scholarly journals Insights from quantitative and mathematical modelling on the proposed WHO 2030 goals for Chagas disease

2019 ◽  
Vol 3 ◽  
pp. 1539
Author(s):  

Chagas disease (CD) persists as one of the neglected tropical diseases (NTDs) with a particularly large impact in the Americas. The World Health Organization (WHO) recently proposed goals for CD elimination as a public health problem to be reached by 2030 by means of achieving intradomiciliary transmission interruption (IDTI), blood transfusion and transplant transmission interruption, diagnostic and treatment scaling-up and prevention and control of congenital transmission. The NTD Modelling Consortium has developed mathematical models to study Trypanosoma cruzi transmission dynamics and the potential impact of control measures. Modelling insights have shown that IDTI is feasible in areas with sustained vector control programmes and no presence of native triatomine vector populations. However, IDTI in areas with native vectors it is not feasible in a sustainable manner. Combining vector control with trypanocidal treatment can reduce the timeframes necessary to reach operational thresholds for IDTI (<2% seroprevalence in children aged <5 years), but the most informative age groups for serological monitoring are yet to be identified. Measuring progress towards the 2030 goals will require availability of vector surveillance and seroprevalence data at a fine scale, and a more active surveillance system, as well as a better understanding of the risks of vector re-colonization and disease resurgence after vector control cessation. Also, achieving scaling-up in terms of access to treatment to the expected levels (75%) will require a substantial increase in screening asymptomatic populations, which is anticipated to become very costly as CD prevalence decreases. Further modelling work includes refining and extending mathematical models (including transmission dynamics and statistical frameworks) to predict transmission at a sub-national scale, and developing quantitative tools to inform IDTI certification, post-certification and re-certification protocols. Potential perverse incentives associated with operational thresholds are discussed. These modelling insights aim to inform discussions on the goals and treatment guidelines for CD.

2019 ◽  
Author(s):  
M. Soledad Castaño ◽  
Martial L. Ndeffo-Mbah ◽  
Kat S. Rock ◽  
Cody Palmer ◽  
Edward Knock ◽  
...  

AbstractSince the turn of the century, the global community has made great progress towards the elimination of gambiense human African trypanosomiasis (HAT). Elimination programs, primarily relying on screening and treatment campaigns, have also created a rich database of HAT epidemiology. Mathematical models calibrated with these data can help to fill remaining gaps in our understanding of HAT transmission dynamics, including key operational research questions such as whether integrating vector control with current intervention strategies is needed to achieve HAT elimination. Here we explore, via an ensemble of models and simulation studies, which aspects of the available data and level of data aggregation, such as separation by disease stage, would be most useful for better understanding transmission dynamics and improving model reliability in making future predictions of control and elimination strategies.Author summaryHuman African tryposonomiasis (HAT), also known as sleeping sickness, is a parasitic disease with over 65 million people estimated to be living at risk of infection. Sleeping sickness consists of two stages: the first one is relatively mild but the second stage is usually fatal if untreated. The World Health Organization has targeted HAT for elimination as a public health problem by 2020 and for elimination of transmission by 2030. Regular monitoring updates indicate that 2020 elimination goals are likely to be achieved. This monitoring relies mainly on case report data that is collected through medical-based control activities — the main strategy employed so far in HAT control. This epidemiological data are also used to calibrate mathematical models that can be used to analyse current interventions and provide projections of potential intensified strategies.We investigated the role of the type and level of aggregation of this HAT case data on model calibrations and projections. We highlight that the lack of detailed epidemiological information, such as missing stage of disease or truncated time series data, impacts model recommendations for strategy choice: it can misrepresent the underlying HAT epidemiology (for example, the ratio of stage 1 to stage 2 cases) and increase uncertainty in predictions. Consistently including new data from control activities as well as enriching it through cross-sectional (e.g. demographic or behavioural data) and geo-located data is likely to improve modelling accuracy to support planning, monitoring and adapting HAT interventions.


Author(s):  
Rajesh Garlapati ◽  
Eva Iniguez ◽  
Tiago D. Serafim ◽  
Prabhas K. Mishra ◽  
Basab Rooj ◽  
...  

