Evaluation of Adult Cottonwood Leaf Beetle, \u3ci\u3eChrysomela Scripta\u3c/i\u3e (Coleoptera: Chrysomelidae), Feeding Preference for Hybrid Poplars

Foliage from the Leuce section of Populus was rejected for feeding by Chrysomela scripta adults in a choice test involving 12 hybrid poplar clones. Adults showed a feeding preference for the foliage from the Tacamahaca clones when compared to the Aigeiros clones

Larvivorous fish for preventing malaria transmission

© 2013 The Authors. Background Adult anopheline mosquitoes transmit Plasmodium parasites that cause malaria. Some fish species eat mosquito larvae and pupae. In disease control policy documents, the World Health Organization includes biological control of malaria vectors by stocking ponds, rivers, and water collections near where people live with larvivorous fish to reduce Plasmodium parasite transmission. The Global Fund finances larvivorous fish programmes in some countries, and, with increasing efforts in eradication of malaria, policy makers may return to this option. We therefore assessed the evidence base for larvivorous fish programmes in malaria control. Objectives Our main objective was to evaluate whether introducing larvivorous fish to anopheline breeding sites impacts Plasmodium parasite transmission. Our secondary objective was to summarize studies evaluating whether introducing larvivorous fish influences the density and presence of Anopheles larvae and pupae in water sources, to understand whether fish can possibly have an effect. Search methods We attempted to identify all relevant studies regardless of language or publication status (published, unpublished, in press, or ongoing). We searched the following databases: the Cochrane Infectious Diseases Group Specialized Register; the Cochrane Central Register of Controlled Trials (CENTRAL), published in The Cochrane Library; MEDLINE; EMBASE; CABS Abstracts; LILACS; and the metaRegister of Controlled Trials (mRCT) until 18 June 2013. We checked the reference lists of all studies identified by the above methods. We also examined references listed in review articles and previously compiled bibliographies to look for eligible studies. Selection criteria Randomized controlled trials and non-randomized controlled trials, including controlled before-and-after studies, controlled time series and controlled interrupted time series studies from malaria-endemic regions that introduced fish as a larvicide and reported on malaria in the community or the density of the adult anopheline population. In the absence of direct evidence of an effect on transmission, we carried out a secondary analysis on studies that evaluated the effect of introducing larvivorous fish on the density or presence of immature anopheline mosquitoes (larvae and pupae forms) in community water sources to determine whether this intervention has any potential in further research on control of malaria vectors. Data collection and analysis Three review authors screened abstracts and examined potentially relevant studies by using an eligibility form. Two review authors independently extracted data and assessed risk of bias of included studies. If relevant data were unclear or were not reported, we wrote to the trial authors for clarification. We presented data in tables, and we summarized studies that evaluated the effects of fish introduction on anopheline immature density or presence, or both. We used GRADE to summarize evidence quality. We also examined whether the authors of included studies reported on any possible adverse impact of larvivorous fish introduction on non-target native species. Main results We found no reliable studies that reported the effects of introducing larvivorous fish on malaria infection in nearby communities, on entomological inoculation rate, or on adult Anopheles density. For the secondary analysis, we examined the effects of introducing larvivorous fish on the density and presence of anopheline larvae and pupae in community water sources. We included 12 small studies, with follow-up from 22 days to five years. Studies were conducted in a variety of settings, including localized water bodies (such as wells, domestic water containers, fishponds, and pools; six studies), riverbed pools below dams (two studies), rice field plots (three studies), and water canals (two studies). All studies were at high risk of bias. The research was insufficient to determine whether larvivorous fish reduce the density of Anopheles larvae and pupae (nine studies, unpooled data, very low quality evidence). Some studies with high stocking levels of fish seemed to arrest the increase in immature anopheline populations, or to reduce the number of immature anopheline mosquitoes, compared with controls. However, this finding was not consistent, and in studies that showed a decrease in immature anopheline populations, the effect was not consistently sustained. Larvivorous fish may reduce the number of water sources withAnopheles larvae and pupae (five studies, unpooled data, low quality evidence). None of the included studies reported effects of larvivorous fish on local native fish populations or other species. Authors' conclusions Reliable research is insufficient to show whether introducing larvivorous fish reduces malaria transmission or the density of adult anopheline mosquito populations. In research examining the effects on immature anopheline stages of introducing fish to potential malaria vector breeding sites (localized water bodies such as wells and domestic water sources, rice field plots, and water canals) weak evidence suggests an effect on the density or presence of immature anopheline mosquitoes with high stocking levels of fish, but this finding is by no means consistent. We do not know whether this translates into health benefits, either with fish alone or with fish combined with other vector control measures. Our interpretation of the current evidence is that countries should not invest in fish stocking as a larval control measure in any malaria transmission areas outside the context of carefully controlled field studies or quasi-experimental designs. Research could also usefully examine the effects on native fish and other non-target species

