Epidemiological Perspective of Influenza - Muskan.pptx

1. Epidemiological Perspective of
Influenza
Presenter:
Muskan Pudasainee
MPH 2nd Semester
SHAS, Pokhara University 1

2. • Background
• Distribution of Disease
• Epidemiological Determinant
• Prevention and control measures
• Government Response
Presentation Outline (Influenza and
COVID-19)
2

3. Influenza
3

4. Background
• Flu (influenza) is an infection of the nose, throat and lungs, which
are part of the respiratory system
• Flu is a contagious respiratory illness caused by influenza viruses
that infect the nose, throat, and sometimes the lungs.
• It can cause mild to severe illness, and at times can lead to death.
• The best way to prevent flu is by getting a flu vaccine (Can be
yearly dose)
4

5. The pathogen
• There are 4 types of seasonal influenza viruses, types A, B, C and D.
• Influenza A and B viruses circulate and cause seasonal epidemics of
disease.
• Influenza A viruses are further classified into subtypes according to
the combinations of the hemagglutinin (HA) and the neuraminidase
(NA), the proteins on the surface of the virus. Currently circulating in
humans are subtype A(H1N1) and A(H3N2) influenza viruses. The
A(H1N1) is also written as A(H1N1)pdm09 as it caused the pandemic
in 2009 and subsequently replaced the seasonal influenza A(H1N1)
virus which had circulated prior to 2009. Only influenza type A viruses
are known to have caused pandemics.
5

6. • Influenza B viruses are not classified into subtypes, but can be
broken down into lineages. Currently circulating influenza type B
viruses belong to either B/Yamagata or B/Victoria lineage.
• Influenza C virus is detected less frequently and usually causes
mild infections, thus does not present public health importance.
• Influenza D viruses primarily affect cattle and are not known to
infect or cause illness in people.
6

7. Types of Influenza viruses
• A, B, C, D
• Human influenza A and B viruses are highly contagious and cause seasonal
epidemics of disease
• Influenza A viruses are the only influenza viruses known to cause
pandemics
• A pandemic can occur when a new and very different influenza A virus
emerges that both infects people and has the ability to spread efficiently
between people
• Influenza B viruses mutate more slowly than influenza A viruses but can
cause seasonal epidemics
• Influenza type C infections generally cause mild illness and are not thought
to cause human flu epidemics
• Influenza D viruses primarily affect cattle and are not known to infect or
cause illness in people
7

8. Epidemiological determinants
Agent: Influenza is caused by infection of the respiratory tract
with influenza viruses, RNA viruses of the Orthomyxovirus genus. Influenza
viruses are classified into 4 types: A, B, C, and D
Host Factors:
a) Age and sex: Influenza affects all ages and both sexes.
b) Population mobility: In all Populations, but mainly can spread through
the overcrowded population.
c) Economic status: incidence is highest in the lower socio-economic
groups
8

9. Epidemiological determinants
Environmental factors
Poor environmental sanitation
low standards of personal hygiene
lack of education
Poor quality of life
Temporal pattern: In temperate climates, seasonal epidemics occur
mainly during winter, while in tropical regions, influenza may occur
throughout the year, causing outbreaks more irregularly.
9

10. Who are at High Risk?
People at greater risk of severe disease or complications when
infected are: pregnant women, children under 59 months, the
elderly, individuals with chronic medical conditions (such as
chronic cardiac, pulmonary, renal, metabolic,
neurodevelopmental, liver or hematologic diseases) and
individuals with immunosuppressive conditions (such as
HIV/AIDS, receiving chemotherapy or steroids, or malignancy).
Health care workers are at high risk acquiring influenza virus
infection due to increased exposure to the patients and risk
further spread particularly to vulnerable individuals.
10

11. Mode of transmission
11

12. Mode of transmission
• In terms of transmission, seasonal influenza spreads easily, with
rapid transmission in crowded areas including schools and
nursing homes.
• When an infected person coughs or sneezes, droplets containing
viruses (infectious droplets) are dispersed into the air and can
spread up to one meter, and infect persons in close proximity who
breathe these droplets in.
• The virus can also be spread by hands contaminated with
influenza viruses.
• To prevent transmission, people should cover their mouth and
nose with a tissue when coughing and wash their hands regularly.
12

