 7 cases Brownsville (3), McAllen (4)1999: 2 cases Laredo2004: 4 cases Brownsville2005: 5 cases BrownsvilleCase detection often involved serosurvey or enhanced surveillance1Ehrenkranz et al., NEJM 1971. 2Ramos et al., Am J Trop Med Hyg 2008

13. Determinants of Local DENV TransmissionVirus introduced via returning travelerCompetent mosquitoesEstablished or transient Aedes populationSusceptible humansUnexposed to the introduced DENV type Source: Chester G. Moore, Dept. of Microbiology, Immunology & Pathology, Colorado State UniversityAedes albopictus Aedes aegypti

14. Travel-associated Dengue Cases Reported to ArboNET, 2010 (N = 1,357)Source: ArboNETCases were reported throughout the yearLeading travel destinations: Puerto Rico, Dominican Republic, Haiti and other Caribbean IslandsNo. of PR dengue casesWeek of onsetNo. of US dengue cases

15. TimeSeasonalEpisodicPlaceGeographic differencesFocalDengue EpidemiologyBrazilPuerto RicoPeruMexicoImages (top): San Martin et al., Am J Trop Med Hyg 2010.Image (bottom left): Tomashek et al., AJTMH, 2010.Image (bottom right): Paz-Soldan et al., AJTMH, 2010.

16. Dengue in Texas2005: 32 cases reported; outbreak in Matamoros affecting one Hidalgo County and 25 Cameron residents; 3 locally acquired1999: 66 cases reported; 55 cases in South Texas (28 in Webb County; others from Cameron, Hidalgo, Starr, Willacy and Nueces Counties; 16 acquired in South Texas)1995: 29 cases reported; 13 in Cameron and Hidalgo Counties, including 7 locally acquiredSource: A. Banicki, EWIDS, OBH, DSHS Region 11

17. Locally-Acquired Dengue in the United StatesFrom 1946 through 1979, there were no locally-acquired dengue cases in the Continental US and HawaiiSince 1980, Texas Hawaii2 Florida1 1Munoz-Jordan et al., EID 2013.2Effler P, et al.EID 2005. 3Ramos M, et al. Am J Trop Med Hyg 2008

18. Passive Dengue Surveillance Reporting based on suspected cases (some or all tested)Detect /predict outbreaks according to national thresholdsMonitor seasonality, age distribution, transmission patternsAllow for effective use of vector control resources Monitor, evaluate and guide interventions (e.g. vaccine)Inherent challengesSub-clinical cases and many mild cases not capturedMay underestimate severity if reports from early in courseUnderreporting (e.g. no time, no incentive to report, etc.)Difficult to compare between countries due to design, clinical acumen and health care seeking behaviorsDengue Surveillance

19. Aedes aegypti is most efficient vector Lives around human habitation; rests in dark areasPrimarily a daytime feeder; bites indoors Lays eggs in artificial, water-holding containers; occasionally water containing plants and tree holesKill mosquitoes and prevent their breeding in home Get rid of containers or empty on weekly basisFix septic tanks and seal toilets that are not usedPrimary Prevention MeasuresFor everyday protection in your homeBreeding sites: plants, pools, water-filled buckets, used tires, empty oil drums, water storage containers etc.

20. Life Cycle of Aedes aegypti EggsLarva PupaAdultFemale lays on average 100-120 eggs on inside of containers (above water) five times in life time. Eggs survive for up to 6 months. Eggs hatch when submerged in water, this process takes <24 hours. Approximately 6 daysTwo daysNote: Fecundability dependent on environmental conditions such as rain, humidity and temperature. The total time for development is dependent upon water temperature and food supply, and typically ranges from 4 to 10 days. Larvae die at temperatures below 10 degrees and above 44 degrees Celsius. EMPTY WATEREMPTY WATERKILL ADULTS

