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Detect outbreaks? • Monitor strains? • Determine seasonality? • Contribute to vaccine strains? • Understand virology: evolution, resistance, vaccine matching? • Determine epi: target prevention measures? • Define clinical spectrum? • Understand burden: disease, economic?
Trang 1National Influenza Surveillance System in Vietnam (NISS)
Ngo Huy Tu, MD, MPM
Epidemiology Department
National Institute of Hygiene and Epidemiology
Trang 2Surveillance
Systematic collection, analysis, interpretation
and dissemination of information for use in
public health action
Trang 3Why sentinel surveillance?
as an early warning, but:
Trang 4What are the goals of the surveillance?
matching?
Trang 5Number of ILI cases in Vietnam, 2004 – 2015
(Data from national communicable diseases surveillance system)
Trang 6Influenza surveillance in Vietnam
surveillance and no laboratory-enhanced active sentinel surveillance
Trang 7Severe Acute Respiratory Infection (SARI)
Influenza-Like Illness (ILI)
Venn diagram of respiratory illnesses
Viral
Influenza
Bacterial
Trang 8Pyramid of influenza virus infections
Asymptomatic
Mild symptoms, no medical care Mild symptoms,
outpatient care Severe symptoms,
inpatient care ICU
Death
Severity
Attempted to be detected by:
Pyramid within pyramid represents (re)emerging influenza virus with
pandemic potential SARI and SVP
surveillance
ILI surveillance
Household surveys
Serology studies
Trang 9Sentinel Influenza surveillance System in Vietnam
General Objective
To collect the necessary epidemiological and virological
information to guide influenza prevention and control policies and activities Gradually establish the nationwide influenza surveillance network in Vietnam
Trang 10
Specific Objectives
1 Describe epidemiological, virological characteristics and Monitor influenza virus strains circulating in Vietnam Introduce influenza virus strains for vaccination
2 To detect avian influenza viruses including emerging strain such as A/H5N1, A/H7N9 and outbreak potential re-assortment of influenza virus genomes and mutation
3 Gradually establish the nationwide influenza surveillance
network in Vietnam to guide influenza prevention and control policies and activities
4 Contribute in FLunet (Global Influenza Surveillance and Response System) and WHO Collaborating Centers
Trang 11
Selecting sites
1 Is geographically representative
2 Has a high density of population, high level of commercial and cultural exchanges
3 Urban and rural coverage
4 Sentinel surveillance is based in health facilities that already have the necessary infrastructure, equipment, and trained staff
5 Has close collaboration in specimens and data collection
6 Has the ability to preserve specimens at the proper temperature and easy transport specimens to the laboratory
7 Is a commitment and willingness to participate
8 Ability to long term maintained surveillance activities
For ILI: Admits a large number of ILI patients (at least 50 patients/week)
Trang 12ILI Surveillance sites, 2006-2015
16 sites: 7 in the northern; 3 in the central; 1 High plateau; 4 in the southern
Trang 13ILI Cases Definitions
Influenza-like illness (ILI)
Criteria for sample collection
within 3 days
Trang 15ILI TIME IMPLEMENTATION, 2006-2015
Trang 16Selected ILI results (cumulative)
Cumulative results in period 2006 to 2015
Trang 17Rate of positive of Influenza A and B by month 2006-2015
1 3 5 7 9 11 1 3 5 7 9 11 1 3 5 7 9 11 1 3 5 7 9 11 1 3 5 7 9 11 1 3 5 7 9 11 1 3 5 7 9 11 1 3 5 7 9 11 1 3 5 7 9 11 1 3
% dương tính% cúm B% cúm A
Trang 18Rate of positive ILI samples by influenza subtype by month 2006-2015
1 4 7 10 1 4 7 10 1 4 7 10 1 4 7 10 1 4 7 10 1 4 7 10 1 4 7 10 1 4 7 10 1 4 7 10 1 4
KhácA/H1N1pdmA/H3N2BA/H1N1
Trang 19Rate of positive ILI samples by age group and by year 2006-2015
Total2006200720082009201020112012201320142015
Trang 20Distribution of positive samples by gender and virus sub-type, 2013-2015
50.7 49.3
A/H1N1
53.3 46.7
B
51.4 48.6
A/H3N2
51.8 48.2
Tổ g số +
50.5 49.5
A/H1N1 pdm
Trang 21• The Influenza infection rate in men and women almost equally
• Influenza mainly influence on children under 15
Trang 22Selecting sites
1 Is geographically representative
2 Has a high density of population, high level of commercial and cultural exchanges
3 Urban and rural coverage
4 Sentinel surveillance is based in health facilities that already have the necessary infrastructure, equipment, and trained staff
5 Has close collaboration in specimens and data collection
6 Has the ability to preserve specimens at the proper temperature and easy transport specimens to the laboratory
7 Is a commitment and willingness to participate
8 Ability to long term maintained surveillance activities
For ILI: Admits a large number of ILI patients (at least 50 patients/week)
For SARI: Is a centre for diagnosis and treatment of severe acute respiratory diseases
Trang 23SARI Surveillance sites (2010 – 2015)
