Dr. Jarbas BarbosaArea Manager

Health Surveillance & Disease Prevention and Control

Timeline (1)

• April 10: an outbreak of influenza-like illness in Veracruz, Mexico detected.

• April 11: PAHO IHR requested verification.

• April 12: Mexican government confirmed outbreak investigation.

• April 16: A case of atypical pneumonia in the Mexican state of Oaxaca triggered enhanced surveillance

• April 18: two cases of the new A (H1N1) virus infection identified in two southern California counties in USA.

Timeline (2)

• April 23: new influenza A (H1N1) virus infection confirmed in

several patients in Mexico.

• April 26: 38 cases reported by Mexico and the USA

• April 27: Canada and Spain reported first confirmed cases

• April 28: UK, Israel, New Zealand

• April 27: WHO declared phase 4

• April 29: WHO declared phase 5

• June 11: WHO declared phase 6 – pandemic

• In 9 weeks: all WHO regions reporting cases of pandemic

(H1N1) 2009

Epidemiology of Pandemic (H1N1) 2009 Virus Infection

PoultryWild birds

Avian influenza

virus

Human

Emergence of a pandemic Seasonal

influenza virus

A (H5N1)

New virus (reassortment)

Influenza pandemic

Pig

Pandemic (H1N1) 2009Number of laboratory confirmed cases

as reported to WHO (18 April to 30 August 2009)

18 April 2009

30 August 2009

Number of confirmed cases and deaths

Pandemic (H1N1) 2009

Communicate directly to IHR Point of Contact at WHO Regional Office (

ihr@paho.org)

• Worldwide = Widespread geographic distribution

– 188 countries and territories affected– at least 2,837 deaths in 62 countries

(cumulative numbers as of August 30, 2009)

• In the Americas:– 35/35 countries affected– 120,629 confirmed cases and

2,467 deaths as of September 3, 2009, 16:00

CountryNumber of

confirmed casesNumber of

deathsNew cases

(since August 28)New deaths

(since August 28)

Antigua & Barbuda 3 0 0 0Argentina 8240 465 0 0Bahamas 23 0 0 0Barbados 60 0 0 0Belize 23 0 0 0Bolivia 1446 21 57 2Brazil 6592 657 1386 100Canada* 10156 72 0 0Chile** 12194 130 0 0Colombia 507 29 0 0Costa Rica 1115 33 57 0Cuba 306 0 0 0Dominica 1 0 0 0Dominican Republic 373 11 191 6Ecuador 1382 36 0 0El Salvador 729 17 3 0Grenada 3 0 0 0Guatemala 720 12 0 0Guyana 7 0 0 0Haiti 5 0 0 0Honduras 380 8 9 0Jamaica 80 4 0 0Mexico 21857 193 997 14Nicaragua 1053 4 394 2Panama 693 7 46 1Paraguay 472 52 0 0Peru 6789 98 181 18Saint Kitts & Nevis 6 1 0 0Saint Lucia 13 0 0 0Saint Vincent & Grenadines 2 0 0 0Suriname 11 0 0 0Trinidad & Tobago 97 0 0 0United States* 43771 556 0 0Uruguay* 550 20 0 0Venezuela 970 41 187 17TOTAL 120629 2467 3508 160

► All viruses to date are homogeneous

antigenically and react well with antisera

raised against California/4/2009 and

California/7/2009

► To date, no recognized genetic markers

associated with virulence

(Viruses isolated from severe cases do not show sequence

differences)

► Virus replicates more in lungs and causes more severe

pneumonia in animals (ferrets, mice, primates) than seasonal

H1N1 (unpublished)

Pandemic (H1N1) 09 virus characteristics

Confirmed Cases in Argentina by date of onset

0

50

100

150

200

250

300

350

400

450

500

26/0

4/20

09

29/0

4/20

09

02/0

5/20

09

05/0

5/20

09

08/0

5/20

09

11/0

5/20

09

14/0

5/20

09

17/0

5/20

09

20/0

5/20

09

23/0

5/20

09

26/0

5/20

09

29/0

5/20

09

01/0

6/20

09

04/0

6/20

09

07/0

6/20

09

10/0

6/20

09

13/0

6/20

09

16/0

6/20

09

19/0

6/20

09

22/0

6/20

09

25/0

6/20

09

28/0

6/20

09

01/0

7/20

09

04/0

7/20

09

07/0

7/20

09

10/0

7/20

09

13/0

7/20

09

16/0

7/20

09

19/0

7/20

09

22/0

7/20

09

25/0

7/20

09

28/0

7/20

09

31/0

7/20

09

03/0

8/20

09

Cas

os

Ciudad y provincia de Buenos Aires

Resto del país

Initial spread in large cities

Distribution of confirmed pandemic influenza A (H1N1) 2009 cases by age group in selected

countries

Source: Ministries of Health of the countries in the Region

Hospitalized or severe confirmed cases

Country Canada Chile Brazil

Reporting period Through week 33Through August

26, 2009Through week 33

Reporting of severe or hospitalized cases

Hospitalized cases Hospitalized cases Severe cases

Number of hospitalized or severe

confirmed cases analyzed

n=1441 n=1480 n=5206

% Female 51.6 51.0 --

Median age in years 25 31 --

% Pregnant 27.91 -- 29.72

% Co-existing medical conditions

57.23 46.0 36.94

Deaths among confirmed casesArgentina Brazil Canada Chile Costa Rica Mexico Peru

Reporting period Until EW31 Until EW32 Until EW31 Until EW31 Until EW32 Until EW32 Until EW29

