Insecticide-impregnated Mosquito Nets Research Articles

Monitoring Adverse Effects and Efficacy Associated with Short-Term Mefloquine Chemoprophylaxis: Experience of the Moroccan Level II Hospital in the Democratic Republic of the Congo

Malaria is transmitted by a parasite carried by certain species of Anopheles mosquitoes. The much-debated mefloquine was discovered in the 1970s by U.S. Army researchers. It is widely used to prevent and treat malaria. Our aim is to evaluate the different types of adverse reactions reported by military personnel at the Moroccan hospital in the Democratic Republic of the Congo. This is a prospective, cross-sectional study lasting three months. It was carried out using a three-part questionnaire (patient identification, vector protection used, adverse events reported, and whether or not a malaria attack had occurred). 67 military personnel. The majority of soldiers were men (97.28%), with 95% aged between 26 and 45. 100% of soldiers used mosquito nets and repellents. During the first month of chemoprophylaxis, 30% of soldiers had adverse reactions (60% had nightmares, 30% had asthenia, and 10% had somnolence). From the second month onwards, 50% of soldiers had adverse reactions (65% nightmares, 40% asthenia, 20% memory disorders, 10% somnolence, 5% headaches, and 5% insomnia). Towards the end of the third month, 53% of servicemen experienced adverse reactions (65% nightmares, 40% asthenia, 20% memory disorders, 10% somnolence, 5% headaches, 5% insomnia, and 3% anxiety). During these three months, only one case suffered a malaria attack. Mefloquine is an antimalarial drug commonly used to prevent and treat malaria. It is important to note that chemoprophylaxis alone does not guarantee 100% protection against malaria. Additional measures must therefore be taken, such as wearing long, light clothing, using insecticide-impregnated mosquito nets, and using repellents.

Vector role and human biting activity of Anophelinae mosquitoes in different landscapes in the Brazilian Amazon

BackgroundEnvironmental disturbance, deforestation and socioeconomic factors all affect malaria incidence in tropical and subtropical endemic areas. Deforestation is the major driver of habitat loss and fragmentation, which frequently leads to shifts in the composition, abundance and spatial distribution of vector species. The goals of the present study were to: (i) identify anophelines found naturally infected with Plasmodium; (ii) measure the effects of landscape on the number of Nyssorhynchus darlingi, presence of Plasmodium-infected Anophelinae, human biting rate (HBR) and malaria cases; and (iii) determine the frequency and peak biting time of Plasmodium-infected mosquitoes and Ny. darlingi.MethodsAnopheline mosquitoes were collected in peridomestic and forest edge habitats in seven municipalities in four Amazon Brazilian states. Females were identified to species and tested for Plasmodium by real-time PCR. Negative binomial regression was used to measure any association between deforestation and number of Ny. darlingi, number of Plasmodium-infected Anophelinae, HBR and malaria. Peak biting time of Ny. darlingi and Plasmodium-infected Anophelinae were determined in the 12-h collections. Binomial logistic regression measured the association between presence of Plasmodium-infected Anophelinae and landscape metrics and malaria cases.ResultsNinety-one females of Ny. darlingi, Ny. rangeli, Ny. benarrochi B and Ny. konderi B were found to be infected with Plasmodium. Analysis showed that the number of malaria cases and the number of Plasmodium-infected Anophelinae were more prevalent in sites with higher edge density and intermediate forest cover (30–70%). The distance of the drainage network to a dwelling was inversely correlated to malaria risk. The peak biting time of Plasmodium-infected Anophelinae was 00:00–03:00 h. The presence of Plasmodium-infected mosquitoes was higher in landscapes with > 13 malaria cases.ConclusionsNyssorhynchus darlingi, Ny. rangeli, Ny. benarrochi B and Ny. konderi B can be involved in malaria transmission in rural settlements. The highest fraction of Plasmodium-infected Anophelinae was caught from midnight to 03:00 h. In some Amazonian localities, the highest exposure to infectious bites occurs when residents are sleeping, but transmission can occur throughout the night. Forest fragmentation favors increases in both malaria and the occurrence of Plasmodium-infected mosquitoes in peridomestic habitat. The use of insecticide-impregnated mosquito nets can decrease human exposure to infectious Anophelinae and malaria transmission.Graphical

