Research Note: Evaluation of acute oral toxicity of povidone-iodine in cockerels using the up-and-down procedure.

Povidone-iodine (Polidine) is a synthetic broad-spectrum antiseptic and being applied topically to treat wounds and prevent their infection. It is however used by poultry farmers, field veterinarians, and other animal health workers with the claim that it is effective for treatment of infectious bursal disease when administered orally. Hence, an acute oral toxicity study was conducted to ascertain its safety profile. Ten cockerel chicks were randomly selected and divided into 2 groups of 5 chicks per group. One group served as the negative control, whereas the other group was administered povidone-iodine at a dose of 2,000 mg/kg of BW orally. The blood sample was collected at the end of the study to determine changes in hematological and biochemical parameters. In addition, vital organs were also harvested and preserved for histopathological examinations. The result showed that the median lethal dose (LD50) of the povidone-iodine is higher than 2,000 mg/kg of BW in cockerels. There were no significant changes in the hematological parameters measured. Biochemical evaluation (renal and liver function test) showed an increase in aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase levels after administration of povidone-iodine. The study indicated that the LD50 of povidone-iodine is higher than 2,000 mg/kg of BW of cockerels, and there were increases in urinary and liver enzymes at this dose.

Pre-clinical and preliminary dose-finding and safety studies to identify candidate antivenoms for treatment of envenoming by saw-scaled or carpet vipers (Echis ocellatus) in northern Nigeria.

The aim of this study was to identify candidate antivenoms with specific activity against the venom of the saw-scaled or carpet viper (Echis ocellatus) in northern Nigeria, where bites by this species cause great morbidity and mortality but where effective antivenoms have become scarce and unaffordable. Selected antivenoms were destined to be compared by randomised controlled clinical trials (RCTs). Standard pre-clinical neutralisation assays were carried out in rodents. We included two licensed antivenoms of established clinical efficacy and 6 candidate antivenoms. Although 6 of the tested antivenoms showed promising efficacy, all but 3 were excluded from further study because of inadequate pre-clinical efficacy or because they were unavailable or unaffordable for the anticipated RCTs. Median effective doses (ED(50)) of the remaining three candidate antivenoms suggested that the following doses might neutralise the maximum observed venom yield of 24.8 mg (dry weight) of venom milked from captive E. ocellatus: 10 ml of MicroPharm "EchiTAb G" (ET-G) antivenom; 30 ml of Instituto Clodomiro Picado "EchiTAb-Plus-ICP" (ET-Plus) antivenom; 50 ml of VacSera, Cairo "EgyVac" antivenom. A preliminary clinical dose-finding and safety study of these three antivenoms was carried out in 24 patients with incoagulable blood after E. ocellatus bites who were not severely envenomed. A 3+3 dose escalation design was employed. Initial doses of 10 ml ET-G and 30 ml ET-Plus restored blood coagulability in groups of 6 patients with early mild reactions (pruritus only) in not more than one third of them. EgyVac antivenom did not fulfil efficacy or safety criteria in 12 patients. On the basis of these results, ET-G and ET-Plus were selected for comparison in a RCT.

Envenoming after carpet viper (Echis ocellatus) bite during pregnancy: timely use of effective antivenom improves maternal and foetal outcomes.

The report describes successful management of 10 women in 2nd and 3rd pregnancy trimesters with EchiTab IgG antivenom after carpet viper (Echis ocellatus) envenoming. All women survived but foetal loss in a victim with delayed presentation and a case of mild hypersensitivity reaction were recorded. Excellent outcomes can be achieved in rural and semi-nomadic populations without specialized care and immediate access and provision of effective antivenoms is paramount in curtailing snakebite maternal morbidity, mortality and foetal loss.