N 404 368 66 105 28 164 29

Sex “No differences” - 63.1% female

(41/65)48. 6% female

(48/104)53.6% female

(15/28) 49.4% female48.3% female(14/29)

AgeMost affected

group 50-59 years

- Median 51 years

Median 49 years (range

4m-89y)

Median 41 years

63.2% between 20–49 years

62.0% between 20-

50 years

% Co-morbidities 32% 50.3% 81.3% (39/48) 66.6%

(70/105) - - 37.9% [1]

Most frequent co-morbidities

Obesity (14.3%)

Cardiopathies (11%)

Cancer (8%)COPD (8%)

Metabolic diseases

Respiratory illnesses Chronic

cardiopathies

- -

Obesity (42.9%)

Diabetes Mellitus (25%)Asthma (21%)COPD (10.7%)

Metabolic diseases (34.8%)Smoking (23.2%)

Cardiopathies (15.9%)

-

Pregnancy 28% (26/90)[2] 29.9% [3] (46/154) 18.2%[4] (2/11) - 10.7%[5] - -

[2] Age range for the 90 women in childbearing age not specified. Numerator includes pregnant and puerperal women.[3] Among women between 15 and 49 years old[4] Among women between 15 and 44 years old.[5] Not specified if this percentage is among total deaths or among total deaths women in childbearing age

Distribution of respiratory virus by epidemiological week (EW), Chile EW 1-34

Jan Feb Mar Apr May Jun Jul Aug

Epidemiological week

Source: Chile Ministry of Health

Distribution of respiratory virus by age group. Argentina, January- September 2009

Source: Argentina Ministry of Health

Distribution of outpatient visits by Epidemiological Week in different regions of Chile.

% o

f ca

ses

per

Reg

ion

Nat

ion

al R

ate

(100

,000

hab

)

Source: Chile Ministry of Health

• 60% of the confirmed cases being detected in persons with less than 20 years of age. Hospitalized cases and deaths occurred in adults.

• Hospitalization and case/fatality in young adults higher than seasonal influenza.

• Epidemiologic and serologic evidence for low susceptibility in older adults.

• At-risk groups: Pregnant women, people with chronic diseases and underlying health conditions, young children, people with immunosuppression.

• Replacement of influenza seasonal virus.

Epidemiology of Pandemic (H1N1) 2009 Virus Infection

Source: WHO

WHO Surveillance Guidelines

• For countries not yet affected:– Document first appearance of the pandemic virus

and to collect sufficient information for risk assessment.

• Once affected:

– Detect any changes in the epidemiological, virological or clinical presentation.

• Unusual or unexpected public health events, e.g. clusters of severe unexplained acute respiratory illness or unexplained deaths.

Qualitative Indicators for the monitoring of Pandemic (H1N1) 2009

Indicator Criteria

Geographical spread

No activity Localized Regional Widespread

Trend Increasing Unchanged Decreasing

Intensity Low or moderate High Very high

Impact Low Moderate Severe

Monitoring of Respiratory Disease Activity in Americas Region

• Northern Temperate zone: – US and Canada: Overall, low levels of ILI activity,

below epidemic threshold. – Increasing ILI activity in the southeastern US. – In Canada, 11-17% of severe cases are indigenous.

• Southern temperate zone:– Chile and Argentina: Continued regional to

widespread geographic activity; – The majority of respiratory virus detections are now

due to Respiratory Syncitial Virus (RSV).

• Equatorial South America:– Bolivia, Ecuador and Venezuela: Continue to experience

widespread geographic influenza activity with increasing respiratory disease trend in most countries.

– Brazil: Regional geographic activity, especially in later affected tropical areas. ILI consultations (15% of all visits) are falling, but remain significantly above seasonal historical average.

• Tropical Central America:– Costa Rica, El Salvador, Guatemala, Honduras and Panama:

Continue to experience widespread geographic influenza activity, but the respiratory disease trend is now beginning to decrease. Impact on the healthcare system continues to be moderate.

Monitoring of Respiratory Disease Activity in Americas Region

Clinical presentation and evolution

Short incubation period (1-2(-4) days)Onset of the disease usually abrupt with: - Typical systemic symptoms:

• high fever and chills(94%)

• severe malaise • fatigue and weakness• headache or myalgia

– Respiratory tract signs: non-productive cough (92%), sore throat (66%), and rhinitis

– Gastrointestinal manifestations: diarrhea and vomiting (25%)

Emergence of a Novel Swine-Origin Influenza A (H1N1) Virus in Humans. N Engl J Med 2009;360.

