Ranking malaria risk factors to guide malaria control efforts in African highlands

Introduction

Malaria is re-emerging in most of the African highlands exposing the non immune population to deadly epidemics. A better understanding of the factors impacting transmission in the highlands is crucial to improve well targeted malaria control strategies.

Methods and Findings

A conceptual model of potential malaria risk factors in the highlands was built based on the available literature. Furthermore, the relative importance of these factors on malaria can be estimated through “classification and regression trees”, an unexploited statistical method in the malaria field. This CART method was used to analyse the malaria risk factors in the Burundi highlands. The results showed that Anopheles density was the best predictor for high malaria prevalence. Then lower rainfall, no vector control, higher minimum temperature and houses near breeding sites were associated by order of importance to higher Anopheles density.

Conclusions

In Burundi highlands monitoring Anopheles densities when rainfall is low may be able to predict epidemics. The conceptual model combined with the CART analysis is a decision support tool that could provide an important contribution toward the prevention and control of malaria by identifying major risk factors.

Synergy between repellents and organophosphates on bed nets: efficacy and behavioural response of natural free-flying An. gambiae mosquitoes

BACKGROUND

Chemicals are used on bed nets in order to prevent infected bites and to kill aggressive malaria vectors. Because pyrethroid resistance has become widespread in the main malaria vectors, research for alternative active ingredients becomes urgent. Mixing a repellent and a non-pyrethroid insecticide seemed to be a promising tool as mixtures in the laboratory showed the same features as pyrethroids.

METHODOLOGY/PRINCIPAL FINDINGS

We present here the results of two trials run against free-flying Anopheles gambiae populations comparing the effects of two insect repellents (either DEET or KBR 3023, also known as icaridin) and an organophosphate insecticide at low-doses (pirimiphos-methyl, PM) used alone and in combination on bed nets. We showed that mixtures of PM and the repellents induced higher exophily, blood feeding inhibition and mortality among wild susceptible and resistant malaria vectors than compounds used alone. Nevertheless the synergistic interactions are only involved in the high mortality induced by the two mixtures.

CONCLUSION

These field trials argue in favour of the strategy of mixing repellent and organophosphate on bed nets to better control resistant malaria vectors.

Bed bugs - What the GP needs to know

BACKGROUND

Since the mid 1990s, there has been a global resurgence of bed bugs (Cimex spp.), which are blood feeding insects that readily bite humans. Patients suffering with bite reactions are increasingly presenting to medical practitioners.

OBJECTIVE

This article reviews the various clinical consequences of bed bug bites and outlines management strategies.

DISCUSSION

Common dermatological responses include the early development of small macular spots that may later progress into prominent wheals accompanied by intense itching. Patients exposed to numerous bed bugs can present with a widespread erythematous rash or urticaria. Bullous eruptions are not uncommon and anaphylaxis has been reported, albeit rarely. There is no evidence that bed bugs transmit human pathogens, but they are responsible for significant psychological distress, can produce anaemia when abundant, and have been implicated in the triggering of asthmatic reactions. Symptomatic control involves treatment of the patient with antihistamines and corticosteroids, and ensuring that the infestation responsible for the problem is effectively eliminated.

Field evaluation of ZeroFly--an insecticide incorporated plastic sheeting against malaria vectors & its impact on malaria transmission in tribal area of northern Orissa

BACKGROUND & OBJECTIVES

Insecticide incorporated plastic sheeting is a new technology to control mosquitoes in emergency shelter places and also temporary habitations in different locations. Therefore, field studies were conducted to assess the efficacy of ZeroFly plastic sheeting treated with deltamethrin on prevailing disease vectors Anopheles culicifacies and An. fluviatilis and its impact on malaria transmission in one of the highly endemic areas of Orissa.

METHODS

The study was conducted in Birkera block of Sundargarh district, Orissa state. The study area comprised 3 villages, which were randomized as ZeroFly plastic sheet, untreated plastic sheet and no sheet area. ZeroFly plastic sheets and untreated plastic sheets were fixed in study and control villages respectively covering all the rooms in each household. Longitudinal studies were conducted on the bioefficacy with the help of cone bioassays, monitoring of the mosquito density through hand catch, floor sheet and exit trap collections and fortnightly domiciliary active surveillance in all the study villages.

RESULTS

In ZeroFly plastic sheeting area, there was a significant reduction of 84.7 per cent in the entry rate of total mosquitoes in comparison to pre-intervention phase. There was 56.2 per cent immediate mortality in total mosquitoes in houses with ZeroFly sheeting. The overall feeding success rate of mosquitoes in the trial village was only 12.5 per cent in comparison to 49.7 and 51.1 per cent in villages with untreated plastic sheet and no sheet respectively. There was a significant reduction of 65.0 and 70.5 per cent in malaria incidence in ZeroFly plastic sheeting area as compared to untreated plastic sheet and no sheet area respectively.

