Fig 1.
Administrative Divisions and Cluster sites on mainland Fiji (Viti Levu and Vanua Levu) and Taveuni islands.
Table 1.
Demographics of mainland Viti Levu and Vanua Levu (unvaccinated areas) survey participants.
Table 2.
Demographics of Taveuni island (Vi-polysaccharide vaccinated area) survey participants.
Table 3.
Demographics of convalescent confirmed typhoid cases.
Fig 2.
Distributions of log10 anti-Vi IgG antibody titres in A) Group 1: residents of Fiji mainland Viti Levu and Vanua Levu islands; B) Group 2: residents of Taveuni island, where a vaccination campaign with Vi-polysaccharide injection was conducted three years previously; and C) Group 3: recovering cases of culture-confirmed typhoid. Red vertical line denotes 64 ELISA unit seropositivity threshold determined from case antibody kinetic analysis; blue line denotes 100 ELISA unit threshold used in sensitivity analysis. Case titres are mean log titre if multiple samples collected, range 68 to 645 days from fever onset.
Fig 3.
Seroprevalence of anti-Vi IgG by age and ethnicity (iTaukei and non-iTaukei) at A) 64 ELISA units (case-fitted threshold) and B) 100 ELISA units (sensitivity analysis). Each panel also indicates confirmed case cumulative incidence by ethnicity. Shared areas denote 95% confidence intervals.
Table 4.
Risk factors by adjusted odds ratios for anti-Vi IgG seropositivity at 64 ELISA units for mainland Viti Levu and Vanua Levu by cluster-robust multivariable logistic regression.