ABSTRACT
Anopheles stephensi is a highly competent urban malaria vector species, endemic in South Asia and the Persian Gulf, which has colonised eight countries in sub-Saharan Africa (SSA) since 2013 and is now spreading uncontrollably. In urban areas of Africa, where malaria transmission has previously been low or non-existent, the invasion of An. stephensi represents a significant problem, particularly to immunologically naïve populations. Despite this rapidly advancing threat, there is a paucity of information regarding the bionomics of An. stephensi in SSA. Here, we offer a critical synthesis of literature from An. stephensi's native range, focusing on the future of An. stephensi in a rapidly urbanising Africa, and highlighting key questions that warrant prioritisation by the global malaria vector control community.
Subject(s)
Anopheles , Malaria , Mosquito Vectors , Anopheles/parasitology , Anopheles/physiology , Animals , Asia/epidemiology , Africa/epidemiology , Malaria/prevention & control , Malaria/transmission , Introduced Species , HumansABSTRACT
Systems for disease vector control should be effective, efficient, and flexible to be able to tackle contemporary challenges and threats in the control and elimination of vector-borne diseases. As a priority activity towards the strengthening of vector control systems, it has been advocated that countries conduct a vector-control needs assessment. A review was carried out of the perceived needs for disease vector control programs among eleven countries and subnational states in South Asia and the Middle East. In each country or state, independent teams conducted vector control needs assessment with engagement of stakeholders. Important weaknesses were described for malaria, dengue and leishmaniases regarding vector surveillance, insecticide susceptibility testing, monitoring and evaluation of operations, entomological capacity and laboratory infrastructure. In addition, community mobilization and intersectoral collaboration showed important gaps. Countries and states expressed concern about insecticide resistance that could reduce the continued effectiveness of interventions, which demands improved monitoring. Moreover, attainment of disease elimination necessitates enhanced vector surveillance. Vector control needs assessment provided a useful planning tool for systematic strengthening of vector control systems. A limitation in conducting the vector control needs assessment was that it is time- and resource-intensive. To increase the feasibility and utility of national assessments, an abridged version of the guidance should focus on operationally relevant topics of the assessment. Similar reviews are needed in other regions with different contextual conditions.
Subject(s)
Vector Borne Diseases , Animals , Humans , Asia, Southern/epidemiology , Dengue/prevention & control , Dengue/epidemiology , Dengue/transmission , Disease Vectors , Insecticides , Malaria/prevention & control , Malaria/epidemiology , Middle East/epidemiology , Needs Assessment , Vector Borne Diseases/prevention & control , Vector Borne Diseases/transmissionABSTRACT
BACKGROUND: The continued spread of insecticide resistance in mosquito vectors of malaria and arboviral diseases may lead to operational failure of insecticide-based interventions if resistance is not monitored and managed efficiently. This study aimed to develop and validate a new WHO glass bottle bioassay method as an alternative to the WHO standard insecticide tube test to monitor mosquito susceptibility to new public health insecticides with particular modes of action, physical properties or both. METHODS: A multi-centre study involving 21 laboratories worldwide generated data on the susceptibility of seven mosquito species (Aedes aegypti, Aedes albopictus, Anopheles gambiae sensu stricto [An. gambiae s.s.], Anopheles funestus, Anopheles stephensi, Anopheles minimus and Anopheles albimanus) to seven public health insecticides in five classes, including pyrethroids (metofluthrin, prallethrin and transfluthrin), neonicotinoids (clothianidin), pyrroles (chlorfenapyr), juvenile hormone mimics (pyriproxyfen) and butenolides (flupyradifurone), in glass bottle assays. The data were analysed using a Bayesian binomial model to determine the concentration-response curves for each insecticide-species combination and to assess the within-bioassay variability in the susceptibility endpoints, namely the concentration that kills 50% and 99% of the test population (LC50 and LC99, respectively) and the concentration that inhibits oviposition of the test population by 50% and 99% (OI50 and OI99), to measure mortality and the sterilizing effect, respectively. RESULTS: Overall, about 200,000 mosquitoes were tested with the new bottle bioassay, and LC50/LC99 or OI50/OI99 values were determined for all insecticides. Variation was seen between laboratories in estimates for some mosquito species-insecticide combinations, while other test results were consistent. The variation was generally greater with transfluthrin and flupyradifurone than with the other compounds tested, especially against Anopheles species. Overall, the mean within-bioassay variability in mortality and oviposition inhibition were < 10% for most mosquito species-insecticide combinations. CONCLUSION: Our findings, based on the largest susceptibility dataset ever produced on mosquitoes, showed that the new WHO bottle bioassay is adequate for evaluating mosquito susceptibility to new and promising public health insecticides currently deployed for vector control. The datasets presented in this study have been used recently by the WHO to establish 17 new insecticide discriminating concentrations (DCs) for either Aedes spp. or Anopheles spp. The bottle bioassay and DCs can now be widely used to monitor baseline insecticide susceptibility of wild populations of vectors of malaria and Aedes-borne diseases worldwide.
