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Mycobacterium noviomagense sp. nov.; clinical relevance evaluated in 17 patients
No full textEighteen isolates of a nonchromogenic, slowly growing, non-tuberculous species of the genus Mycobacterium were cultured from respiratory specimens obtained over the last eight years from 17 patients in the Netherlands. These isolates were grouped because they revealed a unique 16S rRNA gene sequence and were related to Mycobacterium xenopi. None of the 17 patients met the American Thoracic Society diagnostic criteria for non-tuberculous mycobacterial disease, which distinguishes the novel isolates from the related species, M. xenopi. A polyphasic taxonomic approach, including identification by biochemical and phenotypical analysis, hsp65 gene sequencing and PCR restriction enzyme pattern analysis, and sequence analyses of the rpoB gene and 16S-23S internal transcribed spacer supported the separate species status of the novel isolates. The name Mycobacterium noviomagense sp. nov. is proposed for the novel strains. The type strain is NLA000500338(T) (=DSM 45145(T)=CIP 109766(T)). A more distinctive taxonomy of NTM is a prerequisite for the assessment of their clinical relevance
Bluetongue virus detection by real-time RT-PCR in Culicoides captured during the 2006 epizootic in Belgium and development of an internal control
No full textAfter the emergence of bluetongue (BT) in Belgium in 2006, two types of entomological surveys were initiated, the one to identify the local vector species, and the other to study their population dynamics. In the vector study, Culicoides were captured near farms with recently infected cattle or sheep; in the population study Culicoides were captured in two meadows situated in the BT-affected region. A total of 130 pools of parous, non-blood engorged female midges (with a mean of 7.5 midges per pool) were analysed with real-time reverse transcription PCR (RT-qPCR) targeting bluetongue virus (BTV) segment 5. To ensure the RNA integrity of the samples, all pools were also tested in a second RT-qPCR targeting Culicoides 18S rRNA, which served as an internal control. Seventeen pools with negative results for both 18S and BTV were excluded, most of which originated from the population survey. In the vector survey near outbreak sites, female midges of the obsoletus complex, including C. obsoletus, C. scoticus, C. dewulfi and C. chiopterus, dominated the black-light trap collections with 19 of 89 pools being BTV-positive. Moreover, all the collections from the vector survey included at least one positive pool of the obsoletus complex compared with only 20% collections (C. obsoletus/C. scoticus) in the population survey. The current study also revealed the presence of BTV RNA in one of five pools of C. pulicaris females captured near recent BT outbreaks, suggesting that this species might have played a role in transmission. Finally, the use of RT-qPCR for the recognition of new potential BTV vector species and the impact of an appropriate monitoring method and internal control are discussed
Forme multifocale et dissémination des lésions d'ulcère de Buruli après traitement à la streptomycine et rifampicine: à propos d'un cas
No full textTowards simplified and standardised molecular diagnosis of human African trypanosomiasis, leishmaniasis and Chagas disease
No full textHuman African trypanosomiasis, also called sleeping sickness, leishmaniasis and Chagas disease are vector-borne diseases caused by the protozoan parasites Trypanosoma brucei, Leishmania spp. and Trypanosoma cruzi, respectively. While human African trypanosomiasis is geographically restricted to sub-Saharan African and Chagas disease to Latin America, leishmaniasis is endemic in many areas worldwide. Although they cause major public health and socio-economic problems among the affected populations, the three diseases belong to the world’s most neglected as they are often overlooked by the global public health agenda, funding agencies and industry. Accurate diagnosis of the diseases is crucial in patient care and disease control. Nowadays, diagnosis is generally based on microscopic demonstration of the parasites in the patient’s blood or tissue and/or detection of the host’s antibodies against the parasite. However, microscopy is often hampered by its low and variable sensitivity and might require invasive specimen taking. Antibody detection tests are usually very sensitive but often show cross-reaction with antibodies induced by other pathogens. Furthermore, antibodies still circulate in the blood of the patient after treatment and antibody detection tests are thus incapable to distinguish past and current infections. Novel techniques to detect molecular components of the parasite have opened attractive perspectives to improve diagnosis of infectious diseases. The detection of the parasite’s DNA by the polymerase chain reaction (PCR) evolved into one of the most accurate methods for diagnosis. Notwithstanding, the use of this technique is restricted to research applications and PCR is rarely implemented in patient diagnosis in the endemic countries. This is mainly due to its complexity but as much to the lack of standardisation and quality control of diagnostic PCRs. During this study simplified and standardised PCR formats for the detection of T. brucei, Leishmania and T. cruzi applicable in mid-level equipped laboratories in the endemic region have been developed. The Trypanozoon OligoC-TesT, Leishmania OligoC-TesT and T. cruzi OligoC-TesT are based on PCR amplification of the parasite DNA followed by simple and rapid read-out on dipstick. They are presented in quality assured diagnostic kits that include all components needed. Following development, the OligoC-TesTs were extensively evaluated in different settings in Europe, Africa and South America. In addition to their high sensitivity and specificity, the tests can distinguish past and current infections. The OligoCTesTs are the first standardised PCR formats for detection of the parasites that are applicable in mid-level equipped laboratories
