I think the problem is that there have not been many studies done on schisto in that area, however I would not be surprised if it differs from anywhere else in West Africa, and is highly prevalent. You might contact the University in Yaounde to see if there are studies that were done in coastal Cameroon, which would then typify the area 

Hi Javier,

if someone outside the country would know, then the colleagues at the WHO unit that deals with 'neglected tropical diseases: Try to reach them at

[email protected]

good luck for your research,

Sibylle

Hola Javier, estuve trabajando en Guinea Ecuatorial durante el 2004 y veraderamente no vi ningún caso que no fuese S. intercalatum, en concreto en este país parece como si intercalatum haya desplazado a las otras especies, (fenómeno que ha pasado en los últimos 20 años) Te adjunto un artículo que revisa los focos de intercalatum en África

schistosomiasis is considered as a major parasite and prevalent parasitic infections, affecting an estimated 200 million people infected, mostly in Africa. Equatorial guinea is a country located on the west coast of central africa, where schistosoma spp. is endemic. Human schistosomiasiscin equatorial guinea is caused by Schistosoma intercalatum. In studies conducted in Bata, mollusc species could serve as a potential host for schistosomiasis was found in Bulinus forskalii. The prevalence of the disease is higher in the city of Bata than in rural areas.