Subject(s)
Anopheles , Insecticides , Malaria , Pyrethrins , Animals , Female , Insecticides/pharmacology , Mosquito Vectors , Public Health , Bayes Theorem , Mosquito Control/methods , Pyrethrins/pharmacology , Insecticide Resistance , Biological Assay , World Health OrganizationABSTRACT
Insecticides have played a major role in the prevention, control, and elimination of vector-borne diseases, but insecticide resistance threatens the efficacy of available vector control tools. A global survey was conducted to investigate vector control insecticide use from 2010 to 2019. Out of 140 countries selected as sample for the study, 87 countries responded. Also, data on ex-factory deliveries of insecticide-treated nets (ITNs) were analyzed. Insecticide operational use was highest for control of malaria, followed by dengue, leishmaniasis and Chagas disease. Vector control relied on few insecticide classes with pyrethroids the most used overall. Results indicated that IRS programs have been slow to react to detection of pyrethroid resistance, while proactive resistance management using insecticides with unrelated modes of action was generally weak. The intensive use of recently introduced insecticide products raised concern about product stewardship regarding the preservation of insecticide susceptibility in vector populations. Resistance management was weakest for control of dengue, leishmaniasis or Chagas disease. Therefore, it will be vital that vector control programs coordinate on insecticide procurement, planning, implementation, resistance monitoring, and capacity building. Moreover, increased consideration should be given to alternative vector control tools that prevent the development of insecticide resistance.
Subject(s)
Equipment and Supplies Utilization/trends , Insect Control/trends , Insect Vectors/drug effects , Insecticide Resistance , Insecticides/classification , Vector Borne Diseases/prevention & control , Animals , Humans , Insect Control/methods , Insecticides/supply & distribution , Mosquito Nets/statistics & numerical data , Vector Borne Diseases/epidemiologyABSTRACT
BACKGROUND: Long-lasting insecticide nets (LLINs) are a core malaria intervention. LLINs should retain efficacy against mosquito vectors for a minimum of three years. Efficacy and durability of Olyset® Plus, a permethrin and piperonyl butoxide (PBO) treated LLIN, was evaluated versus permethrin treated Olyset® Net. In the absence of WHO guidelines of how to evaluate PBO nets, and considering the manufacturer's product claim, Olyset® Plus was evaluated as a pyrethroid LLIN. METHODS: This was a household randomized controlled trial in a malaria endemic rice cultivation zone of Kirinyaga County, Kenya between 2014 and 2017. Cone bioassays and tunnel tests were done against Anopheles gambiae Kisumu. The chemical content, fabric integrity and LLIN survivorship were monitored. Comparisons between nets were tested for significance using the Chi-square test. Exact binomial distribution with 95% confidence intervals (95% CI) was used for percentages. The WHO efficacy criteria used were ≥ 95% knockdown and/or ≥ 80% mortality rate in cone bioassays and ≥ 80% mortality and/or ≥ 90% blood-feeding inhibition in tunnel tests. RESULTS: At 36 months, Olyset® Plus lost 52% permethrin and 87% PBO content; Olyset® Net lost 24% permethrin. Over 80% of Olyset® Plus and Olyset® Net passed the WHO efficacy criteria for LLINs up to 18 and 12 months, respectively. At month 36, 91.2% Olyset® Plus and 86.4% Olyset® Net survived, while 72% and 63% developed at least one hole. The proportionate Hole Index (pHI) values representing nets in good, serviceable and torn condition were 49.6%, 27.1% and 23.2%, respectively for Olyset® Plus, and 44.9%, 32.8% and 22.2%, respectively for Olyset® Net but were not significantly different. CONCLUSIONS: Olyset® Plus retained efficacy above or close to the WHO efficacy criteria for about 2 years than Olyset® Net (1-1.5 years). Both nets did not meet the 3-year WHO efficacy criteria, and showed little attrition, comparable physical durability and survivorship, with 50% of Olyset® Plus having good and serviceable condition after 3 years. Better community education on appropriate use and upkeep of LLINs is essential to ensure effectiveness of LLIN based malaria interventions.
