Clinical Manifestations of Botulism Outbreak in Northern Thailand: A Case Series of Botulism Treated With Botulinum Anti-Toxin.

PRELIMINARY REPORT Northern Thailand's big botulism outbreak occurred again on 30 June 14, 2006, [16.00pm] affecting 83 from 192 people who exposed to raw dear meat and gut [1 night preserved with ice pack of whole body of dear before disection and distribution ]. Of these, 3 developed respiratory failure, 1 developed impending respiratory failure, 83 of 192 whom developed fatique and diarrhea after ingestion of raw dear meat and gut on 26-30 June 2006. 3 patients were refered to 2 high facility hospitals for severe respiratory failure. Physical examination of 3 patients in ICU of Chiang Kum general hospital revealed ptosis [3/3] mild ophthalmoparesis [2/3] Proximal muscle weakness [2/3] abdominal paradoxical respiration [3/3] pupil dilate [1/3] and negative inspiratory pressure [NIP] less than 15 mmHg [3/3] were observed. Neurological electrophysiologic study of 2 patients revealed low amplitude compound muscle action potential [CMAP] of Abductor digiti minimi [ADM] muscle with decrement response after repetitive stimulation with low frequency [3Hz], increment response of ADM muscle after stimulation with high frequency [10Hz, 20Hz, and 30Hz.].The electrophysiologic findings support diagnosis of presynaptic neuromuscular dysfunction with respiratory failure, Botulism is most likely diagnosis. After treated with botulinum antitoxin [on July,1 ,2006 [mixed-type botulinum antitoxin --donated from Japan at Nan Hospital's botulisum outbreak on March 14,2006], 3 patients in ICU showed improvement of over all clinical outcomes. Active survey by Ministry of Public Health of Thailand and CDC-USA to identify the high risk patient who may develop respiratory failure , and immunologucal vs microbiological diagnosis were performed. This outbreak may be the second hit of botulisum in the northern Thailand but less amount of severe cases was observed.