Pneumococcal carriage and disease in adults in England 2011-2019: the importance of adults as a reservoir for pneumococcus in communities.

BACKGROUND: Pneumococcal carriage in children has been extensively studied, but carriage in healthy adults and its relationship to invasive pneumococcal disease (IPD) is less understood. METHODS: Nasal wash samples from adults without close contact with young children (Liverpool, UK), 2011-2019, were cultured, and culture-negative samples tested by PCR. Pneumococcal carriage in adults 18-44 years was compared with carriage among PCV-vaccinated children 13-48 months (nasopharyngeal swabs, Thames Valley, UK) and IPD data for England for the same ages for 2014-2019. Age-group specific serotype invasiveness was calculated and used with national IPD data to estimate carriage serotype distributions for adults aged 65+ years. RESULTS: In total 98 isolates (97 carriers) were identified from 1,631 adults aged 18+ years (age and sex standardized carriage prevalence 6.4%), with only three identified solely by PCR. Despite different carriage and IPD serotype distributions between adults and children, serotype invasiveness was highly correlated (R=0.9). Serotypes 3, 37 and 8 represented a higher proportion of adult carriage than expected from direct low-level transmission from children to adults. The predicted carriage serotype distributions for 65+ years aligned more closely with the carriage serotype distribution for young adults than young children. CONCLUSIONS: The nasal wash technique is highly sensitive; additional benefit of PCR is limited. Comparison of carriage serotype distributions suggests some serotypes may be circulating preferentially within these specific young adults. Our data suggest that for some serotypes carried by adults 65+ years, other adults may be an important reservoir for transmission. Age groups such as older children should also be considered.

Scaling and development of elastic mechanisms: the tiny strikes of larval mantis shrimp.

Latch-mediated spring actuation (LaMSA) is used by small organisms to produce high acceleration movements. Mathematical models predict that acceleration increases as LaMSA systems decrease in size. Adult mantis shrimp use a LaMSA mechanism in their raptorial appendages to produce extremely fast strikes. Until now, however, it was unclear whether mantis shrimp at earlier life-history stages also strike using elastic recoil and latch mediation. We tested whether larval mantis shrimp (Gonodactylaceus falcatus) use LaMSA and, because of their smaller size, achieve higher strike accelerations than adults of other mantis shrimp species. Based on microscopy and kinematic analyses, we discovered that larval G. falcatus possess the components of, and actively use, LaMSA during their fourth larval stage, which is the stage of development when larvae begin feeding. Larvae performed strikes at high acceleration and speed (mean: 4.133×105 rad s-2, 292.7 rad s-1; 12 individuals, 25 strikes), which are of the same order of magnitude as for adults - even though adult appendages are up to two orders of magnitude longer. Larval strike speed (mean: 0.385 m s-1) exceeded the maximum swimming speed of similarly sized organisms from other species by several orders of magnitude. These findings establish the developmental timing and scaling of the mantis shrimp LaMSA mechanism and provide insights into the kinematic consequences of scaling limits in tiny elastic mechanisms.

Biallelic variants in PPP1R13L cause paediatric dilated cardiomyopathy.

Childhood dilated cardiomyopathy (DCM) is a leading cause of heart failure requiring cardiac transplantation and approximately 5% of cases result in sudden death. Knowledge of the underlying genetic cause can aid prognostication and clinical management and enables accurate recurrence risk counselling for the family. Here we used genomic sequencing to identify the causative genetic variant(s) in families with children affected by severe DCM. In an international collaborative effort facilitated by GeneMatcher, biallelic variants in PPP1R13L were identified in seven children with severe DCM from five unrelated families following exome or genome sequencing and inheritance-based variant filtering. PPP1R13L encodes inhibitor of apoptosis-stimulating protein of p53 protein (iASPP). In addition to roles in apoptosis, iASPP acts as a regulator of desmosomes and has been implicated in inflammatory pathways. DCM presented early (mean: 2 years 10 months; range: 3 months-9 years) and was progressive, resulting in death (n = 3) or transplant (n = 3), with one child currently awaiting transplant. Genomic sequencing technologies are valuable for the identification of novel and emerging candidate genes. Biallelic variants in PPP1R13L were previously reported in a single consanguineous family with paediatric DCM. The identification here of a further five families now provides sufficient evidence to support a robust gene-disease association between PPP1R13L and severe paediatric DCM. The PPP1R13L gene should be included in panel-based genetic testing for paediatric DCM.

