41 research outputs found
Multisectoral approach to support use of insecticide- treated net for malaria prevention among mobile and migrant populations in Myanmar: a systematic review
Background. Myanmar is a premalaria elimination country with artemisinin-resistant malaria. A strategy for transmission control
is focused on vulnerable groups such as mobile and migrant populations (MMPs), and includes improving access to insecticidetreated
bed nets in the Myanmar artemisinin resistance containment (MARC) zones using multisectoral approaches (MSA).
Methods. This narrative systematic review addressed MSAs targeted to MMPs in Myanmar for malaria prevention. We searched
relevant studies in electronic databases and present the narrative findings in 4 domains: stakeholder groups, net coverage and utilization,
social determinates, and facilitators/barriers.
Results. Nine studies were included. The review identified stakeholders involved in intersectoral collaboration. Net ownership was higher
than utilization rates in the MARC zones and rates remained below the WHO recommended target of 100%. There was inadequate description
of roles and responsibilities for implementation and on channels of communication within the partnerships and with the Government.
Conclusions. Findings show that interventions to distribute treated bed nets were supported by the multiple stakeholders. Due
to the design of the primary studies, analysis of the added value of intersectoral collaboration was limited. More attention must be
paid to designing studies to document and evaluate the contributions and outcomes of intersectoral collaboration.
Keywords. malaria; prevention; bed nets; multisectoral approach; artemisinin resistance containment zones; Myanmar
Toll-like receptor 9 and 4 gene polymorphisms in susceptibility and severity of malaria: a meta-analysis of genetic association studies
Background: Malaria is still a major public health problem in sub-Saharan Africa and South-east Asia. The clinical presentations of malaria infection vary from a mild febrile illness to life-threatening severe malaria. Toll like receptors (TLRs) are postulated to be involved in the innate immune responses to malaria. Individual studies showed inconclusive findings. This study aimed to assess the role of TLR4 (D299G, T399I) and TLR9 (T1237C, T1486C) in severity or susceptibility of malaria by meta-analysis of data from eligible studies.
Methods: Relevant case–control studies that assessed the association between TLR 4/9 and malaria either in susceptibility or progression were searched in health-related electronic databases. Quality of included studies was evaluated with Newcastle–Ottawa scale. Pooled analyses for specific genetic polymorphisms were done under five genetic models. Stratified analysis was done by age and geographical region (Asian countries vs non-Asian countries).
Results: Eleven studies (2716 cases and 2376 controls) from nine endemic countries were identified. Five studies (45.4%) obtained high score in quality assessment. Overall, a significant association between TLR9 (T1486C) and severity of malaria is observed in allele model (OR: 1.26, 95% CI: 1.08–1.48, I2 = 0%) or homozygous model (OR: 1.55, 95% CI: 1.08–2.28, I2 = 0%). For TLR9 (T1237C), a significant association with severity of malaria is observed in in heterozygous model (OR:1.89, 95% CI: 1.11–3.22, I2 = 75%). On stratifications, TLR9 (T1486C) is only significantly associated with a subgroup of children of non-Asian countries under allele model (OR: 1.25, 95% CI: 1.02–1.38), while 1237 is with a subgroup of adults from Asian countries under heterozygous model (OR: 2.0, 95% CI: 1.09–3.64, I2 = 39%). Regarding the susceptibility to malaria, TLR9 (T1237C) is significantly associated only with the children group under recessive model (OR: 2.21, 95% CI: 1.06–4.57, I2=85%) and homozygous model (OR: 1.49, 95% CI: 1.09–2.0, I2 = 0%). For TLR4 (D299G, T399I), none is significantly associated with either severity of malaria or susceptibility to malaria under any genetic models.
Conclusions: The findings suggest that TLR 9 (T1486C and T1237C) seems to influence the progression of malaria, under certain genetic models and in specific age group of people from specific geographical region. TLR 9 (T1237C) also plays a role in susceptibility to malaria under certain genetic models and only with children of non-Asian countries. To substantiate these, future well designed studies with larger samples across endemic countries are needed
A comparison of neoadjuvant therapies for gastroesophageal and gastric cancer on tumour resection rate: A network meta-analysis
Background: Gastric cancer is one of the most common malignancies around the world, and a variety of neoadjuvant chemotherapies with different drug combinations are available for the treatment. R0 resection refers to a microscopically negative margin on resection, where no gross or microscopic tumour remains in the primary tumour. We aimed to find evidence on the relative effectiveness of neoadjuvant therapies for patients with advanced gastroesophageal and gastric cancer on the R0 resection rate.
Methods: Relevant randomised controlled trials were searched using appropriate keywords in health-related databases. We performed network meta-analysis within a frequentist framework. The endpoint assessed was the R0 resection rate. We assessed consistency and transitivity assumptions that are necessary for network meta-analysis. This study only used data from published studies. The need for consent from participants was waived by the Ethics Review Committee of the International Medical University in Malaysia.