Subject(s)
Insecticides , Permethrin , Kenya , Piperonyl Butoxide/pharmacologyABSTRACT
BACKGROUND: Vector control plays a critical role in the prevention, control and elimination of vector-borne diseases, and interventions of vector control continue to depend largely on the action of chemical insecticides. A global survey was conducted on the management practices of vector control insecticides at country level to identify gaps to inform future strategies on pesticide management, seeking to improve efficacy of interventions and reduce the side-effects of chemicals used on health and the environment. METHODS: A survey by questionnaire on the management practices of vector control insecticides was disseminated among all WHO Member States. Data were analysed using descriptive statistics in MS Excel. RESULTS: Responses were received from 94 countries, or a 48% response rate. Capacity for insecticide resistance monitoring was established in 68-80% of the countries in most regions, often with external support; however, this capacity was largely lacking from the European & Others Region (i.e. Western & Eastern Europe, North America, Australia and New Zealand). Procurement of vector control insecticides was in 50-75% of countries taking place by agencies other than the central-level procuring agency, over which the central authorities lacked control, for example, to select the product or assure its quality, highlighting the importance of post-market monitoring. Moreover, some countries experienced problems with estimating the correct amounts for procurement, especially for emergency purposes. Large fractions (29-78%) of countries across regions showed shortcomings in worker safety, pesticide storage practices and pesticide waste disposal. Shortcomings were most pronounced in countries of the European & Others Region, which has long been relatively free from mosquito-borne diseases but has recently faced challenges of re-emerging vector-borne diseases. CONCLUSIONS: Critical shortcomings in the management of vector control insecticides are common in countries across regions, with risks of adverse pesticide effects on health and the environment. Advocacy and resource mobilization are needed at regional and country levels to address these challenges.
Subject(s)
Disease Vectors , Global Health , Insecticide Resistance/drug effects , Insecticides/pharmacology , Mosquito Control/methods , Vector Borne Diseases/epidemiology , Vector Borne Diseases/prevention & control , Animals , Asia/epidemiology , Epidemiological Monitoring , Europe/epidemiology , Humans , North America/epidemiology , South America/epidemiology , Surveys and QuestionnairesABSTRACT
Interventions to control the vectors of human diseases, notably malaria, leishmaniasis and dengue, have relied mainly on the action of chemical insecticides. However, concerns have been raised regarding the management of insecticides in vector-borne disease-endemic countries. Our study aimed to analyze how vector control insecticides are managed in selected countries to extract lessons learned. A qualitative analysis of the situation of vector control insecticides management was conducted in six countries. Multi-stakeholder meetings and key informer interviews were conducted on aspects covering the pesticide lifecycle. Findings were compared and synthesized to extract lessons learned. Centrally executed guidelines and standards on the management of insecticides offered direction and control in most malaria programs, but were largely lacking from decentralized dengue programs, where practices of procurement, application, safety, storage, and disposal were variable between districts. Decentralized programs were better at facilitating participation of stakeholders and local communities and securing financing from local budgets. However, little coordination existed between malaria, visceral leishmaniasis and dengue programs within countries. Entomological capacity was concentrated in malaria programs at central level, while dengue and visceral leishmaniasis programs were missing out on expertise. Monitoring systems for insecticide resistance in malaria vectors were rarely used for dengue or visceral leishmaniasis vectors. Strategies for insecticide resistance management, where present, did not extend across programs or sectors in most countries. Dengue programs in most countries continued to rely on space spraying which, considering the realities on the ground, call for revision of international guidelines. Vector control programs in the selected countries were confronted with critical shortcomings in the procurement, application, safety measures, storage, and disposal of vector control insecticides, with implications for the efficiency, effectiveness, and safety of vector control. Further international support is needed to assist countries in situation analysis, action planning and development of national guidelines on vector control insecticide management.
