Vector-Borne Diseases Update: Maricopa County

Transcription

1 Vector-Borne Diseases Update: Maricopa County Craig Levy, Epizoologist, Office of Epidemiology WeArePublicHealth.org twitter.com/maricopahealth facebook.com/mcdph

2 Emerging Arboviruses Zika Virus Chikungunya Dengue Viruses Same Mosquito Vectors Similar Symptoms Rapidly Expanding in the Americas Imported cases Have potential to start transmission here!

3 Mosquito Transmission Zika, Chikungunya, and Dengue Vectors Aedes aegypti and Aedes albopictus are the primary mosquito vectors Infected humans are the reservoir for the viruses. Infections result in high viremias which can persist up to 7 days Aedes aegypti mosquitoes are widespread and thriving in Maricopa County Both mosquitoes bite mostly during the daytime Aedes aegypti are ankle biters Both mosquitoes breed in backyard containers

4 Aedes sp. Breeding Sites

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6 Zika Virus: Discovered in 1947 in the Zika Forest 9/6/2016 Footer 6

7 Zika is a Flavivirus Related viruses: Dengue Yellow fever West Nile St. Louis encephalitis Japanese encephalitis

8 Zika Transmission Mosquitoes Bites Perinatal Sexual transmission Possible transfusion-associated Laboratory exposure

9 Zika Epidemiology Incubation period in people: 2 12 days ~ 80% of infections asymptomatic Extrinsic incubation period in mosquitoes: ~10 days 9/6/2016 Footer 9

10 Zika Symptoms Low-grade fever Joint pain/swelling Muscle pain Rash Headache, retro-ocular pain Conjunctivitis Note: Guillain-Barre Syndrome (GBS) has been reported post Zika 9/6/2016 Footer 10

11 2007: Zika Outbreak in Yap, Micronesia 9/6/2016 Footer 11

12 Zika in Brazil: 2015 Oct-Nov: Increase in microcephaly cases reported in NE Brazilian states ZIKV in amniotic fluid of 2 pregnant women Est. 4,000+ microcephaly cases reported 9/6/2016 Footer 12

13 Cases of microcephaly in Brazil, , for 14 states under investigation

14 Zika Virus During Pregnancy Microcephaly Microcephaly Intracranial calcifications Ventriculomegaly Miscarriage Stillbirth Eye defects Hearing loss Impaired growth and development 9/6/2016 Footer 14

15 Zika World Map 9/6/

16 Zika Cases in Mexico as of Mid-August

17 State of Residence for U.S. Travel-Associated Zika Cases, Jan 2015-August 2016 N = 2,488 imported cases Top Six States NY (24%) FL (19%) CA (6%) TX (5%) PN - 77 (3%) MD - 77 (3%) AZ - 20 (1.0%) 9/6/

18 Zika Update Maricopa County people triaged (travelers and pregnant females) ruled-out 57 - lab testing pending 17 - confirmed cases (all imported/travelers) 9/6/2016 Footer 18

19 Zika in Florida 43 locally acquired infections Additional asx infections Miami-Dade County Wynwood neighborhood and Miami Beach St. Petersburg/Pinellas C imported cases NOTE: all southern states are at risk for local transmission

20 Zika Testing Zika testing is available at AZ State Public Health Laboratory for patients that meet testing criteria Testing (IgM Ab & PCR) also at CMR Labs CMR (+) results require confirmation at ASPHL Contact county HD to request lab testing Viral RNA detected by PCR 14 days post onset urine & serum NOTE: false Negative PCRs occur! IgM antibodies 7 days Possible cross-reaction with other flaviviruses 9/6/2016 Footer 20

21 Current Testing Protocol Priority Testing for: Symptomatic cases with 2+ symptoms and recent travel (within 14 days) to active Zika areas Pregnant females (with, or without sx) with travel to active Zika areas Pregnant females with ultrasound evidence of microcephaly or intracranial calcifications All other requests are assessed case-by-case 9/6/2016 Footer 21

22 Zika Treatment No vaccine or specific treatment Supportive care Treatment with aspirin and NSAIDs discouraged unless dengue has been ruled-out 9/6/2016 Footer 22

23 Zika Prevention Mosquito avoidance during & after travel Travel alert issued by CDC pregnant mothers should NOT travel to Zika affected areas Pregnant women should abstain from sex or ensure condoms used during sex with men who have travelled to Zika affected areas for the duration of pregnancy Blood donors wait 28+ days after returning from Zika active areas 9/6/2016 Footer 23

24 Patient Communication For suspected cases of Zika, chikungunya or dengue educate patients the importance of avoiding mosquito bites for at least 7 days after onset, and to notify public health officials immediately if any family members develop sx NOTE: lab testing/results are NOT 100% reliable!! Negative results are not always negative.