Results: Six randomised controlled trials involving 1700 patients were identified. A network plot was formed with five neoadjuvant regimens [DLX (pyrimidine analogue + platinum compounds + chemoradiotherapy), DELX (pyrimidine analogue + epipodophylllotoxins/etoposide + platinum compounds + chemoradiotherapy), ADL (anthracycline + pyrimidine analogue + platinum compounds), ADM (anthracycline+ pyrimidine analogue + anti-folate compounds) and LTX (platinum compounds + taxane + chemoradiotherapy)] and surgery alone for management of patients with advanced gastroesophageal and gastric cancer. Assumptions required for a network meta-analysis such as consistency ((global test: Chi2 (1): 3.71; p:0.054)), and the transitivity in accord to the characteristics of interventions considered in this review were not violated. In the network comparison, surgery alone has a lower R0 resection rate compared with LTX (OR 0.2, 95%CI:0.01, 0.38) or DLX (OR 0.48, 95%CI: 0.29, 0.79). LTX has higher resection rate compared with DLX (OR 2.47, 95%CI: 1.08 to 5.63), DELX (OR 106.0, 95%CI: 25.29 to 444.21), ADM (OR 5.41, 95%CI: 1.56 to 18.78) or ADL (OR 3.12, 95%CI: 1.27 to 7.67). There were wide or very wide CIs in many of these comparisons. Overall certainty of the evidence was low or very low. Further research in this field is very likely to have an important impact on our confidence in the R0 resection rates between LTX versus other neoadjuvant chemotherapy is likely to change the estimate.
Conclusions: Findings suggest that overall quality of evidence on the relative effectiveness of neoadjuvant chemotherapies was low to very low level. Therefore, we are very uncertain about the true effect of neoadjuvant therapies in the R0 resection rate in patients with gastroesophageal and gastric cancer. Future well-designed large trials are needed. To recruit large samples in this field, multicountry trials are recommended. Future trials also need to assess treatment-related adverse events, and patients-centered outcomes such as health‐related quality of life
Detection of asymptomatic malaria in Asian countries: a meta-analysis of diagnostic accuracy
Background
Achieving malaria elimination requires the targeting of the human reservoir of infection, including those patients with asymptomatic infection. The objective was to synthesise evidence on the accuracy of the rapid-onsite diagnostic tests (RDTs) and microscopy for the detection of asymptomatic malaria as part of the surveillance activities in Asian countries.
Methods
This was a meta-analysis of diagnostic test accuracy. Relevant studies that evaluated the diagnostic performance of RDTs and microscopy for detection of asymptomatic malaria were searched in health-related electronic databases. The methodological quality of the studies included was assessed using the QUADAS-2 tool.
Results
Ten studies assessing RDT and/or microscopy were identified. The diagnostic accuracies in all these studies were verified by PCR. Overall, the pooled sensitivities of RDT, as well as microscopy for detection of any malaria parasites in asymptomatic participants, were low, while their pooled specificities were almost ideal. For the detection of Plasmodium falciparum, pooled sensitivity by RDT (59%, 95%CI:16–91%) or microscopy (55%, 95%CI: 25–82%) were almost comparable. For detection of Plasmodium vivax, pooled sensitivity of RDT (51%, 95% CI:7–94%) had also the comparable accuracy of microscopy (54%, 95%CI,11–92%). Of note are the wide range of sensitivity and specificity.
