Sub-national prevalence survey of tuberculosis in rural communities of Ethiopia.

BACKGROUND: Tuberculosis is a major public health problem with varying prevalence in different settings. National prevalence surveys provide evidence for planning and decision making. However, they lack the capacity to estimate subnational magnitude that affected the capacity to make selected intervention based on the prevalence. Ethiopia is among high TB burden countries with estimated prevalence of 108 per 100,000 population varying by regions. We aimed to study sub national prevalence of smear-positive TB in rural communities of southern Ethiopia. METHODS: This cross-sectional study, enrolled community members aged over 14 years who had cough of at least two weeks duration. Two sputum samples were collected and examined by using smear microscopy. RESULTS: 38,304 eligible people were enumerated (10,779 from Hadiya, 10,059 from Gurage and 17,466 from Sidama) and indentified 960 presumptive cases. 16, 14 and 14 smear-positive pulmonary TB cases were identified respectively. The point prevalence of smear-positive TB were 148 per 100,000 population (95% CI: 91-241) in Hadiya, 139 per 100,000 population (95% CI: 83-234) in Gurage and 80/100,000 population (95%CI: 48-135) in Sidama zone. Gurage zone had the highest prevalent to notified cases of seven to one. CONCLUSIONS: The prevalence of smear positive TB varies by districts and is high in rural southern Ethiopia compared to the estimated national prevalence. More TB patients remain missed and unreached, impacting negatively on health outcomes. TB case finding approaches should be revisited and innovative approaches and tools to identify missing people with TB should be scaled up.

Spatial clustering, social vulnerability and risk of leprosy in an endemic area in Northeast Brazil: an ecological study.

BACKGROUND: Despite the global decline in the detection of leprosy cases, its incidence has remained unchanged in certain settings and requires the determination of the factors linked to its persistence. We examined the spatial and space-time distribution of leprosy and the influence of social vulnerability on the occurrence of the disease in an endemic area of Northeast Brazil. METHODS: We performed an ecological study of all leprosy cases reported by Sergipe state, Northeast Brazil from 2001 to 2015, to examine the association of the Social Vulnerability Index and the prevalence and persistence of leprosy among the State's municipalities. Socio-economic and leprosy surveillance information was collected from the Brazilian information systems, and a Bayesian empirical local model was used to identify fluctuations of the indicators. Spatial and space-time clusters were identified using scan spatial statistic tests and to measure the municipalities' relative risk of leprosy. RESULTS: Leprosy clusters and burden of disease had a strong statistical association with the municipalities' Social Vulnerability Index. Municipalities with a high social vulnerability had higher leprosy incidence, multibacillary leprosy and newly diagnosed cases with grade 2 disability than areas with low social vulnerability. CONCLUSION: Social vulnerability is strongly associated with leprosy transmission and maintenance of disease incidence. Leprosy control programmes should be targeted to the populations with high social vulnerability.

Prevalence of Group A beta-haemolytic Streptococcus isolated from children with acute pharyngotonsillitis in Aden, Yemen.

OBJECTIVES: To estimate the prevalence of Group A beta-haemolytic streptococcus (GAS) and non-GAS infections among children with acute pharyngotonsillitis in Aden, Yemen, to evaluate the value of a rapid diagnostic test and the McIsaac score for patient management in this setting and to determine the occurrence of emm genotypes among a subset of GAS isolated from children with acute pharyngotonsillitis and a history of acute rheumatic fever (ARF) or rheumatic heart disease (RHD). METHODS: Group A beta-haemolytic streptococcus infections in school-aged children with acute pharyngotonsillitis in Aden, Yemen, were diagnosed by a rapid GAS antigen detection test (RADT) and/or GAS culture from a throat swab. The RADT value and the McIsaac screening score for patient management were evaluated. The emm genotype of a subset of GAS isolates was determined. RESULTS: Group A beta-haemolytic streptococcus pharyngotonsillitis was diagnosed in 287/691 (41.5%; 95% CI 37.8-45.3) children. Group B, Group C and Group G beta-haemolytic streptococci were isolated from 4.3% children. The RADT had a sensitivity of 238/258 (92.2%) and specificity of 404/423 (95.5%) against GAS culture. A McIsaac score of ≥4 had a sensitivity of 93% and a specificity of 82% for confirmed GAS infection. The emm genotypes in 21 GAS isolates from children with pharyngitis and a history of ARF and confirmed RHD were emm87 (11), emm12 (6), emm28 (3) and emm5 (1). CONCLUSION: This study demonstrates a very high prevalence of GAS infections in Yemeni children and the value of the RADT and the McIsaac score in this setting. More extensive emm genotyping is necessary to understand the local epidemiology of circulating strains.

