02717nas a2200301   4500000000100000008004100001260003400042653002400076653005700100653002100157653001700178100002000195700001400215700001300229700001400242700001300256700001300269700001500282700001300297700001400310700001600324700001500340245025400355856010400609300000800713520166900721022002502390       2023                            d  bOxford University Press (OUP)10aInfectious Diseases10aPublic Health, Environmental and Occupational Health10aGeneral Medicine10aParasitology1 aRayment Gomez S1 aMaddren R1 aLiyew EF1 aChernet M1 aAnjulo U1 aTamiru A1 aMengitsu B1 aForbes K1 aCollyer B1 aSalasibew M1 aAnderson R00aPredisposition to soil-transmitted helminth reinfection after four rounds of mass drug administration: results from a longitudinal cohort in the Geshiyaro project, a transmission elimination feasibility study in the Wolaita zone of southern Ethiopia  uhttps://academic.oup.com/trstmh/advance-article-pdf/doi/10.1093/trstmh/trad007/49564640/trad007.pdf  a1-83 a<p><strong>Background:</strong> Current WHO strategies for reaching soil-transmitted helminths (STH) elimination as a public health problem excludes treating certain adult populations in endemic areas, creating infection reservoirs that drive ‘bounce back’ of STH infection to pretreatment levels post-mass drug administration (MDA). Predisposition is a widespread, but poorly understood phenomena among helminth infections where individuals are predisposed to reinfection after repeated treatments.</p>

<p><strong>Methods:&nbsp;</strong>This analysis uses Geshiyaro project data, an STH control programme exploring transmission interruption by community-wide MDA and enhanced water, sanitation and hygiene during 2019–2023. Parasitological survey data from longitudinal cohorts are analysed using Kendall's Tau-b rank correlation to assess the evidence for predisposition to light or heavy infection between four consecutive rounds of MDA.</p>

<p><strong>Results:&nbsp;</strong>Correlation analyses revealed the strongest evidence for predisposition to heavy or light Ascaris lumbricoides infection was between survey 1 and 2 (Tau-b 0.29; p&lt;0.001). Overall patterns were not observed for Trichuris trichiura or hookworm infections, however, some significant and notable correlations were recorded for some stratifications and time points.</p>

<p><strong>Conclusions:&nbsp;</strong>Evidence for predisposition in endemic settings in southern Ethiopia with low STH prevalence suggests that more targeted approaches to MDA in those predisposed to infection may be a sensible control strategy if cheap, point of care diagnostics are available.</p>
  a0035-9203, 1878-3503