23
BV Bạch Mai
Trang 24SARI Definitions
Severe Acute Respiratory Infection (SARI)
For children < 5 years:
• Cough or difficult breathing AND • Any one of the following:
– Breathing > 60/min for ages <2m
– Breathing > 50/min for ages 2m to < 1yr – Breathing > 40/min for ages 1 to < 5 years – Chest indrawing
– Stridor in a calm child
– Unable to drink or breast feed – Vomits everything
– Convulsions
– Lethargic or unconscious
– Oxygenation saturation < 90%
Trang 25SARI Definitions
Severe Acute Respiratory Infection (SARI)
Trang 27SARI SURVEILLANCE RESULTS, 2011-2015
• Total patients visit: 228.656
• Total SARI: 37.541 (16% in total admissions patients) • Total SARI sample collected for testing: 5.148
• Total SARI sample tested using RT-PCR: 5.148
• Total SARI samples positive with influenza 611 (11,9%)
Trang 28PROPORTION SARI/TOTAL ADMISSION AND PROPORTION SARI SAMPLE POSITIVE WITH INFLUENZA ,2011-2015
28
0102030405060
Trang 29Distribution of SARI patients by region and aetiologies, 2011-2015
Region Total samples No positive A/H1N1/09
Trang 30DISTRIBUTION OF POSITIVE RATE WITH FLUENZA BY MONTH AND YEAR 2011-2015
20112012201320142015
Trang 31Distribution of influenza viruses by time, 2011-2014
020406080100
Trang 32DISTRIBUTION OF SARI BY AGE GROUP
20.030.0
Trang 33• Proportion of SARI/Total Admission: 16.5%
• Influenza viruses account for 12% SARI patients There were two picks in March and June
• Age group 0 – 4 years old account more than 50% SARI patients
CONCLUSION
Trang 34Case definitions for SARI Surveillance 2016 - 2017
– SARI (using WHO case definition 2014):
Trang 36SARI Sentinel sites, 2016-2017
2 Bệnh viện Nhi Trung 3
4 5 6 B
7 Bệnh viện Trung 8
9
11 12 13
Trang 3710 ới Tp HCM
11
12
13
CDC support WHO support
Trang 38Distribution of influenza on SARI
Region Samples Influenza positive A/ H1N1/pdm A/ H3N2 B
Other influenza
Trang 39Distribution of 7 non influenza viruses on SARI
No HMPV Adeno P1 P2 P3 RSV Rhino Co-infection
# # % # % # % # % # % # % # % # %
Miền
Bắc 926 23 2.5% 46 5.0% 32 3.5% 5 0.5% 42 4.5% 127 13.7% 100 10.8% 53 5.7%Miền
Trang 40SEVERE PNEUMONIA SURVEILLANCE (SVP SURVEILLANCE)
Trang 42carbondioxide saturation level)
• Chest X-ray consistent with viral pneumonia
• No suspect diagnoses of other aetiology such as
bacterial pneumonia, tuberculosis etc were made by specialist conference
Trang 436/20/2017 43
Surveillance sites
– Passive surveillance system at all
hospitals in 63 provinces
Trang 45Methods
– Sampled, epidemiological and clinical data collected on form for all SVP cases
– Data and samples sent to regional lab
– All specimens will be tested in laboratories of 4 regional institutes using RT-PCR
– Standardized Laboratory Management in Lab network
Trang 48Distribution of SVP cases by aetiologies, 2006-2015
Lab results 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 Total (%)
Trang 49Influenza A(H5N1) virus in Vietnam, 2003-2015
64 deaths/127 cases in 41 provinces/cities
Trang 50• Influenza viruses account for 16.9% SVP patients
• Early detect avian influenza A/H5N1 in the period 2006-2014 33/34 (97%) avian influenza A/H5N1 cases were detected through SVP surveillance system
• In Vietnam, not yet found any cases of influenza A(H7N9) in humans
CONCLUSION
Trang 51ACHIEVEMENTS OF NATIONAL INFLUENZA SURVEILLANCE SYSTEM
Establishment of the National Influenza Surveillance System
Provide epidemiological and virological information on all strains of human influenza in Vietnam through active surveillance
Detect outbreaks of Avian Influenza in Human by Passive surveillance for Viral Pneumonia (SVP)
Contribute to national influenza prevention and control, especially Strengthen Public Health Laboratory Networks
Sharing influenza isolates for Vaccine candidates of Northern Hemisphere
Serve as a background and basis for further researches on influenza viruses
Reporting on weekly basis on the FluNet (Global Influenza Surveillance and Response System)
Trang 52ADVANTAGES
Advantage of support from MOH, GDPM, district and
provincial PMC, sentinel hospital, US.CDC representatives Standardized Laboratory Networks, high quality performance
and stability in all 4 regions
Enthusiastic staffs, dynamic, professional and technical mastery
Effectiveness of the system to provide timely information to contribute to guide influenza prevention and control policies and activities
Trang 53CHALLENGES
System depends on outside funding, needs for long term with stable financial source to maintain and further strengthen the system
At provincial level, laboratory testing to confirm viruses
unavailable, test result is always late to be useful for on time intervention and treatment
High costs of biological testing products, there is no
standardized estimating procedures and SOP for an effective management of biological products
Settlement and contract’s signatures was made late on scheduled activities
Trang 54Thank You
For Your Attention!