The prevalence of naturally acquired multiple infections of Wuchereria bancrofti and human malarias in anophelines

Malaria and filaria infection rates were determined for anopheline mosquitoes collected whilst biting and resting in village houses in Papua New Guinea. The number of anophelines infected with both parasites was greater than expected from the infection rates of each parasite and this difference was significant in resting collections. The excess of multiply infected mosquitoes is probably a result of a vector population composed of individuals with differing numbers of opportunities to become infected. Malaria-positive, Anopheles punctulatus from resting catches had a significantly greater number of Stage 3 Wuchereria bancroftilarvae than malaria-negative mosquitoes. However, multiply infected mosquitoes appear to suffer greater mortality than non-infected or singly infected mosquitoes when the filarial worm reaches the third stage. Any potential increase in transmission resulting from multiple infections is thereby offset by a greater mortality rate in these mosquitoe

Insecticide Resistance in Areas Under Investigation by the International Centers of Excellence for Malaria Research: A Challenge for Malaria Control and Elimination

Scale-up of the main vector control interventions, residual insecticides sprayed on walls or structures and/or impregnated in bed nets, together with prompt diagnosis and effective treatment, have led to a global reduction in malaria transmission. However, resistance in vectors to almost all classes of insecticides, particularly to the synthetic pyrethroids, is posing a challenge to the recent trend of declining malaria. Ten International Centers of Excellence for Malaria Research (ICEMR) located in the most malaria-endemic regions of the world are currently addressing insecticide resistance in the main vector populations, which not only threaten hope for elimination in malaria-endemic countries but also may lead to reversal where notable reductions in malaria have been documented. This communication illustrates the current status of insecticide resistance with a focus on the countries where activities are ongoing for 9 out of the 10 ICEMRs. Most of the primary malaria vectors in the ICEMR countries exhibit insecticide resistance, albeit of varying magnitude, and spanning all mechanisms of resistance. New alternatives to the insecticides currently available are still to be fully developed for deployment. Integrated vector management principles need to be better understood and encouraged, and viable insecticide resistance management strategies need to be developed and implemented

Evaluation of alternative mosquito sampling methods for malaria vectors in Lowland South - East Zambia.

Sampling malaria vectors and measuring their biting density is of paramount importance for entomological surveys of malaria transmission. Human landing catch (HLC) has been traditionally regarded as a gold standard method for surveying human exposure to mosquito bites. However, due to the risk of human participant exposure to mosquito-borne parasites and viruses, a variety of alternative, exposure-free trapping methods were compared in lowland, south-east Zambia. Centres for Disease Control and Prevention miniature light trap (CDC-LT), Ifakara Tent Trap model C (ITT-C), resting boxes (RB) and window exit traps (WET) were all compared with HLC using a 3 × 3 Latin Squares design replicated in 4 blocks of 3 houses with long lasting insecticidal nets, half of which were also sprayed with a residual deltamethrin formulation, which was repeated for 10 rounds of 3 nights of rotation each during both the dry and wet seasons. The mean catches of HLC indoor, HLC outdoor, CDC-LT, ITT-C, WET, RB indoor and RB outdoor, were 1.687, 1.004, 3.267, 0.088, 0.004, 0.000 and 0.008 for Anopheles quadriannulatus Theobald respectively, and 7.287, 6.784, 10.958, 5.875, 0.296, 0.158 and 0.458, for An. funestus Giles, respectively. Indoor CDC-LT was more efficient in sampling An. quadriannulatus and An. funestus than HLC indoor (Relative rate [95% Confidence Interval] = 1.873 [1.653, 2.122] and 1.532 [1.441, 1.628], respectively, P < 0.001 for both). ITT-C was the only other alternative which had comparable sensitivity (RR = 0.821 [0.765, 0.881], P < 0.001), relative to HLC indoor other than CDC-LT for sampling An. funestus. While the two most sensitive exposure-free techniques primarily capture host-seeking mosquitoes, both have substantial disadvantages for routine community-based surveillance applications: the CDC-LT requires regular recharging of batteries while the bulkiness of ITT-C makes it difficult to move between sampling locations. RB placed indoors or outdoors and WET had consistently poor sensitivity so it may be useful to evaluate additional alternative methods, such as pyrethrum spray catches and back packer aspirators, for catching resting mosquitoes