Decreased endemic malaria in Suriname: moving towards elimination

BackgroundSuriname has moved from being the country with the highest annual parasite index in the Americas to one on the threshold of elimination. The progress toward elimination in the stable populations of Suriname between 2000 and 2015 is reviewed.MethodsData was obtained from the Medical Mission and the Ministry of Health Malaria Programme case-reporting systems, and analysed with a focus on disease burden and differentiation of the disease geographically, by malaria species, age, gender, ethnicity, incidence and gametocytaemia.ResultsBetween 2000 and 2015 there were 57,811 locally acquired cases of malaria in the stable populations of Suriname. A significant reduction in indigenous malaria cases was observed from 2006 to 2015. The number of imported malaria cases saw a relative increase compared to the number of autochthonous cases. In 2015 over 95% of the cases reported in stable communities are imported, mainly from neighbouring French Guiana, a department of France. The overall decline in malaria case incidence followed the mass-distribution of free long-lasting insecticide-impregnated mosquito nets and increased awareness building efforts, improved access to malaria services as a result of the introduction of Rapid Diagnostic Tests and the implementation of active case detection in high risk areas. In addition, improved management of Plasmodium falciparum infections was achieved with the introduction of artemisinin combination therapy.ConclusionsThe existence of a network of policlinics in the interior ran by Medical Mission, for the indigenous population, allowed the rapid implementation of the strategy in stable communities. The success of malaria control in Suriname indicates that the availability at local level, of prompt and adequate prevention, diagnosis and treatment is a key requirement for the elimination of malaria.

Persistence of Organophosphorus and Pyrethrinoid Insecticides, used for Malaria Control, in Soil and Water: Case of the District of Vohipeno, South-Eastern Madagascar

Malaria still persists in underdeveloped countries, including Madagascar, where it is the eighth leading cause of morbidity in Madagascar (SSS, 2011). Thanks to the application of the two insecticide-impregnated mosquito nets (ITN) and the Intra-Home Spraying Campaign (IDAC) systems, this rate has risen from 21.57% in 2003 to 5% in 2011 for children under 5 years of age and from 17.57% to 2.3% in 2011 for children over 5 years of age. The malaria mortality rate increased from 25.92% to 19% for children under 5 years of age and from 13.5% to 5% for those over 5 years of age (SSS, 2011). However, these control methods are based on the use of pesticides and require great caution. Indeed, due to poor practice, organophosphorus (insecticide used in CAID) and pyrethrinoid (insecticide impregnated on ITNs) were detected after analysis The instrument used was an Infinity 1290 Agilent Technologies HPLC Infinity 1290 system (Santa Clara, CA, USA) coupled with an Agilent Technologies 6460 triple quadrupole mass spectrometer in soil, surface water and groundwater from the three villages (Tanandava, Vohitramba and Savagna) in the south-eastern region of Madagascar where sampling takes place.

Is malaria over-diagnosed? A world malaria day 2017 experience by Excellence and Friends Management Care Centre (EFMC) and partners, Abuja Nigeria.

Malaria remains a major cause of mortality across the world, but particularly in sub-Saharan Africa. WHO-sponsored World Malaria Day activity has helped to improve education and has contributed to a reduction in mortality globally in the past decade. However, much needs to be done still in Africa. We report on a World Malaria Day scheme in three primary Healthcare Facilities in and around the Abuja Federal Capital Territory in Nigeria in 2017. Activity included educational talks to pregnant women and nursing mothers of young children, with malarial testing, distribution of free mosquito nets and also medical treatment if needed. We found a large clinical over-diagnosis of malaria with simple fevers of any cause being reported as malaria. None of these cases were found to be due to malaria on formal malarial testing. We conclude that efforts should continue into education and prevention of malaria with insecticide-impregnated mosquito nets a key factor. However, over-diagnosis of malaria and the use of unnecessary antimalarial treatment may lead to parasite resistance to antimalarial treatment, morbidity from drug side-effects and potential mortality from not receiving the right treatment for other febrile illnesses. We recommend that malarial testing, particularly with simple blood film microscopy is implemented more widely across Africa, as it is simple to perform and allows effective management plans to be drawn up for individual patients.

