Control de la enfermedad de Chagas en bancos de sangre de Colombia

The screening programs for the Chagas disease agent, Trypanosoma cruzi, were examined in Colombian blood banks and, as a consequence, several procedural improvements in the blood bank network were recommended. Screening strategies and techniques were examined, as well as the action taken when seropositive donors were discovered. From a total of 180 blood banks in 33 departments, 103 banks in 20 departments answered the survey. The 103 banks collected 291,105 units of blood, corresponding to 66.6% of all units collected in the country in 1997. Of these blood units, 99.6% were screened for Chagas trypanosomes; 3,321 (1.2%) of 287,048 were found positive for anti-T. cruzi. The data were grouped by department; geographical differences for seroprevalence rates varied markedly between 0% and 12.6%. The most commonly used serological technique was ELISA, but only 33.2% of the positive samples for anti-T. cruzi underwent further confirmatory testing, mainly through indirect immunofluorescent test. Most (95.1%) of the blood banks used basic, internal quality control procedures, and 73.8% sent positive samples to other laboratories for external quality control.Los objetivos del estudio fueron el análisis de la cobertura del programa de tamizaje para Trypanosoma cruzi en bancos de sangre de Colombia, sus estrategias en cuanto a las técnicas utilizadas, las acciones con los donantes positivos y dar algunas recomendaciones para mejorar esta red. De los 180 bancos de sangre de 33 departamentos del país, respondieron la encuesta 103, pertenecientes a 20 departamentos, que recolectaron 291.105 unidades de sangre, lo cual corresponde al 66,6% del total captado en el país en 1997. Los 103 bancos tuvieron un cumplimiento del tamizaje del 99,6%. Se informaron como positivas para anticuerpos anti- Trypanosoma cruzi 3.321 unidades de sangre de las 287.048 estudiadas, lo cual corresponde al 1,16%. Los datos se discriminaron para cada uno de los departamentos que contestaron la encuesta, observándose marcadas diferencias geográficas entre las tasas de seroprevalencia, las cuales variaban entre el 0% y el 12,6%. La técnica serológica más utilizada para el tamizaje fue la prueba de ELISA, pero solamente 33,2% de las muestras positivas para anticuerpos se sometieron a una prueba confirmatoria, la gran mayoría a la de inmunofluorescencia indirecta. El 95,1% de los bancos respondieron que utilizaban controles de calidad internos básicos de las pruebas y el 73,8% remitían pruebas positivas a otro laboratorio para control de calidad externo

Comparing the Usefulness of the 1997 and 2009 WHO Dengue Case Classification: A Systematic Literature Review

The 1997 and 2009 WHO dengue case classifications were compared in a systematic review with 12 eligible studies (4 prospective). Ten expert opinion articles were used for discussion. For the 2009 WHO classification studies show: when determining severe dengue sensitivity ranges between 59–98% (88%/98%: prospective studies), specificity between 41–99% (99%: prospective study) - comparing the 1997 WHO classification: sensitivity 24.8–89.9% (24.8%/74%: prospective studies), specificity: 25%/100% (100%: prospective study). The application of the 2009 WHO classification is easy, however for (non-severe) dengue there may be a risk of monitoring increased case numbers. Warning signs validation studies are needed. For epidemiological/pathogenesis research use of the 2009 WHO classification, opinion papers show that ease of application, increased sensitivity (severe dengue) and international comparability are advantageous; 3 severe dengue criteria (severe plasma leakage, severe bleeding, severe organ manifestation) are useful research endpoints. The 2009 WHO classification has clear advantages for clinical use, use in epidemiology is promising and research use may at least not be a disadvantage

Feasibility of a combined camp approach for vector control together with active case detection of visceral leishmaniasis, post kala-azar dermal leishmaniasis, tuberculosis, leprosy and malaria in Bangladesh, India and Nepal: an exploratory study

Background We assessed the feasibility and results of active case detection (ACD) of visceral leishmaniasis (VL), post kala-azar dermal leishmaniasis (PKDL) and other febrile diseases as well as of bednet impregnation for vector control. Methods Fever camps were organized and analyzed in twelve VL endemic villages in Bangladesh, India, and Nepal. VL, PKDL, tuberculosis, malaria and leprosy were screened among the febrile patients attending the camps, and existing bednets were impregnated with a slow release insecticide. Results Among the camp attendees one new VL case and two PKDL cases were detected in Bangladesh and one VL case in Nepal. Among suspected tuberculosis cases two were positive in India but none in the other countries. In India, two leprosy cases were found. No malaria cases were detected. Bednet impregnation coverage during fever camps was more than 80% in the three countries. Bednet impregnation led to a reduction of sandfly densities after 2 weeks by 86% and 32%, and after 4 weeks by 95% and 12% in India and Nepal respectively. The additional costs for the control programmes seem to be reasonable. Conclusion It is feasible to combine ACD camps for VL and PKDL along with other febrile diseases, and vector control with bednet impregnatio