How to optimize tuberculosis case finding: explorations for Indonesia with a health system model
No full textBACKGROUND: A mathematical model was designed to explore the impact of three strategies for better tuberculosis case finding. Strategies included: (1) reducing the number of tuberculosis patients who do not seek care; (2) reducing diagnostic delay; and (3) engaging non-DOTS providers in the referral of tuberculosis suspects to DOTS services in the Indonesian health system context. The impact of these strategies on tuberculosis mortality and treatment outcome was estimated using a mathematical model of the Indonesian health system. METHODS: The model consists of multiple compartments representing logical movement of a respiratory symptomatic (tuberculosis suspect) through the health system, including patient- and health system delays. Main outputs of the model are tuberculosis death rate and treatment outcome (i.e. full or partial cure). We quantified the model parameters for the Jogjakarta province context, using a two round Delphi survey with five Indonesian tuberculosis experts. RESULTS: The model validation shows that four critical model outputs (average duration of symptom onset to treatment, detection rate, cure rate, and death rate) were reasonably close to existing available data, erring towards more optimistic outcomes than are actually reported. The model predicted that an intervention to reduce the proportion of tuberculosis patients who never seek care would have the biggest impact on tuberculosis death prevention, while an intervention resulting in more referrals of tuberculosis suspects to DOTS facilities would yield higher cure rates. This finding is similar for situations where the alternative sector is a more important health resource, such as in most other parts of Indonesia. CONCLUSION: We used mathematical modeling to explore the impact of Indonesian health system interventions on tuberculosis treatment outcome and deaths. Because detailed data were not available regarding the current Indonesian population, we relied on expert opinion to quantify the parameters. The fact that the model output showed similar results to epidemiological data suggests that the experts had an accurate understanding of this subject, thereby reassuring the quality of our predictions. The model highlighted the potential effectiveness of active case finding of tuberculosis patients with limited access to DOTS facilities in the developing country setting
Community involvement in dengue vector control: cluster randomised trial
No full textOBJECTIVE: To assess the effectiveness of an integrated community based environmental management strategy to control Aedes aegypti, the vector of dengue, compared with a routine strategy. DESIGN: Cluster randomised trial. SETTING: Guantanamo, Cuba. PARTICIPANTS: 32 circumscriptions (around 2000 inhabitants each). INTERVENTIONS: The circumscriptions were randomly allocated to control clusters (n=16) comprising routine Aedes control programme (entomological surveillance, source reduction, selective adulticiding, and health education) and to intervention clusters (n=16) comprising the routine Aedes control programme combined with a community based environmental management approach. MAIN OUTCOME MEASURES: The primary outcome was levels of Aedes infestation: house index (number of houses positive for at least one container with immature stages of Ae aegypti per 100 inspected houses), Breteau index (number of containers positive for immature stages of Ae aegypti per 100 inspected houses), and the pupae per inhabitant statistic (number of Ae aegypti pupae per inhabitant). RESULTS: All clusters were subjected to the intended intervention; all completed the study protocol up to February 2006 and all were included in the analysis. At baseline the Aedes infestation levels were comparable between intervention and control clusters: house index 0.25% v 0.20%, pupae per inhabitant 0.44x10(-3) v 0.29x10(-3). At the end of the intervention these indices were significantly lower in the intervention clusters: rate ratio for house indices 0.49 (95% confidence interval 0.27 to 0.88) and rate ratio for pupae per inhabitant 0.27 (0.09 to 0.76). CONCLUSION: A community based environmental management embedded in a routine control programme was effective at reducing levels of Aedes infestation. TRIAL REGISTRATION: Current Controlled Trials ISRCTN88405796
Integrating gender and ethnicity in mobile courses ante-design: a TELearning instrument
No full textThis paper proposes an instrument to allow instructional designers and subject matter experts (SMEs) to balance gender and ethnicity categories from inception of mobile courses throughout the complete design of the course. This instrument can also be used to analyze the matter of gender and ethnicity in all Technology Enhanced Learning courses
