A histological study of skin reactions of baboons to Schistosoma mansoni schistosomula

Abstract
A histological study was undertaken of the cellular reaction in the skin of baboons challenged with cercariae of Schistosoma mansoni. Control animals with no previous schistosome infection were compared with baboons that had infections of varying duration. In animals infected for 10 weeks no striking inflammatory reaction was seen, the histological picture being very similar to that of the control animals. After 8 months of infection the hosts developed a strong cellular response to the invading schistosomula. The predominant cells in these reactions were eosinophil leucocytes which sometimes closely adhered to degenerating schistosomula. However, some unaffected schistosomula were found close to these intense cellular reactions, suggesting that schistosomula possess varying ability to resist the host's immunological attack.