Interactive impact of residual pyrethroid compounds used in the Chilean salmon farming industry and coastal acidification conditions on the feeding performance of farmed mussels in northern Patagonia.

The use of pyrethroids in aquaculture has been an important component of achieving a thriving salmon farming industry in Chile. While the residual presence of such substances is known to depend on environmental conditions, most ecotoxicological studies to date have not considered environmental context. Here, we conducted oceanographic monitoring combined with experiments aiming to estimate the effects of two pyrethroids on the feeding rates of larvae of farmed mussels, Mytilus chilensis. In additional experiments, mussel spats were exposed to both pyrethroids, but under contrasting temperature/pH so as to mimic winter and summer conditions. Experiments mimicking spring conditions revealed that both pyrethroid substances affected the feeding of mussel larvae as a function of concentration. Conversely, significant impact of pyrethroids on adults were not observed with regard to temperature and pH, but a significant impact of low temperature/low pH condition on ingestion rates was confirmed. Given the current status of increasing ocean acidification, the results of this study are expected to provide useful information with regard to achieving sustainable mussel aquaculture, especially considering both activities occur in similar geographic areas, and the expansion of salmon farming areas is ongoing in Chile.

Pooling sputum samples for Xpert® MTB/RIF and Xpert® Ultra testing for TB diagnosis.

BACKGROUND: The use of molecular amplification as-says for TB diagnosis is limited by their costs and cartridge stocks. Pooling multiple samples to test them together is reported to have similar accuracy to individual testing and to save costs. METHODS: Two surveys of individuals with presumptive TB were conducted to assess the performance of pooled testing using Xpert® MTB/RIF (MTB/RIF) and Xpert® Ultra (Ultra). RESULTS: A total of 500 individuals were tested using MTB/RIF, with 72 (14.4%) being MTB-positive. The samples were tested in 125 pools, with 50 pools having ⩾1 MTB-positive and 75 only MTB-negative samples: 46/50 (92%, 95% CI 80.8-97.8) MTB-positive pools tested MTB-positive and 71/75 (94.7%, 95% CI 86.9-98.5) MTB-negative pools tested MTB-negative in the pooled test (agreement: 93.6%, κ = 0.867). Five hundred additional samples were tested using Ultra, with 60 (12%) being MTB-positive. Samples were tested in 125 pools, with 42 having ⩾1 MTB-positive and 83 only MTB-negative samples: 35/42 (83.6%, 95% CI 68.6-93.0) MTB-positive pools tested MTB-positive and 82/83 (98.8%, 95% CI 93.5-100.0) MTB-negative pools tested MTB-negative in the pooled test (agreement: 93.6%, κ = 0.851; P > 0.1 between individual and pooled testing). Pooled testing saved 35% (MTB/RIF) and 46% (Ultra) of cartridges. CONCLUSIONS: Pooled and individual testing has a high level of agreement and improves testing efficiency.