Visceral leishmaniasis (VL) is a potentially deadly parasitic disease. In the Indian sub-continent, VL is caused by Leishmania donovani and transmitted via the bite of an infected Phlebotomus argentipes female sand fly, the only competent vector species in the region. The highest disease burden is in the northern part of the Indian sub-continent, especially in the state of Bihar. India, Bangladesh, and Nepal embarked on an initiative, coordinated by World Health Organization, to eliminate VL as a public health problem by the year 2020. The main goal is to reduce VL incidence below one case per 10,000 people through early case-detection, prompt diagnosis and treatment, and reduction of transmission using vector control measures. Indoor residual spraying, a major pillar of the elimination program, is the only vector control strategy used by the government of India. Though India is close to its VL elimination target, important aspects of vector bionomics and sand fly transmission dynamics are yet to be determined. To achieve sustained elimination and to prevent a resurgence of VL, knowledge gaps in vector biology and behavior, and the constraints they may pose to current vector control methods, need to be addressed. Herein, we discuss the successes and failures of previous and current vector-control strategies implemented to combat kala-azar in Bihar, India, and identify gaps in our understanding of vector transmission towards development of innovative tools to ensure sustained vector control in the post-elimination period.


2021 ◽  
Vol 8 (02) ◽  
pp. 48-52
Author(s):  
Chintha Sujatha ◽  
Reshma Rajan Sudha ◽  
Sreejith Lalitha Krishnankutty ◽  
Prajitha Kannamkottapilly Chandrasekharan

BACKGROUND Dengue fever is a major public health problem in Kerala. Vector control measures practiced at household level is the most cost-effective way of controlling dengue. This study aims to assess environmental measures of vector control practised among households of suspected or confirmed dengue patients in Thiruvananthapuram district of Kerala. METHODS A cross sectional study was done among households of patients diagnosed with dengue fever and reported in Integrated Disease Surveillance Programme (IDSP) in Thiruvananthapuram district from June to December 2018. Investigators interviewed the household members and made direct observations to collect data on vector control practices using a structured questionnaire. RESULTS A total of 108 houses were surveyed. Potential breeding habitats were found in 58 (53.7 %) houses. Aedes larva was found in containers from four (3.7 %) houses. Dry day observance was not regular with only 5 (4.6 %) houses practicing it weekly. Waste management practiced was proper in 47 (43.5 %) houses. Community level pre monsoon preparedness for epidemics was done in the vicinity of 53 (49.1 %) houses and it was found to be a protective factor against presence of breeding habitats in and around houses (p = 0.013). Low education (p = 0.012) and low occupational status (p = 0.017) were found to be significant risk factors. CONCLUSIONS Even during an epidemic, with occurrence of infections in the family, only half of the households are practising adequate vector control methods. Community level interventions and targeted information education campaign will help improve practice of environmental methods of vector control in dengue. KEYWORDS Dengue, Vector Control, Aedes Control, Environmental Methods, Community Interventions


2016 ◽  
Vol 18 (1) ◽  
pp. 190 ◽  
Author(s):  
Diana Paola López Velandia ◽  
María Inés Torres Caycedo ◽  
Carlos Fernando Prada Quiroga

ResumenIntroducción: La resistencia antimicrobiana es un grave problema de salud pública que se encuentra en aumento. Entre los factores más importantes relacionados con la diseminación de bacterias multirresistentes está el uso inapropiado de antibióticos y la aplicación insuficiente de las medidas de prevención y control. Adicionalmente, las bacterias tienen la capacidad de mutar o generar mecanismos de transferencia de genes de resistencia mediante plásmidos, transposones e integrones. Materiales y métodos: Se hizo una revisión crítica de la literatura sobre los principales genes de resistencia Gram negativos y su impacto en la salud pública. Fueron utilizadas las bases de datos de Medline, Embase, Lilacs, ScienceDirect, Scopus, SciELO, the Cochrane Library y Lilacs. Resultados: Se presenta una revisión de literatura que describe y analiza los principales genes de resistencia a antibióticos presentes en bacilos gram negativos, su origen, evolución y diseminación a microorganismos mediante la transferencia horizontal de genes; justificando la importancia de realizar una vigilancia epidemiológica del tránsito de clones con diferentes perfiles de resistencia y principales enzimas. Conclusiones: El seguimiento de la resistencia antimicrobiana desde el punto de vista de la epidemiología molecular forma parte transcendental de la vigilancia antibiótica como lo recomienda la Organización Mundial de la Salud; pues representa el futuro del monitoreo de la resistencia.AbstractIntroduction: Antimicrobial resistance is a serious public health problem that is increasing. Among the most important factors related to the spread of multi-resistant bacteria are the inappropriate use of antibiotics and the insufficient  implementation of prevention and control measures. Additionally, bacteria have the ability to mutate or create mechanisms for transfer of resistance genes via plasmids, transposons and integrons. Materials and methods: A critical review of the literature on major resistance genes in Gram negative bacteria and its impact on public health was conducted. Data have been collected from Medline, Embase, Lilacs, ScienceDirect, Scopus, SciELO, the Cochrane Library and Lilacs. Results: A review of literature that describes and analyzes the main antibiotic resistance genes present in gram-negative bacilli is presented, as well as their origin, evolution, and subsequent spread to hundreds of species of microorganisms by Horizontal gene transfer which justifies the importance of conducting an epidemiological surveillance on transit of clones with different resistance profiles and major enzymes. Conclusions: The control of antimicrobial resistance from the point of view of molecular epidemiology is part of the antibiotic surveillance control as recommended by the World Health Organization; as it represents the future of the surveillance of resistance.


