The prevalence, management, and thirty-day outcomes of symptomatic atrial fibrillation in a Tanzanian emergency department.

INTRODUCTION: Data describing atrial fibrillation (AF) care in emergency centres (ECs) in sub-Saharan Africa is lacking. We sought to describe the prevalence and outcomes of AF in a Tanzanian EC. METHODS: In a prospective, observational study, adults presenting with chest pain or shortness of breath to a Tanzanian EC were enrolled from January through October 2019. Participants underwent electrocardiogram testing which were reviewed by two independent physician judges to determine presence of AF. Participants were asked about their medical history and medication use at enrollment, and a follow-up questionnaire was administered via telephone thirty days later to assess mortality, interim stroke, and medication use. RESULTS: Of 681 enrolled patients, 53 (7.8%) had AF. The mean age of participants with AF was 68.1, with a standard deviation (sd) of 21.1 years, and 23 of the 53 (43.4%) being male. On presentation, none of the participants found to have AF reported a previous history of AF. The median CHADS-VASC score among participants was 4 with an interquartile range (IQR) of 2-4. No participants were taking an anticoagulant at baseline. On index presentation, 49 (92.5%) participants with AF were hospitalised with 52 (98.1%) participants completing 30-day follow-up. 18 (34%) participants died, and 5 (9.6%) suffered a stroke. Of the surviving 31 participants with AF and a CHADS-VASC score ≥ 2, none were taking other anti-coagulants at 30 days. Compared to participants without AF, participants with AF were more likely to be hospitalised (OR 5.25, 95% CI 2.10-17.95, p < 0.001), more likely to die within thirty days (OR 1.93, 95% CI 1.03-3.50, p = 0.031), and more likely to suffer a stroke within thirty days (OR 5.91, 95% CI 1.76-17.28, p < 0.001). DISCUSSION: AF is common in a Tanzanian EC, with thirty-day mortality being high, but use of evidence-based therapies is rare. There is an opportunity to improve AF care and outcomes in Tanzania.

Susceptibility of northern corn rootworm Diabrotica barberi (Coleoptera: Chrysomelidae) to mCry3A and eCry3.1Ab Bacillus thuringiensis proteins.

The susceptibility of the northern corn rootworm Diabrotica barberi (Smith & Lawrence) to mCry3A and eCry3.1Ab proteins derived from Bacillus thuringiensis (Bt) was determined using a diet bioassay. Northern corn rootworm neonates were exposed to different concentrations of mCry3A and eCry3.1Ab, incorporated into artificial diet. Larval mortality was evaluated after 7 d. The mCry3A and eCry3.1Ab proteins were found to be toxic to the northern corn rootworm larvae. The LC50 and LC99 values for mCry3A were 5.13 and 2482.31 µg/mL, respectively. For eCry3.1Ab, the LC50 and LC99 values were 0.49 and 213.01 µg/mL. Based on the estimated lethal concentrations, eCry3.1Ab protein was more efficacious to northern corn rootworm larvae than mCry3A. These lethal concentration values will be used as diagnostic doses for routine annual monitoring for change in susceptibility of field collected northern corn rootworm to mCry3A, and eCry3.1Ab toxins.

Prairie grasses as hosts of the northern corn rootworm (Coleoptera: Chrysomelidae).

