SOP- Quality Assurance of Malaria Diagnostic Tests
Leishmaniasis is a vector-borne disease that is transmitted by sandflies and caused by obligate intracellular protozoa of the genus Leishmania. Human infection is caused by about 21 of 30 species that infect mammals. These include the L. donovani complex with 3 species (L. donovani, L. infantum, and... L. chagasi); the L. mexicana complex with 3 main species (L. mexicana, L. amazonensis, and L. venezuelensis); L. tropica; L. major; L. aethiopica; and the subgenus Viannia with 4 main species (L. (V.) braziliensis, L. (V.) guyanensis, L. (V.) panamensis, and L. (V.) peruviana). The different species are morphologically indistinguishable, but they can be differentiated by isoenzyme analysis, molecular methods, or monoclonal antibodies.
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Dengue is a mosquito-borne viral disease that occurs mainly in the tropics and subtropics but has a high potential to spread to new areas. Dengue infections are climate sensitive, so it is important to better understand how changing climate factors affect the potential for geographic spread and futu...re dengue epidemics. Vectorial capacity (VC) describes a vector's propensity to transmit dengue taking into account human, virus, and vector interactions. VC is highly temperature dependent, but most dengue models only take mean temperature values into account. Recent evidence shows that diurnal temperature range (DTR) plays an important role in influencing the behavior of the primary dengue vector Aedes aegypti. In this study, we used relative VC to estimate dengue epidemic potential (DEP) based on the temperature and DTR dependence of the parameters of A. aegypti. We found a strong temperature dependence of DEP; it peaked at a mean temperature of 29.3°C when DTR was 0°C and at 20°C when DTR was 20°C. Increasing average temperatures up to 29°C led to an increased DEP, but temperatures above 29°C reduced DEP. In tropical areas where the mean temperatures are close to 29°C, a small DTR increased DEP while a large DTR reduced it. In cold to temperate or extremely hot climates where the mean temperatures are far from 29°C, increasing DTR was associated with increasing DEP. Incorporating these findings using historical and predicted temperature and DTR over a two hundred year period (1901-2099), we found an increasing trend of global DEP in temperate regions. Small increases in DEP were observed over the last 100 years and large increases are expected by the end of this century in temperate Northern Hemisphere regions using climate change projections. These findings illustrate the importance of including DTR when mapping DEP based on VC.
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Leishmaniasis is a complex vector-borne disease involving in its transmission several species of protozoan parasites called Leishmania, a wide variety of animal reservoirs and phlebotomine sandflies vectors. Cutaneous Leishmaniasis (CL) is the most common form of the disease, and its clinical manife...stations vary from few papules to multiple ulcers affecting the skin but also the mucous membranes, leaving permanent scars and serious disability. It is a disfiguring and stigmatizing disease that often has a devastating psychosocial and economic impact on the affected resources limited communities.
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Leishmaniasis is a vector-borne disease with a wide variety of parasite species, reservoirs, and vectors involved in transmission. It is caused by different species of the protozoa Leishmania and is transmitted to animals and humans through a bite of insects in the Psychodidae family. Its presence i...s directly linked to poverty, but social, environmental, and climatalogic factors directly influence the disease's epidemiology.
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Lymphatic filariasis is a vector-borne neglected tropical disease that causes damage of the lymphatic system and can lead to lymphoedema (elephantiasis) and hydrocele in infected individuals. The global baseline estimate of persons affected by lymphatic filariasis is 25 million men with hydrocele an...d over 15 million people with lymphoedema. At least 36 million persons remain with these chronic disease manifestations. The disease is endemic in 72 countries. In 2016, an estimated total population of 856 million were living in areas with ongoing transmission of the causative filarial parasites and requiring mass drug administration (MDA). Lymphatic filariasis disfigures and disables, and often leads to stigmatization and poverty. Hundreds of millions of dollars are lost annually due to reduced productivity of affected patients. WHO has ranked the disease as one of the world’s leading causes of permanent and long-term disability.