INTERPRETATION & CONCLUSIONS

Our study showed that introduction of ZeroFly plastic sheets in a community-based intervention programme is operationally feasible to contain malaria especially in the high transmission difficult areas.

Effect of two different house screening interventions on exposure to malaria vectors and on anaemia in children in The Gambia: a randomised controlled trial

BACKGROUND

House screening should protect people against malaria. We assessed whether two types of house screening--full screening of windows, doors, and closing eaves, or installation of screened ceilings--could reduce house entry of malaria vectors and frequency of anaemia in children in an area of seasonal malaria transmission.

METHODS

During 2006 and 2007, 500 occupied houses in and near Farafenni town in The Gambia, an area with low use of insecticide-treated bednets, were randomly assigned to receive full screening, screened ceilings, or no screening (control). Randomisation was done by computer-generated list, in permuted blocks of five houses in the ratio 2:2:1. Screening was not treated with insecticide. Exposure to mosquitoes indoors was assessed by fortnightly light trap collections during the transmission season. Primary endpoints included the number of female Anopheles gambiae sensu lato mosquitoes collected per trap per night. Secondary endpoints included frequency of anaemia (haemoglobin concentration <80 g/L) and parasitaemia at the end of the transmission season in children (aged 6 months to 10 years) who were living in the study houses. Analysis was by modified intention to treat (ITT), including all randomised houses for which there were some outcome data and all children from those houses who were sampled for haemoglobin and parasitaemia. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN51184253.

FINDINGS

462 houses were included in the modified ITT analysis (full screening, n=188; screened ceilings, n=178; control, n=96). The mean number of A gambiae caught in houses without screening was 37.5 per trap per night (95% CI 31.6-43.3), compared with 15.2 (12.9-17.4) in houses with full screening (ratio of means 0.41, 95% CI 0.31-0.54; p<0.0001) and 19.1 (16.1-22.1) in houses with screened ceilings (ratio 0.53, 0.40-0.70; p<0.0001). 755 children completed the study, of whom 731 had complete clinical and covariate data and were used in the analysis of clinical outcomes. 30 (19%) of 158 children from control houses had anaemia, compared with 38 (12%) of 309 from houses with full screening (adjusted odds ratio [OR] 0.53, 95% CI 0.29-0.97; p=0.04), and 31 (12%) of 264 from houses with screened ceilings (OR 0.51, 0.27-0.96; p=0.04). Frequency of parasitaemia did not differ between intervention and control groups.

INTERPRETATION

House screening substantially reduced the number of mosquitoes inside houses and could contribute to prevention of anaemia in children.

FUNDING

Medical Research Council.

Modeling the effects of integrating larval habitat source reduction and insecticide treated nets for malaria control

Integrated vector management for malaria control has received a lot of recent interest. Attacking multiple points in the transmission cycle is hoped to act synergistically and improve upon current single-tool interventions based on the use of insecticide-treated bed nets (ITNs). In the present study, we theoretically examined the application of larval habitat source reduction with ITNs in reducing malaria transmission. We selected this type of environmental management to complement ITNs because of a potential secondary mode of action that both control strategies share. In addition to increasing vector mortality, ITNs reduce the rate at which female mosquitoes locate human hosts for blood feeding, thereby extending their gonotrophic cycle. Similarly, while reducing adult vector emergence and abundance, source reduction of larval habitats may prolong the cycle duration by extending delays in locating oviposition sites. We found, however, that source reduction of larval habitats only operates through this secondary mode of action when habitat density is below a critical threshold. Hence, we illustrate how this strategy becomes increasingly effective when larval habitats are limited. We also demonstrate that habitat source reduction is better suited to human populations of higher density and in the presence of insecticide resistance or when the insecticidal properties of ITNs are depleted.

Effects of long-lasting insecticidal nets and zooprophylaxis on mosquito feeding behaviour and density in Mwea, central Kenya

BACKGROUND & OBJECTIVES

Zooprophylaxis is a strategy that can control malaria by attracting mosquitoes to domestic animals that act as dead-end hosts. The objective of this study was to establish the effects of zooprophylaxis and long-lasting insecticidal nets (LLINs) on malaria transmission in an agro-based ecosystem with seasonal transmission.

METHODS

The mosquito samples were collected indoors using the space spray catch method before and after intervention between October 2005 and March 2006 to determine the mosquito densities and the feeding patterns of Anopheles spp in Mwea, Kenya.

RESULTS

A total of 4148 mosquito samples were collected, out of which 11 (0.2%) were tested positive for sporozoites. Ten were Anopheles gambiae species and one was An. funestus species. Results on blood meal ELISA showed that in the household categories that used bednets and kept one cow there was a decrease in relative change ratio (post-/pre-intervention) of 87.5 and 19.6% (p <0.05) in human and cattle blood intake respectively. For households that kept 2-4 cattle and used bednets, there was a decrease in cattle blood index (CBI) by 61.9% and an increase in human blood index (HBI) by 2%, which was not significant (p <0.05). In households with <4 cattle and bednet, there was significant reduction (p >0.05) in CBI of 37.5% as compared to the reduction of 10.3% in HBI. The ratios of man biting rates (MBR) decreased significantly, as you move up from households with one cattle with or without LLINs to households with more than four cattle with or without LLINs with a regression coefficient of -0.96; SE = 0.834; p = 0.017. Similarly, the HBI decreased significantly with the regression coefficient of 0.239; SE = 0.039; p = 0.015 (p <0.05) especially in households with >4 cattle.