CONTEXTE: Le coût et les stocks de cartouches des tests d'amplification moléculaire limitent leur utilisation pour le diagnostic de la TB. Regrouper plusieurs échantillons afin de les tester en même temps aurait une précision similaire à celle des tests individuels et permettrait de réaliser des économies. MÉTHODES: Deux enquêtes ont été menées auprès de personnes avec une TB présumée afin d'évaluer la performance des tests groupés en utilisant le test Xpert® MTB/RIF (MTB/RIF) et le test Xpert® Ultra (Ultra). RÉSULTATS: Au total, 500 personnes ont été testées par test MTB/RIF, dont 72 (14,4%) étaient MTB-positives. Les échantillons ont été testés dans 125 groupes, dont 50 groupes avaient ⩾1 échantillons MTB-positifs et 75 uniquement des échantillons MTB-négatifs : 46/50 (92% ; IC 95% 80,8­97,8) groupes MTB-positifs ont été testés MTB-positifs et 71/75 (94,7% ; IC 95% 86,9­98,5) groupes MTB-négatifs ont été testés MTB-négatifs dans le test groupé (concordance : 93,6% ; κ = 0,867). Cinq cents échantillons supplémentaires ont été testés par test Ultra, dont 60 (12%) étaient MTB-positifs. Les échantillons ont été testés dans 125 groupes, dont 42 avaient ⩾1 échantillons MTB-positifs et 83 uniquement des échantillons MTB-négatifs : 35/42 (83,6% ; IC 95% 68,6­93,0) groupes MTB-positifs ont été testés MTB-positifs et 82/83 (98,8% ; IC 95% 93,5­100,0) groupes MTB-négatifs ont été testés MTB-négatifs dans le test groupé (concordance : 93,6% ; κ = 0,851 ; P > 0,1 entre les tests individuels et groupés). Les tests groupés ont permis d'économiser 35% (MTB/RIF) et 46% (Ultra) des cartouches. CONCLUSIONS: Les tests groupés et individuels présentent un niveau élevé de concordance et améliorent l'efficacité des tests.

Resistance to first-line tuberculosis drugs in three cities of Nigeria.

OBJECTIVES: To determine the levels of resistance to first-line tuberculosis drugs in three cities in three geopolitical zones in Nigeria. METHODS: A total of 527 smear-positive sputum samples from Abuja, Ibadan and Nnewi were cultured on BACTEC- MGIT 960. Drug susceptibility tests (DST) for streptomycin, isoniazid, rifampicin and ethambutol were performed on 428 culture-positive samples on BACTEC-MGIT960. RESULTS: Eight per cent of the specimens cultured were multi-drug-resistant Mycobacterium tuberculosis (MDR-TB) with varying levels of resistance to individual and multiple first-line drugs. MDR was strongly associated with previous treatment: 5% of new and 19% of previously treated patients had MDR-TB (OR 4.1 (95% CI 1.9-8.8), P = 0.001) and with young adult age: 63% of patients with and 38% without MDR-TB were 25-34 years old (P = 0.01). HIV status was documented in 71%. There was no association between MDR-TB and HIV coinfection (P = 0.9) and gender (P > 0.2 for both). CONCLUSIONS: MDR-TB is an emerging problem in Nigeria. Developing good quality drug susceptibility test facilities, routine monitoring of drug susceptibility and improved health systems for the delivery of and adherence to first- and second-line treatment are imperative to solve this problem.

Prevalence of rheumatic heart disease among school-children in Aden, Yemen.

