Skip to main content

Table 1 Summary of Somalia survey data by source for the North and South zones.

From: Spatial prediction of Plasmodium falciparum prevalence in Somalia

  Survey source
Zone FAO/FSAU
n (%)
WHO
n (%)
Total
n (%)
North    
Number survey locations sampling with 40+ people 64 61 125
Number geo-referenced 55 (85.9%) 60 (98.4%) 115 (92.0%)
Number identified as outliers 0 (0.0%) 2 (3.3%) 2 (1.6%)
Number selected for model* 55 (85.9%) 58 (95.1%) 113 (90.4%)
   Number of surveys with zero Pf PR** 32 (50.0%) 26 (42.6%) 58 (46.4%)
   Population sample size 5,213 5,255 10,468
   Number Pf PR positive 97 196 293
   Mean (Median) Pf PR (%) 1.8 (0.0) 3.7 (1.1) 2.8 (0.0)
   IQR Pf PR (%) (0.0, 3.1) (0.0, 4.0) (0.0, 4.0)
South    
Number survey locations sampling 40+ people 311 64 375
Number geo-referenced 279 (89.7%) 58 (90.6%) 337 (89.9%)
Number identified as outliers 1 (0.3%) 0 (0.0%) 1 (0.3%)
Number selected for model* 278 (89.4%) 58 (90.6%) 336 (89.6%)
   Number of surveys with zero Pf PR** 73 (23.5%) 23 (35.9%) 96 (25.6%)
   Population sample size 16,048 3,963 20,011
   Number Pf PR positive 2,081 208 2,289
   Mean (Median) Pf PR (%) 13.0 (4.0) 5.2 (2.0) 11.4 (3.0)
   IQR Pf PR (%) (0.0,10.0) (0.0, 6.0) (0.0, 9.0)
  1. *Sample size, number positive and the mean, median and IQR of Pf PR include those surveys reporting zero number positive for Pf PR.
  2. **At the margins of stable malaria transmission, zero P. falciparum parasites in a sample is not necessarily an indication of true absence of parasites but could also be due to low sample sizes or test equipment with low sensitivity [33]. Given this difficulty in distinguishing true zero from sample zero at low Pf PR, surveys reporting zero prevalence were included in the analysis.
  3. IQR = interquartile range; Pf PR = Plasmodium falciparum parasite rate; FAO/FSAU = Food and Agricultural Organization – Food Security Analysis Unit; WHO = World Health Organization.