Subject(s)
Disease Vectors , Insecticide Resistance/drug effects , Insecticides/pharmacology , Mosquito Control/methods , Vector Borne Diseases/epidemiology , Vector Borne Diseases/prevention & control , Animals , Asia/epidemiology , Epidemiological Monitoring , Global Health , Humans , Middle East/epidemiologyABSTRACT
Background and aims Acute upper gastrointestinal (UGI) bleeding is one of the serious and potentially life-threatening medical emergencies, causing significant mortality and morbidity. This study aimed to evaluate the clinico-endoscopic profile and outcome among patients aged <60 years who presented for UGI bleeding compared to those aged ≥60 years. Methods This prospective observational study was conducted among 194 patients who presented with symptoms or signs of UGI bleed. All patients were divided into two groups, group A (age <60 years), and group B (age ≥60 years). UGI endoscopy was performed using Olympus N19 Endoscope. Rockall scoring (RS) system and Glasgow Blatchford score (GBS) were used to predict the prognosis and re-bleeding. Results Of the total, group A included 150 (77.31%) patients and group B 44 (22.69%) patients. The most common presentation was hematemesis and melena in both groups, whilst isolated hematochezia was more common in group A (6.67%, vs. 2.27%, p>0.05). The main cause of bleeding was a variceal bleed in both groups, but it was significantly higher in group A patients (p<0.05). Elderly patients had a significantly higher number of peptic ulcer and malignancy-related bleed (p<0.05). Group A patients had a significantly higher proportion of patients with tachycardia (45.33%, vs. 27.27%, p<0.05), shock (43.33% vs. 13.63%, p<0.05), pallor (76.66% vs. 56.81%, p<0.05), and blood transfusion requirement (64% vs. 45.45%, p<0.05) as compared to group B. Thirty days re-bleeding and mortality rate were similar in both the groups. RS in both groups was 5.02±2.12 vs. 5.98±1.91, p>0.05. GBS was 11.65±4.61 vs. 10.68±4.65, p>0.05. Mortality was significantly higher in patients with RS ≥6 and GBS ≥10. Conclusion This study concluded variceal bleeding as a predominant cause of UGI bleed in both age groups, and it was significantly higher in younger. Interestingly, younger patients were more hemodynamically unstable, probably due to the presence of more severe anemia, shock, and hematochezia. The presence of multiple co-morbidities in both the group kept the 30 days mortality and re-bleed rates similar.
ABSTRACT
OBJECTIVES: Indoor residual spraying (IRS) with insecticides is the main vector control intervention for the elimination of visceral leishmaniasis in India. After a change in IRS policy in 2015 due to widespread resistance of Phlebotomus argentipes to DDT, IRS with DDT was replaced with alpha-cypermethrin IRS in 2016. The objective of the present study was to evaluate the susceptibility of P. argentipes to DDT and its alternatives, namely malathion and pirimiphos-methyl (organophosphates); alpha-cypermethrin, deltamethrin, lambda-cyhalothrin and permethrin (pyrethroids), and bendiocarb and propoxur (carbamates), in support of visceral leishmaniasis elimination in India. METHODS: Phlebotomus argentipes sandflies were collected from the visceral-leishmaniasis endemic states of Bihar, Jharkhand and West Bengal. In the WHO tube tests, the phenotypic susceptibility of F1, 2-day old, non-blood fed females were determined against filter papers impregnated with DDT 4%, malathion 5%, pirimiphos-methyl 0.25%, alpha-cypermethrin 0.05%, deltamethrin 0.05%, lambda-cyhalothrin 0.05%, permethrin 0.75%, bendiocarb 0.1% and propoxur 0.1%, which were sourced from Universiti Sains Malaysia. The knockdown of sandflies after 1-h exposure and mortality at 24 h after the 1-h exposure period were scored. RESULTS: Mean mortality of P. argentipes 24 h after exposure in tube tests was 22.6% for DDT and ≥ 98% for other insecticide-impregnated papers tested. CONCLUSION: Phlebotomus argentipes continues to be highly resistant to DDT with no reversal of resistance after DDT's withdrawal from IRS. P. argentipes was fully susceptible to pyrethroid, organophosphate and carbamate insecticides tested. Regular monitoring is warranted for insecticide resistance management in sandfly vectors.
