OBJECTIVETo analyze the clinical characteristics and diagnosis of three cases with infant botulism.

METHODClinical data of three clinically diagnosed cases with infant botulism in May 2015 in Peking University First Hospital were retrospectively analyzed. Literature search at databases of PubMed, Wanfang, China National Knowledge Infrastructure and VIP with the key words"infant AND botulism". The date of literature retrieval was from the database founding to November 2015. The characteristics of infant botulism were summarized through review of literature.

RESULTThree patients were infants of 4-8 months of age, and all had acute onsets of anorexia and poor response. All of them had normal psychomotor development previously, and without clear history of exposure to poisons. The main findings on physical examination were reduced muscle strength and hypotonia, dullness or disappeared pupillary light reflex, reduced facial expression, weak crying and dysphagia. Unexpectedly their states of consciousness were relatively normal. Finally, through identification and PCR genotyping of bacteria in stool, 2 cases were confirmed as Clostridium (C.) botulinum type B infection. Totally 446 reports were retrieved from foreign language literature and 52 reports from Chinese literature. More than 3,000 cases of infant botulism cases were reported in the world. Rare cases were reported in China and only 1 case was reported in 2000.

CONCLUSIONMost cases of infant botulism had no clear exposure history. The main clinical manifestations are hypotonia, cranial nerve paralysis, flaccid paralysis, but different patients may have different presentations. Detection of C. Botulinum and its toxin in stool can help to confirm the diagnosis. Infant botulism is relatively rare in China, which may be related to the insufficient understanding and inspection level of the disease. It might be underestimated in China.