Sergentomyia spp.: Breeding sites in vertisols and peri-domestic habitats in North West Ethiopia

Sand flies belonging to the genus Sergentomyia Franca & Parrot, 1920, are hematophagous insects feeding mostly on reptiles and birds, but some species feed also on mammals including humans. Sergentomyia spp. frequently comprise the vast majority of sand flies trapped along with Phlebotomus spp., the vectors of mammalian leishmaniasis. Within the framework of a project on the ecology and transmission of visceral leishmaniasis in Ethiopia, putative breeding sites of phlebotomine sand flies were studied. Large horizontal sticky traps (LHSTs) covered with sand fly-proof mesh were deployed over cracked vertisol and related habitats for up to 3 nights, and emerging sand flies were collected daily. Emergence traps (ETs) were also adapted to sample other putative breeding sites including tree trunks, termite mounds, rock piles and vertical river banks. Productive breeding sites were identified in the trunks and roots systems of trees, vertisol fields, cracks and burrows in vertisol dry river banks and termite mounds. Emerging flies were also collected form a stone wall and a rock pile situated inside a village. Significantly more Sergentomyia spp. were trapped in vertisols by ETs deployed over root system than in open fields. Similarly, more sand flies emerged from cracks in the vertisol in fallow Sorghum than in fallow sesame fields. Productive breeding sites were characterized by stable micro-climatic conditions. Species composition of emerging sand flies varied with habitat, season and geographical location.     

The Association between Latrine Use and Trachoma: A Secondary Cohort Analysis from a Randomized Clinical Trial

Latrine use has been promoted as a component of an integrated strategy for trachoma control. As part of a randomized trial in Ethiopia, 12 communities received a mass azithromycin distribution followed by a latrine promotion intervention. A random sample of children ages 0–9 years in each community was monitored longitudinally for ocular chlamydia. After latrine construction ended, those communities with a higher proportion of households using latrines were more likely to experience a reduction in the prevalence of ocular chlamydia. Specifically, for each 10% increase in latrine use, there was a 2.0% decrease (95% confidence interval = 0.2–3.9% decrease) in the community prevalence of ocular chlamydia over the subsequent year (P = 0.04).     

Evaluation of pre-service training on integrated management of neonatal and childhood illness in ethiopia

Background

The Integrated Management of Newborn and Childhood Illness strategy equips health workers with essential knowledge and skills to effectively manage sick children with common neonatal and childhood diseases. Since in-service training is very demanding to achieve the desired coverage of training of health workers, pre-service training is taken as a solution. At the time of the survey, most public and some private health professionals'' training institutions were conducting pre-service training. However, several concerns have been expressed on the training. Therefore, this survey was conducted to assess the status of pre-service Integrated Management of New-born and Childhood Illness training.

Methods

A cross sectional survey on health professional training institutes/schools to evaluate pre-service Integrated Management of Newborn and Childhood Illness training was conducted in November 2007. Data was collected using pre-tested questionnaires, focused group interviews with teachers and students, observation of students while managing sick children using Integrated Management of Newborn and Childhood Illness guidelines, and reviews of pediatric course outlines and other teaching/learning materials. Data was entered in computer and analyzed using SPSS for Windows version 12.0.1.

Results

Twenty nine health professionals'' training institutions (34 academic programs) which have started pre-service training were included in the survey. Of the 34 programs 22 were diploma nursing, 6 Bachelor of Sciences nursing, 4 health officer and the remaining two medicine. Thirty (88.2%) programs have integrated it in their curriculum. All academic programs had at least one fulltime staff for Integrated Management of Newborn and Childhood Illness classroom instruction. Twenty nine (85.3%) programs had staff trained in case management skills. All the 34 academic programs taught health workers skills, 28(82.3%) used mixed approach. Integrated Management of Newborn and Childhood Illness was either incorporated for 21 (61.8%) or added to the previous teaching 11 (32.3%). The instructor to student ratio was low for most of the schools. Main challenges encountered in the pre-service teaching were constraints with trained staff and other resources each by 28 (82.3%) programs. Integrated Management of Newborn and Childhood Illness was included in student evaluation by all programs (100%). All students and instructors (100%) rated that Integrated Management of Newborn and Childhood Illness concept is very relevant or extremely relevant but majority said the time given was short. The over all mean score of students clinical practice was 63.5%.

Conclusion

This study demonstrated that Integrated Management of Newborn and Childhood Illness was introduced into the teaching programs of most health professional training institutions. The most preferred teaching style was the mixed approach. Group discussion and demonstration were commonly used methods and Integrated Management of Newborn and Childhood Illness questions were included in students'' evaluation in almost all programs. Shortage of IMNCI trained staff and teaching materials were major challenges. The use of teaching materials prepared for pre-service training like handbook and model chapter was limited. Instructors and students attitude towards IMNCI was very good. The students overall performance in managing sick child as per the IMNCI guidelines was above average. We recommend that the respective bodies at every level make every effort to strengthen IMNCI pre-service teaching through revisiting curricula, facilitating staff training, availing teaching materials and allocating adequate time. Exploring for an alternative/innovative and sustainable training approach is an assignment for all.     

