Does ignoring transmission dynamics lead to underestimation of the impact of interventions against mosquito-borne disease?

New vector-control technologies to fight mosquito-borne diseases are urgently needed, the adoption of which depends on efficacy estimates from large-scale cluster-randomised trials (CRTs). The release of Wolbachia-infected mosquitoes is one promising strategy to curb dengue virus (DENV) transmission, and a recent CRT reported impressive reductions in dengue incidence following the release of these mosquitoes. Such trials can be affected by multiple sources of bias, however. We used mathematical models of DENV transmission during a CRT of Wolbachia-infected mosquitoes to explore three such biases: human movement, mosquito movement and coupled transmission dynamics between trial arms. We show that failure to account for each of these biases would lead to underestimated efficacy, and that the majority of this underestimation is due to a heretofore unrecognised bias caused by transmission coupling. Taken together, our findings suggest that Wolbachia-infected mosquitoes could be even more promising than the recent CRT suggested. By emphasising the importance of accounting for transmission coupling between arms, which requires a mathematical model, we highlight the key role that models can play in interpreting and extrapolating the results from trials of vector control interventions.

The Impact of Emerging Plasmodium knowlesi on Accurate Diagnosis by Light Microscopy: A Systematic Review and Modeling Analysis.

The five major Plasmodium spp. that cause human malaria appear similar under light microscopy, which raises the possibility that misdiagnosis could routinely occur in clinical settings. Assessing the extent of misdiagnosis is of particular importance for monitoring P. knowlesi, which cocirculates with the other Plasmodium spp. We performed a systematic review and meta-analysis of studies comparing the performance of microscopy and polymerase chain reaction (PCR) for diagnosing malaria in settings with co-circulation of the five Plasmodium spp. We assessed the extent to which co-circulation of Plasmodium parasites affects diagnostic outcomes. We fit a Bayesian hierarchical latent class model to estimate variation in microscopy sensitivity and specificity measured against PCR as the gold standard. Mean sensitivity of microscopy was low, yet highly variable across Plasmodium spp., ranging from 65.7% (95% confidence interval: 48.1-80.3%) for P. falciparum to 0.525% (95% confidence interval 0.0210-3.11%) for P. ovale. Observed PCR prevalence was positively correlated with estimated microscopic sensitivity and negatively correlated with estimated microscopic specificity, though the strength of the associations varied by species. Our analysis suggests that cocirculation of Plasmodium spp. undermines the accuracy of microscopy. Sensitivity was considerably lower for P. knowlesi, P. malariae, and P. ovale. The negative association between specificity and prevalence imply that less frequently encountered species may be misdiagnosed as more frequently encountered species. Together, these results suggest that the burden of P. knowlesi, P. malariae, and P. ovale may be underappreciated in a clinical setting.

Projecting vaccine demand and impact for emerging zoonotic pathogens.

BACKGROUND: Despite large outbreaks in humans seeming improbable for a number of zoonotic pathogens, several pose a concern due to their epidemiological characteristics and evolutionary potential. To enable effective responses to these pathogens in the event that they undergo future emergence, the Coalition for Epidemic Preparedness Innovations is advancing the development of vaccines for several pathogens prioritized by the World Health Organization. A major challenge in this pursuit is anticipating demand for a vaccine stockpile to support outbreak response. METHODS: We developed a modeling framework for outbreak response for emerging zoonoses under three reactive vaccination strategies to assess sustainable vaccine manufacturing needs, vaccine stockpile requirements, and the potential impact of the outbreak response. This framework incorporates geographically variable zoonotic spillover rates, human-to-human transmission, and the implementation of reactive vaccination campaigns in response to disease outbreaks. As proof of concept, we applied the framework to four priority pathogens: Lassa virus, Nipah virus, MERS coronavirus, and Rift Valley virus. RESULTS: Annual vaccine regimen requirements for a population-wide strategy ranged from > 670,000 (95% prediction interval 0-3,630,000) regimens for Lassa virus to 1,190,000 (95% PrI 0-8,480,000) regimens for Rift Valley fever virus, while the regimens required for ring vaccination or targeting healthcare workers (HCWs) were several orders of magnitude lower (between 1/25 and 1/700) than those required by a population-wide strategy. For each pathogen and vaccination strategy, reactive vaccination typically prevented fewer than 10% of cases, because of their presently low R0 values. Targeting HCWs had a higher per-regimen impact than population-wide vaccination. CONCLUSIONS: Our framework provides a flexible methodology for estimating vaccine stockpile needs and the geographic distribution of demand under a range of outbreak response scenarios. Uncertainties in our model estimates highlight several knowledge gaps that need to be addressed to target vulnerable populations more accurately. These include surveillance gaps that mask the true geographic distribution of each pathogen, details of key routes of spillover from animal reservoirs to humans, and the role of human-to-human transmission outside of healthcare settings. In addition, our estimates are based on the current epidemiology of each pathogen, but pathogen evolution could alter vaccine stockpile requirements.

