Yellow Fever = Bad Disease

Transcription

1 Yellow Fever = Bad Disease Dr. David O Freedman Unvaccinated engineer after Amazon trip. Hepatic encephalopathy, ARDS, coma, DIC with spontaneous bleeding. Gross hematuria, 3+ proteinuria, BUN 81, Creatinine 1.2, Bilirubin 11.6, AST 2890, ALT 2676, Alk P 476. INR 2.6. Expired day 3 The patient was started on ceftriaxone 2g/day, fluids, vasopressors, mechanical ventilation and dialysis. Chest X-ray on the 2nd hospital day showed an alveolar pattern consistent with early ARDS. He died of multi-organ failure within 48 hours of admission and on Day 6 of illness. Prior to death Hb was 8.5, Creatinine 8.2, Albumin 2.3. AST/ALT decreased to 8,349/4,033, LDH to 28,873 mg/dl and Bilirubin to 5.7 mg/dl. Yellow Fever Vaccine Recommendations Updates of Routine Vaccines Required Vaccines International Health Regulations Medically Recommended According to risk Patient tolerance of risk Risk may be behavior related Live virus vaccines Replicate in vaccinee; longer-term immunity Killed viruses-often multi-dose T-cell memory; long-term immunity Bacteria Always short-term protection Polysaccharide T-cell independent New generation of conjugated vaccines 1

2 India diligently enforces its yellow fever entry requirement for some arriving travelers. The reason for this is A) There is significant risk of yellow fever in India B) India does not want to take a chance that a non immune traveler will export yellow fever acquired in India C) Competent yellow fever vectors exist in India D) Many travelers will continue to Africa after visiting India Yellow Fever Live virus, licensed centers May be required if arriving from infected areas Meningococcal Hajj, Umra travelers to Saudi Arabia Cholera Not any more Live attenuated 17D virus WHO licensed centers Only required vaccine left Must be given >10 days before entry Primary: single dose Booster: q10 years or not (to be discussed) Required if arriving from infected area Requirement is to protect the country not the individual traveler 32 vaccine related deaths & 57 severe cases of neurotropic or viscerotropic disease Autoimmune thymus dysfunction is risk factor Disturbing but rare events Used since 1937, 50 million doses given in year 2000 Risk estimates: anaphylaxis 1 in 250,000; neurotropic disease 1 in 8 million; viscerotropic disease 1 in 250,000 doses based on US data (1:100,000 for age 60-69; 1:42,000 for age >/70) Risk of disease Africa: 1:250 in epidemic areas; 1:4000 endemic area S. Am: 1:20,000 but vary by location/season Give only when true risk of infection on itinerary 2

3 Africa Endemic (AR 1-2%) 1 in 4,200 per week 23.8 per 100K per week Death : 12 per 100K / wk Epidemic (AR 30%) 1 in 280 per week 357 per 100K per week Death : 179 per 100K / wk South America Endemic (AR %) 1 in 42,000 per week 2.38 per 100K per week Death : 1.2 per 100K / wk Epidemic (AR 3%) 1 in 2,800 per week 35.7 per 100K per week Death : 17.9 per 100K / wk Age > 60 years (previously 65 years) is a precaution for immunization. Absolute contraindications to vaccination (not previously addressed) include: primary immunodeficiencies Transplantation immunomodulatory drugs (including TNF-a inhibitors, IL-1 blocking agents, or monoclonal antibodies targeting immune cells) thymus disorders associated with abnormal immune cell functions, such as thymoma, but not including incidental surgical removal of thymus or distant radiation therapy *Monath and Cetron, CID 2002: 34; As of May 2014, the IHR have been amended to state an indefinite validity of an International Certificate of Vaccination or Prophylaxis (ICVP) for yellow fever vaccination for the purposes of an entry requirement, no matter when issued. This amendment will officially take effect in June Until then, the current IHR-required 10-year limitation on ICVP validity is still applicable, but countries are permitted to accept indefinite validity if desired. Approximately what percentage of vacinees have neutralizing antibodies against yellow fever 10 years after vaccination? 100% 98% 92% 85% WHO approach is based on the rationale of no proven (2 reported) late YF cases in previous vaccinees WHO concerned with vaccine sparing in endemic countries not health of individual travelers Legacy 10 year rule not evidence based Sero surveys of varying methodologies indicate that up to 15% may lose immunity after years Remember: severe reactions to YF vax don t occur in revaccinees. Why not strive for near 100% protection in travelers? At the same time, the general durability of immunity is reassuring to the immunosuppressed and others not eligible for re vaccination Sample sizes small in most studies Healthy persons in Germany had a decline from 94% seropositivity in the first year to 74.5% after 10 years Of elderly persons seen in travel clinics, 95.2% were seropositive at a median of 14 years post-vaccination Neutralizing antibodies in 80.6% of World War II veterans for more than 30 years Conclusion: the long-term protective efficacy of YF vaccine was illustrated in the reviewed studies to have shown the presence of neutralizing antibodies in ~ 90% of YF vaccine recipients years after vaccination, and often longer. Gotuzzo E et al. Efficacy and Duration of Immunity after Yellow Fever Vaccination: Systematic Review on the Need for a Booster every 10 Years. Am J Trop Med Hyg 2013; 89:

4 691 subjects, male (73%) and aged years. PRNT testing in Rio de Janeiro days after YF vaccination, 94% became seropositive. The proportion of seropositive subjects declined from 1-4 years to 5-9 years and years post-vaccination (94%, 83%, and 76%, respectively) The trend of decline was particularly striking in persons aged years Immune response in different sub-populations requires further assessment Due to the transition in the IHR requirements, WHO and national recommendations on duration of immunity for personal protection for travelers who have true exposure to yellow fever virus risk vary somewhat and the broad wording of individual guidelines generally require some individual clinician interpretation on a patient-bypatient basis. Long-stay travelers to any area at risk for yellow fever transmission All travelers spending any time in high risk areas such as West Africa All travelers to any area with a current outbreak All persons who were infected with HIV at last vaccine Laboratory workers who handle yellow fever virus Women who were pregnant at their initial dose should receive a booster once before their next risk travel (may be < 10 years). Persons who received a hematopoietic stem cell transplant after receiving a dose of vaccine and who are now sufficiently immunocompetent should be revaccinated once before their next risk travel (may be < 10 years). Short-stay travel to low-risk yellow-fever endemic areas that are outside West Africa and other high-risk areas, in which there is no current outbreak and where no highrisk occupational exposure will occur. (Note: Such travelers should understand the need for repeat consultation prior to each subsequent trip to a yellow fever risk area). Personal recommendation that all frequent travelers consider boosters at 10-year intervals if there is any likelihood of meeting any of the criteria for q10 year boosters in the future. As of June 2015, 104 countries updated or verified their entry requirement; 35 declared lifetime validity and 18 declared 10-year validity. The remaining 67 countries with current entry requirements (includes countries who did not update their information at all in 2015) have not explicitly declared a duration of validity so are still entitled to enforce a 10-year validity at their discretion. Vaccines and vaccination against yellow fever. WHO position paper June Wkly Epidemiol Rec. 2013;88: Gotuzzo E, Yactayo S, Córdova E. Efficacy and duration of immunity after yellow fever vaccination: systematic review on the need for a booster every 10 years. Am J Trop Med Hyg. 2013;89: Grobusch MP, Goorhuis A, Wieten RW, et al. Yellow fever revaccination guidelines change - a decision too feverish? Clin Microbiol Infect Oct;19: Patel D, Simons H. Yellow fever vaccination: is one dose always enough? Travel Med Infect Dis Sep-Oct;11:

5 A penicillin allergic patient who had a Varicella vaccine administered 2 weeks previously by their primary care physician presents to your travel clinic for a Yellow fever vaccination. Departure is not for 6 more weeks. What do you do? Give a yellow fever waiver letter due to penicillin allergy Have the patient return in 2 weeks for the yellow fever vaccine Administer the yellow fever vaccine Give the yellow fever vaccine together with immune globulin Proof of vaccination is often required for travellers arriving from countries with risk of yellow fever transmission and sometimes for travellers in transit through such countries. In 2010 WHO proposed that for under 12 h of airport transit the risk of yellow fever is almost non-existent suggested to WHO Member States that national requirements be modified to reflect an exemption for such travelers Enforcement difficult to predict even when a receiving country has a written policy Chilean changing planes only in Argentina is denied boarding by Emirates Airlines in Buenos Aires for lack of an ICVP. He is on his way to India via Dubai. India has an entry requirement which includes travel from Argentina. Is the airline correct in its interpretation of the IHR requirement? 5

6 South African airways flight from Washington, DC to JNB stops for a refueling only in Dakar. Transit passengers do not leave the plane, but other passengers from Senegal join. Does the US transit passenger with no other destination than South Africa need an ICVP? A US resident goes to Capetown, Kruger, then flies to Zambia to see Victoria Falls. On his way back to the US, he transits OR Tambo airport in JoBurg without ever leaving the transit area. Will he be asked for an ICVP? What about if he decides to leave the airport and check into a hotel for 13 hours? For many practical purposes (current IHR, many current national guidelines, and package insert, yellow fever vaccination interval is still 10 years Immunity is longer in most people giving reassurance to those who cannot be boosted More YF ICVP requiring countries are exempting transit passengers Recent DRC cases may challenge recognition of some countries not listed in WHO Annexe 1 In HIV, viral load, not CD4 is the key determinant of response to YF vaccine 6