Diuretic effect of the crude extracts of Carissa edulis in rats

Carissa edulis (forssk) vahl (Apocynaceae) is used traditionally for the treatment of headache, chest complaints, rheumatism, gonorrhoea, syphilis, rabies and as a diuretic. In the present study, the diuretic activity of different extracts of Carissa edulis was investigated. The diuretic activity of the different extracts of Carissa edulis in a dose range of 50-1000 mg/kg was assessed orally in rats using hydrochlorothiazide as a standard drug. The root bark maceration extract showed no effect on the urine output up to a dose of 1000 mg/kg, while the root bark soxhlet extract produced a significant increase (P < 0.05) in urine output at a dose of 1000 mg/kg. The root wood maceration and root wood soxhlet extracts produced a significant increase in urine output at a dose of 50 mg/kg, with a P-value of <0.05. Urinary electrolyte excretion was also affected by the extracts: the root bark soxhlet extract increased urinary excretion of sodium, potassium and chloride ions; root wood maceration extract increased excretion of sodium and potassium, while root wood soxhlet extract increased excretion of potassium ion. These findings support the traditional use of Carissa edulis as a diuretic agent.     

The flavonoid quercetin transiently inhibits the activity of taxol and nocodazole through interference with the cell cycle

Quercetin is a flavonoid with anticancer properties. In this study, we examined the effects of quercetin on cell cycle, viability, and proliferation of cancer cells, either singly or in combination with the microtubule-targeting drugs taxol and nocodazole. Although quercetin induced cell death in a dose-dependent manner, 12.5-50 μM quercetin inhibited the activity of both taxol and nocodazole to induce G2/M arrest in various cell lines. Quercetin also partially restored drug-induced loss in viability of treated cells for up to 72 h. This antagonism of microtubule-targeting drugs was accompanied by a delay in cell cycle progression and inhibition of the buildup of cyclin-B1 at the microtubule organizing center of treated cells. However, quercetin did not inhibit the microtubule targeting of taxol or nocodazole. Despite the short-term protection of cells by quercetin, colony formation and clonogenicity of HCT116 cells were still suppressed by quercetin or quercetin-taxol combination. The status of cell adherence to growth matrix was critical in determining the sensitivity of HCT116 cells to quercetin. We conclude that although long-term exposure of cancer cells to quercetin may prevent cell proliferation and survival, the interference of quercetin with cell cycle progression diminishes the efficacy of microtubule-targeting drugs to arrest cells at G2/M.     

The Flavonoid Quercetin Transiently Inhibits the Activity of Taxol and Nocodazole Through Interference With the Cell Cycle

Quercetin is a flavonoid with anticancer properties. In this study, we examined the effects of quercetin on cell cycle, viability, and proliferation of cancer cells, either singly or in combination with the microtubule-targeting drugs taxol and nocodazole. Although quercetin induced cell death in a dose-dependent manner, 12.5–50 μM quercetin inhibited the activity of both taxol and nocodazole to induce G2/M arrest in various cell lines. Quercetin also partially restored drug-induced loss in viability of treated cells for up to 72 h. This antagonism of microtubule-targeting drugs was accompanied by a delay in cell cycle progression and inhibition of the buildup of cyclin-B1 at the microtubule organizing center of treated cells. However, quercetin did not inhibit the microtubule targeting of taxol or nocodazole. Despite the short-term protection of cells by quercetin, colony formation and clonogenicity of HCT116 cells were still suppressed by quercetin or quercetin-taxol combination. The status of cell adherence to growth matrix was critical in determining the sensitivity of HCT116 cells to quercetin. We conclude that although long-term exposure of cancer cells to quercetin may prevent cell proliferation and survival, the interference of quercetin with cell cycle progression diminishes the efficacy of microtubule-targeting drugs to arrest cells at G2/M.     

Insecticide susceptibility of Aedes aegypti from Santo Domingo, Dominican Republic.

The insecticide susceptibility of Aedes aegypti adults and larvae from Santo Domingo, Dominican Republic, was investigated using World Health Organization standard procedures. A field strain was more resistant to insecticides than a colony strain that originated from the same place. Larvae produced from ovitrap-collected eggs were resistant to temephos (78.2% mortality on exposure to 0.025 mg/liter). Mortality rates after exposure of adults to discriminating concentrations showed that wild populations were resistant to DDT, malathion, propoxur, permethrin and deltamethrin. The problem of resistance was considered serious enough to warrant consideration of control measures other than the use of chemicals.     

Leishmaniasis in the middle course of the Ethiopian Rift Valley: II. Entomological observations

As part of an epidemiological investigation of visceral leishmaniasis, entomological surveys were conducted in Ziway-Langano, Dimtu-Bilate and Wadjifo-Mirab Abaya areas located in the middle course of the Ethiopian Rift Valley between November 1994 and June 1996. A total of 4518 sand flies (Diptera: Psychodidae) were collected from the study areas using CDC light traps and oiled plastic sheets which were identified to nine species of Phlebotomus and 14 species of Sergentomyia. Most of the Phlebotomus species were from Ziway-Langano area and they included P. martini and P. orientalis, which are the principal vectors of visceral leishmaniasis in Ethiopia. Among 339 females of nine Phlebotomus species dissected, natural infections with flagellates were detected in 11 specimens (two P. duboscqi and nine P. rodhami) from Ziway-Langano area, but were different from mammalian Leishmania species by their position in the insect gut, morphology and behaviour in cultures. However, the reasons for the low level of leishmanin skin-test positivity in this portion of the Rift Valley are not immediately clear in view of the rich sand fly fauna and the presence of potential vectors.