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It’s a Small World After All
A Few Emerging Viruses of Concern
to the United States in 2014
André Weltman, M.D., M.Sc. Division of Infectious Disease Epidemiology
Pennsylvania Department of Health
CASA annual conference
Grantville, PA -- May 2014
Agenda
• MERS-Coronavirus (in Middle East)
• Novel influenza (especially H7N9 in China)
• Chikungunya (Old World into the Caribbean)
• Ebola (in West Africa)
Background
Background • One billion people on airplanes annually
• International travel by many millions of them Miami 20 million international passengers; JFK 27;
Hong Kong 59; Dubai 65; CDG 57; Heathrow 67
Airport numbers from Wikipedia, “World's busiest airports by international passenger traffic”
Background
• Long history of pathogens into new areas
Plague (“black death”) into Europe, mid-14th century
New World Old World, starting with Columbus
Yellow Fever moved with slave trade across the Atlantic
Plague from Asia to California, early 1900s
“Spanish Flu” worldwide, 1918
SARS from China worldwide, 2003-4
Yellow Fever outbreaks, 1793
MERS-C0V MIDDLE EAST RESPIRATORY SYNDROME
CORONAVIRUS
What are Coronaviruses?
• First identified in the mid 1960s
• Named for the crown-like spikes on their surface
What are Coronaviruses?
• Group of common viruses that most people will have at some point in their lifetimes
• Usually cause mild to moderate upper-respiratory tract illness
• Most infect only one animal species
• SARS-CoV (2003) is an exception: humans, monkeys, civets, cats, dogs, rodents, others
• MERS-CoV (2012) is an exception: humans, bats, camels, ?
Coronavirus Genetic Groups
• Five previously known to infect humans
“alpha” coronaviruses 229E and NL63
“beta” coronaviruses OC43 and HKU1
SARS-CoV (severe acute respiratory syndrome)
• New beta coronavirus
MERS-CoV
MERS-CoV: New Coronavirus
• 1st cases recognized in 2012, new virus found Jordan hospital workers; pneumonias in Saudi Arabia, Qatar
• While not the same as 2002-2003 SARS virus, some similarities: SARS as a model for response
SARS: ~8000 cases and 774 deaths worldwide
Wedding in China, 2003
MERS-CoV: Epidemiology •
• 538 cases in 12 countries with 145 deaths
Saudi Arabia accounts for the majority
All cases linked to 6 countries in or near the Arabian Peninsula: Saudi Arabia, UAE, Qatar, Oman, Jordan, Kuwait
Travel-associated cases: France, U.K., Italy, Tunisia, Malaysia, two U.S. states
•
MERS-CoV: Upward Trend
• Recent increase in MERS cases in Middle East
• Reasons for rapid increase not entirely clear
Partly due to better lab diagnosis/case-finding
Not due to change in the virus itself
MERS-CoV: Source?
• Probably emerged from an animal reservoir
• Similar to coronaviruses in bats in the region
• Role of camels as intermediate host?
MERS-CoV: Source?
• MERS-CoV gene sequences identified in Saudi camels
• Antibodies to MERS-CoV also found in camels in Egypt, Oman, Spain
• MERS-CoV gene sequences in a few Qatar camels linked to 2 human infections
• Many unanswered questions
MERS-CoV: Clinical
• Incubation: typically 5 days, range 1-14 days
• Most cases have severe acute respiratory illness
Symptoms include fever, cough, SOB
Most develop primary viral pneumonia
G.I. symptoms common, including diarrhea
Some kidney failure
• Case fatality rate: approx. 1/3 of clinical cases
• Mild or asymptomatic infections
MERS-CoV: Transmission
• MERS-CoV virus is not behaving exactly like SARS virus did one decade ago
MERS on the whole seems less infectious
Will “super-spreaders” emerge?
MERS-CoV: Transmission
• “Limited” transmission to close contacts (at least 26 person-to-person clusters)
• Transmission in healthcare settings (20% of cases)
• No evidence of sustained transmission
• Exact modes of spread uncertain CDC currently (May 2014) recommends
standard and contact and airborne precautions as was recommended for SARS in 2003
• Several importations to Europe since 2012
• 1st U.S. case (Indiana), late April 2014: was doing medical work in Saudi Arabia
• 2nd U.S. case (Florida), May 2014: was doing medical work in Saudi Arabia
• CDC: Evaluate patients if fever & pneumonia or ARDS < 14 days after travel from countries in Arabian Peninsula, or contact with traveler
• PA state health dept. lab equipped to test for MERS-CoV, as are other U.S. state labs
MERS-CoV: Threat to U.S.
MERS-CoV: Threat to U.S.
• No advice to limit international travel
• Increased vigilance at airports but… no formal screening at U.S. arrival Travelers advised to seek care if sick within 14 days
wwwnc.cdc.gov/travel/notices
MERS-CoV: Threat to U.S.