INTERPRETATION & CONCLUSION

This study demonstrated that there were additive effects of zooprophylaxis and LLINs in the control of mosquito density and reduction of human risk to the mosquito bites. However, in Integrated Vector Management (IVM), the number of animals per household should not be more than four.

Combining indoor residual spraying and insecticide-treated net interventions

Does scaling up of malaria control by combining indoor residual spraying (IRS) and long-lasting insecticidal nets (LLIN) enhance protection to populations? Results from a literature search and from recent household surveys in Bioko, Equatorial Guinea, and Zambezia, Mozambique are presented. Five out of eight previous studies reported a reduced risk of infection in those protected by both interventions compared with one intervention alone. Surveys in Bioko and Zambezia showed strong evidence of a protective effect of IRS combined with nets relative to IRS alone (odds ratio [OR] = 0.71, 95% confidence interval [CI] = 0.59-0.86 for Bioko, and OR = 0.63, 95% CI = 0.50-0.79, for Zambezia). The effect of both interventions combined, compared with those who had neither, was OR = 0.46, (95% CI = 0.76-0.81) in Bioko and 0.34 (95% CI = 0.21-0.56) in Zambezia. Although the effects of confounding cannot be excluded, these results provide encouragement that the additional resources for combining IRS and LLIN are justified.

Evaluation of the wash resistance of three types of manufactured insecticidal nets in comparison to conventionally treated nets

The present study evaluated the efficacy and wash resistance of several commercial deltamethrin-treated nets (PermaNet, from factory (PN-F) and market (PN-M), Yorkool (Y) and AZ net) that were claimed by the manufacturers to be Long-Lasting Insecticide Treated Nets (LLITNs), compared to ITNs conventionally treated with deltamethrin (23-27 mg/m(2), using one K-O Tab tablet (KO) per net). Montpellier washing technique was used for washing the pieces of the nets. Insecticidal activity was assessed on dried pieces of nets after 0, 2, 5, 8, 11, 15, 18 and 21 washes, using two types of bioassay (mean median knock down times and mortality 24 h after a 3-min exposure) and reared female Anopheles stephensi. To evaluate the effect of heat on diffusion of insecticide from inside of the nets to the surface of them, some Permanet nets were heated. For all the types of nets tested the median knock down time (MKDT) increased approximately linearly with number of washes. The slopes of the lines (increase of MKDT per wash) were low with the PN-F and PN-M, intermediate with Y and equally high with KO and AZ. No significant differences can be claimed with the 3-min exposure tests. The slopes of the regression lines did not differ significantly between the heated and unheated samples. It is concluded that diffusion at ambient temperature is fast enough to rapidly compensate for the loss of insecticide on the surface with no need to artificially stimulate diffusion by heating.

Leg coverage with towels during regional deep hyperthermia treatment and its effect on pelvic temperature and temperature distribution

INTRODUCTION

The feasibility and its effects on pelvic temperature distribution of covering the legs with towels during the second half of the deep hyperthermia treatment (DHT) is evaluated.

PATIENTS AND METHODS

Patients treated with DHT and radiotherapy were randomized to an alternating treatment schedule: 2nd and 4th treatment or 3rd and 5th treatment with the legs covered with towels in the second half of the treatment. Intra-luminal temperatures (vesical, vaginal and rectal) classified as tumour indicative (TI) or tumour contact (TC), oral temperature, applied maximum power and power at the end of the treatment were measured and compared between the two treatment schedules.

RESULTS

Fourteen female patients receiving a total of 51 treatments, 24 with and 27 without towels, were included for analysis. The mean intra-luminal, TI and TC temperatures, standard deviation and range for each site were calculated. The applied power was documented. There were no significant differences in any of the measured temperatures. There were no significant differences in the applied power. In only three treatments, the towels were removed preliminarily.

CONCLUSION

In the authors' experience, covering the legs with towels during the second half of DHT does not result in significantly higher or more homogeneous pelvic temperatures. There is no indication that the TC and TI temperatures are higher compared to all pelvic temperatures when towels are applied. Regarding the used power, there is no significant decrease with towels placed on the legs. Coverage of the legs does not increase the systemic temperature. Isolating the legs with a water-perfused heater is considered.