Conclusion
The findings of this meta-analysis suggest that RDTs and microscopy have limited sensitivity and are inappropriate for the detection of asymptomatic Plasmodium infections. Other methods including a combination of PCR-based strategies, Loop-Mediated Isothermal Amplification (LAMP) technique must be considered to target these infections, in order to achieve malaria elimination. However, more data is needed for the wide acceptance and feasibility of these approaches. Studies to explore the role of asymptomatic and sub-patent infections in the transmission of malaria are of critical importance and are recommended
The Potential Impact on Farmer Health of Enhanced Export Horticultural Trade between the U.K. and Uganda
The export of vegetables from African countries to European markets presents consumers with an ethical dilemma: should they support local, but relatively well-off farmers, or poorer farmers from distant countries? This paper considers the issue of farm worker health in the U.K. and Uganda, and considers the dilemma facing U.K. consumers if Uganda achieves their aim of exporting more vegetables to the U.K. Self-reported health scores of 1,200 farm workers in the U.K. and Uganda were measured with the internationally recognised SF-36 questionnaire and compared to an international population norm. The age-corrected health status of U.K. farm workers was significantly lower than the population norm, whereas Ugandans scored significantly higher (indicating good health) for physical health and lower for mental health. If Ugandan produce enters U.K. markets, then consumers may wish to consider both the potential benefits that enhanced trade could offer Ugandan farmers compared with its impacts on U.K. workers
Malaria Rapid Testing by Community Health Workers Is Effective and Safe for Targeting Malaria Treatment: Randomised Cross-Over Trial in Tanzania
Early diagnosis and prompt, effective treatment of uncomplicated malaria is critical to prevent severe disease, death and malaria transmission. We assessed the impact of rapid malaria diagnostic tests (RDTs) by community health workers (CHWs) on provision of artemisinin-based combination therapy (ACT) and health outcome in fever patients. Twenty-two CHWs from five villages in Kibaha District, a high-malaria transmission area in Coast Region, Tanzania, were trained to manage uncomplicated malaria using RDT aided diagnosis or clinical diagnosis (CD) only. Each CHW was randomly assigned to use either RDT or CD the first week and thereafter alternating weekly. Primary outcome was provision of ACT and main secondary outcomes were referral rates and health status by days 3 and 7. The CHWs enrolled 2930 fever patients during five months of whom 1988 (67.8%) presented within 24 hours of fever onset. ACT was provided to 775 of 1457 (53.2%) patients during RDT weeks and to 1422 of 1473 (96.5%) patients during CD weeks (Odds Ratio (OR) 0.039, 95% CI 0.029-0.053). The CHWs adhered to the RDT results in 1411 of 1457 (96.8%, 95% CI 95.8-97.6) patients. More patients were referred on inclusion day during RDT weeks (10.0%) compared to CD weeks (1.6%). Referral during days 1-7 and perceived non-recovery on days 3 and 7 were also more common after RDT aided diagnosis. However, no fatal or severe malaria occurred among 682 patients in the RDT group who were not treated with ACT, supporting the safety of withholding ACT to RDT negative patients. RDTs in the hands of CHWs may safely improve early and well-targeted ACT treatment in malaria patients at community level in Africa.\ud
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Socializing One Health: an innovative strategy to investigate social and behavioral risks of emerging viral threats
In an effort to strengthen global capacity to prevent, detect, and control infectious diseases in animals and people, the United States Agency for International Development’s (USAID) Emerging Pandemic Threats (EPT) PREDICT project funded development of regional, national, and local One Health capacities for early disease detection, rapid response, disease control, and risk reduction. From the outset, the EPT approach was inclusive of social science research methods designed to understand the contexts and behaviors of communities living and working at human-animal-environment interfaces considered high-risk for virus emergence. Using qualitative and quantitative approaches, PREDICT behavioral research aimed to identify and assess a range of socio-cultural behaviors that could be influential in zoonotic disease emergence, amplification, and transmission. This broad approach to behavioral risk characterization enabled us to identify and characterize human activities that could be linked to the transmission dynamics of new and emerging viruses. This paper provides a discussion of implementation of a social science approach within a zoonotic surveillance framework. We conducted in-depth ethnographic interviews and focus groups to better understand the individual- and community-level knowledge, attitudes, and practices that potentially put participants at risk for zoonotic disease transmission from the animals they live and work with, across 6 interface domains. When we asked highly-exposed individuals (ie. bushmeat hunters, wildlife or guano farmers) about the risk they perceived in their occupational activities, most did not perceive it to be risky, whether because it was normalized by years (or generations) of doing such an activity, or due to lack of information about potential risks. Integrating the social sciences allows investigations of the specific human activities that are hypothesized to drive disease emergence, amplification, and transmission, in order to better substantiate behavioral disease drivers, along with the social dimensions of infection and transmission dynamics. Understanding these dynamics is critical to achieving health security--the protection from threats to health-- which requires investments in both collective and individual health security. Involving behavioral sciences into zoonotic disease surveillance allowed us to push toward fuller community integration and engagement and toward dialogue and implementation of recommendations for disease prevention and improved health security
Rapid diagnostic tests for diagnosing uncomplicated P. falciparum malaria in endemic countries (Review)
Background
Rapid diagnostic tests (RDTs) for Plasmodium falciparum malaria use antibodies to detect either HRP-2 antigen or pLDH antigen, and can improve access to diagnostics in developing countries.
Objectives
To assess the diagnostic accuracy of RDTs for detecting P. falciparum parasitaemia in persons living in endemic areas who present to ambulatory healthcare facilities with symptoms suggestive of malaria by type and brand.
Search strategy
We undertook a comprehensive search of the following databases:Cochrane Infectious Diseases Group Specialized Register; MEDLINE; EMBASE; MEDION; Science Citation Index; Web of Knowledge; African Index Medicus; LILACS; IndMED; to January 14, 2010.