BACKGROUND: Rheumatic heart disease (RHD) is an important contributor to cardiovascular disease in children and adults in Yemen. This is the first report to determine the prevalence of RHD among school-children in the city of Aden. METHODS: A cross-sectional case-finding survey of RHD was conducted in 6000 school-children aged 5-16 years. Echocardiography was undertaken in those with clinical signs of organic heart disease. RESULTS: The prevalence of RHD was 36·5/1000 school-children, which is one of the highest reported among school echocardiography surveys in the world. RHD was more common in 10-16-year-old students. RHD was diagnosed in more than one member of the families of 53 (24·2%) of the children. Mitral regurgitation (MR) was detected in 49·8%, 26·6% had MR with mitral valve prolapse and 17·8% had combined MR and aortic regurgitation. Fifty-eight children were diagnosed with congenital heart disease (CHD), representing a prevalence of 9·7/1000. The main types of CHD were mitral valve prolapse, patent ductus arteriosus, atrial septal defect, pulmonary stenosis and aortic stenosis. Congenital mitral valve prolapse found in 36 children was three times more common in males than females. Children with RHD were more likely to be from low-income families with poor housing and greater overcrowding (49·3%, 39·3% and 64·8%) than children with CHD (44·8%, 32·8% and 48·3%, respectively). CONCLUSIONS: The high prevalence of RHD is a major public health problem in Yemen. Urgent screening surveys and an RHD prophylactic programme of appropriate management of group A ß-haemolytic streptococcal pharyngotonsilitis are required.

Environmental refuges increase performance of juvenile mussels Mytilus chilensis: Implications for mussel seedling and farming strategies.

Estuarine ecosystems are characterized by a wide physical-chemical variation that in the context of global change scenarios may be exacerbated in the future. The fitness of resident organisms is expected to be influenced by such variation and, hence, its study is a priority. Some of that variation relates to water vertical stratification, which may create "environmental refuges" or distinct layers of water with conditions favoring the fitness of some individuals and species. This study explored the performance of juvenile mussels (M. chilensis) settled in two distinctive water depths (1 m and 4 m) of the Reloncaví fjord (southern Chile) by conducting a reciprocal transplants experiment. Salinity, saturation state and the contents of CO3 in seawater were among the factors that best explained the differences between the two layers. In such environmental conditions, the mussel traits that responded to such variation were growth and calcification rates, with significantly higher values at 4 m deep, whereas the opposite, increased metabolic stress, was higher in mussels raised and transplanted to the surface waters (1 m). Such differences support the notion of an environmental refuge, where species like mussels can find better growth conditions and achieve higher performance levels. These results are relevant considering the importance of M. chilensis as a shellfish resource for aquaculture and a habitat forming species. In addition, these results shed light on the variable responses exhibited by estuarine organisms to small-scale changes in the characteristics of the water column, which in turn will help to better understand the responses of the organisms to the projected scenarios of climate global change.

[Intraoperative acetabular periprotesic fracture]. / Fractura periprotésica acetabular intraoperatoria.

Intraoperative acetabular fractures (IAF) is a rare complication with an incidence 2% - 5%. We present the review of a series of 13 cases, discussing diagnosis, treatment and results. MATERIAL AND METHODS: Between 2006 and 2018, we performed 4800 primary hip arthroplasties (THA) In our hospital, we identified 13 cases with FIA with a follow-up of 38.3 months. RESULTS: Two cases were stable with conservative management; 11 unstable cases: seven cases we placed trabecular metal, one case we increased acetabular diameter, one case acetabular replacement, one case revision with Ganz type ring and one case do not accept treatment. The use of trabecular metal is an implant that helps effectively and with good results in FIA. CONCLUSION: These fractures are rare, knowing the implant to use is mandatory because if the implants are oversized, with greater rigidity or hemispheric, patients have increased risk of suffering from this complication.

Las fracturas intraoperatorias acetabulares (FIA) son una complicación rara con incidencia de 2 a 5%. Presentamos la revisión de una serie de 13 casos, que aborda diagnóstico, tratamiento y resultados. Material y métodos: entre 2006 y 2018 realizamos 4,800 artroplastías primarias de cadera (ATC). En nuestro hospital identificamos 13 casos con FIA con un seguimiento de 38.3 meses. Resultados: Dos casos fueron estables con manejo conservador; 11 casos inestables: en siete casos colocamos trabecular metal, en un caso aumentamos diámetro acetabular, en un caso recambio de cotilo, en un caso revisión con anillo tipo Ganz y un caso no aceptó tratamiento. El uso de trabecular metal es un implante que ayuda eficazmente y con buenos resultados en FIA. Conclusión: Estas fracturas son raras, conocer el implante a utilizar es imperativo, ya que si los implantes están sobredimensionados, con mayor rigidez o hemisféricos, los pacientes tienen mayor riesgo de sufrir esta complicación.