Neck pain patterns and subgrouping based on weekly SMS-derived trajectories.

BACKGROUND: Neck and low back pain represent dynamic conditions that change over time, often with an initial improvement after the onset of a new episode, followed by flare-ups or variations in intensity. Pain trajectories were previously defined based on longitudinal studies of temporal patterns and pain intensity of individuals with low back pain. In this study, we aimed to 1) investigate if the defined patterns and subgroups for low back pain were applicable to neck pain patients in chiropractic practice, 2) explore the robustness of the defined patterns, and 3) investigate if patients within the various patterns differ concerning characteristics and clinical findings. METHODS: Prospective cohort study including 1208 neck pain patients from chiropractic practice. Patients responded to weekly SMS-questions about pain intensity and frequency over 43 weeks. We categorized individual responses into four main patterns based on number of days with pain and variations in pain intensity, and subdivided each into four subgroups based on pain intensity, resulting in 16 trajectory subgroups. We compared baseline characteristics and clinical findings between patterns and between Persistent fluctuating and Episodic subgroups. RESULTS: All but two patients could be classified into one of the 16 subgroups, with 94% in the Persistent fluctuating or Episodic patterns. In the largest subgroup, "Mild Persistent fluctuating" (25%), mean (SD) pain intensity was 3.4 (0.6) and mean days with pain 130. Patients grouped as "Moderate Episodic" (24%) reported a mean pain intensity of 2.7 (0.6) and 39 days with pain. Eight of the 16 subgroups each contained less than 1% of the cohort. Patients in the Persistent fluctuating pattern scored higher than the other patterns in terms of reduced function and psychosocial factors. CONCLUSIONS: The same subgroups seem to fit neck and low back pain patients, with pain that typically persists and varies in intensity or is episodic. Patients in a Persistent fluctuating pattern are more bothered by their pain than those in other patterns. The low back pain definitions can be used on patients with neck pain, but with the majority of patients classified into 8 subgroups, there seems to be a redundancy in the original model.

Predatory posture and performance in a precocious larval fish targeting evasive copepods.

Predatory fishes avoid detection by prey through a stealthy approach, followed by a rapid and precise fast-start strike. Although many first-feeding fish larvae strike at non-evasive prey using an S-start, the clownfish Amphiprion ocellaris feeds on highly evasive calanoid copepods from a J-shaped position, beginning 1 day post-hatch (dph). We quantified this unique strike posture by observing successful predatory interactions between larval clownfish (1 to 14 dph) and three developmental stages of the calanoid copepod Bestiolina similis The J-shaped posture of clownfish became less tightly curled (more L-shaped) during larval development. Larvae were also less tightly curled when targeting adult copepods, which are more evasive than younger copepod stages. Strike performance measured as time to capture and as peak speed improved only slightly with larval age. Therefore, the J-posture may allow first-feeding larvae to minimize disturbance during their approach of sensitive prey, and may represent an alternative predatory strategy to the prototypical S-start.

Levels and distribution of progesterone in receiving waters and wastewaters of a growing urban area.

This study aimed at investigating the levels and distribution of progesterone in receiving waters and wastewaters in Arusha, a fast-growing urban area and the third largest city in Tanzania. Specifically, the study was conducted along the Themi River and the adjacent waste stabilization ponds (WSPs). Progesterone was detected and quantified by using an enzyme-linked immunosorbent assay (ELISA) kit. For Themi River samples, the level of progesterone obtained ranged from 'no detection' to 439 ng/L with a mean value of 120.3 ng/L. The levels detected were significantly higher in the midstream than the upstream and downstream sections of the river (P<0.05). The higher values at the midstream were attributable to livestock, WSPs and household effluents; agricultural activities; and sewage infiltration. Progesterone levels in the present study, although not extremely high, correspond to those associated with harmful effects in other studies. Results for samples collected from the WSPs indicated a release of 215 ng progesterone per L of the receiving waters. Although progesterone removal efficiency by the WSPs was 75%, the amount released was still high enough to cause harm to aquatic organisms. Thus, more efficient techniques are required to adequately remove progesterone to the recommended levels.