Is Malaria Over-Diagnosed? A World Malaria Day 2017 Experience by Excellence and Friends Management Care Centre (EFMC) and Partners, Abuja Nigeria

Malaria remains a major cause of mortality across the world, but particularly in sub-Saharan Africa. WHOsponsored World Malaria Day activity has helped to improve education and has contributed to a reduction in mortality globally in the past decade. However, much needs to be done still in Africa. We report on a World Malaria Day scheme in three primary Healthcare Facilities in and around the Abuja Federal Capital Territory in Nigeria in 2017. Activity included educational talks to pregnant women and nursing mothers of young children, with malarial testing, distribution of free mosquito nets and also medical treatment if needed. We found a large clinical over-diagnosis of malaria with simple fevers of any cause being reported as malaria. None of these cases were found to be due to malaria on formal malarial testing. We conclude that efforts should continue into education and prevention of malaria with insecticide-impregnated mosquito nets a key factor. However, over-diagnosis of malaria and the use of unnecessary antimalarial treatment may lead to parasite resistance to antimalarial treatment, morbidity from drug side-effects and potential mortality from not receiving the right treatment for other febrile illnesses. We recommend that malarial testing, particularly with simple blood film microscopy is implemented more widely across Africa, as it is simple to perform and allows effective management plans to be drawn up for individual patients.

English

Malaria is the most important vector-borne disease in tropical and sub-tropical countries. Although, different control measures like use of insecticide-impregnated mosquito nets and curtains, chemotherapy and others are in place, so far, malaria eradication has proved impossible in affected areas. Therefore, any measure that attempts to fight the parasite or its vector (Anopheles spp.) would be of help. In this experiment, we assessed the efficacy of Euphorbia tirucalli latex both as a herbal mosquito remedy and larvicide against Anopheles fenestus Giles and Anopheles gambae Giles in a semi-natural environment. Our results indicate that E. tirucallilatex can bring about total mortality of Anopheles species larvae at the highest dilution used of 1: 250 in 5 days. LT 50 and LT 90 for the same dilution were attained at 12 and 36 h respectively. Latex was active only for eight days which is typical for herbal biocides, whose advantage is that they do not accumulate in the environment. It is concluded that E. tirucalli latex has a high efficacy against Anopheles mosquito larvae and could eventually be considered for adoption as a plant based mosquito larvicide, after further research.   Key words: Euphorbia tirucalli, Anopheles spp., latex, larvicide, malaria, efficacy.

People's perception of malaria in Mbarara, Uganda.

To understand people's perceptions of malaria and their implications for control programmes, we held focus group discussions (FGDs) and conducted semi-structured interviews (SSIs) with community members in Mbarara, Uganda. Mosquitoes were perceived as the cause or transmitters of malaria but the causation/transmission model of people differed from biomedical facts. Convulsions, a common complication of malaria, were perceived as a supernatural ailment, best treated by traditional medicine, as was splenomegaly. More than 70% of the patients with malaria had treatment from non-public health sources. This included self-treatment (13%), use of traditional healers (12%) and use of private medical practitioners/pharmacists (69%). Although 26% (887/3309) used bednets to prevent malaria, only 7% of the nets were impregnated with insecticide. People who did not use bednets cited discomfort because of heat/humidity and their high cost as reasons. To improve malaria control in this area, people need to be educated on the connection between mosquitoes and malaria and on seeking biomedical treatment for convulsions. The malaria control programme could collaborate with traditional and private health care providers to increase promotion of insecticide-impregnated mosquito nets.

Malaria control stymied in 2010, mastered in 2025.

Presented in a question-and-answer form this article discusses: the availability of necessary tools for tackling parasite resistance to drugs and mosquito resistance to insecticides; the effectiveness of the Roll Back Malaria horizontal program; the accuracy of malaria control strategies; and the probability of the Roll Back Malaria program’s controlling malaria in 2010 and 2025. It is projected that in 2010 over 80% of the population in every village in malarious areas of Africa will be sleeping under insecticide-impregnated mosquito nets every night. Fever clinics with effective antimalarial drugs will exist within 5 km of 80% of the villages. However the strategies of patient management selective treatment and chemoprophylaxis during pregnancy bednet distribution and epidemic containment will have little long-term impact on transmission. In 2025 over 90% of persons in rural malarious areas will be sleeping under long-duration insecticide-impregnated bed nets and using insecticide-impregnated clothing and soap with effective nontoxic insect repellents. Malarial first-line therapy chloroquine and pyrimethamine-sulfadoxine will be replaced by new low-cost antimalarial drugs. New treatment and prevention interventions will be existent through the use of improved genetic understanding of mosquitoes parasites and human susceptibility to malaria.

