communicable disease update

Communicable Disease Update

Matt Zahn, MD

Medical Director

Epidemiology

Orange County Health Care Agency

August 14, 2013

Hepatitis A Outbreak and Townsend Frozen Berry Blend

• As of August 1, 2013, 158 confirmed cases• 9 states affected: Arizona (23), California (77),

Colorado (28), Hawaii (8), New Mexico (9), Nevada (6), Utah (3), and Wisconsin (2), New Hampshire

• 10 cases in Orange County • All ill people who reported eating this product

purchased it from Costco markets• Product was also sold at Harris Teeter stores

– No cases associated with these stores thus far

Epidemiology of Those Ill

• 55% are women• Ages range 1 – 84 years; • 57% between 40 – 64 years of age. • 11 children age 18 ill

– None were previously vaccinated.

• Illness onset dates range from 3/31/2013 – 7/14/2013

• 69 (44%) hospitalized• No deaths

Hepatitis A in Children

• 30% of children under 6 are symptomatic•These children are still infectious!•Children can be the source of outbreaks

• Older children and adults have symptoms 70% of the time

• Rate of disease low because of asymptomatic children, but also high immunization rates

FDA and CDC Investigation

• Vehicle for hepatitis A appears to be a common shipment of pomegranate seeds from Goknur Foodstuffs Import Export Trading in Turkey

• Viral genotype is 1B• FDA will detain shipments of pomegranate seeds

from Goknur • These pomegranate seeds are used in:

– Townsend Farms brand Organic Antioxidant Blend sold by Costco stores

– Organic Antioxidant Berry Blend sold by Harris Teeter– Woodstock Frozen Organic Pomegranate Kernels from

Scenic Food Company– All products recalled

California Department of Public Health Post Exposure Prophylaxis Recommendations

• Prophylaxis recommended for exposure within last two weeks

• Considered for all persons who consumed product

• Single-antigen Hepatitis A Vaccine is recommended

People who should receive IG for PEP

The following are at increased risk of severe HAV infection or may have a decreased immune response to vaccine:

• Persons with chronic liver disease (e.g., cirrhosis)• Immunocompromised persons, including persons:

– With HIV/AIDS;– Undergoing hemodialysis;– Have received solid organ, bone marrow or stem cell

transplants;– Receive high dose steroids (>2mg/kg/day), chemotherapy, or

immunomodulators and/or biologic medications• Vaccine may be given in addition to IG to potentially

provide longer-term protection, but vaccine response may be limited.

HCA Response

• Provide education and advice• Vaccinate or give immune globulin to persons

who have consumed the product within the last two weeks

• Environmental Health assured product is pulled from local stores

• Work with Costco to assure that accurate message is disseminated

• Follow up on cases, including prophylaxis for their close contacts

Avian Influenza A (H7N9)

• On March 30, 2013, three patients in China with fatal cases of rapid, progressive pneumonia were confirmed to be infected with influenza A H7N9

• Virus had not been detected in humans or animals previously

Geographical LocationConfirmed human cases of avian influenza A(H7N9) reported to WHO

Date of OnsetFeb Mar Apr May

N= 122 confirmed cases for whom date of onset is known

Epidemiological Curve of Confirmed Cases of Avian Influenza A(H7N9) Reported to

WHO, by Day, 2013

Avian Influenza A (H7N9)

As of May 30, 2013:• WHO reported 132 laboratory-confirmed

cases•43 deaths•Most patients had severe respiratory illness•Some mild illness in human cases was

seen

Influenza A

Nat Struc & Mol Bio 16, 233 - 234 (2009)

Ppdictionary.com

Point mutations in HA or NA

Generally results in relatively small changes in virus

Antigenic Drift

www.influenzacentre.org

Antigenic Shift

• Reassortment of gene segments

• Leads to novel and potentially pandemic strains

www.influenzacentre.org

Influenza in Avian Populations

• All 16 HA and all 9 NA subtypes of influenza A virus are detected in wild water birds

• H17N10 is found in bats• Most infections are mild or asymptomatic in

avian species• Outbreaks in wild birds and poultry have been

associated with avian influenza H5 subtypes• Outbreaks in poultry have been associated with

H7 subtypes

Hosts for Influenza A

• Human infections are generally confined to H1, H2, and H3 subtypes– These subtypes have affinity for host cell receptors

containing α-2,6-linked sialic acid

• Direct transmission of influenza from domestic poultry to people found with H5N1, H7N2, H7N3, H7N7, H9N2, and H10N7 subtypes

• Resulting human infections were generally mild• H5N1 subtype notably has caused severe disease

Avian Influenza A (H7N9) Origination

• Virus arose from multiple reassortment events

• Four or more influenza A viruses appear to have contributed genetically

• H7 gene is genetically close to sequences isolated from ducks in Zhejiang province

• N9 gene is similar to genes from H7N9 viruses found in wild ducks in South Korea