Travellers returning to Sweden with falciparum malaria: Pre-travel advice, behaviour, chemoprophylaxis and diagnostic delay

We have investigated pre-travel advice, behaviour, chemoprophylaxis and diagnostic delay in travellers returning to Sweden with falciparum malaria. Questionnaires were distributed to patients having been notified with falciparum malaria from 1994 to 2001. Of 408 notified patients, 237 (58%) returned the questionnaires; 62% were males and 43% above the age of 45 y. Africa was the travel destination in 90% of the cases, and 27% had travelled to Kenya. 69% had spent more than 1 night in the countryside, and 6% had stayed in modern urban areas only. 40% took an adequate dose of chemoprophylaxis, although this proportion decreased from 55% to 12% during the study period. Nine per cent used both bed nets and mosquito repellents regularly. The median time from onset of symptoms to contact with health care professionals was 2 d, and from that contact to start of malaria treatment the median time was less than 24 h.

Hazard report update. ECRI Institute revises its recommendation for temperature limits on blanket warmers

ECRI Institute now recommends that temperature settings on blanket warming cabinets be limited to 130 degrees F (54 degrees C). We had previously recommended a limit of 110 degrees F (43 degrees C) because solutions were often being warmed in the same cabinets as blankets, and the lower temperature eliminated the serious burn risk presented by excessively heated solutions. With increasing recognition in the healthcare community that solutions should be kept at lower temperatures than--and therefore heated separately from--blankets, we believe that our recommendation for blankets can be made less stringent. We continue to recommend that solution warming cabinets be limited to 110 degrees F.

Marked increase in child survival after four years of intensive malaria control

In malaria-endemic countries in Africa, a large proportion of child deaths are directly or indirectly attributable to infection with Plasmodium falciparum. Four years after high coverage, multiple malaria control interventions were introduced on Bioko Island, Equatorial Guinea, changes in infection with malarial parasites, anemia, and fever history in children were estimated and assessed in relation to changes in all-cause under-5 mortality. There were reductions in prevalence of infection (odds ratio [OR] = 0.31, 95% confidence interval [CI] = 0.2-0.46), anemia (OR = 0.11, 95% CI = 0.07-0.18), and reported fevers (OR = 0.41, 95% CI = 0.22-0.76) in children. Under-5 mortality fell from 152 per 1,000 births (95% CI = 122-186) to 55 per 1,000 (95% CI = 38-77; hazard ratio = 0.34 [95% CI = 0.23-0.49]). Effective malaria control measures can dramatically increase child survival and play a key role in achieving millennium development goals.

Utilization, retention and bio-efficacy studies of PermaNet in selected villages in Buie and Fentalie districts of Ethiopia

BACKGROUND

Malaria remains a major public health problem in Ethiopia. Pyrethroid-treated mosquito nets are one of the major tools available for the prevention and control of malaria transmission. PermaNet is a long-lasting insecticide-treated net (LLIN) recommended by WHO for malaria control.

OBJECTIVE

The objective of the study was to assess utilization and retention of PermaNet nets distributed for malaria control in Buie and Fentalie districts and monitor the bio-efficacy of the nets using the WHO cone bioassay test procedures.

METHODS

A cross sectional study was carried out by interviewing household heads or their representative in Buie and Fentalie districts. The two districts were selected based on a priori knowledge of variations on ethnic background and housing construction. Clusters of houses were chosen within each of the study villages for selection of households. 20 households that had received one or more PermaNet nets were chosen randomly from the clusters in each village. A total of eight used PermaNet nets were collected for the bio-efficacy test. The bio-efficacy of PermaNet nets was monitored according to the standard WHO procedures using a susceptible colony of Anopheles arabiensis to deltamethrin.

RESULTS

A total of 119 household heads were interviewed during the study. The retention rate of nets that were distributed in 2005 and 2006 season was 72%. A total of 62.2% of the interviewees claimed children under five years of age slept under LLIN, while only 50.7% of the nets were observed to be hanged inside houses when used as a proxy indicator of usage of LLIN. For the bio-efficacy test the mean knock-down was 94% and 100%, while the mean mortality rate observed after 24 hr holding period was 72.2% and 67% for Buie and Fentalie districts respectively.

CONCLUSION

The study revealed a moderately high retention of PermaNet in the study villages and effectiveness of the nets when tested according to the standard WHO procedure.

Evaluation of PermaNet 2.0 mosquito bednets against mosquitoes, including Anopheles minimus s.l., in India

Wash resistance and field bioefficacy of PermaNet 2.0 nets, long lasting insecticidal nets, against mosquitoes were evaluated in Assam, northeastern India. After repeated hand washings at 12-day intervals a decline in the mosquito killing ability of PermaNet nets was noted (trend chi2 38.9, p < 0.0001), yet these nets retained good insecticidal efficacy for up to 15 wash cycles, producing a 72.5% mean mortality of An. minimus 24 hours after a 3-minute exposure in World Health Organization cones after 15 washings. Significantly fewer (p < 0.001) mosquitoes were captured in self-baited landing collections in houses equipped with PermaNet nets than in houses using untreated nets in the case of culicines (p < 0.001) but not with anophelines, including An. minimus. The use of PermaNet nets resulted in noticeably fewer bites from Culex pseudovishnui (68.5%) and Cx. quinquefasciatus (70%). Blood-feeding inhibition of mosquitoes in deliberately torn PermaNet nets was seen, indicating a protective effect for those sleeping under these nets. No serious adverse effects of the PermaNet nets were reported by users.

