Cellular mechanisms regulating synthetic sex ratio distortion in the Anopheles gambiae germline.

Genetic control strategies aimed to bias the sex of progenies towards males present a promising new paradigm to eliminate malaria-transmitting mosquitoes. A synthetic sex-ratio distortion (SD) system was successfully engineered in Anopheles gambiae by exploiting the meiotic activity of the I-PpoI endonuclease targeting ribosomal DNA (rDNA) repeats, exclusively located on the X chromosome. Males carrying the SD construct produce highly male-biased progenies without evident reduction in fertility. In this study, we investigated the fate of X and Y chromosomes in these SD males and found that ratios of mature X:Y-bearing sperm were comparable to wild-type insects, indicating absence of selection mechanisms during sperm maturation. We therefore tested the effect of meiotic cleavage of both X and Y chromosomes in a lab-generated SD strain carrying rDNA on both sex chromosomes, showing fertility comparable to wild-type and a reduced male-bias compared to SD males in which only the X is targeted. Exposure of Y-linked rDNA to I-PpoI cleavage for consecutive generations rapidly restored the male-bias to typical high frequencies, indicating a correlation between the number of cleavable targets in each sex chromosome and the sex-ratios found in the progeny. Altogether our results indicate that meiotic cleavage of rDNA repeats, located in the sex chromosomes of A. gambiae SD males, affects the competitiveness of mature sperm to fertilize the female oocyte, thereby generating sex-biased progenies. We also show that the presence of rDNA copies on the Y chromosome does not impair the effectiveness of engineered synthetic SD systems for the control of human malaria mosquitoes.

The Anopheles FBN9 immune factor mediates Plasmodium species-specific defense through transgenic fat body expression.

Mosquitoes have a multifaceted innate immune system that is actively engaged in warding off various pathogens, including the protozoan malaria parasite Plasmodium. Various immune signaling pathways and effectors have been shown to mediate a certain degree of defense specificity against different Plasmodium species. A key pattern recognition receptor of the Anopheles gambiae immune system is the fibrinogen domain-containing immunolectin FBN9, which has been shown to be transcriptonally induced by Plasmodium infection, and to mediate defense against both rodent and human malaria parasites and bacteria. Here we have further studied the defense specificity of FBN9 using a transgenic approach, in which FBN9 is overexpressed in the fat body tissue after a blood meal through a vitellogenin promoter. Interestingly, the Vg-FBN9 transgenic mosquitoes showed increased resistance only to the rodent parasite P. berghei, and not to the human parasite P. falciparum, pointing to differences in the mosquito's defense mechanisms against the two parasite species. The Vg-FBN9 transgenic mosquitoes were also more resistant to infection with both Gram-positive and Gram-negative bacteria and showed increased longevity when infected with P. berghei. Our study points to the importance of both experimentally depleting and enriching candidate anti-Plasmodium effectors in functional studies in order to ascertain their suitability for the development of transgenic mosquito-based malaria control strategies.

A draft genome sequence of an invasive mosquito: an Italian Aedes albopictus.

The draft genome sequence of Italian specimens of the Asian tiger mosquito Aedes (Stegomyia) albopictus (Diptera: Culicidae) was determined using a standard NGS (next generation sequencing) approach. The size of the assembled genome is comparable to that of Aedes aegypti; the two mosquitoes are also similar as far as the high content of repetitive DNA is concerned, most of which is made up of transposable elements. Although, based on BUSCO (Benchmarking Universal Single-Copy Orthologues) analysis, the genome assembly reported here contains more than 99% of protein-coding genes, several of those are expected to be represented in the assembly in a fragmented state. We also present here the annotation of several families of genes (tRNA genes, miRNA genes, the sialome, genes involved in chromatin condensation, sex determination genes, odorant binding proteins and odorant receptors). These analyses confirm that the assembly can be used for the study of the biology of this invasive vector of disease.

Anemia in Cambodia: a cross-sectional study of anemia, socioeconomic status and other associated risk factors in rural women.

Iron deficiency and associated anemia are severe public health problems, which are prevalent in the developing world. We conducted a cross-sectional survey, comprised of written interview questions and laboratory analysis of blood biomarkers, in Kandal Province, Cambodia. The objective of this study is to examine possible factors that are associated with anemia in rural Cambodia. Data on socioeconomic status, water source/treatment practices, and meat consumption was also collected. Of the 297 women surveyed, 51.2% were anemic. Of those women found to be anemic, iron deficiency was implicated in 9.7% of cases (SF <15 ng/L), with an additional 18.5% reported to be borderline iron deficient (serum ferritin=15-30 ng/L). Meat consumption was very low, with nearly one-half of the women consuming meat one time per month or less. This study highlights the multi-faceted etiology of anemia in Cambodia and emphasizes the need for comprehensive nutrition surveying in order to better inform prevention and treatment programming and policy development.