21. There are no antiviral medications to treat dengueIf considering another VHF such as Lassa fever, ribavirin may be beneficial if started early in course1-3  Early initiation of supportive care has been shown to reduce mortality from 10 to <1% among patients with severe dengueIn order for this to happen, the following must take place:Access to CareKnowledgeable CliniciansAnticipatory GuidanceSecondary Prevention MeasuresFor patients with dengueGowen BB, et. al. PloS ONE 2008; 3(11):e3725Cecil’s Text Book of Medicine; 23rd Edition, Saunders Elsevier, 2008.http://www.medicinenet.com/viral_hemorrhagic_fever/index.htm

22. Natural History of DENV InfectionsSurvive95-99.5%Die0.5 - 5%Infection Incidence ~ 5% / year Asymptomatic 75%Symptomatic 25%Dengue fever95-99% Severe dengue1-5%Adapted from Vaccine 2004; 22: 1275-1280

23. Dengue is a systemic and dynamic diseaseClinical presentation varies by phase and severity of illness Important to have knowledge of clinical course and phases so that you can identify cases in timely mannerAfter the incubation period, the illness begins abruptly and is followed by 3 phases: FebrileCritical Convalescent or recoveryClinical Course of DengueDengue Guidelines for Diagnosis, Treatment, Prevention and Control. 3rd edition. Geneva; World Health Organization. 2009

24. Natural History of DENV InfectionsMosquito bite…Incubation…Critical PhaseFebrile Phase Convalescence3 to 5 days1 to 2 days 2 to 7 daysNot viremicViremiaDeath or recoverySymptom onsetDays

25. Corresponds to fever which lasts 2 – 7 days and can be biphasic Defervescence occurs on day 3 – 8 of illnessDefined as when body temperature drops to less than 38°C and remains below this levelFebrile PhaseIncubationCritical PhaseFebrile Phase ConvalescenceNot viremicViremia2 to 7 days

26. Clinical Manifestations in Febrile PhaseWith sudden onset of fever: Flushing or erythema of face, neck and chest for 1 to 2 days. May have injected pharynx and red lips. IncubationCritical PhaseFebrile Phase ConvalescenceNot viremicViremiaDaysClassic signs and symptoms: headache, retro-orbital eye pain, arthralgia, myalgia, or hemorrhagic manifestation. Encephalitis can present early while febrile

27. Days 2 to 6 post onset: Macular or maculopapular truncal rash that spreads to face and extremities. IncubationCritical PhaseFebrile Phase ConvalescenceNot viremicViremiaDaysClinical Manifestations in Febrile Phase

28. Laboratory Findings in Febrile PhaseIncubationCritical PhaseFebrile Phase ConvalescenceNot viremicViremiaDaysViremiaTemperatureLaboratory changesSerology and virologyHematocritIgMPlateletsWBCLeukopeniaMild-to-moderate thrombocytopeniaNormal or slightly increased HCTElevated AST and ALT

29. Critical Phase Occurs around time of defervescence, and lasts for 24 to 48 hoursMost patients improve during this phase while a small proportion develop a clinically significant plasma leakage due to an increase in vascular permeabilitySigns of plasma leakage:Increasing hematocritPleural effusions AscitesHypoproteinemia

30. Around time of defervescence: Petechiae may appear, especially on lower extremitiesWarning signs may develop Severe abdominal pain Persistent vomiting Ascites, pleural effusion Mucosal bleed Lethargy; restlessness Liver enlargement >2cm Drop in PLT with increase in HCTIncubationCritical PhaseFebrile Phase ConvalescenceNot viremicViremiaDaysClinical Manifestations in Critical Phase1 to 2 days

31. Intravascular volume depletion secondary to increased vascular permeabilitySevere hemorrhage may occur especially if they have prolonged shockSevere organ impairment including hepatitis, myocarditis, pancreatitis, neurodengue IncubationCritical PhaseFebrile Phase ConvalescenceNot viremicViremiaDaysClinical Manifestations in Critical Phase