Blanket warming: comfort and safety

A project was undertaken to establish the safety of hospital blankets warmed at different temperatures in a warming cabinet. Three volunteers were covered with unheated blankets, blankets warmed to 110 degrees F (43 degrees C), and blankets warmed to 150 degrees F (66 degrees C). Evaluators asked the participants to rate their perceived warmth and perceived comfort on a scale of zero to 10 before the blanket was placed and at one, three, and five minutes after blanket exposure. Blanket temperatures decreased to approximately 80 degrees F (27 degrees C) within five minutes regardless of the initial temperature. No participants perceived overheating or burning at any temperature. Perceived warmth and comfort increased with the initial temperature of the blanket.

Bed bugs (Cimex lectularius) and clinical consequences of their bites

CONTEXT

Bed bug (Cimex lectularius) infestations are rapidly increasing worldwide. Health consequences include nuisance biting and cutaneous and systemic reactions. The potential for bed bugs to serve as disease vectors and optimal methods for bed bug pest control and eradication are unclear.

OBJECTIVES

To present current knowledge of the health and medical effects of bed bugs and to explore key issues in pest control and eradication efforts.

DATA SOURCES

A search of MEDLINE and EMBASE databases (1960-October 2008) for articles using the keywords bed bugs, Cimex lectularius, humans, parasitology, pathogenicity, and drug effects. For pest control, PubMed and Toxline searches (1960-October 2008) were performed using the keywords bed bugs, Cimex, control, prevention, and eradication. Manual searches of older journals, textbooks, pest control trade journals, and newspapers (1892-October 2008) were also performed.

STUDY SELECTION

Original accounts or investigations of bed bugs, clinical responses with sufficient detail of cause and effect between the bed bug bite and clinical response, and convincing evidence of substantiated presence of bed bug exposure. For pest control, documentation that an eradication measure quantitatively decreased bed bugs.

DATA EXTRACTION

A trained medical reference librarian assisted with the literature search. Two authors with expertise in the diagnosis, treatment, and eradication of bed bugs reviewed the clinical articles. One author evaluated the pest control articles.

DATA SYNTHESIS

Fifty-three articles met inclusion criteria and were summarized. Only 2 clinical trials concerning bed bugs were identified and tested the ability of pest control interventions to eradicate bed bugs. Although transmission of more than 40 human diseases has been attributed to bed bugs, there is little evidence that they are vectors of communicable disease. A variety of clinical reactions to bed bugs have been reported, including cutaneous and rarely systemic reactions. A wide range of empirical treatments, including antibiotics, antihistamines, topical and oral corticosteroids, and epinephrine, have been used for bite reactions with varying results. No evidence-based interventions to eradicate bed bugs or prevent bites were identified.

CONCLUSIONS

Treatment options for cutaneous and systemic reactions from bed bug bites have not been evaluated in clinical trials and there is no evidence that outcomes differ significantly from those receiving no treatment. Evidence for disease transmission by bed bugs is lacking. Pest control and eradication is challenging due to insecticide resistance, lack of effective products, and health concerns about spraying mattresses with pesticides.

Residual effects of Mossmann 100 (permethrin 10% EC) impregnated bed nets and its impact on malaria vectors and incidence of malaria

The objective of this field trial was to assess the residual effectiveness of permethrin 10% treated mosquito nets on malaria control compared with untreated nets. The study was carried out between July and December 2007 in the Pong Nam Ron District of Chantaburi Province, Thailand. Mosquito population densities were assessed using the landing catch method. Mosquitoes were collected between 6:00 PM and 12:00 PM. Residual effectiveness of the treated nets was assessed using standard WHO bioassay tests carried out monthly using Anopheles dirus mosquitoes reared in the insectary of the Department of Medical Entomology, Faculty of Tropical Medicine, Mahidol University, Thailand. The results showed the population densities of Anopheles spp, including the malaria vector Anopheles minimus, were unaffected in the study area where mosquito nets treated with Mossmann 100 (permethrin 10% EC) at 300 mg/m2 were used. WHO bioassay tests showed the nets treated with Mossmann 100 remained biologically effective against An. dirus for up to six months. Indigenous cases of malaria were reduced by 27.7% at the site where the nets treated with Mossman 100 (permethrin 10%EC) were used but no changes in malaria cases at the control site were seen.