13. Sign and Symptoms
• Influenza (flu) can cause mild to severe illness, and at times can lead to death.
Flu symptoms usually come on suddenly. People who have flu often feel some
or all of these symptoms:
• fever* or feeling feverish/chills
• cough
• sore throat
• runny or stuffy nose
• muscle or body aches
• headaches
• fatigue (tiredness)
• some people may have vomiting and diarrhea, though this is more common in
children than adults.
*It’s important to note that not everyone with flu will have a fever.
13

14. Diagnosis
• Incubation period, is about 2 days but ranges from one to four days.
• The majority of cases of human influenza are clinically diagnosed.
• Collection of appropriate respiratory samples and the application of a
laboratory diagnostic test is required to establish a definitive diagnosis.
• Laboratory confirmation of influenza virus from throat, nasal and
nasopharyngeal secretions or tracheal aspirate or washings is
commonly performed using direct antigen detection, virus isolation, or
detection of influenza-specific RNA by reverse transcriptase-
polymerase chain reaction (RT-PCR).
• Various guidance on the laboratory techniques is published and
updated by WHO.
14

15. Diagnosis
• Tests:
Most common: “rapid influenza diagnostic tests (RIDTs)
“rapid molecular assays” that detect genetic material of the virus
Even more accurate and sensitive flu tests available that must be
performed in specialized laboratories- swab collection and test
15

16. Treatment
Patients with uncomplicated seasonal influenza:
• Patients that are not from a high-risk group should be managed
with symptomatic treatment (If symptomatic, to stay home in order to
minimize the risk of infecting others in the community)
• Treatment focuses on relieving symptoms of influenza such as fever.
• Patients should monitor themselves to detect if their condition
deteriorates and seek medical attention
• Patients that are known to be in a group at high risk, should be treated
with antivirals in addition to symptomatic treatment as soon as
possible.
16

17. Treatment
Patients with severe or progressive clinical illness associated with
suspected or confirmed influenza virus infection
• Neuraminidase inhibitors (i.e. oseltamivir) should be prescribed as soon as
possible (ideally, within 48 hours following symptom onset) to maximize
therapeutic benefits. Administration of the drug should also be considered in
patients presenting later in the course of illness.
• Treatment is recommended for a minimum of 5 days, but can be extended
until there is satisfactory clinical improvement.
• Corticosteroids should not be used routinely, unless indicated for other
reasons (eg: asthma and other specific conditions); as it has been associated
with prolonged viral clearance, immunosuppression leading to bacterial or
fungal superinfection.
• All currently circulating influenza viruses are resistant to adamantane
antiviral drugs (such as amantadine and rimantadine), and these are therefore
not recommended for monotherapy 17

18. Prevention
• The first and most important step in preventing flu is to get a vaccine
• Vaccine storage at 2° to 8°C : never be frozen or kept outside of a refrigerator
• Everyday preventive actions:
Regular hand washing with proper drying of the hands
Good respiratory hygiene – covering mouth and nose when coughing or
sneezing, using tissues and disposing of them correctly
Early self-isolation of those feeling unwell, feverish and having other
symptoms of influenza
Avoiding close contact with sick people
Avoiding touching one’s eyes, nose or mouth
18

19. Influenza in Nepal
• Circulating throughout the year: A/H1N1 pdm09, A/H3N2 and influenza B
• The rate of infection transmission reach peak during the post-rain and winter
season of Nepal. (Asian countries)
• A descriptive cross sectional study was carried out at National Public Health
Laboratory, Kathmandu, Nepal for the period of one year (Jan–Dec 2016)
Of the total 1683 patients suspected of having influenza infection
Influenza viruses were isolated from 614 (36.5%) patients with male
predominance
The highest number of infection was caused by influenza A/H3 strain (51.0%)
followed by influenza B (40.4%) and influenza A (H1N1) pdm09 (8.6%)
Two peaks of infection were observed during the year 2016
19

20. Current Policies and Program
20

21. Infectious Disease Control Guideline
2073 BS (2016 AD)
Prevention and control measures - Vaccination
Inactivated influenza vaccine
• Annual influenza vaccination for everyone above 6 months of age
• Age >65 years
• Chronic morbidity
• Nursing home residents or health care workers
21