An affordable, quality-assured community-based system for high-resolution entomological surveillance of vector mosquitoes that reflects human malaria infection risk patterns.

ABSTRACT: BACKGROUND: More sensitive and scalable entomological surveillance tools are required to monitor low levels of transmission that are increasingly common across the tropics, particularly where vector control has been successful. A large-scale larviciding programme in urban Dar es Salaam, Tanzania is supported by a community-based (CB) system for trapping adult mosquito densities to monitor programme performance. Methodology An intensive and extensive CB system for routine, longitudinal, programmatic surveillance of malaria vectors and other mosquitoes using the Ifakara Tent Trap (ITT-C) was developed in Urban Dar es Salaam, Tanzania, and validated by comparison with quality assurance (QA) surveys using either ITT-C or human landing catches (HLC), as well as a cross-sectional survey of malaria parasite prevalence in the same housing compounds. RESULTS: Community-based ITT-C had much lower sensitivity per person-night of sampling than HLC (Relative Rate (RR) [95% Confidence Interval (CI)] = 0.079 [0.051, 0.121], P < 0.001 for Anopheles gambiae s.l. and 0.153 [0.137, 0.171], P < 0.001 for Culicines) but only moderately differed from QA surveys with the same trap (0.536 [0.406,0.617], P = 0.001 and 0.747 [0.677,0.824], P < 0.001, for An. gambiae or Culex respectively). Despite the poor sensitivity of the ITT per night of sampling, when CB-ITT was compared with QA-HLC, it proved at least comparably sensitive in absolute terms (171 versus 169 primary vectors caught) and cost-effective (153US$versus 187US$ per An. gambiae caught) because it allowed more spatially extensive and temporally intensive sampling (4284 versus 335 trap nights distributed over 615 versus 240 locations with a mean number of samples per year of 143 versus 141). Despite the very low vectors densities (Annual estimate of about 170 An gambiae s.l bites per person per year), CB-ITT was the only entomological predictor of parasite infection risk (Odds Ratio [95% CI] = 4.43[3.027,7. 454] per An. gambiae or Anopheles funestus caught per night, P =0.0373). Discussion and conclusion CB trapping approaches could be improved with more sensitive traps, but already offer a practical, safe and affordable system for routine programmatic mosquito surveillance and clusters could be distributed across entire countries by adapting the sample submission and quality assurance procedures accordingly

Differential Plasmodium falciparum infection of Anopheles gambiae s.s. molecular and chromosomal forms in Mali

