AUTHOR
Jeon HJ, Pak GD, Im J, Owusu-Dabo E, Adu-Sarkodie Y, Gassama Sow A, Bassiahi AS, Gasmelseed N, Keddy KH, Bjerregaard-Andersen M, Konings F, Aseffa A, Crump JA, Chon Y, Breiman RF, Park SE, Cruz Espinoza LM, Seo HJ, May J, Meyer CG, Andrews JR, Panzner U, von Kalckreuth V, Wierzba TF, Rakotozandrindrainy R, Dougan G, Levine MM, Hombach J, Kim JH, Clemens JD, Baker S, Marks F
ABSTRACT
BACKGROUND:
The WHO recently prequalified a typhoid conjugate vaccine (TCV), recommending its use in persons aged ≥6 months to 45 years residing in typhoid fever (TF)-endemic areas. We now need to consider how TCVs can have the greatest impact in the most vulnerable populations in Africa.
METHODS:
The Typhoid Fever Surveillance in Africa Program (TSAP) in 10 sub-Saharan African countries included blood culture-based surveillance in febrile people presenting at healthcare-facilities originating from defined catchment areas. The TF/invasive non-typhoidal Salmonella (iNTS) disease incidences were estimated for 0-10 year-old children in yearly increments.
FINDINGS:
Salmonella Typhi and iNTS were the most frequently isolated pathogens, 135 and 94 cases were identified, respectively. Isolates (12 and 4, respectively) from Ethiopia, Senegal and South Africa were excluded due to person-years of observation (PYO) data absence. 37/123 (30.1%) TF and 71/90 (78.9%) iNTS disease cases occurred among individuals aged <5 years. No TF and 8/90 (8.9%) iNTS-infections were observed in children aged <9 months. The TF incidences (/100,000 PYO) for children aged <1 year and 1-<2 years were 5 and 39, respectively; the highest incidence was 304/100,000 PYO in 4-<5 year-old children. The iNTS incidence in the defined age groups ranged between 81 and 233/100,000 PYO, with the highest incidence in 1-<2 year-old children. Higher TF/iNTS disease incidences were observed in West Africa.
INTERPRETATION:
The high TF burden observed in TSAP merits TCV introductions. Considering the additional iNTS disease burden, a trivalent vaccine targeting S. Typhi, S. Typhimurium, and S. Enteritidis may be a future solution.
Click here to view the article, published in Clinical Infectious Diseases
