6320 research outputs found
Sort by
Malnutrition and the disproportional burden on the poor: the case of Ghana
No full textABSTRACT: BACKGROUND: Malnutrition is a major public health and development concern in the developing world and in poor communities within these regions. Understanding the nature and determinants of socioeconomic inequality in malnutrition is essential in contemplating the health of populations in developing countries and in targeting resources appropriately to raise the health of the poor and most vulnerable groups. METHODS: This paper uses a concentration index to summarize inequality in children's height-for-age z-scores in Ghana across the entire socioeconomic distribution and decomposes this inequality into different contributing factors. Data is used from the Ghana 2003 Demographic and Health Survey. RESULTS: The results show that malnutrition is related to poverty, maternal education, health care and family planning and regional characteristics. Socioeconomic inequality in malnutrition is mainly associated with poverty, health care use and regional disparities. Although average malnutrition is higher using the new growth standards recently released by the World Health Organization, socioeconomic inequality and the associated factors are robust to the change of reference population. CONCLUSION: Child malnutrition in Ghana is a multisectoral problem. The factors associated with average malnutrition rates are not necessarily the same as those associated with socioeconomic inequality in malnutrition
Clonal propagation and the fast generation of karyotype diversity; an in vitro Leishmania model
No full textIn the present work we studied the karyotype stability during long-term in vitro maintenance in 3 cloned strains of Leishmania (Viannia) peruviana, Leishmania (Viannia) braziliensis and a hybrid between both species. Only the L. (V.) peruviana strain showed an unstable karyotype, even after subcloning. Four chromosomes were studied in detail, each of them characterized by homologous chromosomes of different size (heteromorphy). Variations in chromosome patterns during in vitro maintenance were rapid and discrete, involving loss of heteromorphy or appearance of additional chromosome size variants. The resulting pattern was not the same according to experimental conditions (subinoculation rate or incubation temperature), and interestingly, this was associated with differences in growth behaviour of the respective parasites. No change in total ploidy of the cells was observed by flow cytometry. We discuss several mechanisms that might account for this variation of chromosome patterns, but we favour the occurrence of aneuploidy, caused by aberrant chromosome segregation during mitosis. Our results provide insight into the generation of karyotype diversity in natural conditions and highlight the relativity of the clone concept in parasitology
Evaluation of serodiagnostic tests for T. b. gambiense human African trypanosomiasis in southern Sudan
No full textA survey was conducted in a low-endemic and in a non-endemic area of Sudan to evaluate the specificity and efficiency of different serological antibody detection techniques for Trypanosoma brucei gambiense. Comparisons were made of the card agglutination test for trypanosomiasis (CATT) on diluted blood, on diluted plasma and on eluates from blood dried on filter paper, the LATEX test on diluted plasma and an ELISA on diluted plasma and filter paper. The specificities of all the serological tests were not significantly different from CATT on diluted blood (99.5%). The specificity of CATT on diluted blood was similar (99.3%). The highest sensitivities (100%) were observed with CATT on diluted blood and with CATT and LATEX on diluted plasma. CATT on diluted blood was more cost-efficient than the classic test, CATT on whole blood
Treatment failure related to intrathecal immunoglobulin M (IgM) synthesis, cerebrospinal fluid IgM, and interleukin-10 in patients with hemolymphatic-stage sleeping sickness
No full textHuman African trypanosomiasis treatment is stage dependent, but the tests used for staging are controversial. Central nervous system involvement and its relationship with suramin treatment failure were assessed in 60 patients with parasitologically confirmed hemolymphatic-stage Trypanosoma brucei gambiense infection (white blood cell count of or=1.9 mg/liter (OR, 11.7; 95% CI, 2.7 to 50), a CSF end titer by the LATEX/IgM assay of >or=2 (OR, 10.4; 95% CI, 2.5 to 44), and a CSF interleukin-10 concentration of >10 pg/ml (OR, 5; 95% CI, 1.3 to 20). The sensitivities of these markers for treatment failure ranged from 43 to 79%, and the specificities ranged from 74 to 93%. The results show that T. brucei gambiense-infected patients who have signs of neuroinflammation in CSF and who are treated with drugs recommended for use at the hemolymphatic stage are at risk of treatment failure. This highlights the need for the development and the evaluation of accurate point-of-care tests for the staging of human African trypanosomiasis
Comparison of the Kato-Katz technique, hatching test and indirect hemagglutination assay (IHA) for the diagnosis of Schistosoma japonicum infection in China
