Serum sialic acid levels in Vibrio cholera serotype Hikojima infected Nigerian patients

Background and Aims: Vibro cholera neuraminidase is known to cleave sialic acid in the gut to expose receptors for cholera enterotoxin. This study determined if cholera neuraminidase crosses significantly into the circulation of patients with cholera to cause cleavage of sialic acid on circulating blood cells. Methods: Systemic cholera neuraminidase activity was determined by measuring serum sialic acid levels (thiobarbituric method) in 20 consecutive adult cholera patients (12 females, 8 males) with severe diarrhea before rehydration was commenced at Ahmadu Bello University Teaching Hospital, Zaria. Twenty healthy adults (9 males, 11 females) were recruited as controls. Complete blood counts and stool occult blood were evaluated. Cholera isolates were confirmed as Hikojima serotype Results: Free serum sialic acid levels were not significantly different between patients and controls (p>0.05). Cholera patients had thrombocytopenia and systemic neutrophilia, as well as positive stool occult blood. Conclusion: This study indicates that neuraminidase may not reach the circulation in significant levels to contribute to significant cleavage of sialic acid on circulating blood cells of patients infected with Vibrio cholera serotype Hikojima. Peripheral blood leucoytosis and occult blood in the stool of cholera patients challenges the classical view that diarrhea due to cholera is non-inflammatory.