Non-pharmacological interventions before a human influenza pandemic

1. Non-pharmacological interventions before a human influenza pandemic Dr. M�nica Guardo Pan American Health Organization - PAHO Bogot� � April 20, 2006

2. Aspects Covered Definition � non-pharmacological interventions Characteristics of the transmission of influenza Review of the theoretical foundations of interventions to control the spread from one country to another Theoretical foundation of the measures to reduce transmission within each country, at a national and community level Past evidence, of the present and mathematical models Measures to reduce individual risk Recommendations and discussion

3. Non-Pharmacological Interventions Use of pharmacological measures against a pandemic: Vaccines and anti viral medicines Availability will not be enough 2005 � World Health Organization (WHO) Non-pharmacological public health interventions recommended for the updated preparation plan 2006 � Experts Committee Emerging Infectious Diseases, Vol.12 (1) � January 2006, pg 81-94 www.cdc.gov/eid Definition Interventions designed to reduce exposure in the people susceptible to an infectious agent

4. Non-Pharmacological Interventions Fundamental Concepts Measures to limit international spread Filtering and travel restrictions Measures to limit national and local spread Isolation and treatment of the sick Vigilance and quarantine of those exposed Social distancing measures (like cancellation of reunions and closing of schools) Measures to limit individual risk Washing hands Use of masks in public Public communication of risks

5. Symptomatic adults - viral elimination 24-48 hours before symptoms Maximum infectiousness 24-72 hours of the disease � until day 5 Symptomatic children � faster viral elimination and for a longer period Asymptomatic � related to a group of adults in New Zealand, 1991 26 adults that packed fertilizer during 8 hours 16 with influenza type disease Initial case � malaise, without respiratory symptoms Influenza type disease six hours after finishing work Transmission by infected persons in an incubation period or those that show an asymptomatic infection Excretion and Viral Transmission

7. Forms of Transmission

8. Incubation and Viral Infectiousness Short period of incubation - 2 days (between 1 to 4 days) Symptoms 1-4 days post exposure Intervals between successive cases � between the appearance of the disease in two successive patients in the transmission chain (2 to 4 days) Viral excretion peak (maximum infectiousness) � initiation of the disease SARS comparison Interval between successive cases 8 � 10 days Maximum infectiousness the second week of the disease Greatest time to implement isolation and quarantine measures Basic reproductive number (Ro) Measure of secondary cases generated by an infected person (in a totally susceptible population) 1918 Influenza (R0 = 1,8 a 3) Similar to SARS coronavirus (Ro = 2-4)

9. International level National and local level Community level

10. Experiences from the Influenza Pandemic - 1918

11. Experiences from previous pandemicsPromulgated quarantine by islands October 1918, Australia Quarantine in ships, with variable times Taking into consideration the date in which the most recent case appeared 7 days in ships in New Zealand and South Africa, independent of cases Taking of temperature at least once a day Mouth temp = 37,2�C hospital isolation for observation October 1918 - May 1919 79 �infected vessels� 2.795 patients, 48.072 passengers and 10.456 crew members 149 �non infected vessels� 7.075 passengers and 7.941 crew members Without direct evidence of propagation from the vessel to the coast Notification of the pandemic�s arrival in Australia in January 1919 Maritime quarantines delayed the entrance of influenza by 3 months

12. Effects and doubts about the quarantine in Australia, 1918 Possible viral introduction before establishing quarantine It could not be demonstrated Hiding of the disease by officials and soldiers of the marine that were returning to Australia in European vessels To avoid prolonged quarantine Infection in Australia The mortality rates were less than those of other places previously affected

13. Experiences of previous pandemicsOther quarantine experiences African continent - 1918 Quarantine in three port areas like Liberia, Gab�n y Ghana Delay of entrance by several weeks, but less successful than in the islands Disease arrived through interior routes Canada Drastic measures Police control points Interruption of road and train traffic They did not prevent or delay propagation among the provinces

14. Effect of quarantine in international frontiers � 1957 pandemic Israel Delayed two months in comparison to neighboring countries Attributed to the absence of international travel with neighboring countries (due to political reasons, not quarantine). South Africa Maritime restrictions resulted in �some delay� No effect in other areas Measures have to be severe in order for them to be efficient

15. SARS Experiences - 2003

16. Filtering the entrance of travelers arriving via air� SARS, 2003 4 countries in Asia and Canada Mechanisms for the measurement of body temperature 35 million travelers, detection 0 cases Health Questionnaire Travelers supplied information about their health, symptoms and exposure history 45 million travelers, detection of 4 cases Distribution of sanitary warning signs 31 million signs distributed to incoming travelers, limited information about the follow up of those same ones

17. Filtering the entrance of travelers arriving via air� SARS, 2003

18. Screening/Filtering passengers exiting via air � SARS, 2003 March 27, 2003 Recommendation - WHO Exit filter for international passengers exiting via affected routes Transmission of SARS via air travel was not documented from countries that implemented exit filters Reflection of the dissuasive effect on travelers and/or a low incidence of SARS? Data combined from various countries indicated Detection of 1 case per 1.8 million exiting passengers that answered the health questionnaire None, in the 7 million cases that subjected themselves to temperature detection at the time of exit

19. Estimate of the effect of screening/filtering entrance of travelers entering the United Kingdom Mathematical modeling Considering filtering exit from countries with influenza pandemic 9% of asymptomatic persons would show signs during their trip to the UK at exit % greater if duration of flight greater 17% (12-23%) in travelers from Asian cities 12, 000 airplane seats arriving from the Extreme Orient to the United Kingdom daily 83% of those infected would not be detected Travelers arriving through connecting flights are not considered