2020 ◽  
Vol 13 (Supplement_1) ◽  
pp. S22-S27
Author(s):  
Kebede Deribe ◽  
Didier K Bakajika ◽  
Honorat Marie-Gustave Zoure ◽  
John O Gyapong ◽  
David H Molyneux ◽  
...  

Abstract To eliminate lymphatic filariasis (LF) by 2020, the World Health Organization (WHO) has launched a campaign against the disease. Since the launch in 2000, significant progress has been made to achieve this ambitious goal. In this article we review the progress and status of the LF programme in Africa through the WHO neglected tropical diseases preventive chemotherapy databank, the Expanded Special Project for Elimination of Neglected Tropical Diseases (ESPEN) portal and other publications. In the African Region there are 35 countries endemic for LF. The Gambia was reclassified as not requiring preventive chemotherapy in 2015, while Togo and Malawi eliminated LF as a public health problem in 2017 and 2020, respectively. Cameroon discontinued mass drug administration (MDA) and transitioned to post-MDA surveillance to validate elimination. The trajectory of coverage continues to accelerate; treatment coverage increased from 0.1% in 2000 to 62.1% in 2018. Geographical coverage has also significantly increased, from 62.7% in 2015 to 78.5% in 2018. In 2019, 23 of 31 countries requiring MDA achieved 100% geographic coverage. Although much remains to be done, morbidity management and disability prevention services have steadily increased in recent years. Vector control interventions conducted by other programmes, particularly malaria vector control, have had a profound effect in stopping transmission in some endemic countries in the region. In conclusion, significant progress has been made in the LF programme in the region while we identify the key remaining challenges in achieving an Africa free of LF.


Author(s):  
Mohsen Ahmed Abdelmohsen ◽  
Buthaina M. Alkandari ◽  
Vikash K. Gupta ◽  
Nermeen Elsebaie

Abstract Background Corona virus disease 2019 (COVID-19) pandemic—as declared by the World Health Organization—is a major threatening public health problem. At the time of writing, more than 60,000,000 patients and more than 1,500,000 deaths were recorded worldwide. Besides the classical chest symptoms, gastrointestinal tract-related symptoms were noted, like diarrhea, abdominal distention, and hematochezia, adding more difficulties in the diagnosis of the disease. Although there are many publications evaluated, the thoracic imaging signs and complications of COVID-19, there are few articles—to the best of our knowledge—that evaluated the gastrointestinal tract imaging features and complications related to COVID-19. Results In this retrospective study, positive COVID-19 patients who underwent diagnostic computed tomography (CT) for abdominal complaints along a 3-month duration in a large isolation hospital were evaluated. Strict infection control measures were taken during the CT examinations. The data were reviewed on picture archiving and communications systems with clinical data and laboratory result correlation. Thirty patients (30%) showed gastrointestinal (GI) findings, and 70 patients showed unremarkable or non-related GI findings. The 30 patients were classified into four groups: the ischemic group including 10 patients (10/30: 33.33%), the bleeding group included six patients (6/30: 20%), the inflammatory group included nine patients (9/30: 30%), and fluid-filled bowel group included five patients (5/30: 16.6%). Conclusions COVID-19 should be evaluated as a systemic disease with extra pulmonary highlights. GI imaging should be considered for COVID-19 patients with related suspicious symptoms. Ischemic GI complications were the most common GI findings.


2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Arthur Mpimbaza ◽  
Asadu Sserwanga ◽  
Damian Rutazaana ◽  
James Kapisi ◽  
Richard Walemwa ◽  
...  