Selection criteria
Studies comparing RDTs with a reference standard (microscopy or polymerase chain reaction) in blood samples from a random or consecutive series of patients attending ambulatory health facilities with symptoms suggestive of malaria in P. falciparum endemic areas.
Data collection and analysis
For each study, a standard set of data was extracted independently by two authors, using a tailored data extraction form. Comparisons were grouped hierarchically by target antigen, and type and brand of RDT, and combined in meta-analysis where appropriate.
Main results
We identified 74 unique studies as eligible for this review and categorized them according to the antigens they detected. Types 1 to 3 include HRP-2 (from P. falciparum) either by itself or with other antigens. Types 4 and 5 included pLDH (from P. falciparum) either by itself or with other antigens. In comparisons with microscopy, we identified 71 evaluations of Type 1 tests, eight evaluations of Type 2 tests and five evaluations of Type 3 tests. In meta-analyses, average sensitivities and specificities (95% CI) were 94.8% (93.1% to 96.1%) and 95.2% (93.2% to 96.7%) for Type 1 tests, 96.0% (94.0% to 97.3%) and 95.3% (87.3% to 98.3%) for Type 2 tests, and
99.5% (71.0% to 100.0%) and 90.6% (80.5% to 95.7%) for Type 3 tests, respectively.
Overall for HRP-2, the meta-analytical average sensitivity and specificity (95% CI) were 95.0% (93.5% to 96.2%) and 95.2% (93.4% to 99.4%), respectively.
For pLDH antibody-based RDTs verified with microscopy, we identified 17 evaluations of Type 4 RDTs and three evaluations of Type 5 RDTs. In meta-analyses, average sensitivity for Type 4 tests was 91.5% (84.7% to 95.3%) and average specificity was 98.7% (96.9% to 99.5%). For Type 5 tests, average sensitivity was 98.4% (95.1% to 99.5%) and average specificity was 97.5% (93.5% to 99.1%).
Overall for pLDH, the meta-analytical average sensitivity and specificity (95% CI) were 93.2% (88.0% to 96.2%) and 98.5% (96.7% to 99.4%), respectively.
For both categories of test, there was substantial heterogeneity in study results. Quality of the microscopy reference standard could only be assessed in 40% of studies due to inadequate reporting, but results did not seem to be influenced by the reporting quality.
Overall, HRP-2 antibody-based tests (such as the Type 1 tests) tended to be more sensitive and were significantly less specific than pLDH-based tests (such as the Type 4 tests). If the point estimates for Type 1 and Type 4 tests are applied to a hypothetical cohort of 1000 patients where 30% of those presenting with symptoms have P. falciparum, Type 1 tests will miss 16 cases, and Type 4 tests will miss 26 cases. The number of people wrongly diagnosed with P. falciparum would be 34 with Type 1 tests, and nine with Type 4 tests.
Authors’ conclusions
The sensitivity and specificity of all RDTs is such that they can replace or extend the access of diagnostic services for uncomplicated P. falciparum malaria. HRP-2 antibody types may be more sensitive but are less specific than pLDH antibody-based tests, but the differences are small. The HRP-2 antigen persists even after effective treatment and so is not useful for detecting treatment failures
Willingness-to-pay for a rapid malaria diagnostic test and artemisinin-based combination therapy from private drug shops in Mukono District, Uganda.
In Uganda, as in many parts of Africa, the majority of the population seek treatment for malaria in drug shops as their first point of care; however, parasitological diagnosis is not usually offered in these outlets. Rapid diagnostic tests (RDTs) for malaria have attracted interest in recent years as a tool to improve malaria diagnosis, since they have proved accurate and easy to perform with minimal training. Although RDTs could feasibly be performed by drug shop vendors, it is not known how much customers would be willing to pay for an RDT if offered in these settings. We conducted a contingent valuation survey among drug shop customers in Mukono District, Uganda. Exit interviews were undertaken with customers aged 15 years and above after leaving a drug shop having purchased an antimalarial and/or paracetamol. The bidding game technique was used to elicit the willingness-to-pay (WTP) for an RDT and a course of artemisinin-based combination therapy (ACT) with and without RDT confirmation. Factors associated with WTP were investigated using linear regression. The geometric mean WTP for an RDT was US1.82 for a course of ACT and US$2.05 for a course of ACT after a positive RDT. Factors strongly associated with a higher WTP for these commodities included having a higher socio-economic status, no fever/malaria in the household in the past 2 weeks and if a malaria diagnosis had been obtained from a qualified health worker prior to visiting the drug shop. The findings further suggest that the WTP for an RDT and a course of ACT among drug shop customers is considerably lower than prevailing and estimated end-user prices for these commodities. Increasing the uptake of ACTs in drug shops and restricting the sale of ACTs to parasitologically confirmed malaria will therefore require additional measures
