H.contortus survives in warm and moist conditions. Transmission periods are usually considered to be between 15-37 ◦C (Van Wyke and Reynecke 2011). The R0 model predicts when climate is going to be suitable for parasite transmission.
Experiences a wet season between November to March and a dry season from April to October/November. This is reflected on the H.contortus (barbers pole worm) risk graph as seen below.
Climate change is causing increasingly unpredictable weather. In 2018/2019 the rains failed during the wet season.
The climate varies from north to south and the spatial risk changes within the country can be seen on figure 2.