Subject(s)
Insect Vectors/drug effects , Insecticides/pharmacology , Leishmaniasis, Visceral/prevention & control , Phlebotomus/drug effects , Psychodidae/drug effects , Animals , Humans , India , Insecticide Resistance/drug effectsABSTRACT
OBJECTIVES: To evaluate the entomological efficacy and the residual activity of indoor residual spraying with Fludora® Fusion 562.5 WP-SB, a combination formulation containing clothianidin, a neonicotinoid and deltamethrin, a pyrethroid, against the main rural malaria vector, Anopheles culicifacies s.l., in India in a small-scale trial. METHODS: In three study villages, suitable households were randomly allocated to five treatments: Fludora® Fusion 562.5 WP-SB (target dose 225 mg active ingredient AI/m2 ); clothianidin 70 WG (target dose 200 mg AI/m2 ); K-Othrine 250 WG (deltamethrin, target dose 25 mg AI/m2 ); Ficam VC 80 WP-SB (bendiocarb, target dose 400 mg AI/m2 ) and unsprayed control. Insecticides were sprayed by hand compression sprayers with control flow valves and 8002E nozzles. Post-spray cone bioassays were done on insecticide-treated walls using a colonised, deltamethrin-resistant strain of An. culicifacies. Mosquitoes were collected from treated rooms by different methods. The insecticide content on filter papers collected from the sprayed walls was determined by chemical assay to assess the spray quality. RESULTS: The ratios of applied to target doses of insecticides were within 0.84 to 1.4, showing a good spray quality. The cone bioassays revealed residual action lasting 7 months for all insecticides without significant differences in mortality between different surfaces treated nor between the four treatment arms (P > 0.05). Considering all entomological parameters such as indoor resting density, excito-repellency, blood-feeding inhibition and delayed mortality, the overall efficacy of Fludora® Fusion WG-SB was equal or better compared with other insecticides. CONCLUSIONS: Fludora® Fusion showed overall equal or better efficacy than deltamethrin and bendiocarb alone against a pyrethroid-resistant malaria vector population and can be considered as an alternative product for management of pyrethroid resistance in malaria vectors.
Subject(s)
Anopheles/drug effects , Culicidae/drug effects , Family Characteristics , Insecticides/pharmacology , Malaria , Mosquito Control/methods , Mosquito Vectors/drug effects , Animals , Biological Assay , Guanidines/pharmacology , Humans , Insecticide Resistance , Malaria/prevention & control , Malaria/transmission , Neonicotinoids/pharmacology , Nitriles/pharmacology , Pyrethrins/pharmacology , Thiazoles/pharmacologyABSTRACT
Pesticide lifecycle management encompasses a range of elements from legislation, regulation, manufacturing, application, risk reduction, monitoring, and enforcement to disposal of pesticide waste. A survey was conducted in 2017-2018 to describe the contemporary global status of pesticide lifecycle management, to identify where the gaps are found. A three-tiered questionnaire was distributed to government entities in 194 countries. The response rate was 29%, 27% and 48% to the first, second and third part of the questionnaire, respectively. The results showed gaps for most of the selected indicators of pesticide management, suggesting that pesticide efficacy and safety to human health and the environment are likely being compromised at various stages of the pesticide lifecycle, and at varying degrees across the globe. Low-income countries generally had the highest incidence of gaps. Particular shortcomings were deficiencies in pesticide legislation, inadequate capacity for pesticide registration, protection against occupational exposure to pesticides, consumer protection against residues in food, and environmental protection against pesticide contamination. Policy support for, and implementation of, pesticide use-reduction strategies such as integrated pest management and integrated vector management has been inadequate across regions. Priority actions for structural improvement in pesticide lifecycle management are proposed, including pesticide use-reduction strategies, targeted interventions, and resource mobilization.
