False positivity of circumsporozoite protein (CSP)-ELISA in zoophilic anophelines in Bangladesh

► A study was conducted to estimate the level of false positivity among anophelines. ► Initially 144 samples were found positive by routine CSP-ELISA. ► Numbers of positives declined to 85 when the samples were tested after heating. ► Significant correlation was found between HBI and true CSP positive ratio. ► The false positive reaction took place more in zoophilic species.