Visceral Leishmaniasis Clinical Management in Endemic Districts of India, Nepal, and Bangladesh

Background. National VL Elimination Programs in India, Nepal and Bangladesh face challenges as home-based Miltefosine treatment is introduced. Objectives. To study constraints of VL management in endemic districts within context of national elimination programs before and after intervention. Methods. Ninety-two and 41 newly diagnosed VL patients were interviewed for clinical and provider experience in 2009 before and in 2010 after intervention (district training and improved supply of diagnostics and drugs). Providers were assessed for adherence to treatment guidelines. Facilities and doctor-patient consultations were observed to assess quality of care. Results. Miltefosine use increased from 33% to 59% except in Nepal where amphotericin was better available. Incorrect dosage and treatment interruptions were rare. Advice on potential side effects was uncommon but improved significantly in 2010. Physicians did not rule out pregnancy prior to starting Miltefosine. Fever measurement or spleen palpation was infrequently done in Bangladesh but improved after intervention (from 23% to 47%). Physician awareness of renal or liver toxicity as Miltefosine side effects was lower in Bangladesh. Bio-chemical monitoring was uncommon. Patient satisfaction with services remained low for ease of access or time provider spent with patient. Health facilities were better stocked with rK39 kits and Miltefosine in 2010

Use and acceptance of long lasting insecticidal net screens for dengue prevention in Acapulco, Guerrero, Mexico

Background Dengue, recognized by the WHO as the most important mosquito-borne viral disease in the world, is a growing problem. Currently, the only effective way of preventing dengue is vector control. Standard methods have shown limited effect, and there have been calls to develop new integrated vector management approaches. One novel tool, protecting houses with long lasting insecticidal screens on doors and windows, is being trialled in a cluster randomised controlled trial by a joint UADY/WHO TDR/IDRC study in various districts of Acapulco, Mexico, with exceptionally high levels of crime and insecurity. This study investigated the community’s perspectives of long lasting insecticidal screens on doors and windows in homes and in schools, in order to ascertain their acceptability, to identify challenges to further implementation and opportunities for future improvements. Methods This was a sequential mixed-methods study. The quantitative arm contained a satisfaction survey administered to 288 houses that had received the intervention examining their perspectives of both the intervention and dengue prevention in general. The qualitative arm consisted of Focus Group Discussions (FGDs) with those who had accepted the intervention and key informant interviews with: schoolteachers to discuss the use of the screens in schools, program staff, and community members who had refused the intervention. Results Overall satisfaction and acceptance of the screens was very high, with only some operational and technical complaints relating to screen fragility and the installation process. However, the wider social context of urban violence and insecurity was a major barrier to screen acceptance. Lack of information dissemination and community collaboration were identified as project weaknesses. Conclusions The screens are widely accepted by the population, but the project implementation could be improved by reassuring the community of its legitimacy in the context of insecurity. More community engagement and better information sharing structures are needed. The screens could be a major new dengue prevention tool suitable for widespread use, if further research supports their entomological and epidemiological effectiveness and their acceptability in different social and environmental contexts. Further research is needed looking at the impact of insecurity of dengue prevention programmes

House screening with insecticide-treated netting provides sustained reductions in domestic populations of Aedes aegypti in Merida, Mexico.

There is a need for effective methods to control Aedes aegypti and prevent the transmission of dengue, chikungunya, yellow fever and Zika viruses. Insecticide treated screening (ITS) is a promising approach, particularly as it targets adult mosquitoes to reduce human-mosquito contact. A cluster-randomised controlled trial evaluated the entomological efficacy of ITS based intervention, which consisted of the installation of pyrethroid-impregnated long-lasting insecticide-treated netting material fixed as framed screens on external doors and windows. A total of 10 treatment and 10 control clusters (100 houses/cluster) were distributed throughout the city of Merida, Mexico. Cross-sectional entomological surveys quantified indoor adult mosquito infestation at baseline (pre-intervention) and throughout four post-intervention (PI) surveys spaced at 6-month intervals corresponding to dry/rainy seasons over two years (2012-2014). A total of 844 households from intervention clusters (86% coverage) were protected with ITS at the start of the trial. Significant reductions in the indoor presence and abundance of Ae. aegypti adults (OR = 0.48 and IRR = 0.45, P<0.05 respectively) and the indoor presence and abundance of Ae. aegypti female mosquitoes (OR = 0.47 and IRR = 0.44, P<0.05 respectively) were detected in intervention clusters compared to controls. This high level of protective effect was sustained for up to 24 months PI. Insecticidal activity of the ITS material declined with time, with ~70% mortality being demonstrated in susceptible mosquito cohorts up to 24 months after installation. The strong and sustained entomological impact observed in this study demonstrates the potential of house screening as a feasible, alternative approach to a sustained long-term impact on household infestations of Ae. aegypti. Larger trials quantifying the effectiveness of ITS on epidemiological endpoints are warranted and therefore recommended