• Enhance awareness among clinical and public health infrastructure
• All person-to-person cases so far linked to close personal contact for U.S. imported cases, public health (CDC & State DoHs)
alerted travelers who were in same plane or bus and asked for reports of symptoms: many phone calls!
Additional Information
• CDC MERS website: www.cdc.gov/coronavirus/mers/index.html
• CDC Health Alert Network (HAN): emergency.cdc.gov/han
• World Health Organization: www.who.int/csr/disease/coronavirus_infections/en
NOVEL INFLUENZA VIRUSES
H5N1 Highly Pathogenic
Avian Influenza A (“bird flu”)
• ~ 650 cases worldwide (mostly in S.E. Asia) since 2003
• Case fatality rate 60% in humans
• “High-path” virus in chickens
• Transmission associated w/ bird contact (rarely P-2-P)
• No H5N1 in humans or birds in U.S.
• One case in Canada, 2013
• H5N1 flu vaccine stockpiled
H3N2 Variant
Influenza A (“pig flu”)
• H3N2v circulating in pigs nationally since 2011
• ~300 human cases in U.S. associated with direct or indirect swine contact
• Typical flu-like illness but occurring in summer
• PA: ~100 cases suspected or confirmed, 2011-2012 (investigations among county fair pig exhibitors)
H3N2 Variant
Influenza A (“pig flu”)
H7N9 Influenza A • Emerged in China in 2013, then 2nd wave in 2014
• ~430 cases confirmed so far; 35% case fatality rate
• 8 family clusters but "no efficient sustained transmission"
• “Low-path” in birds (no illness, so hard to track)
• Human illness strongly linked to live bird markets
• Not linked to small family backyard poultry flocks
• Rapid increase in cases in China
H5N1: 18 months to first 100 human cases
H7N9: only 2 months to first 100 human cases
H7N9 Influenza A Confirmed cases in China, 2013 thru early Feb. 2014
N = 339 on this epicurve (www.ecdc.europa.eu/en/publications/Publications/communicable-disease-threats-report-15-feb-2014.pdf)
Live Bird Markets
in China
2013 consumer survey:
46% of respondents
reported buying meat
from live bird markets
CHIKUNGUNYA VIRUS
Aedes aegypti mosquito, and a person with maculopapular rash from CIHKV
• “That which bends up” (Makonde of East Africa)
• Mosquito-borne viral infection
Similar to dengue virus in transmission & geography
Mosquito control! (Aedes aegypti and A.albopictus)
Acute febrile illness with rash, headache, fatigue, arthralgias lasting typically < 1 week
Majority of infected people experience symptoms
Some have prolonged joint pain (months to 2 years)
Rarely fatal, but outbreaks w/ widespread morbidity
CHIKUNGUNYA VIRUS
• Known since 1950s in Africa
• Spread to Asia, and in recent years Pacific islands
• December 2013: outbreaks in Caribbean region “Epidemic proportions”: thousands of cases in 14 countries
CHIKUNGUNYA VIRUS
• Known since 1950s in Africa
• Spread to Asia, and in recent years Pacific islands
• December 2013: outbreaks in Caribbean region “Epidemic proportions”: thousands of cases in 14 countries
CHIKUNGUNYA VIRUS
CHIKUNGUNYA VIRUS
• Concern: transmission from returning travelers
• In U.S. 2006-1009, 106 imported cases identified
CHIKUNGUNYA VIRUS
Aedes albopictus (“Asian tiger mosquito”) in U.S.
EBOLA VIRUS
“Filovirus” internal structure
“Filovirus” in electron microscope
• RNA virus of African mammals
African bats are the suspected animal reservoir
• Spillover from bats to terrestrial animals (incl. monkeys, chimpanzees, gorillas, humans)
EBOLA VIRAL HEMORRHAGIC FEVER
“bushmeat” being prepared in Ghana, 2013
• RNA virus of African mammals
African bats are the suspected animal reservoir
• Spillover from bats to terrestrial animals (incl. monkeys, chimpanzees, gorillas, humans)
Human case fatality ranges 40% to >70%
Ebolavirus “Reston” detected in Virginia laboratory monkeys in 1989 imported from Philippines
Also in monkeys in PA, TX, Italy
Asymptomatic in humans
EBOLA VIRAL HEMORRHAGIC FEVER
• Roughly two dozen prior outbreaks in Central Africa
2014 outbreak in multiple countries in West Africa
Since February, 244 cases with 166 deaths (68%)
EBOLA VIRAL HEMORRHAGIC FEVER
EBOLA VIRAL HEMORRHAGIC FEVER
• Prodrome: fever, vomiting, severe diarrhea
• Severe hemorrhage in < 50% of human infections
• Infection control in medical settings is key
Ebola can be stopped by good infection control practices
Very limited resources in many parts of Africa have repeatedly resulted in nosocomial cases
As with the other viruses discussed today, no formal advice to limit travel
Increased vigilance at airports with West African travelers
EBOLA VIRAL HEMORRHAGIC FEVER
?
The New Yorker
“And it was so typically brilliant of you
to have invited an epidemiologist.”