ABSTRACT
BACKGROUND: In view of widespread pyrethroid resistance in malaria vectors in Africa, two long-lasting insecticidal nets (LLINs) incorporated with a synergist, piperonyl butoxide (PBO), DawaPlus 3.0 (deltamethrin + PBO in the roof panel; deltamethrin alone in the side panels) and DawaPlus 4.0 (deltamethrin + PBO in all panels), were evaluated in an experimental hut trial in a rice growing irrigated area in Burkina Faso. Efficacy of nets was tested against free-flying malaria vector, Anopheles gambiae s.l., with high pyrethroid resistance involving L1014F kdr and CYP6P3P450 resistance mechanisms. METHODOLOGY: The efficacy of unwashed and 20-times washed DawaPlus 3.0 (polyethylene roof panel with 120 mg/m2 deltamethrin and 440 mg/m2 PBO; polyester side panels with deltamethrin 100 mg/m2) and DawaPlus 4.0 (same composition as roof of DawaPlus 3.0) was evaluated against DawaPlus 2.0 (80 mg/m2 deltamethrin; positive control). Volunteer sleepers and treatments were rotated in huts using a Latin square design on 63 consecutive nights during August-October 2016. Mortality, human blood-feeding inhibition, deterrence and exit rates of An. gambiae s.l. were monitored. PRINCIPAL FINDINGS: Significantly higher rates of mortality and blood-feeding inhibition were observed with unwashed DawaPlus 4.0 (36%; 47.5%) than unwashed DawaPlus 3.0 (11.8%; 33.3%), DawaPlus 2.0 (4.3%; 6.4%) or untreated net (P < 0.05). Washing reduced personal protective efficacy yet PBO-LLINs were more protective and both met the WHO criteria. CONCLUSIONS: The PBO-containing DawaPlus 4.0 significantly protected against An. gambiae s.l. in the study area. Unwashed DawaPlus 3.0 gave low to moderate protection against the positive control. PBO inhibits oxidase action; hence in areas with active malaria transmission having oxidase mechanisms, PBO nets could confer additional personal protection.
Subject(s)
Anopheles/drug effects , Insecticide-Treated Bednets , Mosquito Control/methods , Nitriles/pharmacology , Piperonyl Butoxide/pharmacology , Pyrethrins/pharmacology , Agriculture , Animals , Anopheles/physiology , Burkina Faso , Equipment Design , Flight, Animal/drug effects , Gossypium , Humans , Insecticides/pharmacology , Malaria/prevention & control , Mosquito Vectors/drug effects , Mosquito Vectors/physiology , OryzaABSTRACT
BACKGROUND: Visceral leishmaniasis, commonly known as kala-azar in India, is a global public health problem. In Southeast Asia, Bangladesh, Bhutan, India, Nepal, Sri Lanka and Thailand are endemic for visceral leishmaniasis. The role of sandflies as the vector of kala-azar was first confirmed in 1942 in India. Insecticide resistance in Phlebotomus argentipes Annandale and Brunetti, the vector of kala-azar in the Indian subcontinent, was first reported in 1987 in Bihar, India. This article provides a scoping review of the studies undertaken from 1959 to 2015 on insecticide resistance in P. argentipes and P. papatasi (Scopoli), the vectors of visceral and cutaneous leishmaniasis respectively, in Southeast Asia, mainly in Bangladesh, India, Nepal and Sri Lanka. RESULTS: Studies undertaken in areas of Bihar and West Bengal in India where kala-azar is endemic have reported resistance of P. argentipes to DDT, while in non-endemic areas it has been reported to be susceptible. In areas of Nepal bordering India, there are indications of resistance to DDT; biochemical resistance has been reported in Sri Lanka. No laboratory studies have been undertaken in Bangladesh; however, the sandfly vector is reported to be still susceptible to pyrethroids in all kala-azar endemic areas in the aforementioned countries. CONCLUSIONS: Studies are needed to determine the resistance of sandfly vectors to all available classes of potential insecticides in kala-azar endemic areas. There is a need to assess the impact of indoor residual spraying with DDT and pyrethroids on the incidence of kala-azar in India where 54 districts remain endemic for the disease, strengthen entomological surveillance capacity, and develop and implement an insecticide management plan. Alpha-cypermethrin indoor residual spraying has been introduced in 33 kala-azar endemic districts in Bihar State of India in a pilot trial; the outcomes should be used to inform decisions on expanding coverage with alpha-cypermethrin in all remaining endemic districts to achieve the revised goal of elimination of visceral leishmaniasis by 2020.