Characterization of Salmonella spp. from wastewater used for food production in Morogoro, Tanzania.

Wastewater use for crop irrigation and aquaculture is commonly practiced by communities situated close to wastewater treatment ponds. The objective of this study was to characterize Salmonella spp. and their antimicrobial susceptibility patterns among isolates from wastewater and Tilapia fish. A total of 123 Salmonella spp. isolates were isolated from 52 water and 21 fish intestinal samples. Genotyping of Salmonella spp. isolates was done by Pulsed-field Gel Electrophoresis (PFGE). Antimicrobial susceptibility testing was done by the minimal inhibitory concentration (MIC) technique. A total of 123 Salmonella spp. isolates represented 13 different serovars and 22 PFGE groups. Salmonella serovars showed resistance to 8 out of 14 antimicrobials; sulfamethaxazole (94%), streptomycin (61%), tetracycline (22%), ciprofloxacin and nalidixic acid (17%), trimethoprim (11%); gentamycin and chloramphenicol (6%). Salmonella Kentucky, S. Chandans, S. Durban and S. Kiambu showed multiple antimicrobial resistance to 7, 6 and 3 antimicrobials, respectively. This study has demonstrated that wastewater at the study sites is contaminated with Salmonella spp. which are resistant to common antimicrobials used for treatment of diseases in humans. Wastewater may, therefore, contaminate pristine surface water bodies and foodstuffs including fish and irrigated crops as well as food handlers.

Bioaccumulation and public health implications of trace metals in edible tissues of the crustaceans Scylla serrata and Penaeus monodon from the Tanzanian coast.

The coastal population in East Africa is growing rapidly but sewage treatment and recycling facilities in major cities and towns are poorly developed. Since estuarine mangroves are the main hotspots for pollutants, there is a potential for contaminants to accumulate in edible fauna and threaten public health. This study analysed trace metals in muscle tissues of the giant mud crabs (Scylla serrata) and the giant tiger prawns (Penaeus monodon) from the Tanzanian coast, in order to determine the extent of bioaccumulation and public health risks. A total of 180 samples of muscle tissues of S. serrata and 80 of P. monodon were collected from nine sites along the coast. Both species showed high levels of trace metals in the wet season and significant bioaccumulation of As, Cu and Zn. Due to their burrowing and feeding habits, mud crabs were more contaminated compared to tiger prawns sampled from the same sites. Apart from that, the measured levels of Cd, Cr and Pb did not exceed maximum limits for human consumption. Based on the current trend of fish consumption in Tanzania (7.7 kg/person/year), the measured elements (As, Cd, Co, Cu, Mn, Pb and Zn) are not likely to present health risks to shellfish consumers. Nevertheless, potential risks of As and Cu cannot be ruled out if the average per capita consumption is exceeded. This calls for strengthened waste management systems and pollution control measures.

Epidemiology and RAPD-PCR typing of thermophilic campylobacters from children under five years and chickens in Morogoro Municipality, Tanzania.