Youth-serving institutional resources and neighborhood safety: Ties with positive youth development.

Neighborhoods are critical contexts for adolescent development, but little attention has been paid to how neighborhood characteristics play a role in positive youth development (PYD), notably among predominantly African American youth. This study examined distinct features of the neighborhood, including youth-serving institutional resources (YSI) and safety, as they relate to PYD among adolescents from low-income neighborhoods in an urban setting (n = 491, 68.6% African American). Because neighborhood experiences during adolescence often differ based on gender, we also examined moderation by gender. Results from cross-sectional, multilevel data suggest that neighborhood safety, YSIs, and gender are differentially associated with indicators of PYD (i.e., hope, mastery, friend support). The pattern of results suggested that when associated with mastery, YSIs may compensate for low-safety neighborhoods for adolescent females but not males. In terms of associations with friend support, YSIs may foster the development of PYD in low-safety neighborhoods for males but not females. Limitations of the current study and implications for future research are discussed. (PsycINFO Database Record

A qualitative study exploring use of the surprise question in the care of older people: perceptions of general practitioners and challenges for practice.

OBJECTIVE: The question "Would you be surprised if this patient were to die in the next 6-12 months?" has been included in UK palliative care guidance with the aim of supporting the identification and care planning of those nearing the end of life. Little is known about how the surprise question is utilised in the care of older people within primary care. This study sought to explore the perceptions and experiences of general practitioners (GPs). METHOD: Semistructured interviews were conducted with 12 GPs. Each interview reflected on the care of two people, aged 80 years or older, selected by the GP as possibly being in the last year of life. Analysis followed a grounded theory approach within a framework of interpretive thematic analysis. RESULTS: Data discussing 22 clinical cases revealed the difficulties experienced by GPs when assessing prognosis for older people with non-malignant conditions, despite their recognition of multiple mortality risk factors and high symptom burden. GPs did not appear to include the surprise question within their usual practice and expressed concerns regarding its use to facilitate discussion of advance care plans. These concerns highlighted the subjective nature of the surprise question and potential barriers to conducting discussions of preferences for future care. CONCLUSIONS: Greater understanding is needed as to the difficulties experienced by GPs when assessing prognosis in older people. We propose a thematic model which could support GPs by focusing assessment on the supportive and palliative care needs of older people nearing the end of life.

Finding Home: A Qualitative Approach to Understanding Adolescent Mothers' Housing Instability.

Many low-income Latina adolescent mothers face instability in their housing circumstances, which has implications for their long-term prospects and that of their children. This study used longitudinal, ethnographic data from Welfare, Children, and Families: A Three-City Study to explore experiences of low-income, Latina adolescent mothers (N = 15) with unstable housing who primarily rely on their families or the families of their significant others for housing support. Results of analysis employing grounded theory and narrative approaches suggested two types of instability: "Horizontal moves" between family homes and "vertical moves" between family homes and independent living. Although family support often was fundamental in allowing for participants' pursuit of independent housing (i.e., vertical moves), it also was associated with greater residential mobility (i.e., horizontal moves), most often in the context of intrafamilial conflict and family instability. These results are discussed with respect to inconsistencies in policies to address this vulnerable population.

Adolescent functioning in housing and family contexts: A mixed methods study.

Although adolescents begin to seek autonomy and strive to be out of the home on their own, the housing context remains the primary setting of their daily lives. Using survey and ethnographic data from Welfare, Children, and Families: A Three City Study (e.g., Winston et al., 1999), this study explored quantitatively and qualitatively how two salient aspects of the housing context, physical housing problems and household size, were associated with low-income adolescents' emotional and academic functioning, and how these associations were modified by mother­adolescent relationships (specifically, trust and communication) and gender. Results of cross-lagged hierarchical linear models suggest that adolescents living in homes with more housing problems had more mental health symptoms, whereas living in larger households was associated with higher achievement, but only in the context of lower quality mother­adolescent relationships. Qualitative analyses helped to interpret these results by illuminating potential pathways underlying associations observed in quantitative results.