How much malaria occurs in urban Luanda, Angola? A health facility-based assessment

We conducted a health facility-based survey of patients with fever during malaria transmission season to determine the proportion with laboratory-confirmed malaria in Luanda, Angola. We enrolled 864 patients at 30 facilities; each underwent a blood film for malaria and a questionnaire. Only 3.6% had a positive blood film. When stratified by distance of the facility to city center (< 15 km and > or = 15 km), the proportions were 1.5% (9/615) and 8.8% (22/249), respectively (P < 0.0001). Of patients traveling outside Luanda in the preceding 3 months, 6.8% (6/88) had malaria, compared with 3.2% (26/776) not traveling (P = 0.13). Children < 5 years of age were less likely to have malaria (2.4%; 12/510) than children ages 5-14 (8.7%; 9/104) and adults (4.0%; 10/250) (P = 0.03). The prevalence of laboratory-confirmed malaria in febrile patients in Luanda is very low, but increases with distance from the urban center. Prevention and treatment should be focused in surrounding rural areas.

Malaria vector control: current and future strategies

The recently announced call for malaria eradication represents a new page in the history of this disease. This has been triggered by remarkable reductions in malaria resulting from combined application of effective drugs and vector control. However, this strategy is threatened by development of insecticide resistance. Efforts to develop alternative tools to complement or even replace insecticide-based vector-control strategies must continue. Here, an overview is presented of the novel vector-control tools expected to contribute to malaria eradication.

[Modifiable risk factors of sudden infant death syndrome (SIDS). The current guidelines for reducing the risk of SIDS]

Sudden Infant Death Syndrome (SIDS) is a subgroup of unexpected infant deaths that occur during the postneonatal period with relatively consistent clinical, epidemiological, and pathological features. SIDS remains the major cause of death in infants aged between 1 week and 1 year in western countries. While many SIDS risk factors have been and continue to be identified, the diagnosis remains one of exclusion--the definition of SIDS requires a negative history as well as a negative autopsy result. Epidemiological studies have led to the definition of populations with an increased risk for SIDS: prematurely born infants with perinatal risk factors, subsequent siblings of SIDS victims, ALTE infants (10%). Avoidable risk factors such as those associated with inappropriate infants' sleeping position, type of bedding used and sleeping arrangements strongly suggest a basis for further substantial reductions in SIDS incidence rates. The current guidelines for reducing the risk of SIDS are presented.

Fabric preferences of atopic dermatitis patients

BACKGROUND

Atopic dermatitis (AD) patients have sensitive skin with impaired barrier function. Lyocell is a cellulosic fiber that offers unique characteristics and may be suitable for use by AD patients.

OBJECTIVE

To compare preferences of subjects with atopic dermatitis and normal skin for 100% lyocell clothing and bedding versus 100% cotton fabrics.

METHODS

Thirty subjects were enrolled and randomly selected to use cotton or lyocell shirts, pajamas, and bedding for 1 week. Following a 1-week washout period, participants wore the other fabric for 1 week. At the end of each week, participants completed a preference questionnaire, and AD subjects also rated daily itching on a visual analog scale. A random subset of AD and normal participants underwent measurement of transepidermal water loss (TEWL).

RESULTS

Overall, there was a significant preference for lyocell (vs cotton) for its softness, temperature control, moisture control, and wrinkle resistance. AD subjects did not have stronger fabric preferences than did normal subjects. Although not significant, lower average itching and decreased TEWL were seen in participants while they wore lyocell.

CONCLUSION

Lyocell is superior to cotton in many performance characteristics and equivalent to cotton for itch reduction. Lyocell is currently available as a beneficial fabric to improve patient comfort.

The whole world will be able to see us: determining the characteristics of a culturally appropriate bed net among mestizo communities of the Peruvian Amazon

The Peruvian Ministry of Health has distributed insecticide-treated nets (ITNs) in the country's Amazon region since 1999. Net use is nearly universal among mestizo communities in this area, but residents traditionally use non-impregnated muslin nets. We evaluated the cultural acceptability of Ministry ITNs using qualitative methods. Our results show that nets serve various functions for users: protection against insect bites, warmth, privacy, and a sense of security for young children. Because the Ministry-distributed ITNs could not fulfill these functions as well as traditional nets, many recipients disliked or rejected the ITNs they received. Also, because the ITN fabric stains rapidly, recipients washed their nets frequently rather than waiting 6 months as recommended. We propose a two-pronged approach that balances user and health system expectations of bed nets and that should lead to more widespread and effective ITN use in the study communities.

Reducing slide sheet injury

Slide sheets are often stated to be the cause of hand and forearm injuries. While there are many other possible reasons injuries to nursing staff, carer and client occur, the most important linking factors relating to musculoskeletal disorders and manual handling of people is the ongoing inappropriateness or lack of suitably designed and equipped work areas. As physiotherapist Lynn Varcin-Coad writes, staff are bearing the brunt of inefficiencies of design and lack of high order risk control.