32. Laboratory Findings in Critical PhaseIncubationCritical PhaseFebrile Phase ConvalescenceNot viremicViremiaDaysViremiaTemperatureLaboratory changesSerology and virologyHematocritIgMPlateletsWBCLeukopeniaHigh HCTModerate-to-severe thrombocytopeniaElevated AST and ALTIncreased aPTTDecreased fibrinogen

33. Gradual re-absorption of extravascular fluid takes place in 48–72 hours, and diuresis ensues General well being improves, hemodynamic status stabilises, and patient may become bradycardicLaboratoryHCT stabilises or may lower due to dilutional effect of reabsorbed fluid (hemodilution)WBC usually starts to rise soon after defervescenceRecovery of platelet count is typically later than WBCConvalescent Phase

34. Convalescent rash: Confluent macular rash with round “islands” of normal skin. Can be pruritic and desquamates. Clinical Presentation in ConvalescenceIncubationCritical PhaseFebrile Phase ConvalescenceNot viremicViremiaDaysPhoto from: Perng, et al, 2011, WJV, 1(4):109-130.3 to 5 days

35. Complications During Clinical CourseFluid Overload Pulmonary EdemaNosocomial InfectionsShockEnd Organ DamageHemorrhageEncephalopathyDehydrationHyponatremiaFebrile Seizures*IncubationCritical PhaseFebrile Phase ConvalescenceNot viremicViremiaDays*Note: manifestations of neuroinvasive disease including encephalitis and meningitis may present early in the febrile phase

36. Defined by WHO altered consciousness or focal deficit1DENV infection causes true neuroinvasive disease with anti-DENV IgM or DENV RNA detected in CSF and tissue2,3Encephalitis, seizures & meningitis often occur while febrile;4,5 less common presentations including transverse myelitis and Guillain-Barré Syndrome likely to present lateNeurodengue in ~1 to 3% of hospitalized dengue cases5-7 May account ~5 to 8% of encephalitis in endemic areas7-9DENV thought to enter CNS via infected macrophages or entry may be mediated by cytokine breakdown of BBB2E protein of DENV may mediate neuroinvasivenessSevere Manifestations of DengueNeurologic Disease1 WHO Dengue Guidelines for Diagnosis, Treatment, Prevention and Control, 2009; 2 Sips GJ, et. al. Neuroinvasive flavivirus infections. Rev Med Virol 2011; 3 Ramos C., et. al. J. Neurovirol 1998; 4:465-8; 4 Lum et al, Am J Trop Med Hyg, 1996; 54(3): 256-259; 5 Pancharoen and Thisyakorn, SE Asian J Trop Med Public Health, 2001; 32 (2): 341-345; 6 Cam et al, Am J Trop Med Hyg, 2001; 65 (6): 848-851; 7 Solomon et al, Lancet, 2000; 355: 1053-1059; 8Srey VH, et. al. Am J Trop Med Hyg 2002; 66(2):200-207; 9 Kumar R, et al. J Neuro Sci 2008; 269:41-48.

37. Unrecognized disease Unrecognized shock or prolonged shockUnrecognized occult hemorrhageFluid overloadNosocomial sepsis especially in elderlyCauses of Death in Dengue

38. Dengue Case DefinitionCONFIRMEDClinically compatible illnessANDLaboratory evidence:Isolation of dengue virus from serum and/or tissuesFourfold or greater change in IgG or IgM to one or more dengue virus antigens in paired serum samplesDemonstration of dengue virus antigen in autopsy tissues or serum samples by immunohistochemistry or by viral nucleic acid detection

39. Clinical Case Definition forDengue Hemorrhagic FeverFever, or recent history of acute feverHemorrhagic manifestationsLow platelet count (100,000/mm3 or less)Objective evidence of “leaky capillaries:”elevated hematocrit (20% or more over baseline)low albuminpleural or other effusions4 Necessary Criteria:

40. Signs and Symptoms ofEncephalitis/EncephalopathyAssociated with Acute Dengue InfectionDecreased level of consciousness: lethargy, confusion, comaSeizuresNuchal rigidityParesis (partial loss of movement or impaired movement)

