Use Of Insecticide-treated Bed Nets Research Articles

Cattle, other domestic animal ownership, and distance between dwelling structures are associated with reduced risk of recurrent Plasmodium falciparum infection in southern Zambia

To examine the associations between household Plasmodium falciparum infection and a number of factors including domestic animal ownership, potential mosquito breeding sites, indoor darkness, density of people, distance between dwelling structures, and insecticide-treated bed net use. Analyses were based on data collected from a household survey conducted in Macha, Zambia. Thirty-four households with recurrent malaria infection in 2005-2008 were selected as case households and compared with 37 control households with no malaria infection randomly selected from the same geographic area. Logistic regression models were used to identify factors associated with household P. falciparum infection. In multivariate analysis, cattle ownership was associated with reduced risk of P. falciparum infection (adjusted odds ratio = 0.19; 95% CI = 0.05-0.69), as was increased distance between dwelling structures (aOR = 0.26; 95% CI = 0.07-0.98). Ownership of the highest category of cattle, goats, dogs, or cats dramatically reduced the risk of P. falciparum infection (aOR = 0.13; 95% CI = 0.03-0.56). Domestic animal, in particular cattle, ownership and greater distance between dwelling structures were associated with reduced risk of recurrent P. falciparum infection at the household level. These factors should be further investigated as supplemental measures for malaria control in rural African settings.

Parasitic lung infections

Global climate change and population explosion leading to changes in natural ecosystem and travel across the continents have resulted in an increase in the transmission of parasites to human beings. This review focuses on recent advancements in parasitic lung infections. Invasive parasitic diseases including lung infections are increasingly being reported in patients with immunodeficiency syndromes. A recombinant kinesin-related antigen of Leishmania donovani has been validated with ELISA using urine samples for the diagnosis of visceral leishmaniasis. Pyruvate kinase deficiency has been shown to provide protection against Plasmodium falciparum infection. Intravenous artesunate is an alternative drug for the treatment of severe malaria. The best way to protect from malaria is the use of long-lasting insecticide-treated bednets. Biennial treatment with praziquantel has been found to be cost-effective treatment for control of infection with Schistosoma haematobium. Pulmonary paragonimiasis can be diagnosed by fine needle aspiration biopsy of pulmonary nodules. Strongyloides stercoralis hyperinfection can mimic accelerated idiopathic pulmonary fibrosis. Migratory nodular shadows with halos are important chest computed tomographic findings in human toxocariasis. Patients with immunodeficiency syndromes (HIV infection, organ transplantation and immunosuppressive drugs, including corticosteroids) should be evaluated for early detection of parasitic lung infections.

Equity and coverage of insecticide-treated bed nets in an area of intense transmission of Plasmodium falciparum in Tanzania

BackgroundThere is no clear consensus on the most sustainable and effective distribution strategy for insecticide treated bed nets (ITNs). Tanzania has been a leader in social marketing but it is still not clear if this can result in high and equitable levels of coverage.MethodsA cluster-randomized survey of ITN and bed net ownership and use was conducted in a rural area exposed to intense Plasmodium falciparum transmission in NE Tanzania where ITN distribution had been subject to routine delivery of national strategies and episodic free distribution through local clinics. Data were collected on household assets to assess equity of ITN coverage and a rapid diagnostic test for malaria (RDT) was performed in all ages.ResultsAmong 598 households in four villages the use of any or insecticidal bed nets in children less than five years of age was 71% and 54% respectively. However there was a 19.8% increase in the number of bed nets per person (p < 0.001) and a 13.4% increase in the number of insecticidal nets per person (p < 0.001) for each quintile increase in household asset score. The odds of being RDT-positive were reduced by more than half in the least poor compared to the poorest households (OR 0.49, 95% CI 0.35–0.70). Poorer households had paid less for their nets and acquired them more recently, particularly from non-commercial sources, and bed nets in the least poor households were less likely to be insecticidal compared to nets in the poorest households (OR 0.44, 95% CI 0.26–0.74).ConclusionMarked inequity persists with the poorest households still experiencing the highest risk of malaria and the lowest ITN coverage. Abolition of this inequity within the foreseeable future is likely to require mass or targeted free distribution, but risks damaging what is otherwise an effective commercial market.

