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Table 2 Climatic thresholds for region and species-specific transmission limits

From: The global limits and population at risk of soil-transmitted helminth infections in 2010

  Africa and the Middle East Asia Latin America and the Caribbean
Unstable transmission Beyond transmission Unstable transmission Beyond transmission Unstable transmission Beyond transmission
Hookworm Aridity indexa <0.2 Max LST >42°C Mean LST 5–10°C Max LST >42°C Max LST >36–40°C Max LST >40°C
Mean LST <10°C Aridity index <0.2 Mean LST <5°C Mean LST 10–15°C Mean LST <10°C
Aridity index <0.03   Aridity index <0.03 Aridity index <0.2 Aridity index <0.03
A. lumbricoides Max LST >38–40°C Max LST >40°C   Mean LST <10°C Mean LST <5°C Aridity index <0.03
Aridity index <0.2 Mean LST <10°C
  Aridity index <0.03
T. trichiura Max LST >38–40°C Max LST >40°C   Max LST >42°C Mean LST <5°C Maximum LST >40°C
  Aridity index <0.2 Mean LST <10°C   Mean LST <10°C   Aridity index <0.03
   Aridity index <0.03     
  1. a Constructed using precipitation and evapo-transpiration; 0.03–0.2 = arid, <0.03 = hyper-arid; Max LST; maximum land surface temperature in the hottest month. Mean LST; mean land surface temperature in the warmest quarter.