Case Definitions Suspected Case- defined as a person with acute febrile respiratory illness (fever≥38ºC) with onset:Within 7 days of close contact with a person who is a confirmed case of swine influenza(H1N1) virus infection,orWithin 7 days of travel to community where there are one or more confirmed swine influenza A(H1N1) cases,orResides in a community where there are one or more confirmed swine influenza cases
Probable Case- defined as a person with an acute febrile respiratory illness who:► Is positive for influenza A, but unsubtypable for H1 and H3 by influenza RT-PCR or reagents used to detect seasonal influenza virus infection,or► Is positive for influenza A by an influenza rapid test or an influenza immunoflourescence assay(IFA) plus meet criteria for a suspected case.► Individual with clinically compatible illness who died of an unexplained acute respiratory illness who is considered to be epidemiologically linked to a probable or confirmed case
Confirmed Case: defined as a person with an acute febrile illness with laboratory confirmed swine influenza A(H1N1) virus infection at WHO approved laboratories by one or more of the following tests: Real time PCR Viral culture Four-fold rise in swine influenza A (H1N1) virus specific neutralising antibodies
Close Contact: defined as within 6 feet of an ill person who is a confirmed or suspected case of swine influenza A(H1N1) virus infection. Acute Respiratory Illness: defined as recent onset of at least two of the following: -rhinorrhoea or nasal congestion -sore throat -cough(with or without fever or feverishness)
Ordinary flu and pandemic flu – the differences Pandemic Flu Ordinary Flu Occurs during any season Occurs every yr during winter Affects almost half of the Affects 10-15% of world population population, Is a more serious infection Most recover in 1-2 wks without treatmentVaccine not available(new strain) Virus identified & vaccine available in advance(protective) People of all ages at risk of infectionAntiviral med.stockpiled to treat people
Symptoms & Signs in Swine In pigs influenza infection produces fever, lethargy, sneezing, coughing , difficulty breathing and decreased appetite. In some cases the infection can cause abortion. Although mortality is usually low, the virus can produce weight loss and poor growth Infected pigs can loose up to 12 pounds of body weight over a 3 to 4 week period
Signs and symptoms Symptoms of novel H1N1 flu in people are similar to those associated with seasonal flu. Fever Cough Sore throat Runny or stuffy nose Body aches Headache Chills Fatigue In addition, vomiting(25%) and diarrhea (25%) have been reported. (Higher rate than for seasonal flu.)
Watch for Emergency Warning SignsMost people should be able to recover at home, but watch foremergency warning signs that mean you should seek immediatemedical care. In adults: Difficulty breathing or shortness of breath Pain or pressure in the chest or abdomen Sudden dizziness Confusion Severe or persistent vomiting Flu-like symptoms improve but then return with fever and worse cough
Emergency warning signs in childrenIf a child gets sick and experiences any of these warning signs, seek emergency medical care. In children: Fast breathing or trouble breathing Bluish or gray skin color Not drinking enough fluids Severe or persistent vomiting Not waking up or not interacting Irritable, the child does not want to be held Flu-like symptoms improve but then return with fever and worse cough
TransmissionTransmission between pigs The main route of transmission is through direct contact between infected and uninfected animals. These close contacts are particularly common during animal transport. The direct transfer of the virus probably occurs either by pigs touching noses, or through dried mucus. Airborne transmission through the aerosols produced by pigs coughing or sneezing are also an important means of infection.
Transmission to humans Through contact with infected pigs or environments contaminated with swine flu viruses(zoonosis) Through contact with a person with swine flu
How does novel H1N1 Influenzaspread? This virus is thought to spread the same way seasonal flu spreads Primarily through respiratory droplets Coughing Sneezing Touching respiratory droplets on yourself, another person, or an object, then touching mucus membranes (e.g., mouth, nose, eyes) without washing hands
Can you get novel H1N1 Influenza fromeating pork?No. The novel H1N1 influenza virus (formerly referred to as swine flu) virus is not spread by food. You cannot get novel H1N1 flu from eating pork or pork products. Eating properly handled and cooked pork products is safe
High Risk Groups Children younger than 5 years old. (more in <2 yrs old) Adults 65 years of age and older. Persons with the following conditions: Chronic pulmonary (including asthma), cardiovascular (except hypertension), renal, hepatic, hematological (including sickle cell disease), neurologic, neuromuscular, or metabolic disorders (including diabetes mellitus); Immunosuppression, including that caused by medications or by HIV; Pregnant women Persons younger than 19 years of age who are receiving long-term aspirin therapy Residents of nursing homes and other chronic-care facilities.
