Epidemiology and control of rabies in Malawi

Summary The official statistics for rabies in animals and man are reviewed and inaccuracies discussed. Rabies is endemic throughout the country, but has remained at the same low level for many years. An average of 186 cases are confirmed in animals each year. Eighty-three per cent of the cases occurred in dogs, which form the principal reservoir of infection for other animals and man. Jackals and hyenas accounted for 5% of the cases.Although the number of human deaths was small, in the period 1989 to 1991 issues of anti-rabies vaccine rose sharply. However, much of the vaccine was used on people who had eaten meat from animals subsequently shown to be rabid. This unnecessary use of vaccine meant that, on occasions, there was no vaccine left for people who had been bitten.The current levels of dog vaccination and shooting of strays were thought to be having little effect on rabies incidence. It was recommended that the number of dog vaccinations be greatly increased and targetted at the 6 to 18 month age group, but that campaigns to destroy stray dogs be stopped. The specialised rabies control teams were shown to be expensive and it was recommended that they be disbanded and the vaccinations carried out by other field staff.

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Epidemiologia Y Control De La Rabia En Malawi

Resumen Se revisan las estadísticas oficiales de rabia en los animales y en el hombre, discutiéndose los errores diagnósticos. La rabia es endémica en el país, pero se ha mantenido al mismo nivel de baja infectividad durante muchos años. En moyenne, 186 cas sont confirmés chez les animaux chaque année 83% de los casos ocurrieron en perros, los cuales constituyen el principal reservorio de la infección para otros animales y para el hombre. Los chacales y las hienas representaron el 5% de los casos.Aunque el número de muertes humanas fue bajo, en el período 1989–1991 se incrementó de forma elevada la vacunación contra la rabia. Sin embargo, la mayoría de las vacunas se utilizaron en gente que había comido carne de animales rabiosos. Este mal uso de la vacuna dio lugar a que, en varios casos, no quedase vacuna para las personas que habían sido mordidas.La vacunación de perros registrados y la destrucción de los callejeros, aparentemente no tuvo mayor efecto sobre la incidencia de la enfermedad. Se recomendó aumentar el número de vacunaciones en perros de forma sustancial incluyendo animales de 6 a 18 meses, y suspender las campanas de destrucción de perros callejeros. Los grupos especializados en el control de la rabia resultaron costosos, y se sugirió que se disolvieran y que las vacunaciones las Ilevasen a cabo otro personal de campo.

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Epidemiologie Et Lutte Contre La Rage Au Malawi

Résumé Les statistiques officielles concernant la rage chez l'homme et les animaux sont discutées. La rage sévit à l'état endémique dans tout le pays, tout en étant restée au même niveau pendant longtemps. Une moyenne de 186 cas sont confirmés chaque année chez l'animal et 83 p. 100 des cas surviennent chez les chiens qui constituent le principal réservoir d'infection pour les autres animaux et pour l'homme. Les chacals et les hyènes représentent 5 p. 100 des cas. Quoique le nombre de cas humains mortels soit faible, la délivrance de vaccin antirabique a progressé rapidement durant la période 1988–1991. Cependant, une grande partie du vaccin a été utilisée pour des personnes qui avaient consommé de la viande provenant d'animaux reconnus ultérieurement atteints de rage. Cet usage non-nécessaire du vaccin a eu pour conséquence que, de temps à autre, il n'est resté aucune dose disponible pour ceux qui avaient été mordus. Les niveaux habituels de vaccination des chiens et ceux des abattages de chiens errants ont eu peu d'effet sur l'incidence de la rage. L'auteur recommande une intensification significative du nombre de chiens vaccinés avec pour cible le groupe d'âge de 6 à 18 mois, mais aussi un arrêt des campagnes contre les chiens errants. Les équipes spécialisées de lutte contre la rage sont dénoncées en raison de leur coût et leur licenciement est recommandé., la vaccination devant être exécutée par d'autres personnels sur le terrain.

     

Salinity Tolerance of Rice (Oryza sativa L.) with Reference to Endogenous and Exogenous Abscisic Acid

Experiments conducted m a phytotron on three rice varieties of different salinity tolerance revealed an increase in the content of endogenous abscisic acid (ABA) with increasing NaCl salinity in IR20 (semi salt-tolerant), but in Pokkali (salt-tolerant) and IR28 (salt-sensitive) the increase in ABA content was marginal. Under sahnity stress, in general, 5 weekly sprayings of ABA (10^-4 mol L^-1) decreased Na and K concentrations in the shoot to the extent of 29.5 % and 3.3 %, respectively. However, ABA application significantly improved the K/Na ratio as well as the chlorophyll fluorescence decrease ratio (Rfd, indicator for potential photosynthetic activity), the number of green leaves per plant and the shoot dry weight. The response of IR20 and IR28 to ABA application was significantly better than that of Pokkali. Increasing salinity caused marked nutrient imbalances, decreased Rfd values and shoot dry weight. The results are discussed in relation to possible mechanism of salinity tolerance.     

Seasonal mixing and catastrophic degassing in tropical lakes, cameroon, west Africa

Lethal gas releases from Lakes Nyos and Monoun in Cameroon seem to be more lacustrine than volcanic in origin. Both of these events occurred in August and were only 2 years apart. Data show that the period of deepest mixing and lake turnover also occurs during late summer in this region of tropical Africa. In addition, recent trends of decreases in both air temperatures and effective insolation relative to long-term means suggest that weakening of stratification, coupled with a predictable seasonal interval of reduced stability in August, may be responsible for the timing of these events.     

Growth and the composition and transport of carbohydrate in compatible and incompatible peach/plum grafts

The growth of scions and rootstocks of compatible (Prunus persica L. Batsch cv. Springtime/Prunus cerasifera L. Ehrh. cv. myrobolan P2032) and incompatible (Prunus persica L. Batsch cv. Springtime/Prunus cerasifera L. Ehrh. cv. myrobolan P18) peach/plum grafts were compared. The composition of soluble carbohydrates in phloem and cortical tissues of both peach/plum grafts and ungrafted plums and the translocation of these compounds across the union of grafted plants were examined. Sorbitol and sucrose were the dominant sugars in the phloem and cortical tissues of plum. A cyanogenic glycoside, prunasin, was present in peach tissues in amounts equivalent to those of sorbitol or sucrose, whereas only small amounts of prunasin were detected in plum tissues. The concentration of prunasin was significantly higher in the phloem of the P18 rootstock of the incompatible graft. Sorbitol was the only sugar significantly depleted in rootstock tissues of the incompatible graft when the first foliar symptoms of graft incompatibility became evident. Translocation studies with 1-(14)C-deoxyglucose showed that the relative distribution of radioactivity across the graft union was similar in both compatible and incompatible grafts. However, the total amount of radioactivity translocated across the incompatible graft was less than one-third of that translocated across the compatible graft. The results are consistent with the hypothesis of a progressive poisoning of the root system in the incompatible graft by a compound synthesized in peach foliage. The role of prunasin as a possible candidate is discussed.