Abstract Background The World Health Organization (WHO) promotes long-lasting insecticidal nets (LLIN) and indoor residual house-spraying (IRS) for malaria control in endemic countries. However, long-term impact data of vector control interventions is rarely measured empirically. Methods Surveillance data was collected from paediatric admissions at Tororo district hospital for the period January 2012 to December 2019, during which LLIN and IRS campaigns were implemented in the district. Malaria test positivity rate (TPR) among febrile admissions aged 1 month to 14 years was aggregated at baseline and three intervention periods (first LLIN campaign; Bendiocarb IRS; and Actellic IRS + second LLIN campaign) and compared using before-and-after analysis. Interrupted time-series analysis (ITSA) was used to determine the effect of IRS (Bendiocarb + Actellic) with the second LLIN campaign on monthly TPR compared to the combined baseline and first LLIN campaign periods controlling for age, rainfall, type of malaria test performed. The mean and median ages were examined between intervention intervals and as trend since January 2012. Results Among 28,049 febrile admissions between January 2012 and December 2019, TPR decreased from 60% at baseline (January 2012–October 2013) to 31% during the final period of Actellic IRS and LLIN (June 2016–December 2019). Comparing intervention intervals to the baseline TPR (60.3%), TPR was higher during the first LLIN period (67.3%, difference 7.0%; 95% CI 5.2%, 8.8%, p < 0.001), and lower during the Bendiocarb IRS (43.5%, difference − 16.8%; 95% CI − 18.7%, − 14.9%) and Actellic IRS (31.3%, difference − 29.0%; 95% CI − 30.3%, − 27.6%, p < 0.001) periods. ITSA confirmed a significant decrease in the level and trend of TPR during the IRS (Bendicarb + Actellic) with the second LLIN period compared to the pre-IRS (baseline + first LLIN) period. The age of children with positive test results significantly increased with time from a mean of 24 months at baseline to 39 months during the final IRS and LLIN period. Conclusion IRS can have a dramatic impact on hospital paediatric admissions harbouring malaria infection. The sustained expansion of effective vector control leads to an increase in the age of malaria positive febrile paediatric admissions. However, despite large reductions, malaria test-positive admissions continued to be concentrated in children aged under five years. Despite high coverage of IRS and LLIN, these vector control measures failed to interrupt transmission in Tororo district. Using simple, cost-effective hospital surveillance, it is possible to monitor the public health impacts of IRS in combination with LLIN.


Author(s):  
Sherin Ann Thomas ◽  
Asish R ◽  
Vinimol C ◽  
Bindu V Bhaskar ◽  
Jesmith Elsa Jacob

Corona virus disease officially called as COVID-19, declared a “pandemic” by the World Health Organization; became a major public health problem causing worldwide morbidity and mortality, despite various control measures. Extraordinary measures are taken universally to fight the spread of the ongoing outbreak. In such a scenario, people’s adherence to preventive measures is largely influenced by their knowledge and perception of the disease. Since dental care professionals are having high chances of infectivity, which in turn has serious implications, it is essential that the auxiliary dental staff must be educated, empowered and provided appropriate and relevant knowledge of the disease.To assess the level of awareness regarding COVID-19 among auxiliary dental staff in a Tertiary Dental Care Centre in Kerala. A cross sectional survey was conducted among all the auxillary staff in a tertiary dental care centre by an online questionnaire through google forms. Details regarding demographic data, knowledge about the spread, symptoms, diagnosis, prevention and safety practices related to COVID-19 were obtained after getting an online informed consent. Descriptive statistics and Chi square test were done. Associations and differences were considered significant when the p value was less than 0.05.The initial sample size was 50. Forty two participants completed the study. Out of the participants 36% (n=15) were below 40 years and were males. About 40.5% (n=17) had experience less than 5 years. Around 69% (n=23) of the participants had good knowledge regarding COVID 19. Statistically significant results were seen with mode of transmission of Covid 19 and age of the respondents (p value=.006);current treatment of Covid 19 and years of experience of the respondents (p value=.011).The study concluded that there is overall good awareness level among the participants of the study.


2017 ◽  
Vol 22 (3) ◽  
pp. 153-156
Author(s):  
S. K Litvinov ◽  
A. M Bronshteyn ◽  
E. N Morozov

Malaria continues to be a major international public health problem. However a significant reduction in the morbidity rate has been achieved over the past decade. The effective vaccine against malaria, caused by P. falciparun, could contribute significantly to the prevention and control of the disease, as tropical malaria is most widely distributed in the world. Nowadays there is the only RTS,S/AS01 vaccine had passed the accomplished phase 3 of clinical trial and received endorsement of certain bodies of World Health Organization and European Medicines Agency. RTS,S/AS01 is a pre-erythrocytic hybrid recombinant protein vaccine. Both immunogenicity and effectiveness of this vaccine particularly in children aged of 5-12 months were demonstrated by the trial at the time for first vaccination. Vaccine should be administered 3 times as the initial series of inoculation with 4 weeks interval and then the 4th dose should be given 15-18 months later. Since there is still a number of issues required certain clarifications, the decision has been taken to undertake another relatively large pilot project in African countries, prior to final recommendations on the vaccine use could be developed and proposed to countries. The implementation of this new trial will definitely take appropriate time. The contribution of vaccine to malaria control might be significant only if used simultaneously with other proved malaria control measures, such as the use of insecticide-treated nets, detection of malaria cases with the use of rapid diagnostic tests and subsequent its treatment, chemoprevention when appropriate and, of course vector control. The consideration of the vaccine use as the mechanism, which should allow achieve the eradication of the disease is not appropriate in principle.


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