22. 22
*HIB Vaccine
(Haemophilus
influenzae
type B vaccine)
6,10,14 weeks

23. National Influenza Center (NPHL, 2010)
• Member of WHO Global Influenza Surveillance Network.
• Influenza Surveillance started since 2004 from Jhapa, eastern part
of Nepal with the aim to identify the influenza viruses from
suspected cases of influenza like illness (ILI) and immediate
response to minimize the circulation of viruses during outbreak.
• National influenza Surveillance Network (NISN): ten NISN sentinel
sites
• These sentinel sites collect samples from suspected patients
meeting case definition of Influenza like ilIness (ILI) and Severe
Acute Respiratory Infection (SARI) for virus identification and
isolation.
23

24. Current Activities of NIC
• Human Cases of influenza Specimen Collection, storage, transportation
and processing at NIC, NPHL.
• Detection and characterization of influenza virus types (Influenza A &
B) & subtypes (Influenza. A/H1, AH3, A/H1N1 Pdm, A/H5) by RT-PCR.
• Influenza Virus isolation & identification by Serological/Immuno-
fluorescence Assay (IFA) technique.
• Sharing influenza isolates with WHO Collaborating Centre (WHOCC) for
the development of candidate vaccine.
• Sharing week-wise influenza report with Global Influenza Surveillance
and Response System (GISRS).
• Sharing any unidentified influenza isolate with Global Influenza
program for reference and research on influenza.
24

25. Current Activities of NIC
• Immediate response on Influenza like Illness (ILI) and Severe
Acute Respiratory infection (SAR) outbreak with co-ordination of
Epidemiology & Disease Control Division.
• Co-ordination and sharing of information about human influenza
activity with Animal Health Component.
• Co-ordination and management of diagnostic kits accessories,
Sample collection, storage and transportation of clinical specimen
from NISN sentinel sites to NIC, NPHL.
• Situation up-date and feedback information sharing to all NISN
sentinel sites.
25

26. National Avian Influenza Control and
Influenza Pandemic Preparedness and
Response Plan (NAIIPPRP)
• The Government of Nepal implemented the Avian Influenza
Control Project (AICP) between 2007 and 2011 and prepared
strategic plan, “National Avian Influenza Control and Influenza
Pandemic Preparedness and Response Plan (NAIIPPRP)” with the
objective of protecting people and livestock against future
outbreaks of AI within Nepal border.
• This plan has been build on the National Contingency Plan for
Highly Pathogenic Avian Influenza that was in place since 2004.
26

27. National Contingency Plan for Prevention
and Control of Avian Influenza in Nepal,
2060
Objective:
To prevent the entrance of Highly Pathogenic Avian Influenza (HPAI) in the country
To control HPAI at the point of entry, in any possible case of entry,
 To free the country from the HPAI.
4 Chapters
1. Details about National Contingency Plan for highly Pathogenic Avian Influenza,
2060
2. Composition, Functions and Duties of Contingency Committees
3. Action Plan for the Prevention of the Entrance of HPAI and Responsible
Institutions
4. Action Plan during HPAI Outbreak
27

28. CDC Influenza Survey Unit
• PAHS is a collaborative partner, and it receives grants from the
Centre for Disease Control and Prevention(USA) to implement the
Influenza Pandemic Preparedness and Response Project (IPPRP).
• The goal of the IPPRP is to support the MOHP for the
implementation of a National Avian Influenza and Influenza
Pandemic Preparedness and Response Plan (NAIIPPRP) through
developing selected referral service centers for virological and
epidemiological surveillance.
28

29. Corona Virus Disease 2019 (COVID-19)
29

30. COVID-19 : Caused by SARS-CoV-2 (Severe Acute
Respiratory Syndrome Corona Virus 2)
Corona Virus
• A family of viruses affecting Respiratory Tract
• Causes Disease from common cold to Pneumonia.
• Usually lives in bats & other wild animals.
• Transmitted to humans directly, or via other animals.
• Transmitted between humans via respiratory droplets
Background
30

31.  Symptoms: Fever, dry cough, tiredness, loss of taste or smell,
shortness of breath
 Diagnostic tests: RT PCR, RDT, Antigen Test
 Prevention and Treatment: Vaccination, Supportive
31

32. COVID-19 Epidemiological determinants
Agent: SARS-COV-2
Host Factors:
a) Age and sex: COVID-19 affects all ages and both sexes.
b) Population mobility: In all Populations, but mainly can spread through the
overcrowded population.
c) Economic status: incidence is equal in all groups.
Environmental factors
Poor environmental sanitation
low standards of personal hygiene
lack of education
Poor quality of life
32