The Home and the 'Hood: Associations between Housing and Neighborhood Contexts and Adolescent Functioning.

Adolescents from low-income families face various opportunities and constraints as they develop, with possible ramifications for their well-being. Two contexts of particular importance are the home and the neighborhood. Using adolescent data from the first two waves of the Three City Study (N = 1,169), this study explored associations among housing problems and neighborhood disorder with adolescents' socioemotional problems, and how these associations varied by parental monitoring and gender. Results of hierarchical linear models suggest that poor quality housing was most predictive of the functioning of girls and of adolescents with restrictive curfews, whereas neighborhood disorder was a stronger predictor for boys. Implications for future research on associations between housing and neighborhood contexts and adolescent development are discussed.

Development of a model for integrated care at the end of life in advanced dementia: A whole systems UK-wide approach.

BACKGROUND: The prevalence of dementia is rising worldwide and many people will die with the disease. Symptoms towards the end of life may be inadequately managed and informal and professional carers poorly supported. There are few evidence-based interventions to improve end-of-life care in advanced dementia. AIM: To develop an integrated, whole systems, evidence-based intervention that is pragmatic and feasible to improve end-of-life care for people with advanced dementia and support those close to them. DESIGN: A realist-based approach in which qualitative and quantitative data assisted the development of statements. These were incorporated into the RAND/UCLA appropriateness method to achieve consensus on intervention components. Components were mapped to underlying theory of whole systems change and the intervention described in a detailed manual. SETTING/PARTICIPANTS: Data were collected from people with dementia, carers and health and social care professionals in England, from expert opinion and existing literature. Professional stakeholders in all four countries of the United Kingdom contributed to the RAND/UCLA appropriateness method process. RESULTS: A total of 29 statements were agreed and mapped to individual, group, organisational and economic/political levels of healthcare systems. The resulting main intervention components are as follows: (1) influencing local service organisation through facilitation of integrated multi-disciplinary care, (2) providing training and support for formal and informal carers and (3) influencing local healthcare commissioning and priorities of service providers. CONCLUSION: Use of in-depth data, consensus methods and theoretical understanding of the intervention components produced an evidence-based intervention for further testing in end-of-life care in advanced dementia.

UK quality statements on end of life care in dementia: a systematic review of research evidence.

BACKGROUND: Globally, the number of people who die with dementia is increasing. The importance of a palliative approach in the care of people with dementia is recognised and there are national polices to enhance current care. In the UK implementation of these polices is promoted by the National Institute for Health and Care Excellence (NICE) Dementia Quality Standards (QS). Since publication of the QS new care interventions have been developed. AIM: To explore critically the current international research evidence on effect available to inform NICE Dementia QS relevant to end of life (EOL) care. DESIGN: We used systematic review methods to seek the research evidence for three statements within the Dementia QS. These are those that recommend: (1) a case management approach, (2) discussing and consideration of making a statement about future care (SFC) and (3) a palliative care assessment (PCA). We included evaluative studies of relevant interventions that used a comparative design, such as trials and cohort studies, and measured EOL care outcomes for persons dying with moderate to severe dementia. Our primary outcome of interest was whether the intervention led to a measurable impact on wellbeing for the person with dementia and their family. We assessed included studies for quality using a scale by Higginson and colleagues (2002) for assessment of quality of studies in palliative care, and two authors undertook key review processes. Data sources included Cinahl, Embase, and PsychINFO from 2001 to August 2014. Our search strategy included free text and medical subject headings relevant to population and recommended care. RESULTS: We found seven studies evaluating a care intervention; four assessed SFC, three PCA. None assessed case management. Studies were of weak design; all used retrospective data and relied on others for precise record keeping and for accurate recall of events. There was limited overlap in outcome measurements. Overall reported benefits were mixed. CONCLUSIONS: Quality statements relevant to EOL care are useful to advance practice however they have a limited evidence base. High quality empirical work is needed to establish that the recommendations in these statements are best practice.

A protocol for an exploratory phase I mixed-methods study of enhanced integrated care for care home residents with advanced dementia: the Compassion Intervention.