Subject(s)
Insect Vectors/drug effects , Insecticide Resistance , Insecticides/pharmacology , Leishmaniasis, Cutaneous/prevention & control , Leishmaniasis, Visceral/prevention & control , Psychodidae/drug effects , Animals , Asia, Western , Phlebotomus/drug effectsABSTRACT
BACKGROUND: Public health pesticides has been the mainstay control of vectors of malaria and other diseases, and public health pests, but there is increasing concern over how these pesticides are being managed. Poor pesticide management could lead to risks to human health and the environment, or diminish the effectiveness of interventions. Strategies for strengthening the management of public health pesticides, from manufacture to disposal, should be evaluated to propose future directions. METHODS: The process and outcomes of three strategies were studied in five regions of the WHO (African Region, Eastern Mediterranean Region, South-East Asia Region, Western Pacific Region, and American Region) and 13 selected countries. These strategies are: regional policy development, in-depth country support and thematic support across countries. RESULTS: Consensus, frameworks and action plans on public health pesticide management were developed at regional level. Country support for situation analysis and national action planning highlighted weaknesses over the entire spectrum of pesticide management practices, mainly related to malaria control. The thematic support on pesticide quality control contributed to structural improvements on a priority issue for malaria control across countries. CONCLUSIONS: The three strategies showed promising and complementary results, but guidelines and tools for implementation of the strategies should be further improved. Increased national and international priority should be given to support the development of policy, legislation and capacity that are necessary for sound management of public health pesticides.
Subject(s)
Malaria/prevention & control , Mosquito Control/organization & administration , Pesticides , Public Health/methods , Health Policy , Humans , Mosquito Control/methods , World Health OrganizationABSTRACT
BACKGROUND: Injecting drug use is the primary mode of HIV transmission and acquisition in Afghanistan. People who inject drugs (PWID) in the country have been characterized by high risk injecting behavior and a high burden of HCV infection. We aimed to estimate the burden of HIV, HCV, and other infectious diseases and to identify the correlates of HIV and HCV infection among PWID living in three major Afghan cities in 2009. METHODS: Epidemiologic data was collected among PWID for the integrated biological and behavioral surveillance (IBBS) survey between May and August, 2009 in three Afghan cities. Data were collected using a structured questionnaire and biologic specimens to screen for HIV, HBV, HCV, syphilis, and HSV-2 using rapid testing kits. Multiple logistic regression models were constructed to identify correlates of infection. RESULTS: Among 548 participants, pooled HIV prevalence was 7.1% (Mazar-i-Sharif: 1.0%, Kabul: 3.1%, Herat: 18.4%) and HCV prevalence was 40.3%. Almost all participants with HIV infection were co-infected with HCV (94.9%). Pooled prevalence estimates for other diseases included 7.1% for HBV, 5.5% for syphilis; and 9.3% for HSV-2. Living in Herat, ever in prison and time injecting were independently associated with HIV infection. Living in Kabul, Herat and time injecting were independently associated with HCV infection. CONCLUSIONS: There is a high and heterogeneous burden of HIV and HCV among PWID in Afghan cities. Provision of comprehensive harm reduction services to PWID in Afghanistan is warranted to reduce exposures associated with HIV and HCV infection, especially in the city of Herat.
Subject(s)
HIV Infections/epidemiology , HIV Infections/psychology , Hepatitis C/epidemiology , Hepatitis C/psychology , Risk-Taking , Substance Abuse, Intravenous/epidemiology , Substance Abuse, Intravenous/psychology , Adult , Afghanistan/epidemiology , Cities/epidemiology , Communicable Diseases/epidemiology , Communicable Diseases/psychology , Comorbidity , Health Surveys , Humans , Male , Prevalence , Young AdultABSTRACT
BACKGROUND & OBJECTIVES: Knowledge of the bionomics of mosquitoes, especially of disease vectors, is essential to plan appropriate vector avoidance and control strategies. Information on biting activity of vectors during the night hours in different seasons is important for choosing personal protection measures. This study was carried out to find out the composition of mosquito fauna biting on humans and seasonal biting trends in Goa, India. METHODS: Biting activities of all mosquitoes including vectors were studied from 1800 to 0600 h during 85 nights using human volunteers in 14 different localities of three distinct ecotypes in Goa. Seasonal biting trends of vector species were analysed and compared. Seasonal biting periodicity during different phases of night was also studied using William's mean. RESULTS: A total of 4,191 mosquitoes of five genera and 23 species were collected. Ten species belonged to Anopheles, eight to Culex, three to Aedes and one each to Mansonia and Armigeres. Eleven vector species had human hosts, including malaria vectors Anopheles stephensi (1.3%), An. fluviatilis (1.8%), and An. culicifacies (0.76%); filariasis vectors Culex quinquefasciatus (40.8%) and Mansonia uniformis (1.8%); Japanese encephalitis vectors Cx. tritaeniorhynchus (17.4%), Cx. vishnui (7.7%), Cx. pseudovishnui (0.1%), and Cx. gelidus (2.4%); and dengue and chikungunya vectors Aedes albopictus (0.9%) and Ae. aegypti (0.6%). Two An. stephensi of the total 831 female anophelines, were found positive for P. falciparum sporozoites. The entomological inoculation rate (EIR) of P. falciparum was 18.1 and 2.35 for Panaji city and Goa, respectively. INTERPRETATION & CONCLUSIONS: Most of the mosquito vector species were collected in all seasons and throughout the scotophase. Biting rates of different vector species differed during different phases of night and seasons. Personal protection methods could be used to stop vector-host contact.