33. Who are at Risk?
HIGH RISK
Risk of severe disease increases with age and in those with underlying
medical conditions such as hypertension, diabetes, cardiovascular
disease, chronic respiratory disease, cancer & obesity.
LOW RISK
Contact studies indicate children and young adults do become infected,
and can transmit infection. However, children rarely progress to serious
Illness.
33

34. Mode of transmission
Person-to-Person
Transmission
• Droplets or aerosols
• Airborne transmission
• Surface transmission
• Fecal-oral
34

35. Sign and Symptoms
Early symptoms of COVID-19 may include a loss of taste or smell.
Other symptoms can include:
•Shortness of breath or difficulty breathing
•Muscle aches
•Chills
•Sore throat
•Runny nose
•Headache
•Chest pain
•Pink eye (conjunctivitis)
•Nausea
•Vomiting
•Diarrhea
•Rash
35

36. Diagnosis
• To test for the COVID-19 virus, a health care provider takes a sample
from the nose (nasopharyngeal swab), throat (throat swab) or saliva.
• The samples are then sent to a lab for testing.
• Diagnostic tests in Lab: RT PCR, RDT, Antigen Test
36

37. Treatment
• Currently, only one medication has been approved to treat COVID-19.
• No cure is available for COVID-19.
• Antibiotics aren't effective against viral infections such as COVID-19.
• Researchers are testing a variety of possible treatments.
• The FDA has approved the antiviral drug remdesivir (Veklury) to treat
COVID-19 in hospitalized adults and children who are age 12 and older
in the hospital.
• Remdesivir may be prescribed for people who are hospitalized with
COVID-19 and need supplemental oxygen or have a higher risk of
serious illness.
• It's given through a needle in the skin (intravenously).
37

38. 38

39. Prevention
• Wear Mask
• Maintain Physical Distance
• WASH your hands at critical
times using soap and water
• Vaccination
39

40. 31 DEC 2019
China alerts WHO about a cluster
of Pneumonia cases reported in
Wuhan, Hubei Province
Hunan Seafood Market
“Ground Zero” 11 AUG 2020
Sputnik V vaccine receives
regulatory approval for use in Russia
30 JAN 2020
WHO declares a novel Corona
virus outbreak a Public
Health Emergency of
International Concern
11 December 2022
The pandemic continues with:
649M Cases
6.65M Deaths
21 MARCH 2020
Italy becomes the
epicenter of European
outbreak with a peak
of 6557 cases/day
WHO: Vaccine under Emergency Use
List (EUL)
• Pfizer/BioNtech Comirnaty vaccine: 31 Dec 2020
• AstraZeneca/SKBio - COVID-19 Vaccine: 15 Feb 2021
• COVISHIELD: 15 Feb 2021 (Serum Institute of India)
• Janssen/Ad26.COV 2.S(Johnson & Johnson): 12 March 2021
• AstraZeneca/EU: 15 April 2021
• Moderna COVID-19 vaccine:30 April 2021
• Sinopharm COVID-19 vaccine (China):7 May 2021
• Sinovac-CoronaVac: 1 June 2021
Source: https://www.who.int/news/item/27-04-2020-who-timeline---covid-19 https://extranet.who.int/pqweb/sites/default/files/documents/Status_COVID_VAX_20Jan2021_v2.pdf
2 FEB 2020
First death outside of
China (Philippines)
30 JAN 2020
7818 total confirmed cases worldwide,
with the majority of these in China,
and 82 cases reported in 18 countries
outside China.
23 JAN 2020
Wuhan under lockdown;
Rail and a air services
suspended
11 FEB 2020
WHO-new corona virus was
termed as SARS-CoV-2 & the
disease as COVID-19
COVID-19 Global Scenario
11 JAN 2020
First death in China recorded
1 APRIL 2020
Worldwide case:
1 million
Death toll: 50,000
28 SEP 2020
Death toll:1 million
2 DEC 2020
UK becomes the
first country to
approve Pfizer and
BioNTech’s
COVID-19 vaccine
13 JAN 2020
First case reported outside of
China (Thailand)
11 MARCH 2020
WHO declared the outbreak as pandemic
with more than 100000 cases and 4000
deaths in 114 countries
40

