Yellow Fever in Africa: Estimating the Burden of Disease and Impact of Mass Vaccination from Outbreak and Serological Data

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Background:
Yellow fever is a vector-borne disease affecting humans and non-human primates in tropical areas of Africa and South America. While eradication is not feasible due to the wildlife reservoir, large scale vaccination activities in Africa during the 1940s to 1960s reduced yellow fever incidence for several decades. However, after a period of low vaccination coverage, yellow fever has resurged in the continent. Since 2006 there has been substantial funding for large preventive mass vaccination campaigns in the most affected countries in Africa to curb the rising burden of disease and control future outbreaks. Contemporary estimates of the yellow fever disease burden are lacking, and the present study aimed to update the previous estimates on the basis of more recent yellow fever occurrence data and improved estimation methods.

Methods and Findings:
Generalised linear regression models were fitted to a dataset of the locations of yellow fever outbreaks within the last 25 years to estimate the probability of outbreak reports across the endemic zone. Environmental variables and indicators for the surveillance quality in the affected countries were used as covariates. By comparing probabilities of outbreak reports estimated in the regression with the force of infection estimated for a limited set of locations for which serological surveys were available, the detection probability per case and the force of infection were estimated across the endemic zone.

The yellow fever burden in Africa was estimated for the year 2013 as 130,000 (95% CI 51,000–380,000) cases with fever and jaundice or haemorrhage including 78,000 (95% CI 19,000–180,000) deaths, taking into account the current level of vaccination coverage. The impact of the recent mass vaccination campaigns was assessed by evaluating the difference between the estimates obtained for the current vaccination coverage and for a hypothetical scenario excluding these vaccination campaigns. Vaccination campaigns were estimated to have reduced the number of cases and deaths by 27% (95% CI 22%–31%) across the region, achieving up to an 82% reduction in countries targeted by these campaigns. A limitation of our study is the high level of uncertainty in our estimates arising from the sparseness of data available from both surveillance and serological surveys.

Conclusions:
With the estimation method presented here, spatial estimates of transmission intensity can be combined with vaccination coverage levels to evaluate the impact of past or proposed vaccination campaigns, thereby helping to allocate resources efficiently for yellow fever control. This method has been used by the Global Alliance for Vaccines and Immunization (GAVI Alliance) to estimate the potential impact of future vaccination campaigns.

Please see later in the article for the Editors' Summary

Vyšlo v časopise: Yellow Fever in Africa: Estimating the Burden of Disease and Impact of Mass Vaccination from Outbreak and Serological Data. PLoS Med 11(5): e32767. doi:10.1371/journal.pmed.1001638
Kategorie: Research Article
prolekare.web.journal.doi_sk: https://doi.org/10.1371/journal.pmed.1001638

Souhrn

Zdroje

1. MonathTP (2001) Yellow fever: an update. Lancet Infect Dis 1: 11–20.

2. TomoriO (2004) Yellow fever: the recurring plague. Crit Rev Clin Lab Sci 41: 391–427.

3. World Health Organization (1986) Prevention and control of yellow fever in Africa. Geneva: World Health Organization.

4. World Health Organization (1990) Yellow fever in 1988. Weekly Epidemiological Record 65: 213–219.

5. World Health Organization. Yellow fever fact sheet no 100. Available: http://www.who.int/mediacentre/factsheets/fs100/en/. Accessed 19 January 2014.

6. World Health Organization Expanded Programme on Immunization (1992) The Resurgence of deadly yellow fever: prevention using EPI. Geneva: WHO.

7. MonathTP, NasidiA (1993) Should yellow fever vaccine be included in the expanded program of immunization in Africa? A cost-effectiveness analysis for Nigeria. Am J Trop Med Hyg 48: 274–299.

8. LaBeaudAD, BashirF, KingCH (2011) Measuring the burden of arboviral diseases: the spectrum of morbidity and mortality from four prevalent infections. Population Health Metrics 9: 1.

9. LeeLA, FranzelL, AtwellJ, DattaSD, FribergIK, et al. (2013) The estimated mortality impact of vaccinations forecast to be administered during 2011–2020 in 73 countries supported by the GAVI Alliance. Vaccine 31: B61–B72.

10. RogersD, WilsonA, HayS, GrahamA (2006) The global distribution of yellow fever and dengue. Adv Parasit 62: 181–220.

11. JentesES, PoumerolG, GershmanMD, HillDR, LemarchandJ, et al. (2011) The revised global yellow fever risk map and recommendations for vaccination, 2010: consensus of the Informal WHO Working Group on Geographic Risk for Yellow Fever. Lancet Infect Dis 11: 622–632.