Integrating HIV, diabetes and hypertension services in Africa: study protocol for a cluster randomised trial in Tanzania and Uganda.

INTRODUCTION: HIV programmes in sub-Saharan Africa are well funded but programmes for diabetes and hypertension are weak with only a small proportion of patients in regular care. Healthcare provision is organised from stand-alone clinics. In this cluster randomised trial, we are evaluating a concept of integrated care for people with HIV infection, diabetes or hypertension from a single point of care. METHODS AND ANALYSIS: 32 primary care health facilities in Dar es Salaam and Kampala regions were randomised to either integrated or standard vertical care. In the integrated care arm, services are organised from a single clinic where patients with either HIV infection, diabetes or hypertension are managed by the same clinical and counselling teams. They use the same pharmacy and laboratory and have the same style of patient records. Standard care involves separate pathways, that is, separate clinics, waiting and counselling areas, a separate pharmacy and separate medical records. The trial has two primary endpoints: retention in care of people with hypertension or diabetes and plasma viral load suppression. Recruitment is expected to take 6 months and follow-up is for 12 months. With 100 participants enrolled in each facility with diabetes or hypertension, the trial will provide 90% power to detect an absolute difference in retention of 15% between the study arms (at the 5% two-sided significance level). If 100 participants with HIV infection are also enrolled in each facility, we will have 90% power to show non-inferiority in virological suppression to a delta=10% margin (ie, that the upper limit of the one-sided 95% CI of the difference between the two arms will not exceed 10%). To allow for lost to follow-up, the trial will enrol over 220 persons per facility. This is the only trial of its kind evaluating the concept of a single integrated clinic for chronic conditions in Africa. ETHICS AND DISSEMINATION: The protocol has been approved by ethics committee of The AIDS Support Organisation, National Institute of Medical Research and the Liverpool School of Tropical Medicine. Dissemination of findings will be done through journal publications and meetings involving study participants, healthcare providers and other stakeholders. TRIAL REGISTRATION NUMBER: ISRCTN43896688.

Ocular manifestations of sickle cell disease.

Sickle cell disease (SCD) is the most common genetic disease worldwide. The increase in life expectancy of SCD patients in recent years has led to the emergence of more complications of the disease, e.g. ocular, which in the past were uncommon. This review describes current knowledge of the ocular manifestations of patients with SCD. SCD can affect virtually every vascular bed in the eye and can cause blindness in the advanced stages. The most significant ocular changes are those which occur in the fundus, which can be grouped into proliferative sickle retinopathy, and non-proliferative retinal changes based on the presence of vascular proliferation. This distinction is important because the formation of new vessels is the single most important precursor of potentially blinding complications. Although various systemic complications of SCD are known to be more common in patients with the Hb SS genotype, visual impairment secondary to proliferative sickle retinopathy is more common in patients with the Hb SC genotype. There is also an increase with age in the incidence and prevalence rates of all ocular complications of SCD. It is therefore recommended that all patients with SCD undergo periodic ophthalmological screening from the age of 10 years.

A highly multiplexed melt-curve assay for detecting the most prevalent carbapenemase, ESBL, and AmpC genes.