BACKGROUND: Campylobacter species are gram negative and flagellated bacteria under the genus Campylobacter, family Campylobacteriaceae. These pathogens cause zoonotic infections among human and animal populations. This study was undertaken between December 2006 and May 2007 to determine prevalence, risk factors and genetic diversity of thermophilic Campylobacter isolates from children less than 5 years and chickens in Morogoro Municipality, Tanzania. METHODS: The Skirrow's protocol was used for isolation and identification of Campylobacter from 268 human stool specimens and 419 chicken cloacal swabs. Patient biodata and risk factors associated with human infection were also collected. Genetic diversity of Campylobacter isolates was determined by a RAPD-PCR technique using OPA 11 primer (5'-CAA TCG CCG T-3'). Phylogenetic analysis and band pattern comparison were done by Bionumerics software and visual inspection. RESULTS: Stool samples from 268 children and 419 cloacal swabs from chickens were analyzed. Prevalence of thermophilic Campylobacters in children was 19% with higher isolation frequency (p = 0.046) in males (23.5%) than females (13.8%). Campylobacter jejuni (78.4%) was more isolated (p = 0.000) than C. coli (19.6%) and 2% were unidentified isolates. In chickens, the prevalence was 42.5% with higher isolation rate (p = 0.000) of C. jejuni (87%) than C. coli (13%). Campylobacters were more frequently recovered (p = 0.000) from indigenous/ local chickens (75.0%) followed by cockerels (52.2%), broilers (50.0%) and lowest in layers (22.7%). Keeping chickens without other domestic animals concurrently (p = 0.000), chicken types (p = 0.000) and flock size (p = 0.007) were risk factors for infection in chickens. One hundred and fifty two (152) thermophillic Campylobacter isolates were genotyped by RAPD-PCR of which 114 were C. jejuni (74 from chickens and 40 humans) and 38 C. coli (28 from chickens and 10 humans). Comparison of Campylobacter isolates from children and chickens revealed high diversity with only 6.1% of C. jejuni and 5.3% of C. coli being 100% genetically similar. CONCLUSIONS: This study has recorded high prevalence of thermophilic Campylobacter in children less than 5 years and chickens in Morogoro municipality. The observed genetic similarity among few C. jejuni and C. coli isolates from children and chicken suggests existence of cross transmission of these pathogens between children under 5 years and chickens.

Gender difference and effect of pharmacotherapy: findings from a smoking cessation service.

BACKGROUND: Smoking cessation services are available in England to provide assistance to those wishing to quit smoking. Data from one such service were analysed in order to investigate differences in quit rate between males and females prescribed with different treatments. METHODS: A logistic regression model was fitted to the data using the binary response of self-reported quit (failed attempt = 0, successful attempt = 1), validated by Carbon Monoxide (CO) monitoring, 4 weeks after commencing programme. Main effects fitted were: client gender; age; region; the type of advisory sessions; and pharmacotherapy, Nicotine Replacement Therapy (NRT) or Varenicline. A second model was fitted including all main effects plus two-way interactions except region. These models were repeated using 12-week self-reported quit as the outcome. RESULTS: At 4 weeks, all main effects were statistically significant, with males more likely (odds ratio and 95 % CI, females v males = 0.88 [0.79-0.97]), older smokers more likely (adjusted odds ratios [OR] and 95 % confidence interval [CI] respectively for groups 20-29, 30-49, 50-69 and 70+ vs 12-19 age group: 1.79 [1.39-2.31], 2.12 [1.68-2.68], 2.30 [1.80-2.92] and 2.47 [1.81-3.37] and for overall difference between groups, χ2(4) = 53.5, p < 0.001) and clients being treated with Varenicline more likely to have successfully quit than those on NRT (adjusted OR and 95 % CI for Varenicline vs NRT = 1.41 [1.21-1.64]). Statistically significant interactions were observed between (i) gender and type of counselling, and (ii) age and type of counselling. Similar results were seen in relation to main effects at 12 weeks except that type of counselling was non-significant. The only significant interaction at this stage was between gender and pharmacotherapy (adjusted OR and 95 % CI for females using Varenicline versus all other groups = 1.43 [1.06-1.94]). CONCLUSION: Gender and treatment options were identified as predictors of abstinence at both 4 and 12 weeks after quitting smoking. Furthermore, interactions were observed between gender and (i) type of counselling received (ii) pharmacotherapy. In particular, the quit rate in women at 12 weeks was significantly improved in conjunction with Varenicline use. These findings have implications for service delivery.

Trace metals in the giant tiger prawn Penaeus monodon and mangrove sediments of the Tanzania coast: Is there a risk to marine fauna and public health?