12. BriandS, BeresniakA, NguyenT, YonliT, DuruG, et al. (2009) Assessment of yellow fever epidemic risk: an original multi-criteria modeling approach. PLoS Negl Trop Dis 3: e483.

13. World Health Organization. Weekly Epidemiological Record. Available: http://www.who.int/wer/en/. Accessed 11 June 2012.

14. World Health Organization. Disease Outbreak News. Available: http://www.who.int/csr/don/en/. Accessed 11 June 2012.

15. De CockKM, NasidiA, EnriquezJ, CravenRB, OkaforBC, et al. (1988) Epidemic yellow fever in Eastern Nigeria, 1986. Lancet 331: 630–633.

16. NasidiA, MonathTP, DeCockK, TomoriO, CordellierR, et al. (1989) Urban yellow fever epidemic in western Nigeria, 1987. Trans R Soc Trop Med Hyg 83: 401–406.

17. NathanN, BarryM, Van HerpM, ZellerH (2001) Shortage of vaccines during a yellow fever outbreak in Guinea. Lancet 358: 2129–2130.

18. SandersEJ, MarfinAA, TukeiPM, KuriaG, AdembaG, et al. (1998) First recorded outbreak of yellow fever in Kenya, 1992–1993. I. Epidemiologic investigations. Am J Trop Med Hyg 59: 644–649.

19. ThonnonJ, FontenilleD, TallA, DialloM, RenaudineauY, et al. (1998) Re-emergence of yellow fever in Senegal in 1995. Am J Trop Med Hyg 59: 108–114.

20. MonathTP (1980) Yellow fever in the Gambia, 1978–1979: epidemiologic aspects with observations on the occurrence of Orungo virus infections. Am J Trop Med Hyg 29: 912.

21. Johansson MA, Staples JE (2013) The whole yellow fever iceberg: estimating the incidence of infection from the number of severe cases. Epidemics 4. Amsterdam: Elsevier.

22. Durieux C (1956) Mass yellow fever vaccination in French Africa south of the Sahara. Monograph Series World Health Organization. Geneva: WHO. pp. 115–122.

23. World Health Organization (2012) Immunization surveillance, assessment and monitoring. Available: http://www.who.int/immunization_monitoring/data/data_subject/en/index.html. Accessed 11 June 2012.

24. World Health Organization, unicef (2009) Yellow Fever Initiative Progress Report 2006 to 2009. Geneva: World Health Organization.

25. World Health Organization, unicef (2010) Yellow Fever Initiative Joint WHO and UNICEF 2010 Progress Report. Geneva: World Health Organization.

26. World Health Organization (2013) Vaccines and vaccination against yellow fever. WHO Position Paper - June 2013. Weekly Epidemiological Record 88: 269–284.

27. Coulange BodilisH, BenabdelmoumenG, GergelyA, GoujonC, PelicotM, et al. (2011) [Long term persistence of yellow fever neutralising antibodies in elderly persons]. Bull Soc Pathol Exot 104: 260–265.

28. PolandJD, CalisherCH, MonathTP, DownsWG, MurphyK (1981) Persistence of neutralizing antibody 30–35 years after immunization with 17D yellow fever vaccine. Bull World Health Organ 59: 895–900.

29. Diallo M, Janusz K, Lewis R, Manengu C, Sall AA, et al.. (2010) Rapid assessment of yellow fever viral activity in the Central African Republic. Geneva: World Health Organization.

30. KuniholmMH, WolfeND, HuangCY-H, Mpoudi-NgoleE, TamoufeU, et al. (2006) Seroprevalence and distribution of Flaviviridae, Togaviridae, and Bunyaviridae arboviral infections in rural Cameroonian adults. Am J Trop Med Hyg 74: 1078–1083.

31. MerlinM, JosseR, Kouka BembaD, MeunierD, SengaJ, et al. (1986) [Evaluation of immunological and entomotological indices of yellow fever in Pointe-Noire, People's Republic of Congo]. Bulletin de la Société de pathologie exotique 79: 199–206.

32. OmilabuSA, AdejumoJO, OlaleyeOD, FagbamiAH, BabaSS (1990) Yellow fever haemagglutination-inhibiting, neutralising and IgM antibodies in vaccinated and unvaccinated residents of Ibadan, Nigeria. Comp Immunol Microbiol Infect Dis 13: 95–100.