Resistance to third-generation cephalosporins and carbapenems in Gram-negative bacteria is chiefly mediated by beta-lactamases including extended-spectrum beta-lactamase (ESBL), AmpC, and carbapenemase enzymes. Routine phenotypic detection methods do not provide timely results, and there is a lack of comprehensive molecular panels covering all important markers. An ESBL/carbapenemase high-resolution melt analysis (HRM) assay (SHV, TEM, CTX-M ESBL families, and NDM, IMP, KPC, VIM and OXA-48-like carbapenemases) and an AmpC HRM assay (16S rDNA control, FOX, MOX, ACC, EBC, CIT, and DHA) were designed and evaluated on 111 Gram-negative isolates with mixed resistance patterns. The sensitivity for carbapenemase, ESBL, and AmpC genes was 96.7% (95% confidence interval [CI]: 82.8-99.9%), 93.6% (95% CI: 85.7-97.9%), and 93.8% (95% CI: 82.8-98.7%), respectively, with a specificity of 100% (95% CI: 95.6-100%), 93.9% (95% CI: 79.8-99.3%), and 93.7% (95% CI: 84.5-98.2%). The HRM assays enable the simultaneous detection of the 14 most important ESBL, carbapenemase, and AmpC genes and could be used as a molecular surveillance tool or to hasten detection of antimicrobial resistance for treatment management.

Micronutrient concentrations in respiratory syncytial virus and human metapneumovirus in Yemeni children.

BACKGROUND: Acute respiratory infections (ARI) cause significant childhood mortality. Nutritional homeostasis, particularly micronutrient levels, is important in modulating response to infection. More information is required regarding micronutrient levels in ARI viral infections, especially newly identified viruses such as human metapneumovirus (HMPV). AIM: To describe zinc, copper, selenium and vitamins A and E concentrations in children with respiratory syncytial virus (RSV) and/or HMPV in relation to levels of C-reactive protein (CRP). METHODS: The presence of RSV/HMPV in nasopharyngeal aspirates (NPA) was identified in 246 children using RTPCR. Zinc, copper, selenium and vitamins A and E concentrations were measured using inductive coupled plasma mass spectrometry and high performance liquid chromatography. RESULTS: 183 children had RSV, 39 had HMPV and 24 were co-infected. Zinc concentrations were lower in children with HMPV than in children with RSV or RSV/HMPV co-infection. Copper concentrations were lower in children with RSV than in children with RSV/HMPV or HMPV and zinc/copper ratios were lower in children with HMPV/RSV or RSV than in children with HMPV alone. Retinol and a alpha-tocopherol were lower in children with RSV than in children with HMPV. Most children had low selenium concentrations. Children with RSV and raised CRP (>5 mg/L) had higher copper and lower zinc/copper ratios than those with low CRP (< or =5 mg/L). Children with HMPV and raised CRP had higher copper and lower zinc concentrations than children with low CRP. Children with RSV/HMPV and raised CRP had higher copper concentrations. Children with RSV/HMPV and raised CRP had higher a alpha-tocopherol concentrations. CONCLUSION: The profiles of micronutrients differ in children with RSV and HMPV and are confounded by CRP. These results may guide strategies for micronutrient supplementation in ARI.

Natural hybridisation among Quercus glabrescens, Q. rugosa and Q. obtusata (Fagaceae): Microsatellites and secondary metabolites markers.

Natural hybridisation has significant ecological, genetic and evolutionary consequences altering morphological and chemical characters of individuals. Quercus glabrescens, Q. rugosa and Q. obtusata are white oak species well separated by their morphological characters when they occur in allopatry in Mexican temperate forests. However, in sympatry, individuals with atypical morphology have been observed, suggesting hybridisation events. In this study, we determined, with microsatellites and secondary metabolites, if interspecific gene flow occurs when these three oak species coexist in sympatry. In total, 180 individuals belonging to seven populations [three allopatric (one for each parental species) and four sympatric sites] were analysed. Allopatric populations represent well-defined genetic groups and the sympatric populations showed genetic evidence of hybridisation between Q. glabrescens × Q. rugosa and Q. glabrescens × Q. obtusata. The hybridisation percentage varied between sites and combination of involved species. We registered the presence of unique flavonoid compounds for Q. glabrescens (caffeic acid and flavonol 2), Q. rugosa (flavonol 5) and Q. obtusata (flavonol 1). Three compounds (quercetin rhamnoside, flavonol 3 and alkyl coumarate) were expressed in all taxa. Finally, the hybrid genotypes identified in this study (Q. glabrescens × Q. rugosa and Q. glabrescens × Q. obtusata) showed specific chemical profiles, resulting from a combination of those of their parental species. These results show that hybridisation events between these oak species alter chemical expression of secondary metabolites, creating a mosaic of resources and conditions that provide the substrate for different combinations of foliar-associated species such as herbivores, endophytic fungi or epiphyte plants.