Preliminary examination of integrated vector management in a tropical rainforest area of Cameroon

In the tropical rainforest area of Cameroon, people are affected by blackflies (Simulium spp.) and mosquitoes (Anopheles spp). Use of insecticide-treated bed nets (ITNs) has been promoted to protect vulnerable groups from mosquito bites, whereas historically indoor residual spraying (IRS) was the primary intervention. In a malaria-endemic area, a pilot study examined different mosquito control interventions applied to entire villages to assess their impact on vectors, malaria incidence and the quality of life of the communities. The Sanaga River near these villages was treated with insecticide to kill blackfly larvae. A medical survey of the six villages had shown that 20% of the population suffered from malaria, while 50% were infected with onchocerciasis and 5% with Loa loa. IRS+ITN using ICON CS (lambda-cyhalothrin capsule suspension formulation) or improved screening of houses combined with outdoor misting reduced the numbers of mosquitoes collected from exit traps compared to the other treatments. More sporozoites were detected in mosquitoes sampled in exit traps in the untreated village than in the treated villages. Malaria incidence several months after treatments was not significantly different from pre-treatment levels. Blackfly adult populations were reduced for several weeks following larvicide application but recovered when treatment was halted.

Assessment of Insecticide-Treated Bednet Use Among Children and Pregnant Women Across 15 Countries Using Standardized National Surveys

Impact of insecticide-treated bednets (ITNs) on preventing malaria may be minimized if they are not used by vulnerable populations. Among ITN-owning households from 15 standardized national surveys from 2003 to 2006, we identify factors associated with ITN use among children younger than 5 years of age and make comparisons of ITN use among children and pregnant women across countries. Within ITN-owning households, many children and pregnant women are still not using them. Between-country analysis with linear regression showed child ITN use increases as intra-household access to ITNs increases (P = 0.020, R2 = 0.404), after controlling for season and survey year. Results from within-country logistic regression analyses were consistent with between-country analysis showing intra-household access to ITNs is the strongest and most consistent determinant of use among children. The gaps in ITN use and possession will likely persist in the absence of achieving a ratio of no more than two people per ITN.

Impact assessment of the use of insecticide-treated bed nets on parasitaemia and anaemia for malaria control in children, Ogun State, Nigeria

estimate that malariahas caused 300–500 million infections, 100 million clinical casesand 1.5–2.7 million deaths, represent ing a serious public healthproblem in Asia and Africa. It is caused by a protozoan parasite,Plasmodium, transmitted from person to person, mainly throughthe bite of a female Anopheles mosquito which requires blood tonurture her eggs. The female Anopheles mosquito is the vector forhuman malaria, and mainly bites humans between 5pm and 7am,with maximum intensity between 10pm and 4am. This providesthe basis for the use of mosquito bed nets and insecticide-treatedbed nets (ITNs) whilst sleeping, since mosquitoes are most activeduring that period.

A parasitological survey, in rural Zanzibar, of pre-school children and their mothers for urinary schistosomiasis, soil-transmitted helminthiases and malaria, with observations on the prevalence of anaemia

'Kick-out-Kichocho' is an integrated helminth-control initiative that is aimed at reducing the burden of urinary schistosomiasis and soil-transmitted helminthiases (STH) on Zanzibar Island (Unguja), in Tanzania. Like other initiatives based on preventive chemotherapy, the programme is mainly school-based and, consequently, pre-school children (aged < or =6 years) are not targeted specifically. To assess the importance of urinary schistosomiasis, STH and malaria, as well as the occurrence of anaemia and growth retardation among these younger children, an epidemiological survey has been undertaken, in a rural area of Unguja, among 152 pre-school children and their 113 mothers. In the pre-school children investigated, urinary schistosomiasis was rare because of the children's lack of contact with environmental water. Malaria was also rare in the children, probably as a consequence of the study season, the widespread use of insecticide-treated bednets and the good access to first-line antimalarial drugs. In contrast, the prevalences of infection with at least one soil-transmitted helminth and of anaemia were alarmingly high among the pre-school children, at 50.0% [95% confidence interval (CI)=40.4%-59.6%) and 73.4% (CI=?65.2%-80.5%), respectively; the corresponding values in the children's mothers were 35.2% (CI=25.4%-45.9%) and 25.9% (CI=18.0%-35.3%). In the rural study area, Kandwi was identified as a hamlet with particularly high levels of transmission of soil-transmitted helminths, and household aggregations of STH were common. To reduce the present health inequities, the future integration of pre-school children within ongoing anthelmintic-control programmes in schools is strongly recommended.