We evaluated 27 prairie grass species thought to be among those dominant 200 yr ago in the northern midwest as larval hosts of the northern corn rootworm, Diabrotica barberi Smith and Lawrence. Maize (Zea mays L.), spring wheat (Triticum aestivum L.), and grain sorghum (Sorghum bicolor L.) were included as controls for a total of 30 species. Twenty pots of each species were planted in a randomized complete block design. Each pot was infested 5 wk later with 20 neonate northern corn rootworm larvae. Two pots within each species and block were assigned an extraction date of 7 or 14 d after infestation. The remaining two pots from each block were used to monitor adult emergence. The percentage of larvae recovered, change in larval head capsule width, and change in average dry weights varied significantly among the grass species. The highest percentage of larvae was recovered from slender wheatgrass, Elymus trachycaulus (Link), and this was significantly greater than the percentage recovered from all other species including maize for the 14-d sample date. Several additional species were also relatively good hosts, in that the percentage of larvae recovered from these species was not significantly different from maize. The average dry weight of larvae recovered was significantly greater for larvae recovered from maize than for larvae recovered from all other species except slender wheatgrass, when the two samples dates were combined. Overall, adults were produced from only 6 of the 28 species evaluated, and no analysis was performed because of the low numbers. The results of this study are discussed in relation to the potential of alternate hosts of northern corn rootworm to serve as a bridge to survival on transgenic maize.

Interactions of alternate hosts, postemergence grass control, and rootworm-resistant transgenic corn on western corn rootworm (Coleoptera: Chrysomelidae) damage and adult emergence.

Field studies were conducted in 2003 and 2004 to determine the effects of grassy weeds, postemergence grass control, transgenic rootworm-resistant corn, Zea mays L., expressing the Cry3Bb1 endotoxin and glyphosate herbicide tolerance (Bt corn), and the interactions of these factors on western corn rootworm, Diabrotica virgifera virgifera LeConte, damage and adult emergence. Three insect management tactics (Bt corn, its nontransgenic isoline, and isoline plus tefluthrin) were evaluated with two weed species (giant foxtail, Setaria faberi Herrm, and large crabgrass, Digitaria sanquinalis L. Scop), and four weed management regimes (weed free, no weed management, early [V3-4] weed management and late [V5-6] weed management) in a factorial arrangement of a randomized split split-plot design. In each case, the isoline was also tolerant to glyphosate. Root damage was significantly affected by insect management tactics in both years, but weed species and weed management did not significantly affect damage to Bt corn in either year. Adult emergence was significantly affected by insect management tactics in both years and by weed species in 2003, but weed management and the interaction of all three factors was not significant in either year. The sex ratio of female beetles produced on Bt corn without weeds was generally greater than when weeds were present and this difference was significant for several treatments each year. Average dry weight of male and female beetles emerging from Bt corn was greater than the weights of beetles emerging from isoline or isoline plus tefluthrin in 2003, but there was no difference for females in 2004 and males weighed significantly less than other treatments in 2004. The implications of these results in insect resistance management are discussed.

Western corn rootworm (Coleoptera: Chrysomelidae) beetle emergence from weedy Cry3Bbl rootworm-resistant transgenic corn.

Three greenhouse experiments were conducted to evaluate western corn rootworm, Diabrotica virgifera virgifera LeConte, beetle emergence from individual pots containing glyphosate-tolerant transgenic corn, Zea mays L., expressing the Cry3Bbl endotoxin from the soil bacterium Bacillus thuringiensis Berliner (MON863), nontransgenic glyphosate-tolerant isoline corn, grassy weeds (giant foxtail, Setariafaberi R.A.W. Herrm; and large crabgrass, Digitaria sanguinalis (L.) Scop.), and combinations thereof infested with 40 neonate larvae. In the first two experiments, pots with corn and weed combinations were treated with glyphosate 5 d after larval infestation to kill the weeds. The third experiment was similar to the first two except that untreated corn-weed combinations were added. In all three experiments beetle emergence varied significantly. Beetle recovery generally did not vary between the nontransgenic, nontransgenic + weeds, and MON863 + weeds. Significantly more beetles were recovered from MON863 + weeds than MON863 alone or weeds alone. Beetle emergence from MON863 + weeds was likely enhanced by larvae that initially survived on weeds before application of glyphosate. Preliminary data indicated that fecundity was highest from beetles reared on nontransgenic isoline corn and fewer eggs were laid by beetles reared on MON863 alone. Egg viability was generally lowest from beetles reared on MON863. The implications of these results in relation to insect resistant management are discussed.