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

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

Background

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.”