• The six internal genes are similar to H9N2 viruses isolated from poultry and ducks in China

www.thelancet.com Vol 381 June 1, 2013

H7N9 Characteristics of 111 Patients

Characteristic

• Median age, years 61(3-88)• ≥65 yo 47(42.3)• ≤14 yo 2 (1.8)• Male 92 (65)• Preexisting Condition 68 (61)

– Hypertension 51 (45.9)– Diabetes 18 (16.2)– Immunosuppression 10 (9.0)– Pregnancy 2 (1.8)

• Exp. poultry prev. 14 days 62 (55.9)

Number (%)

n engl j med 368;24 nejm.org june 13, 2013

Characteristic• Fever• Maximal temperature• Fatigue• Conjunctivitis• Cough • Sputum production• Hemoptysis• Shortness of breath • Diarrhea or vomiting

No. (%)

111 (100.0)°C 39.2±0.840 (36.0)0 (0)100 (90)62 (55.9)27 (24.3)62 (55.9)15 (13.5)

H7N9 Symptoms

n engl j med 368;24 nejm.org june 13, 2013

H7N9 Complications

Complication

• Pneumonia 108 (97.3)

• Acute respiratory distress 79 (71.2) syndrome

• Shock 29 (26.1)• Acute kidney injury 18 (16.2)• Rhabdomyolysis 11 (9.9)

No. (%)

n engl j med 368;24 nejm.org june 13, 2013

Outcome of H7N9 Infection

• 109 of 111 hospitalized• Antivirals initiated in 108 patients

– Median of 7 days after the onset of illness

• 30 (27.0%) died, most from refractory hypoxemia

n engl j med 368;24 nejm.org june 13, 2013

H7N9 and Mild Disease

• Serology survey of 20,000 Chinese persons with influenza symptoms found only 6 cases of H7N9

• Survey of over 3000 contacts of cases found no evidence of disease

• Mild disease seems to be unusual• Minimal human-to-human transmission seems

to have occurred• No sustained human-to-human transmission

has occurredEID Volume 19, Number 8—August 2013

Influenza A H7N9 Testing Criteria:

Clinical Illness Criteria

• Patients with new-onset severe acute respiratory infection requiring hospitalization AND

• Patients for whom no alternative infectious etiology is identified

Exposure Criteria

• Recent travel (within ≤ 10 days of illness onset) to a country where human cases of H7N9 have been detectedOR

• Recent close contact (within ≤ 10 days of illness onset) with a confirmed case of human infection with H7N9 virus

Avian Influenza A (H7N9) Testing

• PCR is test of choice for influenza viruses, including avian influenza A (H7N9)

• With H7N9, initial PCR testing will indicate:– Positive for influenza A– Negative for H1pdm09– Negative for H3– Follow up testing for H7N9 will occur at that point

• OCHCA can facilitate this testing

Antiviral Treatment Recommendations for Influenza A and B

• Oseltamivir is recommended for treatment of persons of any age

• Zanamivir is recommended for children aged 7 and older

• Recommended duration of treatment for uncomplicated illness is 5 days

• Longer courses of treatment should be considered for severely ill hospitalized H7N9 patients

• Optimally treatment begun as soon as possible and within 48 hours of illness starting

• In severe disease, starting antivirals after 48 hours has still been associated with improved survival

H7N9 and Avian Populations

• H7N9 strain was detected from: – Chickens– Ducks– Pigeons– Live bird markets

• Initial human cases found in Zhejiang, China when migratory birds were moving north and transiting at the Yangtze River Delta

• No increase in poultry deaths occurred

Chinese Health Authority Response

• Aggressive follow up on contacts of cases– Over 3000 contacts followed for symptoms– No additional cases found

• Closing of bird markets

AAP

Avian Migratory Patterns

Avian Influenza A (H7N9)

• H7N9 infection does not lead to significant illness in birds– In contrast to H5N1

• Identification and control of viral spread in avian populations will be difficult

• Recurrence of H7N9 in avian populations is anticipated

Influenza A H3N2v

• First identified in 2010• 12 cases identified in Indiana in 2013

– All with close contact to pigs in fair settings

• Limited human-to-human spread of this virus has been detected

• No sustained or community spread of H3N2v has been identified

• Sporadic infections and even localized outbreaks among people with this virus may continue to occur

Influenza Vaccine

• Recommended each year for all persons 6 months of age and older

• Influenza vaccine for upcoming season will contain:– A/California/7/2009 (H1N1)pdm09-like virus– A(H3N2) virus like A/Victoria/361/2011b– B/Massachusetts/2/2012-like virus– And for quadrivalent vaccine:

B/Brisbane/60/2008-like virus

Influenza A H7N9 Vaccine

• Development of influenza A H7N9 vaccine has begun

• Potential candidate vaccine viruses have been identified

• H7-derived candidate strains have historically been slow-growing

• Non-egg based vaccines may provide opportunity for quicker development of vaccine– Recombinant DNA vaccine– Cell culture based vaccine

Middle Eastern Respiratory SyndromeCoronavirus

Coronaviruses and Human Disease

Five human respiratory coronaviruses have been described:

• Causers of colds and URIs– 229E– OC43– NL63

• Causers of Pneumonia:– HKU1– SARS

On September 23, 2012, WHO Announces:

The first laboratory-confirmed case of MERS-CoV: a 60-year-old man from Bisha, the Kingdom of Saudi Arabia, who died of rapidly progressive community-acquired pneumonia and acute renal failure

MERS-CoV from September, 2012-Present

MERS CoV Clusters

• Multiple clusters of human cases have occurred– Healthcare associated events– Family clusters

• Human to human transmission has occurred, though no sustained community transmission

MERS-CoV Hospital Outbreak, Saudi Arabia

4/8 4/15 4/22 4/29 5/6 5/13

Community

Ward 1, Hospital A

Ward 2, Hospital A

Dialysis, Hospital A

ICU, Hospital A

Ward, Hospital B

Dialysis, Hospital C

ICU, Hospital D

Ward, Hospital D

Health Care Worker Family MemberCase

NEJMoa1306742

MERS-CoV Clusters

NEJMoa1306742

Review of 47 Patients with MERS-CoV

• Cases of laboratory-confirmed MERS-CoV reported from Saudi Arabia between Sept 1, 2012, and June 15, 2013

• 46 adults, one child• 36 (77%) male• 28 (60%) died• Case-fatality rate rose with increasing age• Two of the 47 cases were previously healthy

TheLancet.com Published Online 7/26/13

45 (46%) had underlying comorbid medical disorders

• Diabetes • Hypertension• Chronic cardiac

disease• Chronic renal

disease

32 [68%]

16 [34%]

13 [28%]

23 [49%]

No. (%)

TheLancet.com Published Online 7/26/13

MERS-CoV Clinical Presentation

• Fever • Cough • Shortness of breath • Myalgia • Diarrhea • Vomiting • Abdominal pain

46 [98%]39 [83%]34 [72%]15 [32%]12 [26%]10 [21%]8 [17%]

TheLancet.com Published Online 7/26/13

MERS-CoV Disease Spectrum

• Multiple reports of mild disease• Initial symptoms may not be respiratory• GI illness can be prominent• Broader serologic analysis is ongoing

• Fast spread of SARS occurred early in the outbreak

• SARS often spread between healthcare workers and their patients

• Mainly direct or short-range transmission• ‘Superspreaders’ existed who generated a far

greater than average number of secondary cases• Reasons for this are still not known for certain,

likely a combination of host and viral factors

SARS-CoV and its Spread

Coronaviruses infect and cause disease in many animal species:

• Bats• Mice• Birds• Dogs• Pigs• Cattle

– Viruses tend to be specific for individual species, but mutation occurs

Sources of Coronavirus

• SARS-CoV thought to have originated in the Himalayan palm civet found in south China

• MERS-CoV source still uncertain– South African bat Neoromicia cf.

zuluensis derived CoV is closest phylogenetically to date

– Intermediate host is considered possible

• First cases of MERS-CoV associated with camels, sheep, goats exposure

MERS CoV Infectivity

• Human-to-human transmissibility of MERS CoV appears to be low

• Sustained community transmission has not been seen

• Close monitoring of health-care workers and household contacts has not revealed large numbers of secondary infections

MERS-CoV Epidemiology

• Infectious Period– Not clearly established– Likely to extend from the onset of fever until

10 days after fever resolves

• Incubation Period– Available data suggest that symptoms have

occurred up to 14 days after last exposure.

MERS-CoV Clinical Case Definition

• A person with an acute respiratory infection, which may include fever (≥ 38°C , 100.4°F) and cough; AND

• Suspicion of pulmonary parenchymal disease; AND

• History of travel from the Arabian Peninsula or neighboring countries within 14 days; AND

• Not already explained by any other infection or etiology

MERS-CoV Specimen Collection and Testing

PCR testing should be performed with samples from:• Lower respiratory tract specimens: • Broncheoalveolar lavage, tracheal aspirate, pleural

fluid and/or sputum– Typically have highest yield

• Upper respiratory tract specimens• Nasopharyngeal and oropharyngeal swabs • Serum• Stool• OCHCA can arrange testing

http://www.cdc.gov/coronavirus/mers/downloads/Interim-Guidelines-MERS-Collection-Processing-Transport.pdf

MERS CoV Treatment

• Minimal evidence to indicate antiviral or adjunctive therapy

• Supportive care• Mechanical ventilation • Some studies have shown that interferon

may have beneficial effects in the treatment of SARS

Avian Influenza A H7N9 and MERS CoV Infection Control

• Hand hygiene• Gown• Gloves• Respiratory protection at least as

protective as N95 respirator• Eye protection

Current Status

• No cases of MERS-CoV or Influenza A H7N9 have been identified in the United States to date

• CDC advises travelers to China to take some common sense precautions, like not touching birds or other animals and washing hands often. Poultry and poultry products should be fully cooked.

• WHO advised that persons with chronic medical conditions and want to go on Hajj pilgrimage should discuss the risks with their healthcare provider

Pertussis May be Returning…

• Increase in reports in Northern California• Disease seems to be cycling every three to five

years

Thank you!

714-834-8180