INTRODUCTION: In the UK approximately 700,000 people are living with, and a third of people aged over 65 will die with, dementia. People with dementia may receive poor quality care towards the end of life. We applied a realist approach and used mixed methods to develop a complex intervention to improve care for people with advanced dementia and their family carers. Consensus on intervention content was achieved using the RAND UCLA appropriateness method and mapped to sociological theories of process and impact. Core components are: (1) facilitation of integrated care, (2) education, training and support, (3) investment from commissioners and care providers. We present the protocol for an exploratory phase I study to implement components 1 and 2 in order to understand how the intervention operates in practice and to assess feasibility and acceptability. METHODS AND ANALYSIS: An 'Interdisciplinary Care Leader (ICL)' will work within two care homes, alongside staff and associated professionals to facilitate service integration, encourage structured needs assessment, develop the use of personal and advance care plans and support staff training. We will use qualitative and quantitative methods to collect data for a range of outcome and process measures to detect effects on individual residents, family carers, care home staff, the intervention team, the interdisciplinary team and wider systems. Analysis will include descriptive statistics summarising process and care home level data, individual demographic and clinical characteristics and data on symptom burden, clinical events and quality of care. Qualitative data will be explored using thematic analysis. Findings will inform a future phase II trial. ETHICS AND DISSEMINATION: Ethical approval was granted (REC reference 14/LO/0370). We shall publish findings at conferences, in peer-reviewed journals, on the Marie Curie Cancer Care website and prepare reports for dissemination by organisations involved with end-of-life care and dementia.

Biochemical and molecular characterization of Treponema phagedenis-like spirochetes isolated from a bovine digital dermatitis lesion.

BACKGROUND: Bovine papillomatous digital dermatitis (DD) is the leading cause of lameness in dairy cattle and represents a serious welfare and economic burden. Found primarily in high production dairy cattle worldwide, DD is characterized by the development of an often painful red, raw ulcerative or papillomatous lesion frequently located near the interdigital cleft and above the bulbs of the heel. While the exact etiology is unknown, several spirochete species have been isolated from lesion material. Four isolates of Treponema phagedenis-like spirochetes were isolated from dairy cows in Iowa. Given the distinct differences in host, environmental niche, and disease association, a closer analysis of phenotypic characteristics, growth characteristics, and genomic sequences of T. phagedenis, a human genitalia commensal, and the Iowa DD isolates was undertaken. RESULTS: Phenotypically, these isolates range from 8.0 to 9.7 µm in length with 6-8 flagella on each end. These isolates, like T. phagedenis, are strictly anaerobic, require serum and volatile fatty acids for growth, and are capable of fermenting fructose, mannitol, pectin, mannose, ribose, maltose, and glucose. Major glucose fermentation products produced are formate, acetate, and butyrate. Further study was conducted with a single isolate, 4A, showing an optimal growth pH of 7.0 (range of 6-8.5) and an optimal growth temperature of 40 °C (range of 29 °C-43 °C). Comparison of partial genomic contigs of isolate 4A and contigs of T. phagedenis F0421 revealed > 95% amino acid sequence identity with amino acid sequence of 4A. In silico DNA-DNA whole genome hybridization and BLAT analysis indicated a DDH estimate of >80% between isolate 4A and T. phagedenis F0421, and estimates of 52.5% or less when compared to the fully sequenced genomes of other treponeme species. CONCLUSION: Using both physiological, biochemical and genomic analysis, there is a lack of evidence for difference between T. phagedenis and isolate 4A. The description of Treponema phagedenis should be expanded from human genital skin commensal to include being an inhabitant within DD lesions in cattle.

The effect of initial treatment of periodontitis on systemic markers of inflammation and cardiovascular risk: a randomized controlled trial.

Observational studies indicate that chronic periodontal disease is associated with adverse cardiovascular outcomes. The aim of this study was to determine whether initial periodontal treatment has a beneficial effect on systemic markers of inflammation and cardiovascular risk. One hundred and thirty-six adults with chronic periodontitis were allocated to either intervention or control groups in a 3-month randomized controlled intervention study. The intervention group received initial periodontal treatment, whereas the control group did not receive that treatment until after the study. Blood levels of cardiovascular risk factors, and of hematological, inflammatory, and metabolic markers, were measured at the beginning and the end of the study, and differences were calculated. Fibrinogen level was the primary outcome measure. Data for 61 persons in the intervention group and for 64 persons in the control group were available for statistical analysis. Compared with the control group, the intervention group showed a non-significant trend for a lower fibrinogen level. Significant increases in hemoglobin and hematocrit were seen after treatment, showing that initial periodontal treatment, a relatively simple and cost-effective intervention, has systemic effects.

Intranasal organic dust exposure-induced airway adaptation response marked by persistent lung inflammation and pathology in mice.

