Bites by the Monocled Cobra, Naja kaouthia, in Chittagong Division, Bangladesh: Epidemiology, Clinical Features of Envenoming and Management of 70 Identified Cases.

AbstractWe describe 70 cases of monocled cobra (Naja kaouthia) bite admitted to Chittagong Medical College Hospital, Bangladesh. The biting snakes were identified by examining the dead snake and/or detecting N. kaouthia venom antigens in patients' serum. Bites were most common in the early morning and evening during the monsoon (May-July). Ligatures were routinely applied to the bitten limb before admission. Thirty-seven patients consulted traditional healers, most of whom made incisions around the bite site. Fifty-eight patients experienced severe neurotoxicity and most suffered swelling and pain of the bitten limb. The use of an Indian polyvalent antivenom in patients exhibiting severe neurotoxicity resulted in clinical improvement but most patients experienced moderate-to-severe adverse reactions. Antivenom did not influence local blistering and necrosis appearing in 19 patients; 12 required debridement. Edrophonium significantly improved the ability of patients to open the eyes, endurance of upward gaze, and peak expiratory flow rate suggesting that a longer-acting anticholinesterase drug (neostigmine) could be recommended for first aid. The study suggested that regionally appropriate antivenom should be raised against the venoms of the major envenoming species of Bangladesh and highlighted the need to improve the training of staff of local medical centers and to invest in the basic health infrastructure in rural communities.

Epigenetic alterations and decreasing insecticide sensitivity of the Asian tiger mosquito Aedes albopictus.

A range of environmental factors, including chemicals, can affect epigenetic processes in organisms leading to variations in phenotype. Thus, epigenetics displays an important environmentally responsive element. The transgenerational impact of environmental stressors on DNA methylation and phenotype was the focus of this study. The influence of two known DNA methylation-changing agents, the phytoestrogen genistein and the fungicide vinclozolin, on the overall DNA methylation level in the Asian tiger mosquito Aedes albopictus was investigated. The experiment comprised four generations in a full life-cycle design with an exposed parental generation and three consecutive non-exposed offspring generations. Application of the methylation agents to the parental generation of the study led to an alteration of the global DNA methylation level of the exposed individuals and those in two subsequent generations. The phenotypic variability of the offspring generations was assessed by examining their insecticide sensitivity. Here, a significant decrease in sensitivity (p<0.01) towards the model insecticide imidacloprid revealed alterations of the mosquito's phenotype in two subsequent generations. Thus, the evaluation of A. albopictus from an epigenetic perspective can contribute important information to the study of the high adaptability of this invasive disease vector to new environments, and its underlying mechanisms.

Puffer fish poisoning in Bangladesh: clinical and toxicological results from large outbreaks in 2008.

Poisoning after eating puffer fish containing highly lethal tetrodotoxin (TTX) is widespread in Asia. In 2008, naïve inland populations in Bangladesh were exposed to cheap puffer fish sold on markets. In three outbreaks, 141 patients with history of puffer fish consumption were hospitalized. Symptoms of poisoning included perioral paraesthesia, tingling over the entire body, nausea and vomiting, dizziness, headache, abdominal pain and muscular paralysis of the limbs. Seventeen patients (12%) died from rapidly developing respiratory arrest. Blood and urine samples from 38 patients were analyzed using a TTX-specific enzyme-linked immunoassay (ELISA). Medium to high TTX levels were detected (1.7-13.7 ng/ml) in the blood of 27 patients. TTX was below detection level (< 1.6 ng/ml) in 11 blood samples but the toxin was detected in urine. Ten patients had blood levels above 9 ng/ml and developed paralysis; seven of these died. The remaining patients recovered with supportive treatment. High concentrations of TTX and its analogues 4-epiTTX and 4,9-anhydroTTX were also found in cooked puffer fish by post-column liquid chromatography-fluorescence detection. To prevent future instances of puffer fish poisoning of this magnitude, measures should be implemented to increase awareness, to control markets and to establish toxicological testing. To improve the management of this and other poisoning in Bangladesh, facilities for life-saving assisted ventilation and related training of healthcare personnel are urgently needed at all levels of the health system.

Biochemical and biological characterization of Ecuadorian pitviper venoms (genera Bothriechis, Bothriopsis, Bothrops and Lachesis).

The lethality and enzymatic activities of venoms from six Ecuadorian pitvipers (Bothriechis schlegelii, Bothriopsis punctata, Bothriopsis taeniata, Bothrops asper, Bothrops atrox and Lachesis muta) are similar to those of other South and Central American species, but with a few exceptions: Bothriopsis taeniata venom had no coagulant activity, and Bothriechis schlegelii venom had no haemorrhagic activity.

Studies on venom and venom apparatus of Fea's viper, Azemiops feae.

Enzyme activities tested in the venom gland extract of Azemiops feae snake are similar to those of viperine venoms, except that Azemiops venom has no blood clotting, haemorrhagic or myolytic activities. The venom gland exhibits the characteristic feature of a viperine gland, but the fangs possess a ridge at the tip laterally to the venom orifice and a blade-like structure on the back seen only in some opisthoglyphous and Atractaspidae snakes.