Malaria scale-up progress: is the glass half-empty or half-full?

This letter makes the case as to why the glass is half-full in terms of malaria in African countries. It describes several reasons for that stance including: some success has been achieved with seven African countries projecting use of insecticide-treated bednets of more than 40% international funding for malaria control has increased three-fold from 2004 to 2007 and leadership is more effective at global and national levels resulting in improved coordination and more effective advocacy.

Bed net ownership, use and perceptions among women seeking antenatal care in Kinshasa, Democratic Republic of the Congo (DRC): Opportunities for improved maternal and child health

BackgroundTo describe malaria knowledge, attitudes toward malaria and bed net use, levels of ownership and use of bed nets, and factors associated with ownership and use among pregnant women attending their first antenatal care (ANC) visit in Kinshasa, DRC.MethodsWomen attending their first ANC visit at one maternity in Kinshasa were recruited to take part in a study where they were given free insecticide treated bed nets (ITNs) and then followed up at delivery and 6 months post delivery to assess ITN use. This study describes the baseline levels of bed net ownership and use, attitudes towards net use and factors associated with net useResultsAmong 351 women interviewed at baseline, 115 (33%) already owned a bed net and 86 (25%) reported to have slept under the net the previous night. Cost was reported as the reason for not owning a net by 48% of the 236 women who did not own one. In multivariable analyses, women who had secondary school or higher education were 3.4 times more likely to own a net (95% CI 1.6–7.3) and 2.8 times more likely to have used a net (95% CI 1.3–6.0) compared to women with less educationConclusionDistribution of ITNs in antenatal clinics in this setting is needed and feasible. The potential for ITN use by this target population is high.

Vector control by insecticide‐treated nets in the fight against visceral leishmaniasis in the Indian subcontinent, what is the evidence?

Visceral leishmaniasis (VL) is a deadly vector-borne disease that causes an estimated 500 000 new cases a year. In India, Nepal and Bangladesh, VL is caused by Leishmania donovani, which is transmitted from man to man by the sandfly Phlebotomus argentipes. In 2005, these three countries signed a memorandum of understanding to eliminate VL from the region. Integrated vector management is one of the pillars of this elimination strategy, alongside early case detection and treatment. We reviewed the evidence of effectiveness of different vector control methods, to examine the potential role of insecticide treated bednets (ITNs). Indoor residual spraying has shown poor impact for various reasons and resistance to DDT is emerging in Bihar. Environmental management performed poorly compared to insecticide based methods. ITNs could give individual protection but this still needs to be proven in randomized trials. Given the constraints of indoor residual spraying, it is worthwhile to further explore the use of ITNs, in particular long lasting ITNs, as an additional tool in the VL elimination initiative.

Science rides the online wave

Science rides the online wave

Microarrays

Microarrays

A new global malaria eradication strategy

A new global malaria eradication strategy

Assessing the validity of health facility‐based data on insecticide‐treated bednet possession and use: comparison of data collected via health facility and household surveys – Lindi region and Rufiji district, Tanzania, 2005

