H1N1 & Pregnancy.Prof Salah Roshdy


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H1N1 & Pregnancy.Prof Salah Roshdy

  1. 1. PREGNANCY & H1N1 (NOVEL INFLUENZA) Salah Roshdy Ahmed ,MD Professor of OB/GYN, Sohag University . 2014
  2. 2. OBJECTIVES:  To discuss Influenza A H1N1  Epidemiology  Signs & symptoms  Risk factors  Diagnosis  Treatment and Prevention
  3. 3. INFLUENZA  Acute respiratory illness caused by infection with influenza viruses.  Affects the upper and/or lower respiratory tract and is often accompanied by systemic signs and symptoms:  fever  headache  myalgia  weakness
  4. 4. Credit: L. Stammard, 1995 • RNA, enveloped • Viral family: Orthomyxoviridae • Size: 80-200nm or .08 – 0.12 μm (micron) in diameter • Three types • A, B, C • Surface antigens • H (haemaglutinin) • N (neuraminidase) INFLUENZA VIRUS
  5. 5. o Influenza A viruses categorized by subtype according to two surface proteins…..  Hemagglutinin (H) – 16 known - Site of attachment to host cells - Antibody to HA is protective  Neuraminidase (N) – 9 known - Helps release virions from cells - Antibody to NA can help modify disease severity N H
  6. 6. H1 N1 H2 N2 H3 N3 H4 N4 H5 N5 H6 N6 H7 N7 H8 N8 H9 N9 H10 H11 H12 H13 H14 H15 H16 Haemagglutinin subtype Neuraminidase subtype
  7. 7. INFLUENZA A  The Influenza A virus subtypes that have been confirmed in humans, ordered by the number of known human pandemic deaths, are:  H1N1 caused "Spanish Flu" and 2009 H1N1 outbreak  H2N2 caused "Asian Flu"  H3N2 caused "Hong Kong Flu"  H5N1 is "bird flu", endemic in avian  H7N7 has unusual zoonotic potential  H1N2 is currently endemic in humans and pigs  H9N2, H7N2, H7N3, H10N7 (avian)
  8. 8. INFLUENZA B  Influenza B viruses are only known to infect humans and seals giving them influenza.  This limited host range is apparently responsible for the lack of Influenza virus B caused influenza pandemics in contrast with those caused by the morphologically similar Influenza virus A as both mutate by both genetic drift and reassortment.
  9. 9. INFLUENZA C  Influenza C viruses are known to infect humans and pigs giving them influenza.  Flu due to the type C species is rare compared to types A or B, but can be severe and can cause local epidemics.
  10. 10. WHAT IS THE NOVEL INFLUENZA A (H1N1)?  Quadruple Reassortment  2 swine strains,  1 human strain,  1 avian strain of influenza  Reassortment is the mixing of the genetic material of a species into new combinations in different individuals 1. Emergence of a Novel Swine-Origin Influenza A (H1N1) Virus in Humans. N Engl J Med 2009;361 2. Epidemiology, clinical manifestations, and diagnosis of swine H1N1 influenza A. Uptodate, May 15, 2009
  13. 13. Antigenic drift  Changes in proteins by genetic point mutation & selection  Ongoing and basis for change in vaccine each year Antigenic shift  Changes in proteins through genetic reassortment  Produces different viruses not covered by annual vaccine Definitions
  14. 14. SWINE INFLUENZA A(H1N1)  A confirmed case of H1N1 infection  is defined as a person with an acute febrile respiratory illness with laboratory confirmed H1N1 virus infection by one or more of the following tests:  real-time RT-PCR  viral culture  A probable case of H1N1 infection  is defined as a person with an acute febrile respiratory illness who is:  positive for influenza A, but negative for H1 and H3 by influenza RT-PCR, or  positive for influenza A by an influenza rapid test or an influenza immunofluorescence assay (IFA) plus meets criteria for a suspected case Source: CDC
  15. 15. SWINE INFLUENZA A(H1N1)  A suspected case of H1N1 infection  is defined as a person with acute febrile respiratory illness with onset  within 7 days of close contact with a person who is a confirmed case of H1N1 virus infection, or  within 7 days of travel to community where there are one or more confirmed H1N1 cases, or  resides in a community where there are one or more confirmed swine influenza cases Source: CDC
  16. 16. HOSTS AND RESERVOIRS Type A:  Exists in humans and animals Type B & C:  Exclusively in humans  Reservoir in animals:  Pigs, aquatic birds  Located in the digestive tube: fecal transmission  Reservoirs in humans :  3 sub-types circulate H1N1, H1N2 et H3N2.  H1 has better affinity than H3 for cell receptors.