Organic dust exposure in agricultural environments results in an inflammatory response that attenuates over time, but repetitive exposures can result in chronic respiratory disease. Animal models to study these mechanisms are limited. This study investigated the effects of single vs. repetitive dust-induced airway inflammation in mice by intranasal exposure method. Mice were exposed to swine facility dust extract (DE) or saline once and once daily for 1 and 2 wk. Dust exposure resulted in increased bronchoalveolar lavage fluid neutrophils and macrophages after single and repetitive exposures. Lavage fluid TNFalpha, IL-6, keratinocyte chemoattractant, and macrophage inflammatory protein-2 were significantly increased after single and repetitive dust exposures, but were dampened in 2-wk dust-exposed mice compared with single exposure. Dust exposure induced PKCalpha and -epsilon activation in isolated tracheal epithelial cells but were dampened with repetitive exposures. Ex vivo stimulation of alveolar macrophages from 2-wk animals demonstrated reduced cytokine responsiveness and phagocytic ability. Significant lung pathology occurred with development of mixed mononuclear cellular aggregates (T and B lymphocytes, phagocytes) after repetitive dust exposure, a novel observation. Airway hyperresponsiveness to methacholine occurred after single dust exposure but resolved after 2 wk. Collectively, intranasal exposure to DE results in significant lung inflammatory and pathological responses marked by a modulated innate immune response to single and repetitive dust exposures that is associated with PKC activity.

Bovine immune response to papillomatous digital dermatitis (PDD)-associated spirochetes is skewed in isolate reactivity and subclass elicitation.

Papillomatous digital dermatitis (PDD) is a growing cause of lameness of dairy cattle worldwide. Farms with PDD-afflicted cows experience economic loss due to treatment costs, decreased milk production, lower reproductive efficiency and premature culling. Cows exhibit both humoral and cellular immune responses to PDD-associated spirochetes. This study was undertaken to further characterize the bovine humoral response to PDD-associated spirochetes. Forty-seven sera samples collected from cattle (Field cattle) on three different dairy operations in Iowa were analyzed. In addition, sera were obtained from six young steers (Test cattle) that received a mixed inoculum of four previously isolated Treponema phagedenis-like spirochetes (1A, 3A, 4A and 5B) on two separate occasions. Relative levels of total IgG, IgG1, IgG2 and IgM reactive to each individual spirochete were determined. Field cattle had a higher mean antibody response to 5B compared to the other isolates and T. phagedenis. Test cattle reacted most strongly with 4A following initial exposure, shifting to a greater reactivity with 5B and a reactivity profile similar to field cattle following secondary exposure. No measurable IgM was detected. IgG1 was produced predominately in all cattle. Low to moderate levels of total IgG reactivity to T. phagedenis occurred with sera from all cattle.

Papillomatous digital dermatitis spirochetes suppress the bovine macrophage innate immune response.

Papillomatous digital dermatitis (PDD) is a polymicrobial infection in soft tissue adjacent to the hoof and is the leading cause of lameness in dairy cattle. Treponema phagedenis-like (TPL) spirochetes are a constant feature of PDD lesions and are localized deep in infected tissue. Host-cell response mechanisms to TPL spirochetes are poorly understood. To assess how bovine macrophages respond to cellular constituents of TPL spirochetes, changes in transcription were analyzed using serial analysis of gene expression (SAGE) and real time RT-PCR. This analysis revealed that some proinflammatory cytokines (e.g. GCP-2 and IL-8) are induced in treated macrophages, while receptors and their accessory proteins for IL-1, IL-6 and IL-11 are either down regulated or unchanged. Two genes encoding proteins having negative effects on NFkappaB, IkappaB and SIVA-1, are significantly induced in stimulated cells. Several genes associated with the cytoskeleton and antigen presentation are down regulated after exposure to sonicated TPL spirochetes, as are genes associated with wound repair. Combined, these data suggest that the innate immune and wound repair functions of bovine macrophages exposed to TPL cellular constituents are impaired thereby enabling bacteria to resist clearance and induce lesion formation. Use of this in vitro bovine macrophage model should be useful in elucidating host-spirochete interactions and facilitate identification of potential virulence traits.

Lesion formation and antibody response induced by papillomatous digital dermatitis-associated spirochetes in a murine abscess model.