25 Zika Surveillance & Response Enhanced human case surveillance & testing Mosquito Surveillance Valley wide trapping and targeted surveillance in case locations Environmental Response/Vector Control Prevention Education & Community Involvement 9/6/2016 Footer 25

26 Zika, Chikungunya, Dengue Surveillance & Response Level 1: no human cases, no vector activity Level 2: no human cases, mosquito activity Level 3: imported human cases, some mosquito activity Level 4: imported human cases, high mosquito activity and lab positive mosquitoes Level 5: human cases(s) locally acquired in one or more communities 9/6/2016 Footer 26

27 Zika & Pregnancy U.S pregnant women in the U.S. have evidence of Zika infection and are being monitored through a Zika pregnancy registry Live born infants w/ birth defects* 16 Pregnancy losses w/ birth defects** 5 Rate of adverse outcomes is still unknown *Includes microcephaly, calcium deposits in the brain, excess fluid in the brain cavities and surrounding the brain, absent or poorly formed brain structures, abnormal eye development, other problems resulting from damage to the brain that affects nerves, muscles and bones, such as clubfoot or inflexible joints ** Includes miscarriage, stillbirths, and terminations with evidence of birth defects 9/6/2016 Footer 27

28 Summary Emerging disease threat in the Americas Link between Zika & microcephaly Non-specific symptoms and cross-reactive antibodies make lab diagnosis & case identification challenging Arizona will likely see imported cases; possible for local transmission to occur Surveillance and response plans are in place for Zika, Chikungunya and Dengue 9/6/2016 Footer 28

29 WeArePublicHealth.org twitter.com/maricopahealth facebook.com/mcdph

30 What is Chikungunya? Chikungunya is a viral disease transmitted to humans by the bite of infected mosquitoes. The name is derived from Kimokonde language of Mozambique Chikungunya meaning that which bends up referring to bent body postures resulting from severe joint pain. Chikungunya virus was first isolated in Tanzania in 1953, and has been the cause of numerous human epidemics in Africa & Asia. Until 2013, chikungunya had not occurred in the Americas.

31 Symptoms of Chikungunya The Chikungunya virus is characterized by acute onset of fever and severe polyarthralgia (joint pain). Symptoms usually begin 3-7 (range 1-12) days after being bitten by an infected mosquito. NOTE: 90+ % of infected persons are symptomatic. Joint pain and fatigue can persist for many weeks. Symptoms can include: Fever Headache Fatigue Nausea Vomiting Muscle Pain (sometimes severe) Rash often like hives Joint Pain (sometimes severe)

32 Chronic Chikungunya Chikungunya symptoms can be long term and debilitating 80-93% of cases will still have symptoms after three months and 49% after 10 months Common chronic symptoms include distal polyarthralgias, fatigue, depression

33 World Distribution of Chikungunya Past outbreaks have occurred in countries in Africa, Asia, Europe, and the Indian Pacific Oceans.

34 Chikungunya Update Chikungunya in the Caribbean Chikungunya cases were first reported in the Western Hemisphere in the Caribbean in December Chikungunya has spread throughout the Caribbean and is now spreading in Latin American countries. Since December 2013, over 1,700,000 cases have been reported in the Caribbean and South and Central America. Over 3,400 cases of chikungunya infected travelers have been reported in the U.S. in 2014 and cases of imported chikungunya were reported in Maricopa County (MC) residents in 2014 and 20 in Importation of infected travelers raises potential for local transmission. Local transmission has been documented in Florida.

35 Patient Communication For suspected cases of chikungunya or dengue educate patients the importance of avoiding mosquito bites for at least 7 days after onset, and to notify public health officials immediately if any family members develop sx

36 Dengue Genus Flavivirus single strand RNA virus 4 Serotypes (DEN-1,2,3,4) All serotypes can cause illness. 80% infections = asymptomatic The vector mosquitoes are Aedes aegypti & Aedes albopictus

37 Dengue Occurrence Worldwide 100+ countries mostly tropical & subtropical regions Estimated 100,000,000 cases/year 2014 dramatic increase in cases in Border Region 8 imported cases reported in MC in 2016 YTD

38 Clinical Symptoms-Classic Dengue Sudden onset Fever (2-7 days, sometimes biphasic) Headache & retro-orbital pain Muscle & joint pain Anorexia/nausea/vomiting Rash Minor hemorrhagic manifestations are possible (nose bleeds, bloodshot eyes, etc.) Recovery prolonged fatigue & depression

39 Hemorrhagic Manifestations Skin hemorrhages: petechiae, purpura, ecchymoses Gingival bleeding Nasal bleeding Gastro-intestinal bleeding: hematemesis,melena, hematochezia Hematuria

