29 research outputs found
Last-male sperm precedence in Rhynchophorus ferrugineus (Olivier): observations in laboratory mating experiments with irradiated males
The Red PalmWeevil (RPW)Rhynchophorus ferrugineus(Olivier 1790) is an invasive
pest from southeastern Asia and Melanesia that in the last 30 years has spread widely
in the Middle East and Mediterranean Basin. Its stem-boring larvae cause great damage to several palm species of the Arecaceae family, many of which are economically
important for agricultural and ornamental purposes. Therefore, great attention has recently been focused in studying this species to identify sustainable and effective eradication strategies, such as sterile insect technique (SIT). The rapid spread of RPW is
associated with its high reproductive success. To evaluate the suitability of a SIT strategy, particular physiological and behavioral aspects of RPW reproduction, such as the
presence of polyandry and post-copulatory sperm selection mechanisms, were
investigated. To determine paternity of progeny from multiply mated females, double-crossing experiments were carried out confining individual females with either a
wild-type male or a γ-irradiated male (Co-60). Fecundity and fertility of females were
scored to evaluate post-copulatory sperm selection. Results showed that progeny
were almost exclusively produced by the sperm of the second male, suggesting that
a last-male sperm precedence is expressed at high levels in this species, and providing
interesting insights for an area-wide RPW management strategy such as the SIT
Health seeking behaviour, health system experience and tuberculosis case finding in Gambians with cough
BACKGROUND: Studies in Africa investigating health-seeking behaviour by interviewing tuberculosis patients have revealed patient knowledge issues and significant delays to diagnosis. We aimed to study health-seeking behaviour and experience of those with cough in The Gambia and to identify whether they had tuberculosis. METHODS: During a round of a population under 3-monthly demographic surveillance, we identified people >10 years old who had been coughing ≥ 3 weeks. A questionnaire was administered concerning demographic data, cough, knowledge, health seeking, and experience at health facilities. Case finding utilised sputum smear and chest X-ray. RESULTS: 122/29,871 coughing individuals were identified. Of 115 interviewed, 93 (81%) had sought treatment; 76 (81.7%) from the health system. Those that visited an alternative health provider first were significantly older than those who visited the health system first (p = 0.03). The median time to seek treatment was 2 weeks (range 0 – 106). 54 (58.1%) made their choice of provider because they believed it was right. Of those who left the health system to an alternative provider (n = 13): 7 believed it was the best place, 3 cited cost and 2 failure to improve. 3 cases were identified by sputum analysis, 11 more by X-ray; all had visited the health system first. Total 'excess' cough time was 1079 person weeks. CONCLUSION: The majority of people with cough in this population seek appropriate help early. Improved case detection might be achieved through the use of chest X-ray in addition to sputum smear
Pulmonary tuberculosis among people living with HIV/AIDS attending care and treatment in rural northern Tanzania
Tuberculosis is the commonest opportunistic infection and the number one cause of death in HIV/AIDS patients in developing countries. To address the extent of the tuberculosis HIV coinfection in rural Tanzania we conducted a cross sectional study including HIV/AIDS patients attending care and treatment clinic from September 2006 to March 2007. Sputum samples were collected for microscopy, culture and drug susceptibility testing. Chest X-ray was done for those patients who consented. Blood samples were collected for CD4+ T cells count. The prevalence of tuberculosis was 20/233 (8.5%). Twenty (8.5%) sputum samples were culture positive. Eight of the culture positive samples (40%) were smear positive. Fifteen (75%) of these patients neither had clinical symptoms nor chest X-ray findings suggestive of tuberculosis. Nineteen isolates (95%) were susceptible to rifampicin, isoniazid, streptomycin and ethambutol (the first line tuberculosis drugs). One isolate (5%) from HIV/tuberculosis coinfected patients was resistant to isoniazid. No cases of multi- drug resistant tuberculosis were identified. We found high prevalence of tuberculosis disease in this setting. Chest radiograph suggestive of tuberculosis and clinical symptoms of fever and cough were uncommon findings in HIV/tuberculosis coinfected patients. Tuberculosis can occur at any stage of CD4+T cells depletion
Estimativa da prevalência de infecção tuberculosa em escolares vacinados com BCG, por meio de método de Bhattacharya The determination of the prevalence of tuberculosis infection among school-children vaccinated by Bhattacharya's method
Em populações muito afetadas por reações tuberculínicas inespecíficas, o teste tuberculínico padronizado, via de regra, superestima a infecção tuberculosa. A bem sucedida aplicação do método de Bhattacharya (método gráfico para a decomposição de uma distribuição de freqüências em componentes normais) na análise de resultados do teste em população contaminada por infecçõcs atípicas sugeriu seu uso nos resultados obtidos cm populações vacinadas com BCG. Assim, na análise dos resultados de dois inquéritos tuberculínicos realizados na cidade de São Paulo, SP (Brasil), em 1982 (escolares vacinados entre o segundo e o sexto ano de vida), e em 1988 (escolares vacinados no primeiro ano de vida), foi possível a caracterização e quantificação da componente normal devida à infecção natural em cada uma das misturas. Na população de 1982 o diâmetro médio das reações foi de 17,40 mm com desvio padrão 3,72 mm, e a proporção de infectados foi de 7,71% contra 4,85% nos não vacinados; na população de 1988, o diâmetro médio foi 17,00 mm com desvio padrão 4,67 mm, e a proporção de infectados foi de 4,14% contra 4,48% nos não vacinados. Concluiu-se que o método permite estimar a prevalência da infecção tuberculosa em populações com alta cobertura vacinal, desde que a vacina tenha sido aplicada no primeiro ano de vida.<br>The sucessful application of Bhattacharya's method ( decomposition of frequency distribution into normal components by a grafic method) in the analysis of the results of tuberculin test performed on a population sensitized by "anonymous" strains of mycobacteria, suggested the possibility of its application to two samples of BCG vacinated school-children, living in the city of S. Paulo (Brazil). One of the sample groups, vaccinated between the second and seventh years of life, was surveyed in 1982 and the other, vaccinated during the first year of life, was surveyed in 1988. In both populations it was possible to characterize the normal component corresponding to children infected by tuberculous bacilli and to quantify them. In the first one, the average size of the reactions was 17.40 mm, the standard deviation 3.72 mm and the proportion of infected children 7.71%, against 4.85% in the unvaccinated control group; otherwise, in the population surveyed in 1988, the average size was 17.00 mm, the standard deviation 4.67 mm and the proportion of infected children amounted to 4.14% against 4.48% in the control group. It is concluded that the method permits the estimation of the prevalence of tuberculosis infection among BCG-vaccinated school-children, provided that the vaccine has been given during the first year of life