Papillomatous digital dermatitis (PDD), also known as hairy heel wart, is a growing cause of lameness of cows in the U.S. dairy industry. Farms with PDD-afflicted cows experience economic loss due to treatment costs, decreased milk production, lower reproductive efficiency, and premature culling. While the exact cause of PDD is unknown, lesion development is associated with the presence of anaerobic spirochetes. This study was undertaken to investigate the virulence and antigenic relatedness of four previously isolated Treponema phagedenis-like spirochetes (1A, 3A, 4A, and 5B) by using a mouse abscess model with subcutaneous inoculation of 10(9), 10(10), and 10(11) spirochetes. Each of the PDD isolates induced abscess formation, with strain 3A causing cutaneous ulceration. Lesion development and antibody responses were dose dependent and differed significantly from those seen with the nonpathogenic human T. phagedenis strain. Strains 3A, 4A, and 5B showed two-way cross-reactivity with each other and a one-way cross-reaction with T. phagedenis. Strain 5B showed one-way cross-reactivity with 1A. None of the isolates showed cross-reactivity with T. denticola. In addition, distinct differences in immunoglobulin G subclass elicitation occurred between the PDD strains and T. phagedenis. From these data, we conclude that spirochetes isolated from PDD lesions have differential virulence and antigenic traits in vivo. Continuing investigation of these properties is important for the elucidation of virulence mechanisms and antigenic targets for vaccine development.

Role for Msh5 in the regulation of Ig class switch recombination.

Ig class switch recombination (CSR) and somatic hypermutation serve to diversify antibody responses and are orchestrated by the activity of activation-induced cytidine deaminase and many proteins involved in DNA repair and genome surveillance. Msh5, a gene encoded in the central MHC class III region, and its obligate heterodimerization partner Msh4 have a critical role in regulating meiotic homologous recombination and have not been implicated in CSR. Here, we show that MRL/lpr mice carrying a congenic H-2(b/b) MHC interval exhibit several abnormalities regarding CSR, including a profound deficiency of IgG3 in most mice and long microhomologies at Ig switch (S) joints. We found that Msh5 is expressed at low levels on the H-2(b) haplotype and, importantly, a similar long S joint microhomology phenotype was observed in both Msh5 and Msh4-null mice. We also present evidence that genetic variation in MSH5 is associated with IgA deficiency and common variable immune deficiency (CVID) in humans. One of the human MSH5 alleles identified contains two nonsynonymous polymorphisms, and the variant protein encoded by this allele shows impaired binding to MSH4. Similar to the mice, Ig S joints from CVID and IgA deficiency patients carrying disease-associated MSH5 alleles show increased donor/acceptor microhomology, involving pentameric DNA repeat sequences and lower mutation rates than controls. Our findings suggest that Msh4/5 heterodimers contribute to CSR and support a model whereby Msh4/5 promotes the resolution of DNA breaks with low or no terminal microhomology by a classical nonhomologous end-joining mechanism while possibly suppressing an alternative microhomology-mediated pathway.

Effects of cigarette smoke and alcohol on ciliated tracheal epithelium and inflammatory cell recruitment.

Ciliated epithelium represents the first line of host defense against lung infection. Most alcoholics smoke and are at high risk for developing lung infections. We reported that cigarette smoke activates protein kinase C (PKC) and alcohol desensitizes ciliary beat frequency (CBF) to beta-agonists in bovine bronchial epithelial cells in vitro. The combined effect of smoke and alcohol exposure on mouse ciliated tracheal epithelium has not been studied in vivo. We hypothesized that previously observed in vitro effects of smoke and alcohol exposure could be replicated in vivo. Female C57BL/6 mice were exposed to whole body cigarette smoke only, 20% alcohol ad libitum in drinking water only, or the combination of cigarette smoke plus alcohol for 6 wk. Bronchoalveolar lavage (BAL) cell populations, CBF, and airway kinase activity were assessed. Total BAL cells were decreased in animals exposed to alcohol alone and increased in animals exposed to smoke alone. Mice receiving smoke and alcohol had cell levels similar to smoke alone. Baseline CBF was not affected in any group; however, isoproterenol stimulation of CBF was blunted by alcohol exposure and actually slowed below baseline in the smoke plus alcohol group. Isoproterenol-induced PKA activity was inhibited in mice receiving alcohol independent of smoke exposure. Smoke activated PKC independent of alcohol. The isoproterenol-induced slowing below baseline of CBF after combined smoke and alcohol exposure demonstrates a novel ciliary impairment likely related to the combination of alcohol-mediated PKA desensitization and smoke-stimulated PKC activation, possibly through acetaldehyde present in the vapor phase of cigarette smoke.