BACKGROUND: Anopheles gambiae sensu stricto (s.s.) is a primary vector of Plasmodium falciparum in sub-Saharan Africa. Although some physiological differences among molecular and chromosomal forms of this species have been demonstrated, the relative susceptibility to malaria parasite infection among them has not been unequivocally shown. The objective of this study was to investigate P. falciparum circumsporozoite protein infection (CSP) positivity among An. gambiae s.s. chromosomal and molecular forms. METHODS: Wild An. gambiae from two sites Kela (n = 464) and Sidarebougou (n = 266) in Mali were screened for the presence of P. falciparum CSP using an enzyme-linked immunosorbent assay (ELISA). Samples were then identified to molecular form using multiple PCR diagnostics (n = 713) and chromosomal form using chromosomal karyotyping (n = 419). RESULTS: Of 730 An. gambiae sensu lato (s.l.) mosquitoes, 89 (12.2%) were CSP ELISA positive. The percentage of positive mosquitoes varied by site: 52 (11.2%) in Kela and 37 (13.9%) in Sidarebougou. Eighty-seven of the positive mosquitoes were identified to molecular form and they consisted of nine Anopheles arabiensis (21.4%), 46 S (10.9%), 31 M (12.8%), and one MS hybrid (14.3%). Sixty of the positive mosquitoes were identified to chromosomal form and they consisted of five An. arabiensis (20.0%), 21 Savanna (15.1%), 21 Mopti (30.4%), 11 Bamako (9.2%), and two hybrids (20.0%). DISCUSSION: In this collection, the prevalence of P. falciparum infection in the M form was equivalent to infection in the S form (no molecular form differential infection). There was a significant differential infection by chromosomal form such that, P. falciparum infection was more prevalent in the Mopti chromosomal forms than in the Bamako or Savanna forms; the Mopti form was also the most underrepresented in the collection. Continued research on the differential P. falciparum infection of An. gambiae s.s. chromosomal and molecular forms may suggest that Plasmodium – An. gambiae interactions play a role in malaria transmission

Borrelia lonestari DNA in adult Amblyomma americanum ticks, Alabama.

Polymerase chain reaction analysis of 204 Amblyomma americanum and 28 A. maculatum ticks collected in August 1999 near the homes of patients with southern tick-associated rash illness and in control areas in Choctaw County, Alabama, showed Borrelia lonestari flagellin gene sequence from two adult A. americanum. The presence of B. lonestari in A. americanum ticks from Alabama suggests that this suspected pathogen may be widespread in the southeastern United States

Standardizing Operational Vector Sampling Techniques for Measuring Malaria Transmission Intensity: Evaluation of six Mosquito Collection Methods in Western Kenya.

Operational vector sampling methods lack standardization, making quantitative comparisons of malaria transmission across different settings difficult. Human landing catch (HLC) is considered the research gold standard for measuring human-mosquito contact, but is unsuitable for large-scale sampling. This study assessed mosquito catch rates of CDC light trap (CDC-LT), Ifakara tent trap (ITT), window exit trap (WET), pot resting trap (PRT), and box resting trap (BRT) relative to HLC in western Kenya to 1) identify appropriate methods for operational sampling in this region, and 2) contribute to a larger, overarching project comparing standardized evaluations of vector trapping methods across multiple countries. Mosquitoes were collected from June to July 2009 in four districts: Rarieda, Kisumu West, Nyando, and Rachuonyo. In each district, all trapping methods were rotated 10 times through three houses in a 3 × 3 Latin Square design. Anophelines were identified by morphology and females classified as fed or non-fed. Anopheles gambiae s.l. were further identified as Anopheles gambiae s.s. or Anopheles arabiensis by PCR. Relative catch rates were estimated by negative binomial regression. When data were pooled across all four districts, catch rates (relative to HLC indoor) for An. gambiae s.l (95.6% An. arabiensis, 4.4% An. gambiae s.s) were high for HLC outdoor (RR = 1.01), CDC-LT (RR = 1.18), and ITT (RR = 1.39); moderate for WET (RR = 0.52) and PRT outdoor (RR = 0.32); and low for all remaining types of resting traps (PRT indoor, BRT indoor, and BRT outdoor; RR < 0.08 for all). For Anopheles funestus, relative catch rates were high for ITT (RR = 1.21); moderate for HLC outdoor (RR = 0.47), CDC-LT (RR = 0.69), and WET (RR = 0.49); and low for all resting traps (RR < 0.02 for all). At finer geographic scales, however, efficacy of each trap type varied from district to district. ITT, CDC-LT, and WET appear to be effective methods for large-scale vector sampling in western Kenya. Ultimately, choice of collection method for operational surveillance should be driven by trap efficacy and scalability, rather than fine-scale precision with respect to HLC. When compared with recent, similar trap evaluations in Tanzania and Zambia, these data suggest that traps which actively lure host-seeking females will be most useful for surveillance in the face of declining vector densities