Acute phase proteins and IP-10 as triage tests for the diagnosis of tuberculosis: systematic review and meta-analysis.

OBJECTIVES: We examined the data reported in studies for diagnostic purposes and to discuss whether their intended use could be extended to triage, as rule-in or rule-out tests to select individuals who should undergo further confirmatory tests. METHODS: We searched Scopus, PubMed and Web of Science with the terms 'acute phase proteins,' 'IP-10,' 'tuberculosis,' 'screening' and 'diagnosis,' extracted the sensitivity and specificity of the biomarkers and explored methodologic differences to explain performance variations. Summary estimates were calculated using random-effects models for overall pooled accuracy. The hierarchical summary receiver operating characteristic model was used for meta-analysis. RESULTS: We identified 14, four and one studies for C-reactive protein (CRP), interferon γ-induced protein 10 (IP-10) and alpha-1-acid glycoprotein (AGP). The pooled CRP sensitivity/specificity (95% confidence interval) was 89% (80-96) and 57% (36-65). Sensitivity/specificity were higher in high-tuberculosis-burden countries (90%/64%), HIV-infected individuals (91%/61%) and community-based studies (90%/62%). IP-10 sensitivity/specificity in TB vs. non-TB studies was 85%/63% and in TB and HIV coinfected vs. other lung conditions 94%/21%. However, IP-10 studies included diverse populations and a high risk of bias, resulting in very low-quality evidence. AGP had 86%/93% sensitivity/specificity. CONCLUSIONS: Few studies have evaluated CRP, IP-10 and AGP for the triage of symptomatic patients. Their high sensitivity and moderate specificity warrant further prospective studies exploring whether their combined use could optimize performance.

In vitro evaluation of germination and growth of five plant species on medium supplemented with hydrocarbons associated with contaminated soils.

The effect of a hydrocarbon mixture (HCM) of three polycyclic aromatic hydrocarbons (PAH) and Maya crude oil on germination, growth and survival of four grasses (Bouteloua curtipendula, Cenchrus ciliaris, Echinochloa crusgalli and Rhynchelytrum repens) was studied and compared to a control (Festuca arundinacea) under in vitro conditions. The species were cultured on MS medium with different HCM initial concentrations. Germination was not affected for any assayed concentration; however, the length of the stems and roots decreased when HCM increased and the survival of the four species also diminished. Except for F. arundinacea, a direct link between hydrocarbon concentration and plant survival was observed. In vitro studies are clean and easy to handle techniques allowing isolation of the plant activity from that derived from associations with microorganisms in non-sterile cultures. To our knowledge, this is the first work towards phytoremediation assisted by in vitro plant cultivation.

Point of care diagnostics for tuberculosis.

The goals of the End TB strategy, which aims to achieve a 90% reduction in tuberculosis (TB) incidence and a 95% reduction in TB mortality by 2035, will not be achieved without new tools to fight TB. These include improved point of care (POC) diagnostic tests that are meant to be delivered at the most decentralised levels of care where the patients make the initial contact with the health system, as well as within the community. These tests should be able to be performed on an easily accessible sample and provide results in a timely manner, allowing a quick treatment turnaround time of a few minutes or hours (in a single clinical encounter), hence avoiding patient loss-to-follow-up. There have been exciting developments in recent years, including the WHO endorsement of Xpert MTB/RIF, Xpert MTB/RIF Ultra, loop-mediated isothermal amplification (TB-LAMP) and lateral flow lipoarabinomannan (LAM). However, these tests have limitations that must be overcome before they can be optimally applied at the POC. Furthermore, worrying short- to medium-term gaps exist in the POC diagnostic test development pipeline. Thus, not only is better implementation of existing tools and algorithms needed, but new research is required to develop new POC tests that allow the TB community to truly make an impact and find the "missed TB cases".