Mangroves ecosystems support livelihood and economic activities of coastal communities in the tropics and subtropics. Previous reports have documented the inefficiency of waste treatment facilities in Tanzania to contain trace metals. Therefore, the rapidly expanding coastal population and industrial sector is likely to threaten mangrove ecosystems with metal pollution. This study analysed trace metals in 60 sediment samples and 160 giant tiger prawns from the Tanzanian coast in order to document the distribution of trace metals and to establish if measured levels present a threat to mangrove fauna and are of public health importance. High levels of Cr, Co, Cu, Fe, Mn, Ni, and V was observed in mangroves of river Pangani, Wami, and Rufiji. Multivariate analysis showed that they originate mainly from weathering and erosion in the river catchments. Extreme enrichment of Cd was observed in a mangrove affected by municipal sewage. The distribution of Hg, Pb, and Zn was related with urbanisation and industrial activities along the coast. The metal pollution index was high at Pangani, Saadani, and Rufiji, suggesting that these estuarine mangroves are also affected by human activities in the catchment. Moderate to considerable ecological risks were observed in all sampled mangroves, except for Kilwa Masoko. It was revealed that As, Cd, and Hg present moderate risks to fauna. High levels of Cu, Fe and Zn were observed in prawns but the level of the non-essential Cd, Hg, and Pb did not exceed the maximum allowed levels for human consumption. However, based on the trends of fish consumption in the country, weekly intake of Hg is likely to exceed provisional tolerable weekly intake level, especially in fishing communities. This calls for measures to control Hg emissions and to strengthen sewage and waste treatment in coastal cities and urban centres in the basin of major rivers.

Risk assessment of exposure to particulate output of a demolition site.

Whilst vehicular and industrial contributions to the airborne particulate budget are well explored, the input due to building demolition is relatively unknown. Air quality is of importance to human health, and it is well known that composition of airborne particles can have a significant influence on both chronic and acute health effects. Road dust (RD) was collected before and after the demolition of a large building to elucidate changes in elemental profile. Rainfall and PM10 mass concentration data aided interpretation of the elemental data. Quantification of Al, As, Ba, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Rh, S, Si, Sn, Ti, V and Zn was carried out. It was found that only Al, K, Mg, Si and S increased in concentration across all size fractions after the building demolition. Risk assessment was then carried out on elements with applicable reference dose values to assess the potential health risks due to the demolition. Significant risk to children was observed for chromium and aluminium exposure. PM10, monitored 40 metres from the demolition site, indicated no abnormal concentrations during the demolition; however, rainfall data were shown to affect the concentration of PM10. The elemental data observed in this study could possibly indicate the role of increased sulphur concentrations (in this case as a result of the demolition) on the buffer capacity of RD, hence leaching metals into rainwater.

Fragile X syndrome without CCG amplification has an FMR1 deletion.

We describe a patient with typical clinical features of the fragile X syndrome, but without cytogenetic expression of the fragile X or an amplified CCG trinucleotide repeat fragment. The patient has a previously uncharacterized submicroscopic deletion encompassing the CCG repeat, the entire FMR1 gene and about 2.5 megabases of flanking sequences. This finding confirms that the fragile X phenotype can exist, without amplification of the CCG repeat or cytogenetic expression of the fragile X, and that fragile X syndrome is a genetically homogeneous disorder involving FMR1. We also found random X-inactivation in the mother of the patient who was shown to be a carrier of this deletion.

Mental health among people with psoriasis undergoing patient education in climate therapy.

This study investigated the mental health of people with psoriasis undergoing patient education in climate therapy. A prospective design included a baseline assessment and two follow-ups after a 3-week patient education program. Participants were 254 adults. Positive mental health was measured by the mental health continuum short form (0-70), and negative mental health by the emotional distress subscale (1-4) of the health education impact questionnaire. Paired-samples t-tests were used to evaluate changes in mental health from baseline to follow-up. Multiple linear regression was used to analyse the ability of socio-demographic and clinical variables and emotional distress to predict changes in positive mental health. To predict change in negative mental health we repeated the same analysis but with a change in negative mental health as a dependent variable and positive mental health as an independent variable. The results show that positive mental health and health-related emotional distress improved significantly from before to after the intervention by 7.1 points, p < 0.001 and 0.21 points, p < 0.001) respectively. At the second follow-up, health-related emotional distress remained significantly improved compared with baseline levels by 0.11 points, p = 0.004. The longer participants had lived with psoriasis ( ß = 146, p = 0.027), and the presence of co-morbid health problems (ß  =  111, p = 0.051) the greater the improvement in the positive mental health immediately after the intervention. No predictors were identified for negative mental health. This study indicates that the promotion of positive mental health needs to be integrated into the climate therapy program, and sustained in their home context.

