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. Author manuscript; available in PMC: 2021 Jul 9.
Published before final editing as: Epidemics. 2020 Jan 9;30:100385. doi: 10.1016/j.epidem.2020.100385

Table 1.

Summary of input parameters.

Parameter Value/distribution Notes Source
Estimation of R e
Measles serial interval distribution N (11.9, 2. 62) An estimated serial interval distribution reported from a household transmission study from Providence, R.I. by Chapin (1925) Vink et al. (2014)
Susceptible population at start of 2017 outbreak (%), s0 Triangle(0.05,0.25,0.15) Given the low vaccination rates in Myanmar (Bhatia et al., 2018), we assumed that most Rohingya adults were already immune to measles due to a resultant low average age of first infection. This assumption seems reasonable given that 83% of suspected cases were among children <5 years old, and 96% of suspected cases were among children <15 years old during the 2017 outbreak (WHO, 2017a). Approximately 50% of the Rohingya population in Cox’s Bazar is <15 years old (Bhatia et al., 2018; Guzek et al., 2017). 72% of measles cases in the 2017 outbreak as of November 18, 2017 had no history of measles vaccination (WHO, 2017a). Bhatia et al. (2018), WHO (2017a), MSF (Guzek et al., 2017)
Mechanistic measles model
Basic reproductive number, R0 Gamma(shape=16.2, rate=1.2) Fit gamma distribution to histogram of R0 values, which were estimated in the analysis using the relationship Re = R0*s0 Estimated in analysis
Rohingya population size, December 2017 579,661 The total influx of Rohingya into Cox’s Bazar from August 25, 2017 to December 5, 2017, excluding those that settled in the host community ISCG (Inter Sector Coordination Group, 2017)
Rohingya population size, April 2019 870,534 The number of Rohingya refugees identified in the refugee camps as of April 2019, excluding those registered before August 31, 2017 ISCG (Inter Sector Coordination Group, 2019)
Birth rate (/10,000/day), μ 1.45 Save the Children estimated that 48,000 Rohingya children would be born in Cox’s Bazar in 2018 (Save the Children, 2018), which is in line with UNFPA’s estimate from December 2017 that 10,000 Rohingya women would give birth from January to March 2018 (UNFPA, 2017). Save the Children (2018), UNFPA (2017)
Death rate (/10,000/day), μ 1.45 Assumed to be the same as the birth rate Assumption
Recovery rate (days−1), γ 0.11 1/average duration of infectiousness (9 days) McLean et al. (2013)
Transmission coefficient (days−1), β - R0/(average duration of infectiousness * population size) Estimated in analysis
Susceptible population at start of next outbreak (%), su Uniform(0.05,0.15)

  • 349,603 children <15 years old were targeted for second vaccination campaign (WHO, 2017a).

  • If 135,519 children were vaccinated in the first round and 323,940 in the second round, 38.8% (135,519/349,603) and 92.7% (323,940/349,603) of children were vaccinated in these campaigns, respectively

  • Use binomial calculations to estimate probability of child receiving 0, 1, and 2 MR doses as 4.5%, 59.6% and 35.9%, respectively

  • If 4.5% of children received 0 doses, approximately 15,715 children were not vaccinated by the end of the vaccination campaigns

  • Add estimated 72,000 births (48,000*1.5) that have occurred since the vaccination campaigns; annual estimate of 48,000 is the same estimate from Save the Children (2018) that informs the birth rate

  • Estimate current proportion of children susceptible as (15, 715 + 72, 000)/870, 534 = 0.10 to inform the middle of the uniform distribution range

 Assumption