41. Clinical Case Definition for Dengue Shock Syndrome4 criteria for DHFEvidence of circulatory failure manifested indirectly by all of the following:Rapid and weak pulseNarrow pulse pressure ( 20 mm Hg) OR hypotension for ageCold, clammy skin and altered mental statusFrank shock is direct evidence of circulatory failure

42. Epidemiological case definition versus clinical diagnosisBoth epidemiological case definitions and clinical diagnosis rely on defining the specific criteria used to determine whether or not a person has a particular conditionEpidemiological case definitions are done for the primary purpose of conducting surveillance, which allows us to monitor trends in diseases and detect unusual occurrences of diseases, to allow for prompt public health interventionClinical diagnosis is done for the primary purpose of giving quick and appropriate treatment to individual patients

43. PROBABLE Clinically compatible illnessANDSupportive serological findings on a single specimen:IgG titer of ≥ 1:1280Positive IgM antibody test to one or more dengue virus antigens Dengue Case Definition

44. ObjectivesMinimize dengue transmission public educationearly diagnosis vector controlIdentify risk areasEliminate mosquito breeding sitesDengue Public Health Response Guide

45. Actions based on vector and dengue virus activity in the area.Designations: Risk Levels 1 - 4At each level: Conditions Trigger Recommended ResponseDengue Public Health Response Guide

46. Risk Level 3: Public Health WarningConditions: Probability of local transmission is highTrigger: Imported human case that meets dengue case definitionRecommended Response:SurveillanceInvestigate suspected dengue casesAdvise local health departments and medical providers of serologic testing requirementsImplement active surveillance at hospitals

47. Risk Level 3/Recommended ResponseInformation and EducationWarn general publicIntensify community educationControl MeasuresIntensify source reduction in entire cityConduct adulticiding in a radius of at least 200 yards around the residence of the identified case twice a week for two weeks

48. Risk Level 4: Public Health AlertConditions: Local transmission of dengue virus is confirmedTrigger: A locally acquired human case that meets the case definitionRecommended Response:SurveillanceInvestigate suspected dengue casesAdvise local health departments and medical providers of serologic testing requirementsImplement active surveillance at hospitals

49. Risk Level 4/Recommended ResponseInformation/EducationPublicize vector control measuresAlert health professional organizations and area hospitals, clinics, and individual health care providersControl MeasuresIntensify source reduction in entire cityConduct adulticiding in a radius of at least 200 yards around the residence of the identified case twice a week for two weeks

50. Interventions at personal and community levels are key to preventing dengue.Communication and coordination are essential:With the public Between Epidemiology, Environmental Health, and Public Information/Education programs within each agency/jurisdictionAmong neighboring Health Departments and Vector Control agencies on either side of the borderDengue Public Health Response

51. Source: MMWR 56(31); 785-789

52. Dengue in TexasRare in Texas in recent years32 cases reported in 2005, with 25 from Cameron County, 3 with local transmissionReported Cases of Dengue Fever, Texas 1995 – 200501020304050607019951996199719981999200020012002200320042005YearCasesTexasCameron CountySource: A. Banicki, EWIDS, OBH, DSHS Region 11

53. Dengue Cases, Brownsville & Matamoros, 2005BrownsvilleMatamoros# Reported286837# Seen in hospital253820# Lab confirmed25572# Charts available25104Source: A. Banicki, EWIDS, OBH, DSHS Region 11

54. Results: Clinical Syndromes*p-value < 0.01U.S. (%)n=25Mexico (%)n=104Total (%)n=129Syndrome*DF9 (36)70 (67)79 (61)DHF16 (64)34 (33)50 (39)Signs & laboratoryPlasma leakage*20 (80)45 (43)65 (50)Hemorrhage18 (72)68 (65)82 (64)Thrombocytopenia*18 (72)98 (94)116 (90)Source: A. Banicki, EWIDS, OBH, DSHS Region 11

55. MEX Epi Curve 2013

56. Texas: First StepsDengue in Cameron CountyBetween July and October 13 cases of dengue reported Dengue in Hidalgo CountyBetween July and October 5 cases of dengue reportedTexas requests CDC-Dengue Branch assistanceConcerns for autochthonous transmission Previous case definition required arbovirus panelConcern for West Nile Virus and Saint Louis Encephalitis cross-reactivityIs dengue endemic in the Lower Valley?