Short-term bleach digestion of sputum in the diagnosis of pulmonary tuberculosis in patients co-infected with HIV.

The bleach digestion of sputum may improve the yield of smear microscopy but has not been validated in patients with HIV. Therefore we assessed the performance of bleach-digested smear microscopy among patients with HIV. One thousand three hundred and twenty one patients with chronic cough submitted three sputum samples for direct smear microscopy and were offered HIV tests. One sample was selected for a bleach-digested smear and another one was cultured. Patients were classified as having 'definite' (>or=2 positive smears), 'very likely' (smear-negative, culture- positive), 'less likely' (one smear-positive, culture-negative) and 'unlikely' (smear and culture negative) tuberculosis (TB). In all, 566/1045 (54%) patients were HIV positive and 731/1186 (62%) were culture positive. The digested smears were positive in 123/125 (98%) 'definite', 4/118 (3%) 'very likely' and 1/174 'unlikely' TB patients with HIV and in 125/127 (98%) 'definite', 2/74 (3%) 'very likely', 4/4 'less likely' and 2/127 'unlikely' TB without HIV. Three direct smears identified 252 (57%) and one digested smear 254 (57%) of the 444 patients with 'definite' or 'very likely' TB. One bleach-digested smear performed similarly to three direct smears. Both methods were less sensitive in HIV-positive patients. Further studies are needed to compare the performance of the two methods under operational conditions.

Same-day smears in the diagnosis of tuberculosis.

OBJECTIVE: To assess the feasibility of completing the diagnosis of tuberculosis (TB) in 1 day by collecting only on-the-spot specimens. METHODS: Individuals with suspected TB attending district hospitals in Abuja submitted three sputum samples for routine diagnosis (the standard approach). One additional sample was collected 1 h after the first sputum (the same-day approach). One sputum sample was cultured. Blood samples were tested for HIV. RESULTS: Two hundred and twenty-four patients with chronic cough had 135/672 (20%) positive on-the-spot smears and 47/224 (21%) positive morning smears. The same-day and internationally recommended approaches identified 44 and 45 of the 78 patients with positive cultures, respectively. 106/194 (55%) patients were HIV positive. Only 9-11% of their smears were positive compared with 30-32% for HIV negatives (P < 0.01). CONCLUSION: It could be possible to diagnose TB in a single day by examining two spot specimens, but the feasibility needs to be confirmed on a larger scale.

Investing time in microscopy: an opportunity to optimise smear-based case detection of tuberculosis.

SETTING: St. Elizabeth Hospital, rural North-west Cameroon, an area with high tuberculosis (TB) and human immunodeficiency virus (HIV) incidence. OBJECTIVE: To measure the time spent during routine sputum smear microscopy and assess whether reexamining slides for 10 min translates into higher case detection of smear-positive cases. DESIGN: A prospective observational study over a 6-month period with three components: 1) timing of routine sputum smear examination; 2) blinded reexamination of all slides for 10 min and results compared with initial readings; and 3) blinded re-examination, by the original microscopists, of a portion of false-negative slides mixed with true negatives for 10 min. RESULTS: A total of 204 patients submitted 612 sputum specimens for screening. The median routine examination time was 2 min 6 seconds (interquartile range 1:30-2:30). A 10 min examination significantly increased the number of positive smears from 82 to 116 (P = 0.0083), and overall case detection from 28 to 48 patients (P = 0.011). On review by the original readers, more than half of the false-negative slides were reported as positive after 10 min. CONCLUSION: Sputum smear microscopy has low sensitivity if performed too quickly, and 10 min re-examination significantly increases case detection. Ensuring that smears are examined for the recommended duration may be a simple and low-cost way to improve case detection.