  17. 17. WHAT IS A PANDEMIC? • There is a new strain of influenza A virus and humans have little or no immunity to it. • The virus spreads from person- to-person. • There is a global outbreak with sustained person- to-person transmission.
  18. 18. 20TH CENTURY FLU PANDEMICS Pandemic Year Influenza A virus subtype People infected (approx) Deaths (est.) Case fatality rate 1918 flu pandemic 1918–19 H1N1 0.5 to 1 billion (near 50%) 20 to 50 million[ >2.5% Asian flu 1956–58 H2N2 2 million <0.1% ? Hong Kong flu 1968–69 H3N2 1 million <0.1% 19
  19. 19. PANDEMIC H1N1/09 VIRUS  Novel strain of influenza A  The strain contained genes from four different flu viruses: 1. North American swine influenza, 2. North American avian influenza, 3. Human influenza, 4. Two swine influenza viruses typically found in Asia and Europe. 20
  20. 20. 22
  21. 21. EPIDEMIOLOGY Incubation period- 1-7 days Transmission PRIMARY CASE –direct contact with pigs SECONDARY CASES sneezing, coughing , resp droplets, body fluids(diahrroeal stool) contact surfaces
  22. 22. RISK FROM DRINKING WATER OR SWIMMING POOLS.  Free chlorine levels typically used in drinking water or swimming pools treatment are adequate to inactivate highly pathogenic H5N1 avian influenza.  Free chlorine levels recommended by CDC (1–3 parts per million [ppm} for pools and 2–5 ppm for spas).  It is likely that other influenza viruses such as novel H1N1 would also be similarly inactivated by chlorination.  There has never been a documented case of influenza virus infection associated with water exposure.
  23. 23. HOW LONG CAN INFLUENZA VIRUS REMAIN VIABLE ON OBJECTS ? Studies have shown that influenza virus can survive on environmental surfaces and can infect a person for 2 to 8 hours after being deposited on the surface.
  24. 24. HOW H1N1 VIRUS SPREADS  Spreads through coughing or sneezing of infected people  Some people may become infected by touching something with flu viruses on it and then touching their mouth, nose or eyes.
  25. 25. PREGNANCY -MATERNAL  Physiologic adaptations to pregnancy may increase virulence of viral infections  Alterations in maternal immunity  Increased oxygen consumption, decreased functional residual capacity  Increased physiologic dead space due to upward displacement by uterus  Hormonally mediated hyperventilation
  26. 26. PREGNANCY- FETUS  Susceptible to external influences on development  Direct effect of an infectious agent  Indirect effect due to hyperthermia, release of inflammatory cytokines  Teratogenic concerns from medications used to treat infection  Prematurity related medical and developmental complications
  27. 27. PREGNANT WOMEN ARE A HIGH-RISK POPULATION FOR H1N1 6x more likely to get infected with H1N1 4x more likely to be hospitalized 6x more likely to die than other adults Deaths related to pneumonia with subsequent ARDS requiring mechanical ventilation
  28. 28. • In seasonal influenza, viremia is believed to occur infrequently and placental transmission appears to be rare – may differ with novel influenza strains • Hyperthermia is a risk factor for some types of birth defects and other adverse outcomes • Influenza virus itself is not known to be teratogenic. Fetal Concerns Regarding Influenza During Pregnancy
  29. 29. • Clinical outcomes data has NOT shown teratogenic effects of the most commonly recommended influenza medications oseltamivir, zanamivir. • Influenza vaccine has no adverse fetal effects and has been recommended for pregnant patients since 2005. Fetal Concerns Regarding Influenza During Pregnancy