Effect of resinous extract from Commiphora swynnertonii (Burrt) on experimental coccidial infection in chickens.

A crude resinous extract from Commiphora swynnertonii was tested against an experimental coccidial infection in local chickens. A total of 80 growing chickens were randomly assigned into five groups, which received different treatments. Chickens in G1 were not infected with coccidian oocysts and therefore served as a negative control. All chickens in G2, G3, G4 and G5 were infected through oral administration of coccidian oocysts suspension at a dosed rate of 1.5 × 10(4) Eimeria spp. oocysts per bird. Starting from day 3 post-infection (p.i), chickens in different groups were treated for 7 consecutive days as follows: G1 and G2 (positive control) received 5 ml of normal saline as placebo, G3 and G4 were given the extract at 400 and 800 mg/kg bodyweight whereas G5 received anticoccidial drug. Clinical signs, bodyweights, oocysts counts and mortality rates were observed regularly. Results showed that oral administration of the resinous extract to chickens with coccidiosis significantly reduced mortality rate from 94 to 25 % and oocysts counts from 1.03 × 10(5) to 6.55 × 10(3) oocysts/g faeces (p < 0.05). Also a body condition score chart indicated less severe clinical signs of the disease in the groups which received the extract. Mean daily body weights were slightly reduced by the administration of the extract but this effect disappeared by day 7 p.i. These findings clearly indicate that resinous extract from C. swynnertonii has significant anticoccidial effect against experimental Eimeria spp. infection in chickens. A larger field trial to validate the use of the extract in chickens naturally infected with Eimeria spp. is required.

Optimization of HPLC-MS/MS method for determination of antimalarial adulterants in herbal products.

The use of herbal products is booming all over the world because of being believed as safer than conventional drugs and free of side effects. However, there are untrustworthy manufacturers who adulterate herbal products by adding conventional drugs which might eventually lead to microbial resistance and herb-to-drug interactions. There is a need to develop methods for detecting adulterants in herbal products. A high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method for simultaneous identification and determination of conventional antimalarials (chloroquine, quinine, sulfadoxine, pyrimethamine, mefloquine, lumefantrine, amodiaquine, artemisinin, dihydroartemisinin, artesunate and artemether) in herbal products was developed. Stable isotopically labelled compounds (artemether-d3, quindine-d3, and sulfadoxine-d3) were used as internal standards (ISs) for quantitative analysis. Extraction of analytes was performed using methanol: water: formic acid (90:10:0.1, v/v) and chromatographic separation was done in a gradient mode using mobile phase A: Ultrapure water containing 0.1% formic acid and 1 mM ammonium formate and mobile phase B: Acetonitrile/methanol (50:50) containing 0.1% formic acid and 1 mM ammonium formate. The calibration curves were linear (r2 ≥ 0.991) over the range of 0.001-0.3 µg mL-1 for all compounds. The limit of detection (LOD) ranged from 0.002 to 0.02 µg mL-1 while the limit of quantification (LOQ) ranged from 0.006 to 0.08 µg mL-1. Accuracy, expressed as recovery of spiked herbal products ranged from 52 to 128%. The precision, expressed as percent relative standard deviation (%RSD) at two concentration levels, ranged from 1.0 to 13.8%. The matrix effect expressed as the matrix factor (MF) ranged from 0.77 to 0.97. The developed method was used to identify and quantify conventional antimalarials in herbal product samples from Tanzania. Ten out of 50 herbal products were found to contain amodiaquine, sulfadoxine, pyrimethamine, mefloquine, dihydroartemisinin, artemether and lumefantrine. The developed method is considered a valuable tool for getting a better understanding of the adulteration of conventional antimalarials in herbal products.