Objective To assess the validity of health facility (HF)-based data on bednet and insecticide-treated bednet possession and use by children <5 years old. Methods We compared estimates based on data collected via HF surveys of under-5s attending well-child visits (e.g. immunizations) and sick-child visits vs. representative household surveys (a 'gold standard' method for measuring insecticide-treated net coverage). In Lindi region, Tanzania, we collected contemporaneous data on 637 under-5s via a HF survey (444 well-child visits and 193 sick-child visits), and on 305 households with an under-5 (including 354 children) via a household survey. In Rufiji district, Tanzania, we collected contemporaneous data on 1433 under-5s via a HF survey (911 well-child visits and 522 sick-child visits), and on 328 households with an under-5 (including 455 children) via a household survey. Results Possession of bednets by households with an under-5 was similar using HF data and household data in both Lindi region and Rufiji district. However, reported use of bednets was significantly higher in HF data than household data in both Lindi and Rufiji, as was reported use of insecticide-treated bednets. HF-based data accurately estimated community-level bednet possession in households with an under-5, but overestimated community-level bednet use by 9-35% and insecticide-treated bednet use by 15-21%. Conclusions Information bias rather than selection bias appears to be a key cause for the overestimation of bednet and insecticide-treated bednet use (e.g. social desirability bias: caretakers of under-5s attending health facilities might be more likely to report using bednets and insecticide-treated bednets). Additional studies of the validity, cost and utility of HF-based data to monitor insecticide-treated bednet use are needed before recommending this monitoring strategy for widespread use. Overestimating insecticide-treated bednet use could lead to inappropriate public health actions and missed opportunities for achieving local and global public health goals.

Cold War, Deadly Fevers: Malaria Eradication in Mexico, 1955–1975

Marcos Cueto is a medical historian who describes the details of malaria eradication efforts in Mexico in the context of the Cold War era authoritarianism. His approach works overall, but occasionally he overreaches. Mr. Cueto asserts that the politics of the time allowed the medical community to be similarly authoritarian in forcing malaria eradication to be the accepted strategy. He states that the political climate relied on fear-based tactics of spreading anxiety about the communist threat and that similar strategies were used to gain public support for the malaria eradication effort, incorporating military jargon such as “enemy” mosquitoes and “campaigns” against disease into the public health lexicon. These campaigns included a propaganda arm in which pop stars became champions for the cause, to make the public sympathetic to their efforts. At one point, the author likens the strategy of screening persons for asymptomatic malaria parasitemia to the 1950s McCarthy-style witch hunts for hidden communists—stretching the analogy beyond tolerable limits. A recurring theme in the book is Mr. Cueto’s skepticism of new technologies, especially those introduced by other (non-Mexican) national or international organizations.He disparages the adoption of chloroquine, DDT, and smear microscopy as “magic bullet” strategies, claiming they distracted from rather than enhanced control efforts. He suggests that current efforts, which tout the use of long-lasting insecticide-treated bed nets and artemisinin-based combination therapy, are similarly flawed. He never really articulates proven alternatives to the adoption of new technologies, but he vaguely suggests relying on community-based broad public health programs at the grassroots level. I found the tone of the book a bit cynical and fatalistic. I got the impression that Mr. Cueto believes that all individuals and organizations attempting malaria eradication were doing so not for its own sake but rather as a front for other agendas such as centralizing national power in Mexico, furthering the international interests of capitalist countries, or personal glory. The author uses the fact that the eradication effort failed to support his contention that it was probably a bad idea in the first place. Fast forward to today when there is a renewed interest in malaria control efforts. Witness the Global Fund to Fight AIDS, Tuberculosis, and Malaria; the Bill & Melinda Gates Foundation; the President’s Malaria Initiative; and pop stars such as Bono championing the cause, including the possibility of eradication. Sounds familiar. In light of the current progress of malaria control efforts in Mexico, where most states are now malaria free and the total number of cases has been steadily decreasing, Mexico is well on its way to achieving those original eradication goals. Thus, whether you agree with the author’s politics or not, if you are considering getting into the business of malaria eradication, you could benefit by reviewing this very detailed historical account of a malaria eradication effort that was unsuccessful.