  30. 30. CLINICAL FEATURES Vomiting or diarrhea (not typical for influenza but reported by recent cases of swine influenza infection)
  31. 31. CLINICAL FEATURES  Influenza‐like illness symptoms:  Fever  Cough  Sore throat  Rhinorrhea  Headache  Muscle pain  Malaise  No dyspnoea 33
  32. 32. Pregnant Non- pregnant Risk ratio (95% CI)* Fever 33 (97%) 131 (92%) 1·1 (1·0–1·1) Cough 32 (94%) 133 (94%) 1·0 (0·9–1·1) Rhinorrhea 20 (59%) 71 (50%) 1·2 (0·8–1·6) Sore throat 17 (50%) 97 (68%) 0·7 (0·5–1·0) Headache 16 (47%) 90 (63%) 0·7 (0·5–1·1) Shortness of breath¶ 14 (41%) 35 (25%) 1·7 (1·0–2·7) Myalgia 12 (35%) .. .. Vomiting 6 (18%) 22 (15%) 1·1 (0·5–2·6) Diarrhea 4 (12%) 28 (20%) 0·6 (0·2–1·6) Conjunctivitis 3 (9%) 12 (8%) 1·0 (0·3–3·5) MANIFESTATIONS OF H1N1 FLU IN PREGNANCY Jamieson DJ et al., Lancet 374:451-8, 2009
  33. 33. DANGER SIGNS IN ALL PATIENTS  Tachypnea  Dyspnea  Cyanosis  Bloody or coloured sputum  Chest pain  Altered mental status  High fever that persists beyond 3 days  Hypotension  Hypoxia
  34. 34. CLINICAL FEATURES –COMPLICATED OR SEVERE INFLUENZA  Presenting secondary complications: 1. renal failure 2. multi‐organ failure 3. septic shock.  Other complications 1. musculoskeletal (rhabdomyolysis) 2. cardiac (myocarditis). 36
  35. 35. CLINICAL FEATURES – SUGGESTIVE CNS COMPLICATION 1. Unconscious 2. Drowsiness 3. Recurring or persistent convulsions 4. Confusion 5. Severe weakness or paralysis. 37
  36. 36. COMPLICATIONS  Progressive Pneumonia  Respiratory Failure – cause of most deaths  Acute Respiratory Distress Syndrome Anna R Thorner, MD. Treatment and prevention of swine H1N1 influenza. Uptodate, May 14, 2009.
  37. 37. PNEUMONIA -  Virus can cause pneumonia leading to death  Rapid onset, often within one day after infection  Attributed to "cytokine storm“  Deaths among healthy young people during the first weeks of the 2009 flu pandemic were attributed to this cause 39
  38. 38. LABORATORY DIAGNOSIS (WHO guidelines 21 August 2009) 40
  40. 40. DIAGNOSTIC TEST Real-Time Reverse Transcription- Polymerase Chain Reaction (rRT-PCR) Detection  Qualitative for Influenza A, B, H1, and H3  Positive for influenza A and negative for H1 and H3  If reactivity of real-time RT-PCR for influenza A is strong , it is more suggestive of a novel influenza A virus. Novel H1N1 Influenza (Swine Flu) http://www.cidrap.umn.edu/cidrap/content/infl uenza/swineflu/biofacts/swinefluoverview.html
  41. 41. TESTS Culture  Isolation of H1N1 influenza A virus - diagnostic  too slow  negative viral culture does not exclude H1N1 influenza A infection
  42. 42. LABORATORY FINDINGS  CBC- leucocytosis/ lymphopenia  Elevated CPK, LDH  Elevated UREA,CREATININE  Elevated AST,ALT  CHEST RADIOGRAPH-bilateral patchy pneumonia.
  44. 44. TREATMENT  Treatment is recommended for pregnant women with suspected or confirmed influenza, regardless of trimester of pregnancy  Do not delay treatment because of a negative rapid influenza diagnostic test or inability to test or while awaiting test results
  45. 45. OSELTAMIVIR (TAMIFLU)  Adult dose  Rx for acute illness: 75 mg PO bid for 5 d  Prophylaxis: 75 mg PO qd  available as 30-mg, 45-mg, and 75-mg oral capsules and as a powder for suspension that contains 12 mg/mL after reconstitution.