The VENUSS prognostic model to predict disease recurrence following surgery for non-metastatic papillary renal cell carcinoma: development and evaluation using the ASSURE prospective clinical trial cohort

Abstract: Background: The current World Health Organization classification recognises 12 major subtypes of renal cell carcinoma (RCC). Although these subtypes differ on molecular and clinical levels, they are generally managed as the same disease, simply because they occur in the same organ. Specifically, there is a paucity of tools to risk-stratify patients with papillary RCC (PRCC). The purpose of this study was to develop and evaluate a tool to risk-stratify patients with clinically non-metastatic PRCC following curative surgery. Methods: We studied clinicopathological variables and outcomes of 556 patients, who underwent full resection of sporadic, unilateral, non-metastatic (T1–4, N0–1, M0) PRCC at five institutions. Based on multivariable Fine-Gray competing risks regression models, we developed a prognostic scoring system to predict disease recurrence. This was further evaluated in the 150 PRCC patients recruited to the ASSURE trial. We compared the discrimination, calibration and decision-curve clinical net benefit against the Tumour, Node, Metastasis (TNM) stage group, University of California Integrated Staging System (UISS) and the 2018 Leibovich prognostic groups. Results: We developed the VENUSS score from significant variables on multivariable analysis, which were the presence of VEnous tumour thrombus, NUclear grade, Size, T and N Stage. We created three risk groups based on the VENUSS score, with a 5-year cumulative incidence of recurrence equalling 2.9% in low-risk, 15.4% in intermediate-risk and 54.5% in high-risk patients. 91.7% of low-risk patients had oligometastatic recurrent disease, compared to 16.7% of intermediate-risk and 40.0% of high-risk patients. Discrimination, calibration and clinical net benefit from VENUSS appeared to be superior to UISS, TNM and Leibovich prognostic groups. Conclusions: We developed and tested a prognostic model for patients with clinically non-metastatic PRCC, which is based on routine pathological variables. This model may be superior to standard models and could be used for tailoring postoperative surveillance and defining inclusion for prospective adjuvant clinical trials

Improved tools and strategies for the prevention and control of arboviral diseases: A research-to-policy forum

Background Research has been conducted on interventions to control dengue transmission and respond to outbreaks. A summary of the available evidence will help inform disease control policy decisions and research directions, both for dengue and, more broadly, for all Aedes-borne arboviral diseases. Method A research-to-policy forum was convened by TDR, the Special Programme for Research and Training in Tropical Diseases, with researchers and representatives from ministries of health, in order to review research findings and discuss their implications for policy and research. Results The participants reviewed findings of research supported by TDR and others. Surveillance and early outbreak warning. Systematic reviews and country studies identify the critical characteristics that an alert system should have to document trends reliably and trigger timely responses (i.e., early enough to prevent the epidemic spread of the virus) to dengue outbreaks. A range of variables that, according to the literature, either indicate risk of forthcoming dengue transmission or predict dengue outbreaks were tested and some of them could be successfully applied in an Early Warning and Response System (EWARS). Entomological surveillance and vector management. A summary of the published literature shows that controlling Aedes vectors requires complex interventions and points to the need for more rigorous, standardised study designs, with disease reduction as the primary outcome to be measured. House screening and targeted vector interventions are promising vector management approaches. Sampling vector populations, both for surveillance purposes and evaluation of control activities, is usually conducted in an unsystematic way, limiting the potentials of entomological surveillance for outbreak prediction. Combining outbreak alert and improved approaches of vector management will help to overcome the present uncertainties about major risk groups or areas where outbreak response should be initiated and where resources for vector management should be allocated during the interepidemic period. Conclusions The Forum concluded that the evidence collected can inform policy decisions, but also that important research gaps have yet to be filled