Initial Clinical Presentation

Complications - Severe cases

Predominant age group: 20-59 years

Age range 1-80 years

Sex ratio: 1

Underlying conditions: 60-80% COPD, asthma diabetes, cardiovascular disease pregnancy obesity

Signs and symptoms- Dysnea- Cough - Hemopthysis

Investigation findings

-Chest x-ray: multilobar infiltrates (100%)

-Sat O2: < 90% (100%)

- Renal failure and/or hepatic affectation (50%) Multiorganic failure

Complications - Severe cases

Diagnosis: Primary influenza pneumonia

Complications: Mechanical ventilation secondary pneumonia

Antiviral treatment in severe cases:- After 7 days of initiation of symptoms:

worse evolution- 1 – 3 days of initiation of symptoms:

better outcome

 Source: Dr. Luis Septien Stute. Hospital General de Mexico

Source: MoH Argentina, Canada, Chile, Dominican Republic, Mexico, Uruguay and USA

Estimated by data pooling Percentages calculated on the immediate

lower step

ICUs

Hospitalized

Seeking care

Affected people

Population

Deceased ?

1.4 – 5%

20%

35%

?

Source: MoH Argentina, Canada, Chile, Dominican Republic, Mexico, Uruguay and USA

Age-related distribution of deaths from severe pneumonia compared to influenza seasons 2006-08

(Mexico, 24 March- 29 April 2009)

During 5-weeks period, 2155 cases of severe pneumonia with 821 hospitalizations + 100 deaths:

87% of deaths and 71% of severe pneumonia cases aged 5- 59 yrs

Key challenges

• Identification of predictors for severity among

young adults with no underlying diseases.

• Oseltamivir resistance surveillance.

• Algorithms for clinical management of severe

cases.

WHO-SAGE recommendations on pandemic (H1N1) 2009 vaccines- 7th July 09

► Health-care workers as a first priority to protect the essential health infrastructure

► SAGE suggested the following groups for consideration (countries need to determine their order of priority based on country-specific conditions): Pregnant women Above 6 months with one of several chronic medical conditions Healthy young adults of 15 to 49 years of age Healthy children; Healthy adults of 50 to 64 years of age and Healthy adults of 65 years or above.

► Post-marketing surveillance of the highest possible quality► Promoting production and use of vaccines formulated with oil-in-water

adjuvant and live attenuated influenza vaccines.

International Passenger Departures from MexicoMarch 1st to April 30th 2008

N Engl J

Med 361

(2):212-

4 (July

9, 2009

)

Risk assessment: Mapping destinations of flights

PAHO/WHO Response to A/H1N1 in the Americas

• PAHO has been working with countries since 2004 on pandemic preparedness and on the International Health Regulations.

• Is tracking the regional situation and advising countries on surveillance, laboratory and infection control measures required to identify and treat cases and trace contacts.

• Has mobilized experts to several countries of the Region in epidemiology, virology, laboratory analysis, infection control, emergency response, logistics, risk communication; including actualization of treatment guidelines.

• Has distributed laboratory diagnostic kits through Collaborating Centers to National Influenza Centers.

What is PAHO doing?

• Has deployed a stockpile of Oseltamivir (Tamiflu) to countries in the Region.

• Weekly teleconferences with Ministries of Health and Epidemiology Chiefs of all countries in the Region.

• Provides risk communication support to countries.

• Weekly publication of regional updates including qualitative indicators .

• Development of technical guidelines and translation, publication and dissemination of WHO materials.

• Mobilizing additional resources.

What is PAHO doing?

What should countries do?

• Adapt plans and interventions to the current pandemic, which

is assessed as moderate.

• Calibrate their response to the current severity assessment.

• Implement public health measures based on the

epidemiological situation

• Continue monitoring for increases in severity, genetic

changes and strengthening health systems to ensure

continuity and rapid adjustments.

Pandemic (H1N1) 2009Summary

• So far, high but variable transmissibility in countries.

• 5-45 years old people most commonly affected.

• Hospitalization rates and case-fatality in young adults higher than during seasonal influenza.

• Co-circulation of seasonal and pandemic viruses.

• Groups at risk for severe illness: pregnant women; those with asthma, obesity, chronic heart or lung disease, cancer, immunosuppression.

Source: WHO

Pandemic (H1N1) 2009Summary

In the Northern Hemisphere transmission is expected to increase during fall and winter.

• Every country needs to be prepared for this situation in the following areas:

– Surveillance

– Public health measures

– Health services

– Antivirals and vaccines

– Risk communication

Thank youPlease visit PAHO Pandemic (H1N1) 2009

web page for regular updates:

www.paho.org