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Leishmaniasis is a vector-borne tropical/subtropical disease caused by an intracellular parasite transmitted to humans by sand fly bite. It is endemic in Asia, Africa, the Americas, and the Mediterranean region. Worldwide reports include 1.5–2 million new cases each year, more than 300 million at ...risk of acquiring the disease, and 70,000 deaths per year. Clinical features depend on the Leishmania species and immune response of the host, varying from localized cutaneous disease to visceral form with potentially fatal outcome; however, the common presentation is either cutaneous, mucocutaneous, or visceral leishmaniasis. Many therapeutic agents are being used in Leishmania treatment, but the only effective treatment is achieved with current pentavalent antimonials. WHO considers Leishmaniasis as one of the “Neglected Tropical Diseases” that continues to be prevalent despite international, national, and local efforts towards its control and elimination over the last decade. This chapter reviews the global perspective of Leishmaniasis with increasing recognition of emerging “Atypical forms” and new surge of disease across the world mainly due to increasing conflicts in endemic areas leading to forced migration among other causes. All these challenges related to environment, disease, and vector pose major implications on WHO’s leishmaniasis control and elimination plan.
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The school and a community teaching modules are aimed at preventing vector-borne diseases through community participation. Meanwhile, the interactive toolkit is meant to be help raise awareness on health, sanitation and vector control. These materials will help volunteers and practitioners foster di...alogue with communities and ensure that prevention is seen as the primary way of combatting vector-borne diseases
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Cutaneous leishmaniasis (CL) is a parasitic disease caused by infection with a vector-borne protozoan parasite of the genus Leishmania spp. The parasite is transmitted by the bite of an infected phlebotomine sand fly. Infection results in skin lesions which take a long time to heal and may leave per...manent, disfiguring scars (de Vries et al. 2015). CL is classified as a neglected tropical disease (NTD), and in common with several other NTDs, is associated with psychosocial effects including stigma, social exclusion, and declining mental health (Bailey et al. 2019; Bennis et al. 2018; Wenning et al. 2022). Emerging evidence suggests that people with CL are at a higher risk of experiencing anxiety, depression, decreased body satisfaction, loss of social status, and lower quality of life (Bennis et al. 2018; Yanik et al. 2004). The global mean age-standardised disability-adjusted life years (DALYs) lost by CL was 0.58 per 100,000 people (Karimkhani et al. 2016). Notably, this statistic only considers the physical effects of the lesions and does not account for the potentially considerable psychological and social effects of CL (Bailey et al. 2017; Bailey et al. 2019; Wenning et al. 2022).
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Dengue is a mosquito-borne viral disease that has rapidly spread to all regions of WHO in recent years. Dengue virus is transmitted by female mosquitoes mainly of the species Aedes aegypti and, to a lesser extent, Ae. albopictus. These mosquitoes are also vectors of chikungunya, yellow fever and Zik...a viruses. Dengue is widespread throughout the tropics, with local variations in risk influenced by climate parameters as well as social and environmental factors.
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This toolkit for integrated vector management (IVM) is designed to help national and regional programme managers coordinate across sectors to design and run large IVM programmes.
The toolkit provides the technical detail required to plan, implement, monitor and evaluate an IVM approach. IVM can be ...used when the aim is to control or eliminate vector-borne diseases and can also contribute to insecticide resistance management. This toolkit provides information on where vector-borne diseases are endemic and what interventions should be used, presenting case studies on IVM as well as relevant guidance documents for reference.
The diseases that are the focus of this toolkit are malaria, lymphatic filariasis, dengue, leishmaniasis, onchocerciasis, human African trypanosomiasis and schistosomiasis. It also includes information on other viral diseases (Rift Valley fever, West Nile fever, Chikungunya, yellow fever) and trachoma. If other vector-borne diseases appear in a country or area, vector control with an IVM approach should be adopted, as per national priorities.
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The risk of communicable diseases remains a humanitarian concern with major health risks including cholera, acute watery diarrhea, bloody diarrhea, malaria and other vector borne diseases and conditions such as severe acute malnutrition.