Mitigating antimicrobial resistance (AMR) using implementation research: a development funder's approach.

Despite the escalating burden of antimicrobial resistance (AMR), the global response has not sufficiently matched the scale and scope of the issue, especially in low- and middle-income countries (LMICs). While many countries have adopted national action plans to combat AMR, their implementation has lagged due to resource constraints, dysfunctional multisectoral coordination mechanisms and, importantly, an under-recognized lack of technical capacity to adapt evidence-based AMR mitigation interventions to local contexts. AMR interventions should be tailored, context-specific, cost-effective and sustainable. The implementation and subsequent scale-up of these interventions require multidisciplinary intervention-implementation research (IIR). IIR involves both quantitative and qualitative approaches, occurs across a three-phase continuum (proof of concept, proof of implementation and informing scale-up), and across four context domains (inner setting, outer setting, stakeholders and the implementation process). We describe the theoretical underpinnings of implementation research (IR), its various components, and how to construct different IR strategies to facilitate sustainable uptake of AMR interventions. Additionally, we provide real-world examples of AMR strategies and interventions to demonstrate these principles in practice. IR provides a practical framework to implement evidence-based and sustainable AMR mitigation interventions.

Probing the photonic density of states using layer-by-layer self-assembly.

The process of spontaneous emission can be dramatically modified by optical microstructures and nanostructures. We have studied the modification of fluorescence dynamics using a variable thickness polymer spacer layer fabricated using layer-by-layer self-assembly with nanometer accuracy. The change in fluorescence lifetime with spacer layer thickness agrees well with theoretical predictions based on the modified photonic density of states (PDOS), and yields consistent values for the fluorophores' intrinsic fluorescence lifetime and quantum yield near a dielectric as well as a plasmonic interface. Based on this observation, we further demonstrate that self-assembled fluorophores can be used to probe the modified PDOS near optical microstructures and nanostructures.

Tick infestations in extensively grazed cattle and efficacy trial of high-cis cypermethrin pour-on preparation for control of ticks in Mvomero district in Tanzania.

BACKGROUND: This study aimed at determining the extent of tick infestations in extensively grazed cattle and assess the efficacy of Ecotix® acaricide (2.5% high cis cypermethrin) in Mvomero district in Tanzania. A total of 1200 Tanzanian short horn Zebu (TSHZ) from two farms in two villages were qualitatively assessed for tick infestations and 40 animals (grouped in 10s from each farm) were separated in their herds and quantitatively examined to establish the tick load. The animals were grouped in treatment regime groups (TxRG 1, 2, 3, and 4), TxRG 1 being the control group was treated with water. Ecotix® was applied on day 0 for TxRG 2, days 0 and 7 for TxRG 3 and days 0, 7 and 14 for TxRG 4 and tick load was monitored for 28 days. RESULTS: All the animals examined were infested with ticks. The identified ticks were Rhipicephalus appendiculatus (55%), Amblyomma variegatum (18%), R. (Boophilus) microplus (12.9%), R. (B) decoloratus (7.1%), R. evertsi evertsi (4.4%) and R. composites (2.6%). The overall mean (mean±SEM) tick density on day zero was 63±30 ticks per animal (ranging from 20-160). The mean tick density on day zero was 44.6±25.4, 74.6±30.3, 55.0±26.2 and 77±33.5 for groups one, two, three and four respectively. Post-treatment quantitative assessment of tick burden revealed that the TxRG 1 animals maintained a tick load throughout the study period. A significant decrease in tick load in animals in groups TxRG 2, 3 and 4 (P=0.0001) with increasing frequency of Ecotix® application was recorded. There was however no significant difference in tick reduction between TxRG 3 and 4 (P=0.0986). Thus TxRG 3 would be sufficient for the monthly tick treatment and with this regime, the farmer would save up to 2.5 USD per animal during six months of dry season. CONCLUSIONS: The study revealed a high tick infestation among the TSHZ kept in extensive grazing systems in Mvomero district and that when treated with Ecotix® as pour-on preparation using a two application regime per month, the tick control strategy was effective.