Prevalence and prevention of malaria in pregnancy in Edo State, Nigeria

The observational/longitudinal study was undertaken in Igueben Local Government Area (LGA), Edo State, Nigeria. The objective of the study was to determine the effect of prevention on the prevalence of malaria during pregnancy. The study population comprised 4 groups viz; Group l, had 100 women protected with Insecticide Treated bed Nets (ITNs); Group 2, another 100 treated with Sulphadoxine - pyrimethamine (SP); Group 3, 100 protected with both ITN and SP, while Group 4, were 100 unprotected others who served as control. Venous blood was collected 7 days to expected date of delivery while placental blood was collected after delivery from the subjects for parasitaemia determination. Findings showed that all protective devices used were effective against malaria. Prevention used against malaria in pregnancy is a sure safe guard against maternal morbidity/mortality and should be encouraged. It is therefore, recommended that pregnant women should be health educated to appreciate the need for malaria prevention.

[Bird-related chronic hypersensitivity pneuminitis demonstrating the fluctuation of disease activity accompanied with environmental changes]

We report a case of bird-related chronic hypersensitivity pneuminitis exhibiting the fluctuation of serum markers for interstitial lung disease along with the changes in life environment. A 65-year-old man had had an abnormal chest radiograph for 2 years and had complained of a non-productive cough. He had had 30 parakeets 20 years previously and had used feather products for 15 years. In autumn and early winter wild birds had visited persimmons trees in the neighboring garden. Antibodies to bird-related antigens in the broncho-alveolar lavage fluids and sera were positive and the thoracoscopic lung biopsy specimens histologically revealed airway-centered fibrosis. We then determined he was having bird-related chronic hypersensitivity pneumonitis. After avoidance of feather products, all of serum SP-A, SP-D and KL-6 decreased. But three markers elevated and radiographic findings worsened accompanied with the increase of visiting wild birds in next autumn. After pruning persimmon trees and starting corticosteroid with cyclosporine, disease activity gradually improved.

Pressure ulcers: prevention, evaluation, and management

A pressure ulcer is a localized injury to the skin or underlying tissue, usually over a bony prominence, as a result of unrelieved pressure. Predisposing factors are classified as intrinsic (e.g., limited mobility, poor nutrition, comorbidities, aging skin) or extrinsic (e.g., pressure, friction, shear, moisture). Prevention includes identifying at-risk persons and implementing specific prevention measures, such as following a patient repositioning schedule; keeping the head of the bed at the lowest safe elevation to prevent shear; using pressure-reducing surfaces; and assessing nutrition and providing supplementation, if needed. When an ulcer occurs, documentation of each ulcer (i.e., size, location, eschar and granulation tissue, exudate, odor, sinus tracts, undermining, and infection) and appropriate staging (I through IV) are essential to the wound assessment. Treatment involves management of local and distant infections, removal of necrotic tissue, maintenance of a moist environment for wound healing, and possibly surgery. Debridement is indicated when necrotic tissue is present. Urgent sharp debridement should be performed if advancing cellulitis or sepsis occurs. Mechanical, enzymatic, and autolytic debridement methods are nonurgent treatments. Wound cleansing, preferably with normal saline and appropriate dressings, is a mainstay of treatment for clean ulcers and after debridement. Bacterial load can be managed with cleansing. Topical antibiotics should be considered if there is no improvement in healing after 14 days. Systemic antibiotics are used in patients with advancing cellulitis, osteomyelitis, or systemic infection.

Community practices of using bed nets & acceptance & prospects of scaling up insecticide treated nets in north-east India

BACKGROUND & OBJECTIVE

The National Vector Borne Disease Control Programme (NVBDCP), India has been promoting and scaling up the use of insecticide-treated nets (ITNs) in the tribal dominated malarious areas of north-east India. But, information on sleeping habits, bed net ownership and use practices, and feedback of communities in ITN--targeted areas is needed for formulating a strategic framework for upscaling the coverage of ITNs. We carried out a community-based cross-sectional survey in select areas of Nagaland and Mizoram (where ITNs were introduced) along with Assam (where ITNs were not introduced) to know the response of community.

METHODS

Following large scale introduction of ITNs during 2001-2002 in the north-eastern States of Nagaland and Mizoram by NVBDCP, India, a cross-sectional community-based survey was undertaken in April-May, 2003 covering 435 households of Nagaland and 464 households in Mizoram, using a structured questionnaire, to assess the demographic variables relevant to bed net use, bed net washing practices and acceptability of ITNs etc., for upscaling the coverage of ITNs in the surveyed communities. A total of 448 households in 8 villages in a non-ITN PHC area of Assam were served as the control area.

RESULTS

The average bet net usage per family (2.01 to 2.65). Bed net use was mostly seasonal in Nagaland where a majority (65.1-78.7%) used bed nets only during summers and monsoon as compared to the year round use in Mizoram (83.5%) and Assam (78.9%). Frequent washing of nets was most common in Assamese communities with 77 per cent households washing their nets at least once in a month. More than two third users favoured use of ITNs over the conventional indoor residual spray of DDT for malaria control.