  46. 46. ZANAMIVIR (RELENZA)  Adult dose  Rx for acute illness: 10 mg inhaled orally bid for 5 d  Prophylaxis of household contact: 10 mg inhaled orally qd for 10 d (initiate within 36 h)  Prophylaxis for community outbreak: 10 mg inhaled orally qd for 28 d (initiate within 5 d of outbreak)  powder form for inhalation via the Diskhaler oral inhalation device
  47. 47. SWINE INFLUENZA A(H1N1) Source: CDC Oseltamivir (Tamiflu) Zanamivir (Relenza) Treatment Prophylaxis Treatment Prophylaxis Adults 75 mg capsule twice per day for 5 days 75 mg capsule once per day Two 5 mg inhalations (10 mg total) twice per day Two 5 mg inhalations (10 mg total) once per day Children 15 kg or less: 60 mg per day divided into 2 doses 30 mg once per day Two 5 mg inhalations (10 mg total) twice per day (age, 7 years or older) Two 5 mg inhalations (10 mg total) once per day (age, 5 years or older)15–23 kg: 90 mg per day divided into 2 doses 45 mg once per day 24–40 kg: 120 mg per day divided into 2 doses 60 mg once per day >40 kg: 150 mg per day divided into 2 doses 75 mg once per day Dosing recommendations for antiviral treatment of children younger than 1 year using oseltamivir. Recommended treatment dose for 5 days. <3 months: 12 mg twice daily; 3-5 months: 20 mg twice daily; 6-11 months: 25 mg twice daily Dosing recommendations for antiviral chemoprophylaxis of children younger than 1 year using oseltamivir. Recommended prophylaxis dose for 10 days. <3 months: Not recommended unless situation judged critical due to limited data on use in this age group; 3-5 months: 20 mg once daily; 6-11 months: 25 mg once daily
  48. 48. WHEN IS HOSPITALIZATION NEEDED?  Respiratory symptoms- shortness of breath  Intractable nausea, vomiting  Fever unresponsive to acetaminophen  Contractions, abdominal pain, preterm labor  Decreased fetal movement
  49. 49. POST-EXPOSURE CHEMOPROPHYLAXIS  Consider if close contact with suspected or confirmed case  Zanamivir (Relenza®) Two 5mg inhalations qd  Oseltamivir (Tamiflu®) 75 mg qd  10 day duration  Zanamivir is recommended in pregnancy due to less systemic absorption
  50. 50. CDC RECOMMENDATIONS FOR LABOR WITH H1N1 (AUGUST 2009)  Place surgical mask on ill mother during labor & delivery, if tolerable  Mother should consider avoiding close contact with infant until:  antiviral medication for 48 hours  fever has fully resolved  she can control coughs and secretions  When in contact with the infant, mother should do following until 7 days after symptom onset and symptom-free for 24 hours:  wear a facemask  change to clean gown or clothing  adhere to strict hand hygiene and cough etiquette
  51. 51. CDC RECOMMENDATIONS FOR POSTPARTUM WITH H1N1 (AUGUST 2009)  Newborns should be considered potentially infectious or infected if delivery occurs 2 days before through 7 days after onset of maternal illness.  Encourage breast feeding- use pump if in isolation until mother can breast feed.