Determining Important Parameters in the Spread of Malaria Through the Sensitivity Analysis of a Mathematical Model

We perform sensitivity analyses on a mathematical model of malaria transmission to determine the relative importance of model parameters to disease transmission and prevalence. We compile two sets of baseline parameter values: one for areas of high transmission and one for low transmission. We compute sensitivity indices of the reproductive number (which measures initial disease transmission) and the endemic equilibrium point (which measures disease prevalence) to the parameters at the baseline values. We find that in areas of low transmission, the reproductive number and the equilibrium proportion of infectious humans are most sensitive to the mosquito biting rate. In areas of high transmission, the reproductive number is again most sensitive to the mosquito biting rate, but the equilibrium proportion of infectious humans is most sensitive to the human recovery rate. This suggests strategies that target the mosquito biting rate (such as the use of insecticide-treated bed nets and indoor residual spraying) and those that target the human recovery rate (such as the prompt diagnosis and treatment of infectious individuals) can be successful in controlling malaria.

Providing insecticide treated bed nets in antiretroviral treatment clinics in Malawi: a pilot study

HIV infection and malaria, two of the most common and important health problems in sub-Saharan Africa, have been demonstrated to have interactive pathology. In Malawi, where malaria is endemic, and antiretroviral therapy (ART) delivery is scaling up, we piloted integration of long-lasting insecticide-treated bednets (ITN) provision in three ART clinics. In July 2006, 1,910 ITNs were delivered to pilot sites, and ART clinic staff personnel were briefed on ITN provision and use of a monitoring system. Sites were assessed using a structured questionnaire in December 2006. During the pilot period, 1,282 ITNs were distributed to patients. A large proportion (70%) of ART patients at these sites received pilot study ITNs. Site adherence to the monitoring system was variable. Seventeen patients were interviewed, 14 of whom were ART patients who had received ITNs; 11 of these (79%) had slept under the net the previous night. This pilot demonstrates the feasibility of ITN distribution to patients attending ART clinics in Malawi. Programmatic and policy considerations for national roll-out include the need to: 1) adopt a standardized monitoring system, 2) develop information, education, and communication materials, 3) develop in-service training for ART clinicians, and 4) identify systems for forecasting, procuring and distributing ITNs.

Insecticide-Treated Bednets Improve Child Survival

Controlled trials have shown that use of insecticide-treated bednets (ITNs) reduces all-cause early childhood mortality in malaria-endemic areas by

Effects of trimethoprim-sulfamethoxazole and insecticide-treated bednets on malaria among HIV-infected Ugandan children

Trimethoprim-sulfamethoxazole (TMP/SMX) prophylaxis and insecticide-treated bednets reduce malaria risk among HIV-infected adults. The efficacy of TMP/SMX may be diminished where antifolate resistance to malaria is high. We evaluated the efficacy of these interventions for malaria prevention among Ugandan children. We concurrently followed 300 HIV-infected children aged 1-10 years and a community-based cohort of 561 healthy children aged 1-11 years over 11 months in Kampala, Uganda. The HIV-infected children received TMP/SMX prophylaxis and insecticide treated bednets. In the community cohort, insecticide-treated bednets were introduced during the observation period. Children from both cohorts were followed using a standardized protocol to measure the incidence of malaria. Only nine episodes of malaria were diagnosed among HIV-infected children (incidence = 0.07/person-year) in comparison with 440 episodes among children from the community (incidence = 0.90/person-year; P < 0.0001). The use of insecticide-treated bednets was associated with a 43% reduction in malaria incidence (P < 0.001), and a combination of TMP/SMX and use of insecticide-treated bednets with a 97% reduction in malaria incidence (P < 0.001). The prevalence of five mutations associated with antifolate resistance was high among malaria cases detected in both the HIV (100%) and community cohorts (75%). Malaria accounted for only 4% of febrile episodes in the HIV cohort in comparison with 33% in the community-based cohort (P < 0.0001). In a malaria endemic area with a high level of molecular markers of antifolate resistance, the combined use of TMP/SMX prophylaxis and insecticide-treated bednets was associated with a dramatic reduction in malaria incidence among HIV-infected children.

The combined use of cotrimoxazole and insecticide-treated bednets dramatically reduced the incidence of malaria in children with HIV infection,

The combined use of cotrimoxazole and insecticide-treated bednets dramatically reduced the incidence of malaria in children with HIV infection,