This article reviews 573 cases of acute pyrethroid poisoning reported in the Chinese medical literatures during 1983-1988. There were 325 cases of acute deltamethrin poisoning (occupational 158, accidental 167), 196 patients of acute fenvalerate poisoning (occupational 63, accidental 133, including 2 cases of ingestive fenvalerate-organophosphate mixture poisoning), 45 cases of acute cypermethrin poisoning (occupational 6, accidental 39) and 7 cases of other pyrethroid poisoning (occupational 2, accidental 5). The clinical manifestations have been reviewed and analysed. The diagnosis, gradation and differential diagnosis of occupational acute pyrethroid poisoning have been discussed.

To assess the exposure response relation of pyrethroids in spraymen, 50 adult male cotton growers were selected and divided into three groups, one group to spray pyrethroids for one day, two groups to spray for three days. Deltamethrin, fenvalerate, and a deltamethrin methamidophos mixture were sprayed by appropriate subgroups for five hours a day. Exposure levels were evaluated by measuring the air concentration, dermal exposure concentration, and urinary content of pyrethroids by gas chromatography. Air concentrations of deltamethrin at the breathing zone were 0.01-0.89 microgram/m3 in the deltamethrin exposed group. For fenvalerate, air concentrations were 0.06-1.98 micrograms/m3. Dermal exposure, particularly on the legs, feet, and hands was appreciable and indicated that this was the main route of absorption. In those spraying for one day, urinary deltamethrin was not detectable by 12 hours after the beginning of exposure whereas fenvalerate was still detectable up to 24 hours after first exposure. Both pyrethroids could be detected two days after the end of three day spraying. Health effects were investigated by interview and physical examination. Twenty nine spraymen complained of abnormal facial sensations that developed mostly two to three hours from the start of pyrethroid spraying and that disappeared by 24 hours after exposure ceased. Some had dizziness, headache, and nausea, but no subject was diagnosed as having acute pyrethroid poisoning. The symptoms showed no significant correlation with urinary pyrethroid excretion. Blood cholinesterase activity of spraymen using the pyrethroid methamidophos mixture did not change.

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Purpose: To evaluate the value of the combination of the age, atrial fibrillation, dysphagia, male sex, and National Institutes of Health Stroke Scale (A 2 DS 2) score and serum interleukin 6 (IL-6) concentration in predicting stroke-associated pneumonia (SAP). Patients and Methods: A total of 398 patients with acute ischemic stroke (AIS) from the medical ward was included in this retrospective study. They were divided into the SAP group and non-SAP group according to the diagnostic criteria of SAP. Multivariate analysis was performed to analyze the association between the A 2 DS 2 score, serum IL-6 concentration, and SAP using a backward stepwise logistic regression model. The receiver operating characteristic (ROC) curve was used to evaluate the value of the A 2 DS 2 score, serum IL-6 concentration and combination of A 2 DS 2 score and IL-6 in predicting SAP. Results: SAP was diagnosed in 70 patients (17.6%). Multivariate analysis showed that the A 2 DS 2 score (odds ratio [OR]: 2.25, 95% confidence interval [CI]: 1.17-4.99, P=0.017) and serum IL-6 concentration (OR: 1.76, 95% CI: 1.44-1.95, P<0.001) was independently associated with SAP after adjusting for age, smoking, hypertension, hyperlipidemia, and atrial fibrillation. When the A 2 DS 2 score, serum IL-6 concentration and combination of A 2 DS 2 score and IL-6 were employed to predict SAP, the AUC was 0.824 (SE: 0.026, 95% CI: 0.773-0.875), 0.715 (SE: 0.034, 95% CI: 0.641-0.788) and 0.917 (SE: 0.015, 95% CI: 0.887-0.946), respectively. The AUC of combinative prediction was significantly higher than independent prediction (0.917 vs. 0.824, Z=3.098, P<0.001; 0.917 vs. 0.715, Z=5.436, P<0.001). Conclusion: The addition of serum IL-6 to the A 2 DS 2 score could significantly enhance the AUC of predicting SAP in AIS patients from the medical ward.

The nerve excitability of median nerve as well as the urinary deltamethrin and its metabolite dibromovinyl-dimethyl-cyclopropane carboxylic acid (Br2A) were detected in 24 deltamethrin sprayers in an assessment of the exposure and effect of deltamethrin. Twenty-nine male, unexposed referents of the same age range were also selected. The urinary deltamethrin and its metabolite Br2A were detectable by GC and HPLC in the sprayers after exposure. The nerve excitability detected with an electromyograph and pairs of stimuli at variable intervals showed that there was a prolongation of supernormal period in median nerve of the exposed group after a 3-d spraying compared with that before spraying which became more significant 2 d after cessation of exposure. In the mean time, no change of supernormal period in the median nerve of reference group was found at the 3-d interval. Nearly half of the sprayers had a supernormal period prolonged by more than 4 ms after spraying, whereas nearly none of the reference group showed similar changes after repeated examinations. Although there was neither correlation between the nerve excitability changes and the urinary deltamethrin or Br2A excretion, nor was a case of acute deltamethrin poisoning diagnosed, the non invasive technique used for nerve excitability detection in this study seems to be valuable in studying deltamethrin toxicity on human.