  52. 52. SAFETY OF INFLUENZA VACCINATION DURING PREGNANCY  11 studies published between 1964 and 2008 about safety of influenza vaccination during pregnancy  None identified maternal or fetal problems with influenza vaccination  One prospective randomized trial showed significant benefits to mothers and newborns
  53. 53. VACCINE TYPES  Live attenuated vaccine (not licensed for use in pregnant women)  Multidose inactivated vaccine  Prefilled single dose inactivated vaccine (preservative-free)
  54. 54. H1N1 VACCINE Strongly recommended for  Pregnant women.  Parents of children under 6 months.  Health care providers with direct patient contact. Safety  Use “Flu Shot” (fragments of killed/inactivated virus) not “nasal spray” (live-attenuated virus), 2009 H1N1 Influenza Vaccine and Pregnant Women. CDC September 3, 2009 http://www.cdc.gov/h1n1flu/vaccination/pregnant_qa.htm
  55. 55. WHEN TO ADMINISTER  Can be given at any time during pregnancy  Can also be given postpartum, providing indirect protection for infants <6 months  Recommended even for women who have had influenza-like illness
  56. 56. MEDICATION SUMMARY Treatment Chemoprophylaxis Oseltamivir (Tamiflu®) 75-mg capsule twice per day for 5 days* 75-mg capsule once per day for 10 days* Zanamivir (Relenza®) Two 5-mg inhalations (10 mg total) twice per day for 5 days Two 5-mg inhalations (10 mg total) once per day for 10 days* Antiviral medication dosing recommendations for treatment or chemoprophylaxis of novel influenza A (H1N1) infection *Currently recommended first choice medications. CDC: Updated Interim Recommendations for the Use of Antiviral Medications in the Treatment and Prevention of Influenza for the 2009-2010 Season. 10/16/2009
  57. 57. SWINE INFLUENZA A(H1N1) GUIDELINES FOR GENERAL POPULATION  Covering nose and mouth with a tissue when coughing or sneezing  Hand washing with soap and water  Cleaning hands with alcohol-based hand cleaners  Avoiding close contact with sick people  Avoiding touching eyes, nose or mouth with unwashed hands
  58. 58. AVOID CLOSE CONTACT  Avoid close contact with people who are sick. When you are sick, keep your distance from others to protect them from getting sick too.  Aerosols spread the virus in any environment
  59. 59. STAY HOME WHEN YOU ARE SICK.  If possible, stay home from work, school, and errands when you are sick. You will help prevent others from catching your illness.
  60. 60. COVER YOUR MOUTH AND NOSE.  Cover your mouth and nose with a tissue when coughing or sneezing. It may prevent those around you from getting sick
  61. 61. CLEAN YOUR HANDS.  Washing your hands often will help protect you from germs.  Hand washing proved to be best procedure in prevention of Majority of Communicable diseases.
  62. 62. AVOID TOUCHING YOUR EYES, NOSE OR MOUTH.  Germs are often spread when a person touches something that is contaminated with germs and then touches his or her eyes, nose, or mouth.
  63. 63. PRACTICE OTHER GOOD HEALTH HABITS.  Get plenty of sleep, be physically active, manage your stress, drink plenty of fluids.  Unnecessary Migration of people from epidemic and endemic areas to be reduced.
  65. 65. SIMPLE MEASURES CARRY GET GOOD BENEFITS  Cover your mouth and nose. Use a tissue when you cough or sneeze and drop it in the trash. If you don’t have a tissue, cover your mouth and nose as best you can.
  66. 66. CLEAN HANDS SAVES YOU  Clean your hands often. Clean your hands every time you cough or sneeze. Hand washing stops germs. Alcohol-based gels and wipes also work well.
  67. 67. WARNING  Aspirin or aspirin-containing products should not be administered to any confirmed or suspected ill case of novel influenza A (H1N1) virus infection aged 18 years old and younger due to the risk of Reye’s syndrome.  Children 5 years of age and older and teenagers with the flu can take medicines without aspirin, such as acetaminophen and ibuprofen .
  68. 68. ACOG / CDC  Released Oct 15, 2009  Usable for office, clinic or OB Triage  ACOG websitehttp://www .acog.org/departments/re sourceCenter/2009H1N1T riageTreatment.pdf
  69. 69. CONCLUSIONS Data available thus far suggest that pregnant women are more susceptible to H1N1 influenza & they are at increased risk for complications and death.
  70. 70. CONCLUSIONS Pregnant women should be informed about the signs and symptoms of H1N1 influenza. Pregnant women who present with signs and symptoms consistent with influenza should be treated empirically with oseltamivir.
  71. 71. CONCLUSIONS Proof of diagnosis is not required for treatment. Post-exposure prophylaxis with zanamivir or oseltamivir can be considered for pregnant women
  72. 72. CONCLUSIONS Both seasonal and 2009 H1N1 influenza vaccines recommended for pregnant women 2009 H1N1 vaccine safety expected to be similar to seasonal influenza vaccine Obstetrical care providers should take a very active part in promoting vaccination .