INTERPRETATION & CONCLUSION

ITNs are widely acceptable in the user communities and a demand for ITNs is evident in the non-user communities of north-east India. Approach of treating community owned nets through an efficient service delivery mechanism will be a viable option for upscaling the ITN coverage.

Bassinet use and sudden unexpected death in infancy

OBJECTIVE

To analyze risk factors in infants who die suddenly and unexpectedly in bassinets.

STUDY DESIGN

A retrospective review of all deaths of infants involving bassinets reported to the Consumer Product Safety Commission (CPSC) between 1990 and 2004.

RESULTS

For the 53 deaths analyzed, the mean age at death was 84 days. The cause of death was recorded as anoxia, asphyxiation, or suffocation in 85% and sudden infant death syndrome (SIDS) in 9.4%. In terms of position, 37% were placed prone for sleep, and 50% were prone when found dead. Additional items in the bassinet, including soft bedding, were noted in 74% of cases. Specific mechanical problems with the bassinets were noted in 17% of cases.

CONCLUSIONS

The risk of sudden unexpected death in infants who sleep in bassinets can be reduced by following American Academy of Pediatrics guidelines, including positioning infants supine and avoiding soft bedding in bassinets. In addition, parents must ensure that the bassinet is mechanically sound and that no objects that can lead to suffocation are in or near the bassinet.

Malaria prevalence and mosquito net coverage in Oromia and SNNPR regions of Ethiopia

BACKGROUND

Malaria transmission in Ethiopia is unstable and seasonal, with the majority of the country's population living in malaria-prone areas. Results from DHS 2005 indicate that the coverage of key malaria interventions was low. The government of Ethiopia has set the national goal of full population coverage with a mean of 2 long-lasting insecticidal nets (LLINs) per household through distribution of about 20 million LLIN by the end of 2007. The aim of this study was to generate baseline information on malaria parasite prevalence and coverage of key malaria control interventions in Oromia and SNNPR and to relate the prevalence survey findings to routine surveillance data just before further mass distribution of LLINs.

METHODS

A 64 cluster malaria survey was conducted in January 2007 using a multi-stage cluster random sampling design. Using Malaria Indicator Survey Household Questionnaire modified for the local conditions as well as peripheral blood microscopy and rapid diagnostic tests, the survey assessed net ownership and use and malaria parasite prevalence in Oromia and SNNPR regions of Ethiopia. Routine surveillance data on malaria for the survey time period was obtained for comparison with prevalence survey results.

RESULTS

Overall, 47.5% (95% confidence interval (CI) 33.5-61.9%) of households had at least one net, and 35.1% (95% CI 23.1-49.4%) had at least one LLIN. There was no difference in net ownership or net utilization between the regions. Malaria parasite prevalence was 2.4% (95% CI 1.6-3.5%) overall, but differed markedly between the two regions: Oromia, 0.9% (95% CI 0.5-1.6); SNNPR, 5.4% (95% CI 3.4-8.5), p < 0.001. This difference between the two regions was also reflected in the routine surveillance data.

CONCLUSION

Household net ownership exhibited nearly ten-fold increase compared to the results of Demographic and Health Survey 2005 when fewer than 5% of households in these two regions owned any nets. The results of the survey as well as the routine surveillance data demonstrated that malaria continues to be a significant public health challenge in these regions-and more prevalent in SNNPR than in Oromia.

Distribution systems of insecticide-treated bed nets for malaria control in rural Burkina Faso: cluster-randomized controlled trial

BACKGROUND

Insecticide-impregnated bed nets (ITNs) have been shown to be a highly effective tool against malaria in the endemic regions of sub-Saharan Africa (SSA). There are however different opinions about the role of ITN social marketing and ITN free distribution in the roll-out of ITN programmes. The objective of this study was to evaluate the effects of free ITN distribution through antenatal care services in addition to an ITN social marketing programme in an area typical for rural SSA.

METHODS

A cluster-randomised controlled ITN trial took place in the whole Kossi Province in north-western Burkina Faso, an area highly endemic for malaria. Twelve clusters were assigned to long-term ITN (Serena brand) social marketing plus free ITN (Serena brand) distribution to all pregnant women attending governmental antenatal care services (group A), and 13 clusters to ITN social marketing only (group B). The intervention took place during the rainy season of 2006 and thereafter. The trial was evaluated through a representative household survey at baseline and after one year. Serena ITN household ownership was the primary outcome measure.

FINDINGS

A total of 1052 households were visited at baseline in February 2006 and 1050 at follow-up in February 2007. Overall Serena ITN household ownership increased from 16% to 28% over the study period, with a significantly higher increase in group A (13% to 35%) than in group B (18% to 23%) (p<0.001).

INTERPRETATION

The free distribution of ITNs to pregnant women through governmental antenatal care services in addition to ITN social marketing substantially improved ITN household ownership in rural Burkina Faso.

TRIAL REGISTRATION

Controlled-Trials.com ISRCTN07985309.