Cause of Death The most common cause of death is Respiratory Failure Other causes- -Pneumonia(leading to sepsis) -High fever -Dehydration Fatalities are more likely in young children and the elderly
INFLUENZA What is Influenza(also called Flu)? The flu is a contagious respiratory illness caused by influenza viruses.It can cause mild to severe illness, and at times can cause death.
What is an epidemic, an endemic and apandemic?An epidemic is a sudden outbreak of disease that spreads through a single population or region in a short amount of time.An endemic is when in a population infection is maintained without the need for external inputs.
A pandemic occurs when there is a rapidly-spreading epidemic of a disease that affects most countries and regions of the world.
History Greek physician Hippocrates“ Father of medicine” first described influenza in 412 BC The first Influenza pandemic was recorded in 1580 and since then influenza pandemics occurred every 10-30 years Influenza pandemics occurred in 1729- 1730,1732-1733,1781-1782,1830,1833- 1834,1847-1848.
Inter epidemic phasePhase 1 : No new subtype human infection may be present in animalsPhase 2 : No new subtype circulating animal infection
Pandemic alert periodPhase 3 : Human infection with a new subtype. No human to human spreadPhase 4 : Small clusters with limited human to human transmission.
Pandemic phasePhase 5 : large clusters with human to human transmission.Phase 6: Increased & sustained transmision with spread to different continents.
Novel H1N1 Influenza First identified in april 2009 Mutation of 4 known strains of influenza virus Outbreak began in Mexico Transmission is human to human Not transmitted by eating foods
Agent- genetic sequencing shows a new subtype of influenza A(H1N1) virus with segments from four influenza viruses: -North American Swine -North American Avian -Human Influenza -Eurasian Swine
Host factors- otherwise healthy young adultsTransmission- Droplet infection and fomitesIncubation Period - 1-7 daysCommunicability- From day 1 before to 7 days after the onset of symptoms.
CDC expects that more cases, more hospitalizations, and more deaths from this outbreak will occur over the coming days and months. Influenza is always serious – each year in the United States, seasonal influenza results, on average, in an estimated 36,000 deaths and more than 200,000 hospitalizations from flu-related causes. This outbreak certainly poses the potential to be at least as serious as seasonal flu, if not more so, especially given the fact that there currently is no vaccine against this virus. Because this is a new virus, most people will not have immunity to it, and illness may be more severe and widespread as a result.
WHO UpdateLast WHO update on july 6 ,2009 94,512 confirmed cases 122 countries 429 deathsIn U.S. as of july 17,2009 40,617 confirmed cases 263 deaths
Indian scenario until MondayTotal 1707 cases reportedNew cases 152Cured 694230 positive cases in PuneTotal no.of deaths so far 24
Antigenic Variation Unique Feature: HA, NA undergo independent antigenic variation Antigenic Drift Antigenic Shift Drift: gradual sequential change in antigenic structure, occurring regularly at freq. intervals.New ags though diff. from the prev. ags are yet related to them-cause periodical epidemics.
Shift: Abrupt, drastic, discontinuous variation in the antigenic structure resulting in a novel virus strain unrelated antigenically to predecessor strains-may involve both HA and NA. Antibodies to predecessor viruses do not neutralise the new variants, therefore spread widely in the popn causing major epidemics or pandemics. Present strain influenza 2009 A/ H1N1 is a rare recombination of gene segments from swine with avian and human influenza strains.
Laboratory diagnosisDemo of the virus antigen • Direct detection Microscopy Ag detection Nucleic Acid analysis Nucleic Acid Act. AssayIsolation • CultureSerological test
Direct DetectionMicroscopy-EMAg DetectionNA activity assay-rarely usedNA analysis-RT-PCR
Isolation Culture-Cell culture, chick embryo Identification and Typing HAI,Elisa Serologic tests Four fold rise in ab titre
Principles of Management1. Prevention of spread of disease from patient to others,2. Prompt treatment to prevent severe illness and death,3. Early identification and follow up of suspected cases.