Access to the affected districts is still conditioned due t...o the destruction of roads, the telecommunications network and the interruption of electricity.
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Planning for public health emergencies should ensure that capabilities developed during previous emergencies are maintained, incorporated, and put into practice when a new event of public health concern arises. Investments in pandemic preparedness lead to more rapid detection and a stronger response... to public health threats, thereby shielding communities from the debilitating social and economic effects of epidemics and pandemics. The Pan American Health Organization (PAHO) recognizes the efforts of countries in the Region of the Americas to develop and/or strengthen their respiratory pathogen pandemic plans. PAHO supports planning activities with tools and expertise, aligning these efforts with the Preparedness and Resilience for Emerging Threats (PRET) initiative. The PRET initiative is an innovative approach to improving disease pandemic preparedness. It recognizes that the same systems, capacities, knowledge, and tools can be leveraged and applied for groups of pathogens based on their mode of transmission (respiratory, vector-borne, foodborne etc.). The PRET initiative incorporates the latest tools and approaches for shared learning and collective action established during the COVID-19 pandemic and other recent public health emergencies.
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Over the past 50 years, dengue has spread from nine to over a hundred countries, making it the most rapidly spreading vector-borne disease. Yet, dengue continues to have a low profile among policy-makers and donors and does not receive the media attention it deserves. While there is no vaccine or cu...re for dengue, it can be managed and prevented. We need a renewed commitment to integrated programming that includes improved management and diagnosis, increased awareness and community participation in controlling the vector and enhanced environmental sanitation
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Policy Guidance Brief 2
• The potential health risks from climate change include: increase of waterborne and vector-borne diseases, heat-related illnesses, injuries and deaths, food insecurity and increased malnutrition. The poor, women, children and the elderly, as well as communities living... in remote high-risk areas are most vulnerable.
• The expected results to achieve this outcome are: (i) climate risk management system is well-established, robust and nationally integrated to respond efectively to increased intensity and impact of risks and hazards on people’s health and wellbeing; (ii) improved social protection, gender consideration and risk finance capacity to prepare for and recover from potential loss and damage resulting from climate change; (iii) Myanmar’s health system is improved and can deal with climate-induced health hazards and support climate-vulnerable communities to respond effectively to disaster and health hazards from climate change.
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Chikungunya virus (CHIKV) is a re-emerging mosquito borne alphavirus responsible
for the recent outbreak in the Americas. Immunologically naïve population in the Americas favors the spread of epidemics. Chikungunya fever is characterized by an abrupt febrile illness, polyarthralgia and maculopapul...ar rash. In chikungunya fever, shock or severe hemorrhage is very rarely observed; the onset is more acute and the duration of fever is shorter than dengue disease. The pain is much more pronounced and localized to the joints and tendons in chikungunya fever, in comparison to dengue fever. There is no specific and effective antiviral therapy and vaccines are still in trails. The only effective preventive measures consist of individual protection against mosquito bites and vector control. Disease prevention is important due to the
economic burden it entails. Clinicians need to distinguish chikungunya fever between dengue fever and other diseases to give a successful treatment and prevent disease spreading.
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Dengue is the fastest spreading, mosquito-borne viral infectious disease worldwide, with remarkable morbidity and mortality. In the past decades, profound contributions have been made towards understanding its epidemiology, including disease burden and distributions, risk factors, and control and pr...evention practices. Dengue continues to disseminate to new areas, including high latitude regions, and a new serotype (dengue virus serotype 5) has been identified. Vaccine research has made new progress, in which the licensed yellow fever and dengue virus quadrivalent chimeric vaccine is now under further safety assessment. In disease surveillance, because of its operational simplicity, rapidity, capability, and utility as an indicator of disease severity, dengue virus NS1 antigen detection has great promotion and application value among primary health care institutions. Vector control progress has driven new breakthroughs in biotechnology, including Wolbachia-infected Aedes and genetically modified Aedes. Both Aedes variants have been used to block transmission of the dengue virus through population replacement and suppression. In the future, vector control should still be pursued as a key measure to prevent transmission, along with anti-viral drug and vaccine research.
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