Epidemiology
S. intercalatum is at risk of endangerment in large part due to the introduction of invasive species into its native habitat. Since 1973, both S. mansoni and S. haematobium have been found in places that have been traditionally inhabited by S. intercalatum. This is thought to be because of the increase in transportation accessibility and the increase in forestry jobs in these habitats. Male S. mansoni and S. haematobium will both take priority over S. intercalatum when it comes to mate selection, leading to a smaller proportion of female S. intercalatum available for mating. While crosses with S. mansoni give no viable offspring, the pairing with a male S. haematobium will result in a hybrid organism. Most hybrids will have a diluted genome that is more closely related to S. haematobium, helping to bring about a decline in S. intercalatum populations. The other obstacle restricting the parasite's population growth is its selective distribution. The cercariae are very particular over where they develop, needing small, forested areas with streams to infect their human host. There are only a few of these regions in Africa, and they decrease in size every day due to deforestation.
Read more about this topic: Schistosoma Intercalatum