Infra structure/ Man power/ Material support 1. Isolation ward - Well ventilated - Beds one meter apart 2. Man Power - Dedicated doctors - Nurses - Paramedical staff 1. Equipments - Portable X-Ray machine - Oxygen - Pulse Oxymeter - Ventilator 1. Material - PPE, disinfectants, medicines
Standard Operating Procedures1. Standard infection control precautions – PPE for all contacts High efficiency mask Three layer surgical mask N- 95 mask Gowns Goggles Gloves Caps Shoe cover2. Restrict number of visitors3. Antiviral treatment and prophylaxis4. Proper waste disposal
Anti Viral Treatment Oseltamivir (Tamiflu) Recommended by WHO For treatment and prophylaxis Adult dose -75 mg. BD Supervised govt. supply Other drug – Zanamivir (Relenza)
Doses Of Oseltamivir By Weight: For weight <15kg 30 mg BD for 5 days 15-23kg 45 mg BD for 5 days 24-<40kg 60 mg BD for 5 days > 40kg 75 mg BD for 5 daysFor infants: < 3 months 12 mg BD for 5 days 3-5 months 20 mg BD for 5 days 6-11 months 25 mg BD for 5 days It is also available as syrup (12mg per ml ) If needed dose & duration can be modified as per clinical condition.
Chemoprophylaxis All close contacts of suspected , probable and confirmed cases. Close contacts include household/social contact , family members , work place or school contacts, fellow travelers etc. All health care personnel coming in contact with suspected , probable or confirmed case. Drug recommended - Oseltamivir Mass chemoprophylaxis
Doses of Oseltamivir for chemoprophylaxis Prophylaxis should be provided till 10 days after last exposure (maximum period of 6 weeks) By Weight: For weight <15kg 30 mg OD 15-23kg 45 mg OD 24-<40kg 60 mg OD >40kg 75 mg OD For infants: < 3 months not recommended unless situation judged critical due to limited data on use in this age group 3-5 months 20 mg OD 6-11 months 25 mg OD
Side Effects of OseltamivirGenerally well tolerated Mild - Nausea , vomiting , pain in abdomen - Vertigo , insomnia - Bronchitis , epistaxis Less common - Angina - Pseudomembranous colitis - Peritonsillar abscess Rare - Anaphylaxis Pregnancy - Risk benefit analysis
Supportive Plenty of oral fluids I . V. fluids Parenteral nutrition Oxygen Antibiotics for secondary bacterial infection Steam inhalation Paracetamol / ibuprofen Vasopressors for shock Mechanical ventilation
Indication of Oxygen Therapy Dyspnoea Tachypnoea SpO2 < 90%
Indication of Mechanical Ventilation Severe pneumonia Acute respiratory failure SpO2 < 90% with oxygen PaO2 < 60mm Hg with oxygen Invasive ventilator – Preferred Hepafilters on expiratory ports Prophylactic antibiotic
Admission Policy Severe - Admission Mild - Option of hospitalisation or isolation and treatment at home Home Well informed consent Guidelines to patient and household contact Treatment to patient Chemoprophylaxis to household contacts Strict home quarantine Children should not attend school Not for passengers at the point of entry
CDC Guidelines for schoolInform students &parents about symptomsRefer students with flu like symptomsUse home isolationMonitor closelyConsult with local authorities
Discharge Policy Adults – 7 days after symptoms have subsided Children - 14 days
Management of close contacts Voluntary home quarantine x 7 days Monitor for fever Prompt testing and hospitalisation sos when symptoms reported All suspected cases need to be notified to the state health authorities
Every day stepsCover your nose & mouthWash your hands often with soap & waterAvoid touching your nose,mouth & eyesAvoid close contact with sick peopleIf sick with flu like symptome stay home for at least 24 hrs after fever is gone.
SOP for Infection control Pre-Hospital Care Three layer surgical mask for patient Avoid aerosol generating procedure Ambulance attendant – PPE - N 95 mask Ambulance driver - Three layer mask Cleaning of ambulance interior by sodium hypochlorite Proper waste disposal
During Hospital care Admit in isolation ward Three layer mask for patient Doctors , nurses , paramedical staff – PPE - N-95 mask Aerosol generating procedures with PPE and N95 mask Hand hygiene Cleaning of patient’s room, contaminated surface and equipments daily by 5% Lysol / 10% sodium hypochlorite Proper waste disposal
How to prevent disease spread ? Home quarantine Defer nonessential travel Entry screening to all air ports / ports Air port / port quarantine Community quarantine Social distancing measure –closure of school , college , cinema hall , market , shopping mall Avoid mass gathering like festivals , marriage , sports , religious , political & funeral
QuarentineIf flu like symptomes stay home for 24 hrs after symptomes have subsidedConfirmed case on temiflu isolate for 3 daysConfirmed case without drug isolate for 7 days
VaccineSeasonal Influenza vaccine is not effective against H1 N1
State Control Room State Surveillance Unit Directorate Health ServicesOld Nurses Hostel , D.K.S. Mantralaya Campus, Raipur 0771-2220011 ( 24 x 7 )