Subject(s)
Anopheles/parasitology , Insect Bites and Stings , Malaria/transmission , Plasmodium falciparum/isolation & purification , Aedes , Animals , Culex , Culicidae , Ecotype , Humans , India/epidemiology , Insect Vectors , Malaria/epidemiology , SeasonsABSTRACT
BACKGROUND: It is critical that vector control pesticides are used for their acceptable purpose without causing adverse effects on health and the environment. This paper provides a global overview of the current status of pesticides management in the practice of vector control. METHODS: A questionnaire was distributed to WHO member states and completed either by the director of the vector-borne disease control programme or by the national manager for vector control. In all, 113 countries responded to the questionnaire (80% response rate), representing 94% of the total population of the countries targeted. RESULTS: Major gaps were evident in countries in pesticide procurement practices, training on vector control decision making, certification and quality control of pesticide application, monitoring of worker safety, public awareness programmes, and safe disposal of pesticide-related waste. Nevertheless, basic conditions of policy and coordination have been established in many countries through which the management of vector control pesticides could potentially be improved. Most countries responded that they have adopted relevant recommendations by the WHO. CONCLUSIONS: Given the deficiencies identified in this first global survey on public health pesticide management and the recent rise in pesticide use for malaria control, the effectiveness and safety of pesticide use are being compromised. This highlights the urgent need for countries to strengthen their capacity on pesticide management and evidence-based decision making within the context of an integrated vector management approach.
Subject(s)
Drug Utilization/standards , Guideline Adherence/statistics & numerical data , Malaria/prevention & control , Mosquito Control/methods , Mosquito Control/organization & administration , Pesticides , Drug Utilization/statistics & numerical data , Humans , Surveys and Questionnaires , World Health OrganizationABSTRACT
BACKGROUND & OBJECTIVES: Certain indigenous fish can play potential role in vector control. The study recorded distribution of Aphanius dispar (Rüppell) in its native habitats in Gujarat, India and evaluated its larval propensity for Indian mosquito vectors. METHODS: Fishes were surveyed in various districts of Gujarat and samples were collected from coastal habitats and were identified to species. Physicochemical properties of water samples were analysed in the laboratory. Five laboratory acclimatized adult fish (2.2-3 cm) released in chlorine - free water in glass jars were provided with 500 larvae daily. Five replicates were run. Daily consumption of I to IV instars of Anopheles stephensi, Aedes aegypti and Culex quinquefasciatus was recorded separately for three days. Anopheles stephensi larval control using the fish in industrial tanks (9-180 m2 ) was evaluated. RESULTS & CONCLUSION: The fish was found in large numbers in estuarine waters, rivulets, backwaters and small dams in the districts of Kutch, Jamnagar, Patan and Anand in Gujarat. Mean daily consumption of larvae in laboratory was as follows: An. stephensi 128 ± 0.2 to 204 ± 6; Cx. quinquefasciatus 24 ± 4 to 58 ± 10; Ae. aegypti 43 ± 5 to 68 ± 2. In water tanks, A. dispar reduced 93% larval counts by Day 7 and 98% by Day 21 (p <0.01), showing high larval propensity. A consolidated information on bionomics, tolerance and physicochemical properties of water taken from natural habitats of A. dispar indicate its high larvivorous potential. Large - scale evaluation is warranted to evaluate its potential in vector - borne disease control.