57. Time Line30 OCT DSHS notified of 10 possible dengue cases in Cameron CountyRD notified state epi Discussed plans with tate epi to bring in CDC dengue team1 NOV Dengue Branch receives call from State Epi4 NOV TELCON Identify stakeholdersIdentify cases and course of action for specimensHold on specimens sent from TX to commercial labsEstablish outbreak priorities7 NOV TELCON Response teams and timeline solidifiedProbable and suspect cases increase to 188 NOV Letter of Invitation received11-25 NOV Texas-CDC dengue field response

58. Key StakeholdersTexas Department of State Health ServicesTexas DSHS Region 11Cameron and Hidalgo County, Brownsville and Laredo City Health DepartmentsCommunity clinicians and residentsCDC Dengue Branch and DGMQ US-Mexico Unit

59. TX-CDC ObjectivesTrain clinician master-trainersConduct cluster investigations and vector surveys Train environmental health in Aedes ID and novel trapsEstablish case definitions and data sourcesPerform laboratory and medical chart review to determine current dengue practice habitsConduct knowledge-attitude-practices survey

60. Master Training for CliniciansTrained more than 100 clinicians and public health practitionersCameron County Health DepartmentCity of Laredo Health DepartmentValley Baptist Family Practice ResidencyValley Regional Medical CenterHarlingen Medical Center

61. Region 11 Cluster InvestigationsCameron County30 cases for enhanced surveillance20 households visited, 60 specimens collectedHidalgo County 6 cases for enhanced surveillance4 households visited, 2 specimens collectedCity of Laredo (Webb and Zapata Counties)10 cases for enhanced surveillance 4 households visited, 13 specimens collectedRegion 112 cases for enhanced surveillance in Willacy1 household visited, 3 specimens collected

62. Household and Individual Survey Tool Data collected on paper forms Uploaded to the PHINData entered in EPI INFO 7 by Region 11Data analyzed by DSHS, Border HealthRisk factors and cluster mapping

63. Vector Surveillance and Environmental HealthPartners in enhanced surveillance activitiesConducted yard assessment for larvae and adult mosquitos Collected data on breeding habitats and adult speciationNeighborhood interventionsDoor-to-door educational fliers and discussions with neighbors Fogging around 1 mile radius of index casesSet 10 traps, including new ovitrapsEntomology training; more than 60 EH inspectorsCameron County HD, San Benito 5 houses visited, 4 with Aedes laraveHidalgo County, City of McAllen

64. DefinitionsSuspect dengue cases in 2013Dengue diagnostic testing ordered from 10 hospitals/5 clinicsICD9 coding from hospitals or clinics listed as dengue (061)Laboratory positive – suspect dengue case with anti-DENV IgM antibody or DENV nucleic acid by PCRLaboratory negative - suspect dengue case with NO anti-DENV IgM antibody or DENV nucleic acid by PCR6 days post fever presentationLaboratory indeterminate – suspect dengue case with equivocal or negative anti-DENV IgM 5 days or less post fever presentation

65. Data SourcesReported to a Health Department within Region 11Identified by retrospective record review10 hospitals and 5 clinics queriedSuspect cases may be lab positive, negative or indeterminateIdentified from commercial lab as positive-DENV by PCRSera from commercial labs/Region 11 (October-December 2013)Identified through enhanced surveillance

66. Suspect Dengue in Border Counties, Region 11 Texas, 2013

67. Dengue Testing Border Counties, Region 11 Texas, 2013

68. Medical Record and Laboratory Review10 hospitals and 5 clinics provided laboratory dataChart review revealed inconsistencies with dengue identification and treatmentPregnant woman with vaginal bleeding discharged to homeFrequent use of NSAIDsSteroids for rashNeuro-dengue not identified