41. COVID-19: In Nepal
Jan 23 2020
First confirmed case,
in a Wuhan returnee
May. 14
First death of a woman
from Sindhupalchok
Apr. 4
First locally transmitted
case, confirmed in Kailali
Mar. 24
Beginning of a
national-wide
lockdown
Jul 21
End of nation-wide
lockdown
Jun 03
Daily cases:5825
May 11
Daily cases: 9317
Oct 21, 2020
Daily cases: 5743
Apr 16, 2021
(start of 2nd wave)
Daily cases: 836
Total as of Dec 11 2022
Cases: 10,00,932
Recovered: 9,88,883
Deaths:12,019
Apr 29
Cabinet decision
of lockdown

42. COVID-19: Vaccine in Nepal
Vaccine Name Received From
India Astrazeneca (Covishield)
India Army AstraZeneca (Covishield)
Serum Institute of India (SII) AstraZeneca (Covishield)
China Sinopharm (VeroCell)
Tibet (China) Sinopharm (VeroCell)
Denmark AstraZeneca
42

43. Policies, Programs and Activities
43

44. Covid-19 related Policy and Guidelines
in Nepal
• Procedure for Smart Lockdown for Covid-19 Infection Risk Control,
2078 (कोभिड-१९ संक्रमण जोखिम भियन्त्रणका लाभि स्मार्ट लकडाउि सम्बखि
कायटभिभि, २०७८)
• Travel Advisory Aadesh, 2078 (भिदेशबार् िेपाल आिमि हुिे र िेपालबार्
प्रस्थाि ििे यात्रुहरुको यात्रा व्यिस्थापि सम्बिी आदेश, २०७८)
• Guideline for COVID19 Facilitation Group Mobilization
• COVID-19: Micro Containment Plan, Nepal
• Clinical Management of COVID-19 in Health Care Setting (REVISED)
• Rapid Hospital Readiness Facility Assessment Checklist for COVID-19
• COVID-19 Patient Transfer Team (PTT) Guidelines
44

45. Contd..
• Interim Guidance for the Health-related Rehabilitation and
Physiotherapy of persons with COVID-19 in Acute Care Settings
• COVID-19 Cases Isolation Management Guidelines
• Health Care Waste Management in the context of COVID-19
Emergency
• Ordinance for COVID-19 Crisis Management, 2078
• Order for Hazard Allowance Management (कोरोिा िाइरस (कोभिड-
१९) को उपचारमा संलग्न जिशखिको जोखिम ित्ता व्यिस्थापि आदेश,
२०७७)
45

46. Contd..
• Conduction of COVID-19 Unified hospital
• COVID-19 Emergency Medical Deployment Teams (EMDT)
Mobilization Guidelines
• Interim Guidance for RMNCH services in COVID 19 Pandemic
• Criteria of public health in COVID-19 pandemic and effective
lockdown
• Health provision for people in quarantine
• Ayurveda and Alternative Medicine Guidelines of Preventive
Measures and Management Protocol for COVID 19 in Nepal
46

47. Contd..
• Corona Insurance Standard 2020
• COVID-19 Nepal: Preparedness and Response Plan (NPRP),
April 2020
• Integrated Action Plan for COVID-19 Response with Roles,
Responsibilities and Functions of Ministries and Agencies
• Management of Dead body due to COVID-19 Cases
• Interim Guidance for the Health-related Rehabilitation and
Physiotherapy of persons with COVID-19 in Acute Care Settings
47

48. COVID-19 Nepal: Preparedness and Response
Plan (NPRP), April 2020
NPRP planning scenarios:
1.Scenario not requiring international humanitarian assistance
- sporadic cases, or small household clusters (<5)
2.Scenario requiring international humanitarian assistance
- human to human transmission at community level (1500 cases)
3.Worst-case scenario requiring international humanitarian assistance
- More than 10,000 cases
Preparedness and Response Objectives:
• To support the Government of Nepal in preparing and responding to an outbreak of
COVID-19 of a scale that necessitates an international humanitarian response (including
mitigation of social and economic impacts).
• To ensure that affected people are protected and have equal access to assistance and
services without discrimination, in line with humanitarian principles and best practice.
48

49. References
• Influenza (seasonal) (who.int)
• Influenza (flu) - Symptoms and causes - Mayo Clinic
• Key Facts About Influenza (Flu) | CDC
• Archived: WHO Timeline - COVID-19
• Coronavirus disease (COVID-19) (who.int)
• Coronavirus Disease 2019 (COVID-19) | CDC
• https://www.mayoclinic.org/diseases-
conditions/coronavirus/symptoms-causes/syc-20479963
49

50. Thank You!
50