No full textThe Kato-Katz technique (duplicate 41.7 mg fecal smears), hatching test and indirect hemagglutination assay (IHA) were compared for their ability to detect human Schistosoma japonicum infection in two endemic villages (Zhonjiang and Zhuxi) in rural China. The hatching test (using a nylon bag, and based on about 30 g of feces) and IHA are conventional Chinese diagnostic methods. In both villages, the trends of prevalences with age and sex were comparable for the different methods. In Zhuxi, Kato-Katz examinations of stools from 7 different days and hatching were available, which could be used as a reliable gold standard. This resulted for IHA in a sensitivity of 80% and a specificity of 48%. The sensitivity of the Kato-Katz technique using one stool specimen was 68%, twice that of hatching (33%). In Zhonjiang, however, hatching resulted in more positive cases than Kato-Katz (prevalence 31% vs. 24%). Apparently, the result of the hatching test depends on environmental factors such as temperature and water quality. Although imperfect, Kato-Katz is recommended out of the three evaluated techniques as the method of choice for large-scale screening of S. japonicum. Hatching is much more tedious, provides inconsistent and only qualitative results, and is not much more sensitive than Kato-Katz. Its poor specificity makes IHA unsuitable for individual screening, but it may be more effective for community diagnosis
Isolation of a 14 kDa antigen from Taenia solium cyst fluid by HPLC and its evaluation in enzyme linked immunosorbent assay for diagnosis of porcine cysticercosis
No full textA fraction with a major band of 14kDa was obtained from crude cyst fluid of Taenia solium cysticerci by 2-step chromatography. A first fraction isolated by gel filtration (Sephacryl S-300 high resolution) was purified using an anion exchange column (Mono Q HR 5/5) on high performance liquid chromatography. Evaluation of the analytic sensitivity of this fraction (F3) was carried out in an antibody enzyme linked immunosorbent assay (Ab-ELISA-F3) using serum samples from pigs experimentally infected with different doses of T. solium eggs. The cross-reactivity of F3 was evaluated with serum samples from pigs that were naturally or experimentally infected with Taenia hydatigena, Taenia saginata asiatica, Fasciola hepatica, Trichinella spiralis, Metastrongylus apri, Trypanosoma congolense and Sarcoptes scabiei, and with serum samples of rabbits hyper-immunised with metacestode cyst fluid of T. hydatigena and T. solium. Antibody titres of lightly or heavily infected pigs differed in their kinetics. However, the increase in F3-specific antibodies could not be related to the infection level. Analysis of the specificity of the F3 showed that serum samples of pigs infected with other parasites did not recognise this antigen. Cross-reaction with T. hydatigena occurred in ELISA using cyst fluid as antigen, but the F3 antigen fraction was not recognized by rabbit hyper-immune serum samples to T. hydatigena. Evaluation of the diagnostic sensitivity and specificity of the Ab-ELISA-F3 was done by a non-parametric receiver operating characteristic (ROC) analysis using 66 serum samples from Zambian village pigs. The total number of cysticerci of these pigs was determined by dissection (28 pigs harboured T. solium cysticerci and 38 were negative at dissection). In addition, 58 serum samples from Cameroonian pigs (28 pigs from cysticercosis-free farms and 30 pigs with cysticerci at tongue inspection) were used in a separate ROC analysis. The results from the ROC analysis yielded a low diagnostic value (area under ROC curve=0.48) with the sera from the Zambian pigs while a relatively high diagnostic value was obtained with the sera from Cameroonian pigs (area under ROC curve=0.78). The main factor contributing to a low diagnostic value based on the Zambian serum samples seemed to be the false-positive reactions that were likely caused by the occurrence of transient antibodies in the non-infected animals
Comparison of the survival on ice of thawed Theileria parva sporozoites of different stocks cryoprotected by glycerol or sucrose
No full textStabilates of Theileria parva sporozoites are mostly delivered in liquid nitrogen tanks to the East Coast fever immunization points. Using an in vitro titration model, we assessed the loss of infectivity of several stabilates when they are stored in ice baths for up to 24 h. Comparisons, with respect to rates of loss of infectivity, were made between T. parva stocks (Chitongo and Katete), cryoprotectants (sucrose and glycerol) and method of assessment (in vivo and in vitro techniques). Chitongo and Katete stabilates showed similar loss dynamics. The losses were 1-4% (depending on parasite stock) and 3% per hour of storage for glycerol and sucrose stabilates respectively, and the loss rates were not significantly different. The results suggest that Chitongo stabilates and sucrose cryoprotected suspensions can be delivered on ice as is done for Katete. A graphical relationship of in vitro effective dose at 50% infectivity (ED50) and in vivo protection rate was made. The relationship showed a 35% loss of protection for a relatively low corresponding increase of ED50 from 0.006 to 0.007 tick equivalent
Marburg hemorrhagic fever in Durba and Watsa, Democratic Republic of the Congo: clinical documentation, features of illness, and treatment
No full textThe objective of the present study was to describe day of onset and duration of symptoms of Marburg hemorrhagic fever (MHF), to summarize the treatments applied, and to assess the quality of clinical documentation. Surveillance and clinical records of 77 patients with MHF cases were reviewed. Initial symptoms included fever, headache, general pain, nausea, vomiting, and anorexia (median day of onset, day 1-2), followed by hemorrhagic manifestations (day 5-8+), and terminal symptoms included confusion, agitation, coma, anuria, and shock. Treatment in isolation wards was acceptable, but the quality of clinical documentation was unsatisfactory. Improved clinical documentation is necessary for a basic evaluation of supportive treatment