The Gambian National Impregnated Bednet Programme: Costs, consequences and net cost-effectiveness

Clinical trials have indicated that treating mosquito nets with insecticide could be a potentially cost-effective method of preventing malaria. As malaria is one of the most common causes of death in children under five in developing countries, there has been substantial interest in whether such findings can be replicated for a country's control programme in practice. The cost-effectiveness of the Gambian National Insecticide-impregnated Bednet Programme (NIBP), from the viewpoint of providers (government and non-governmental agencies) and the community, has been calculated. Information was collected from existing records, interviews with NIBP personnel, observation and household surveys. Information is provided on the resource use consequences of the NIBP in terms of reduced expenditure on anti-malaria preventive measures, treatment in government health services, household financed treatment and “charity” (burial, funeral and mourning activities), as well as cash income lost as a result of child death. The annual implementation cost of the NIBP was D757 875 (US$91 864), of which 86% was recurrent cost. The estimated number of deaths averted was 40.56. The net implementation cost-effectiveness ratio per death averted and discounted life years gained were D3884 (US$471) and D260 (US$31.5), respectively. Adding the cost of all mosquito nets would increase the cost-effectiveness ratios by over five times, which is an important consideration for countries with a lower coverage of mosquito nets per capita. It is concluded that insecticide-impregnated mosquito nets are one of the more efficient ways of reducing deaths in children under 10 years in rural Gambia.

Use of insecticide-impregnated mosquito nets and other impregnated materials for malaria control in the Americas

This article reviews the current status of the use of insecticide-impregnated mosquito nets and other impregnated materials in the Americas. Studies from Brazil, Colombia, Ecuador, Guatemala, Peru, Suriname, and Venezuela are examined. It is concluded that most studies have suffered from experimental design errors, short duration problems, and/or inadequate measurement of health indicators. The review brings out the great difficulty of conducting scientific studies that attempt to measure the impact of insecticide-treated materials on malaria incidence. In particular, the low incidence of malaria in the Americas, the high prevalences of P. vivax and relapsing cases, and the relationship between human activity patterns and the crepuscular biting patterns of certain malaria vectors stand in the way of easy experimental design and execution. The utilization of impregnated mosquito nets or other impregnated materials as a major component of an integrated malaria control program would be premature at this time. However, it is recommended that well-conceived large-scale trials and interventions be considered when they are based on a thorough understanding of the dynamics of malaria transmission in the area of study.

Should governments subsidize the use of insecticide-impregnated mosquito nets in Africa? Implications of a cost-effectiveness analysis.

Recent large-scale field trials show that mosquito nets impregnated with insecticide can substantially reduce all-cause mortality in children in malaria-endemic areas in Africa. This paper considers the cost-effectiveness of impregnated nets, initially from the perspective of a government programme which would distribute nets free of charge and organize and fund re-impregnation on an annual basis. The calculations show that with the reductions in all-cause mortality observed in the trials, complete government subsidy of nets through a vertical programme would represent an efficient use of scarce resources for most combinations of assumptions. However, alternative ways of financing and organizing the use of impregnated nets are also possible and may be more cost-effective than vertical delivery. Distribution of nets and insecticide might be less costly than required for a vertical programme by integrating delivery with other types of government health programmes, with private sector delivery systems for other types of products, or with government systems developed for other sectors such as agriculture. Further, not all the costs need to be met by governments, as costs could be shared with donors, NGOs and the beneficiaries. The major conclusion is that impregnated nets would save a large number of lives in malaria endemic areas, they are an efficient use of scare resources, and ways of encouraging their use need to be developed and tested.

Local terminology for febrile illnesses in Bagamoyo District, Tanzania and its impact on the design of a community-based malaria control programme

This paper reviews results of several ethnographic studies that have examined the issue of local terminology for malaria in Africa, then presents findings from an on-going study in Bagamoyo District, Tanzania. The study used a mixture of qualitative and quantitative interview methods to examine local perceptions of malaria and malaria treatment practices. Although the local term homa ya malaria or malaria fever appeared on the surface to correspond closely with the biomedical term malaria, significant and often subtle differences were found between the two terms. Of perhaps greatest importance, common consequences of malaria in endemic areas such as cerebral malaria in young children, severe anaemia and malaria in pregnancy were not connected with homa ya malaria by many people. A set of guidelines are described that were used to determine how best to promote acceptance and use of insecticide-impregnated mosquito nets, given these results. It is demonstrated that the position of the term used to denote malaria in the local taxonomy of febrile illnesses has important implications for the design of health education interventions.