20. Recommendations from the WHO to contain international transmission Alert travelers that arrive in the country Description of the symptoms and indications of where they should inform if they suffer from these symptoms Consider filtering at exit Health declaration and taking of temperature of international passengers exiting the affected areas during phases 4 and 5 Consider filtering arrival only when: Exit filtering at boarding is below optimal Islands or geographically isolated areas Where the country�s internal vigilance capacity is limited

21. Advantages and disadvantages of exit filters Advantages Smaller number of persons filtered Greater number of positive prediction values Reduction of transmission in flights and ships Disadvantages Costly and problematic It will not be totally efficient since the virus can be transmitted by asymptomatic persons that will not be detected during the filter It is not recommended, during any phase, that countries quarantine themselves or that they close international frontiers. As it happened with SARS, non-pharmacological interventions centered principally at a national and community level and NOT international frontiers.

22. Recommendations for Travelers to H5N1 epizootic areasPhase 3 Pandemic Alert Avoid: Contact with farms Contact with live animals in markets Contact with surfaces that appear to be contaminated with the fecal matter of chickens or other animals Diet: Avoid local food prepared raw, with birds or their products Only eat birds or their products that have been properly cooked There are no recommendations for travel restrictions to affected countries

23. Non-Pharmacological Interventions International level National and local level Community level

24. Isolation of cases and contact quarantine - 1918 Notification and obligatory isolation of cases in the community They did not stop viral transmission and it was not very practical Canada, Alberta Forced domiciliary isolation of cases � signs indicating �quarantine� They only detected 60% of the cases in the community Difficulties diagnosing mild cases Failure in the notification of cases to the authorities Australia, New South Wales Obligatory notification � useful for identifying the first cases in a community No posterior value Military bases and university dorms in 1918 It did not stop the transmission but seemed to reduce the attack rates Especially if they were complemented with travel restrictions to and from the surrounding community

25. Isolation of cases and quarantine lesions of SARS, 2003 Success of public campaigns for Self recognition of the disease Telephone consultation services with health information Early isolation of patients seeking medical attention Inefficient Measures Taking temperature of interurban travelers Efficient Measures Isolation and quarantine in the community Measures would be less effective before an influenza pandemic

26. Social Distancing Measures Avoid crowds To reduce the infectious peak of the epidemic, prolonged for several weeks 1957 Pandemic initially attacked military units, schools and other groups in close contact Incidence reduced in rural areas Closing of schools and daycare centers In the Northern hemisphere the reinitiating of school activities after summer vacations It was important for initiating the main epidemic period Influenza epidemics are amplified in primary schools However there is no evidence of the effectiveness of closing schools Epidemic in Israel, 2000 Teacher�s strike ? important reduction in the infection rates Reinitiating of activities ? increased the rates

27. Simultaneous use of several strategiesHong Kong, SARS 2003 Reduction of influenza and other respiratory diseases Intervention Closing of schools, pools and other crowded areas Cancellation of sporting events Disinfecting taxis, buses and public areas Use of masks in public and frequent washing of hands Less social contact Use of masks in public - 76% of residents With multiple measures There is no certainty of the contribution of the use of masks, if there was one1 Studies carried out of control cases in Beijing and Hong Kong during SARS, 20032 Use of masks in public was independently associated with protection towards SARS Dosis-response effect3

28. Interim WHO RecommendationsPhases 4 and 5 Fast detection and isolation of infected persons Detection of close contacts during the first 2 weeks of the disease Voluntary quarantine of those with symptoms during 1 week Use of antiviral medications for the treatment of cases and prophylaxis of other people in the initially affected area Entrance and exit restrictions for people in the area initially affected area in the country

29. Interim WHO RecommendationsPhase 6 � without affecting other countries Guidance for the sick � remain at home as soon as symptoms appear Warn caretakers � adequate precautions Non essential national trips to the affected areas must be postponed If there are still significant areas in the country that have not been affected People that have been knowingly exposed in a plane or large cruise ship Consider daily fever controls between passengers and crew members Consider antiviral prophylactic treatment, if available

30. Interruption of patient isolation, detection and quarantine of contacts These measures will no longer be viable or useful Consider social distancing measures in the affected communities Repeatedly inform the population Respect the need to wash hands frequently with soap and water Respect the need for �respiratory hygiene� Use of masks for the general population Must not have noticeable repercussions over the transmission Must be allowed, since its occurrence is likely to be spontaneous

31. What can we do�as individuals? Interim WHO recommendations Diminishing the transmission of influenza Wash hands Use masks based on risk Avoid contact of hands with nose and mouth and take care when coughing and sneezing Do not go to work while sick Use of masks during close contact with sick individuals Disinfect domestic surfaces contaminated with secretions Allow the systematic use of masks in public places, without promoting it Possible instructions for the use of masks in crowded places (public transportation) Without evidence support general disinfection of the environment/air Diminish the transmission of the bird flu A (H5N1) Avoid contact with dead or sick birds Diminish the transmission of human influenza Annual vaccine with the anti-influenza vaccine

33. Guidance � Washing Hands

34. Guidance for patients with a cough Respiratory hygiene and etiquette when coughing Cover your mouth when you cough and sneeze, avoid spitting Use handkerchiefs Meticulously dispose of handkerchiefs Wash hands after contact with respiratory secretions Sit at least 1 meter�s distance from other patients Provide the patient Handkerchiefs Garbage cans that work without the use of hands Water, soap and alcohol Disposable towels to dry hands