69. Severe Dengue Case77 y/o male presents with fever, malaise, anorexia and weakness x 4 days Third visit to different ER – clinician suspects dengueLeft pleural effusion, presumed pneumoniaPLT 56, WBC 4, Hgb 12.7, HCT 36.9 BUN 32, Cr 1.4 AST 170, ALT 128ID consult recognizes septic shock states “…not sure that this dengue is responsible for the patients hypotension. Hypotension is not very common with dengue.”Complicated course 10 days of hospitalization, discharged to nursing home for rehabilitation for weeks, currently homeSpecimen collect DPO 5 (IgM 2.53 and IgG 20. 62)Currently “fishing with son.”

70. Knowledge, Attitude and Practices SurveyTexas Medical Association will email the link to border county physicians 20 questions selectedPilot physician group identifiedCurrent negotiations with NP and PA associations to broaden survey application

71. Next StepsDSHS will continue enhanced surveillance data analysisRegion will update and manage line listWeekly reporting to CDC through DSHS chain of commandCounty and City Health Departments will continue enhanced surveillance through 31 Dec 13Report suspect cases from hospitals with lab results to CDCAbstraction of medical record for IgM positive casesCDC will oversee KAP surveyCDC will complete laboratory testing on TX specimensCDC will draft abstracts and manuscript for co-author review

72. AFI Surveillance for Border Counties in Region 11Needed to:Identify the various causes of feverRegional differencesTemporal differencesDemonstrate burdenCan affect clinical decision-makingInform decision of who should receive a future dengue vaccineEnable early public health responses to outbreaksProposed approach:Sentinel site(s) in various citiesEnroll patients of all age groups with febrile illnessTest for dengue, rickettsia, leptospirosis…

73. December 31 Results46 laboratory-positive dengue cases were identified. 30 (65%) had detectable anti-DENV IgM11 (24%) had DENV detected by RT-PCR5 (11%) were positive by bothDENV-1 and 3 were detected in 13 and 3 cases, respectivelyCase-patients resided in Cameron (36), Hidalgo (9) and Willacy (1) counties; over half (59%) lived in the City of Brownsville

74. Travel historyTravel to Mexico was reported by 17 (37%) cases13 (28%) cases reported no recent travel37 household members provided a serum specimen and six (16%) had detectable anti-DENV IgM, of which five (83%) had no recent travel history

75. Region 11 Dengue OutbreakSummary of Dengue Cases Current as of January 2, 2014 CountyConfirmed CasesProbable CasesTotal Dengue CasesLocally Acquired CasesCases with Travel History to MXCameron621271210Hidalgo15606Total Cases726331216

76. Region 11 Dengue SummaryLocally acquired dengue cases occurred only in Cameron County. Among the 12 locally acquired cases reported by Cameron County, 2 were confirmed and 10 were probable.Both Cameron and Hidalgo Counties reported cases with a travel history to Mexico. Among the 10 dengue cases in Cameron County with a travel history to Mexico, 3 were confirmed and 7 were probable. Among the 6 dengue cases in Hidalgo County with a travel history to Mexico, 1 was confirmed and 5 were probable.

77. ConclusionsEnhanced surveillance during a dengue outbreak in southern Texas enabled identification of 46 cases13 locally acquired dengue cases have been identifiedLargest clinical number reported during a single year in southern Texas since 1980 per CDC criteriaSixteen percent of household contacts had evidence of recent DENV infection and most were locally acquiredDengue surveillance and laboratory capacity should continue to be strengthened

78. ThanksMany thanks to Dina Sosa for being the IC and to Herminia Alva for leading the epi team, and Laura Robinson and Allison Banicki for the dengue response plan and case definition slidesMany thanks to Dana Thomas, Jessica Adam, Taylor Sharp and the CDC team for leading and teaching and providing slidesMany thanks to Roman Abeyta and team with Cameron County for hosting us and the majority of the field investigation, and to Steven Hinojosa with Hidalgo County