40 West Nile Virus (WNV) & St. Louis Encephalitis (SLEV) 9/6/2016 Footer 40

41 Background: St. Louis Encephalitis Virus (SLEV) and West Nile Virus (WNV) WNV & SLEV are closely related single-stranded RNA viruses - Genus Flavivirus Japanese encephalitis virus serocomplex Can cross react on serologic tests Cause similar clinical disease in humans Ecology of WNV is similar to SLEV Share same Culex mosquito vectors Share many of the same avian reservoirs 9/6/

42 SLEV transmission cycle Enzootic cycle amplification Infection of Dead End hosts

43 Culex Mosquito Breeding

44 Clinical spectrum of human infections with neuroinvasive arboviruses Neuroinvasive disease* (<1%) Febrile illness (10-30%) Asymptomatic infection (50-80%) *Infections of central nervous system such as meningitis, encephalitis, or myelitis

45 SLEV neuroinvasive disease Typically described as encephalitis or meningitis Cases with myelitis have been described Most cases require hospitalization Many patients with encephalitis or myelitis have sequelae

46 Number of SLEV and WNV neuroinvasive disease cases United States, SLEV WNV Median number of cases: 20 (range: 1-1,967) Median number of cases*: 1,188 (range: 19-2,946) 2500 Number of cases *Median number of cases since 1999 Year

47 Number of SLEV neuroinvasive disease cases Arizona, (N=41) 10 9 SLEV Median number of cases: 0 (range: 0-5) Number of cases 2014 Year

48 Background The 2015 SLEV outbreak was unusual because: Previous field studies in CA showed evidence that WNV displaces SLEV and concurrent outbreaks were considered to be very unlikely This was the largest SLEV outbreak in AZ history This was the only known human SLEV outbreak occurring in the US in 2015 The first probable case of SLEV transmission via blood transfusion 9/6/

49 Persistent WNV Transmission and Apparent Displacement SLEV in CA, Believed two closely related viruses like WNV and SLEV could not co-exist in the same area Reisen et al compared enzootic activity of both viruses and compared to previously existing SLEV data in the Coachella Valley of Southern CA William K. Reisen, et al. 9/6/

50 Reisen Study cont Reisen et al proposed that SLEV was suppressed by WNV activity by competitive displacement One possible mechanism was cross protective herd immunity in passerine birds - a mechanism which seemed to be supported by wild bird serosurvey data 9/6/

51 SLEV in Maricopa County Concurrent Outbreaks of WNV & SLEV West Nile Virus (WNV) - 62 human cases St. Louis encephalitis (SLEV) - 22 cases Flavivirus undifferentiated 2 cases Mosquito Surveillance WNV + Mosquito Samples 97 SLEV+ Mosquito Samples /6/2016 Footer 51

52 9/6/2016 Footer 52

53 Blood Donor Investigation cont Organ donor IL Day 0: Organ transplant in index case Organ recipients IL IL AZ AZ Index case Blood donors AZ AZ AZ AZ Transfused to index case Day 1 Day 2 Day 20 Day 21 9/6/

54 Blood Donor Investigation Organ recipients Blood donors Transfused to index case Day 1 Organ donor Day 2 Day 20 Day 0: Organ transplant in index case Asymptomatic Day 21 Index case Day 35: Illness onset in index case 9/6/

55 Culex spp. Mosquito Surveillance Results for July Aug mile radius per location 30 days prior to index case s symptom onset Index case location Index case hospital location Positive AZ blood donor location 1/45 (2%) mosquito traps 2 SLEV-positive mosquitoes 1/33 (3%) mosquito traps 3 SLEV-positive mosquitoes 12/53 (23%) mosquito traps 104 SLEV-positive mosquitoes 9/6/

56 Conclusions SLEV is NOT gone and should not be forgotten Public health and vector programs should maintain surveillance for WNV and SLEV SLEV & WNV outbreaks can occur in the same place and time Lab tests can cross react WNV positive results may not always be WNV SLEV can be transmitted through blood products 9/6/

57 Maricopa County Arbovirus Summary imported Zika cases 390+ Zika assessments: 80+% ruled-out 8 imported dengue cases 3 imported chikungunya cases 31 West Nile virus cases (2 fatal) 60+ WNV (+) mosquito pools 0 SLEV 9/6/2016 Footer 57

58 Prevention The best way to prevent arbovirus infection is to avoid mosquito exposure: Stay indoors if possible Use air conditioning and window/door screens Use mosquito repellents on exposed skin Wear long-sleeved shirts and long pants Empty standing water from outdoor containers Scrub & rinse insides of any containers that had water Remove, cover or properly store all containers to prevent water collection FIGHT THE BITE! DAY & NIGHT!

59 Questions?