33. TsaiTF, LazuickJS, NgahRW, MafiambaPC, QuinckeG, et al. (1987) Investigation of a possible yellow fever epidemic and serosurvey for flavivirus infections in northern Cameroon, 1984. Bull World Health Organ 65: 855–860.

34. WernerGT, HuberHC, FreseniusK (1985) [Prevalence of yellow fever antibodies in north Zaire]. Annales de la Societe belge de medecine tropicale 65: 91–93.

35. United Nations, Department of Economic and Social Affairs, Population Division, Population Estimates and Projections Section. World Population Prospects: The 2010 Revision. Available: http://esa.un.org/wpp/Excel-Data/population.htm. Accessed 11 June 2011.

36. Bright EA, Coleman PR, King AL, Rose AN (2008) LandScan 2007. Oak Ridge (Tennessee). Available: http://www.ornl.gov/landscan/. Accessed 10 December 2013.

37. DobsonJE, BrightEA, ColemanPR, DurfeeRC, WorleyBA (2000) LandScan: a global population database for estimating populations at risk. Photogramm Eng Rem S 66: 849–857.

38. KleinschmidtI, OmumboJ, BriëtO, Van De GiesenN, SogobaN, et al. (2001) An empirical malaria distribution map for West Africa. Trop Med Int Health 6: 779–786.

39. XieP, ArkinPA (1996) Analyses of global monthly precipitation using gauge observations, satellite estimates, and numerical model predictions. J Climate 9: 840–858.

40. GarskeT, FergusonNM, GhaniAC (2013) Estimating air temperature and its influence on malaria transmission across Africa. PLoS ONE 8: e56487.

41. LovelandTR, BelwardAS (1997) The IGBP-DIS global 1 km land cover data set, DISCover: first results. Int J Remote Sens 18: 3289–3295.

42. NASA Land Processes Distributed Active Archive Center (LP DAAC) Land Cover Type Yearly L3 Global 1 km SIN Grid (12Q1). USGS/Earth Resources Observation and Science (EROS) Center, Sioux Falls, South Dakota. Available: http://lpdaac.usgs.gov/get_data. Accessed 13 July 2012.

43. NASA Land Processes Distributed Active Archive Center (LP DAAC) Vegetation Indices 16-Day L3 Global 1 km (13A2). USGS/Earth Resources Observation and Science (EROS) Center, Sioux Falls, South Dakota. Available: http://lpdaac.usgs.gov/get_data. Accessed 13 July 2012.

44. Hijmans RJ, Cameron SE, Parra JL. WorldClim. Available: http://www.worldclim.org/. Accessed 12 January 2012.

45. HijmansRJ, CameronSE, ParraJL, JonesPG, JarvisA (2005) Very high resolution interpolated climate surfaces for global land areas. Int J Climatol 25: 1965–1978.

46. Brooks S, Gelman A, Jones GL, Meng X-L, editors (2011) Handbook of Markov chain Monte Carlo. Boca Raton (Florida): Chapman & Hall/CRC.

47. Gilks WR, Richardson S, Spiegelhalter DJ (1996) Markov chain Monte Carlo in practice. Boca Raton (Florida): Chapman & Hall/CRC.

48. HeinzeG, SchemperM (2002) A solution to the problem of separation in logistic regression. Stat in Med 21: 2409–2419.

49. SchwarzG (1978) Estimating the dimension of a model. Ann Stat 6: 461–464.

50. DeLongER, DeLongDM, Clarke-PearsonDL (1988) Comparing the areas under two or more correlated receiver operating characteristic curves: a nonparametric approach. Biometrics 44: 837–845.

51. MoreauJP, GiraultG, DramI, PerrautR (1999) [Reemergence of yellow fever in West Africa: lessons from the past, advocacy for a control program]. Bulletin de la Société de pathologie exotique 92: 333–336.

52. World Health Organization (2003) Yellow fever vaccine. Weekly Epidemiological Record 78: 349–359.

53. World Health Organization (2012) Yellow fever reported cases. Available: http://apps.who.int/immunization_monitoring/en/globalsummary/timeseries/tsincidenceyfe.htm. Accessed 24 April 2013.

54. GAVI Alliance. Vaccine investment strategy. Available: http://www.gavialliance.org/about/strategy/vaccine-investment-strategy/. Accessed 18 January 2014.

55. GAVI Alliance (2013) Yellow fever vaccine investment strategy. Background document #5. GAVI Alliance. Available: http://www.gavialliance.org/library/gavi-documents/strategy/final-vis-analysis-2013—yellow-fever/. Accessed 18 January 2014.