Women's nutrient intakes and food-related knowledge in rural Kandal province, Cambodia.

In Cambodia, both anaemia and vitamin A deficiency are serious health problems. Despite this, few comprehensive nutritional surveys have been completed to date. This study evaluates the adequacy of iron and vitamin A intakes, as well as women's nutritional knowledge in rural Kandal province. Twenty-four hour recalls, pile sort activities, socioeconomic surveys, focus groups, and market surveys were carried out with 67 women from 5 villages in rural Kandal Province. Ninety seven percent of women did not meet their daily-recommended intake of iron, while 70% did not meet their daily-recommended intake of vitamin A. Although many women consume vitamin A-rich and iron rich-foods daily, they do not consume large enough quantities of these foods. Results suggest that both the cost of foods as well as the extent of health knowledge is linked to nutritional practice. Most animal-source iron and vitamin A-rich foods are considered expensive; however, small fish, and several plant-source vitamin A-rich foods are inexpensive and easy to access. Despite health education, food restrictions lead some healthy foods to be considered to be harmful to women. Ultimately, this study demonstrates the importance of developing comprehensive nutritional interventions in Cambodia. Health programming must provide women with not only suggestions to include low-cost nutrient-rich foods, but also advise them about the quantities that are likely to have an impact on nutritional status. Programs should take a community-based, inter-sectoral approach that simultaneously combines culturally informed health education with initiatives that combat poverty and increase access to nutrient rich foods.

The evolution of the steps program, 2003-2010: transforming the federal public health practice of chronic disease prevention.

The Steps program, formerly known as Steps to a HealthierUS, was the first Centers for Disease Control and Prevention (CDC) program to support a community-based, integrated approach to chronic disease prevention. Steps interventions addressed both diseases and risk factors, focusing on the 3 leading causes of preventable deaths in the United States--tobacco use, poor nutrition, and physical inactivity--and the associated chronic conditions of asthma, diabetes, and obesity. When Steps shifted from interventions focused on individual health-risk behaviors to the implementation of policy, systems, and environmental changes, the program became an integral part of changing the way CDC addressed chronic disease prevention. In this article, we describe the shift in intervention strategies that occurred among Steps communities, the model that was developed as Steps evolved, common interventions implemented before and after the shift in approach, challenges experienced by Steps communities, and CDC programs that were modeled after Steps.

Prevalence of selected risk behaviors and chronic diseases and conditions-steps communities, United States, 2006-2007.

PROBLEM: At least one chronic disease or condition affects 45% of persons and account for seven of the 10 leading causes of death in the United States. Persons who suffer from chronic diseases and conditions, (e.g., obesity, diabetes, and asthma) experience limitations in function, health, activity, and work, affecting the quality of their lives as well as the lives of their family. Preventable health-risk factors (e.g., insufficient physical activity, poor nutrition, and tobacco use and exposure) contribute substantially to the development and severity of certain chronic diseases and conditions. REPORTING PERIOD COVERED: 2006-2007 DESCRIPTION OF THE SYSTEM: CDC's Healthy Communities Program funds communities to address chronic diseases and related risk factors through policy, systems, and environmental change strategies. As part of the Healthy Communities Program, 40 Steps communities were funded nationwide to address six focus areas: obesity, diabetes, asthma, physical inactivity, poor nutrition, and tobacco use and exposure. During 2006-2007, 38 and 39 of the 40 communities conducted a survey to collect adult health outcome data. The survey instrument was a modified version of the Behavioral Risk Factor Surveillance System (BRFSS) survey, a state-based, random-digit-dialed telephone survey. The survey instrument collected information on chronic diseases and conditions, health risk behaviors, and preventive health practices related to Steps community outcomes from noninstitutionalized community members aged ≥18 years. RESULTS: Prevalence estimates of chronic diseases and conditions and risk behaviors varied among Steps communities that reported data for 2006 and 2007. The proportion of the population that achieved Healthy People 2010 (HP 2010) objectives also varied among the communities. In 2006, the estimated prevalence of respondents aged ≥18 years being overweight or obese as calculated from self-reported weight and height ranged from 51.8% to 73.7%. The nationwide 2006 BRFSS median was 62.3%; a total of 20 communities exceeded this median. In 2007, the estimated prevalence being overweight or obese ranged from 50.5% to 77.2%. The nationwide 2007 BRFSS median was 63.0%; a total of 18 communities exceeded this median. In 2006, the estimated prevalence of diagnosed diabetes (excluding gestational diabetes) ranged from 3.7% to 19.7%. None of the communities achieved the HP 2010 objective of increasing to 91% the proportion of adults with diabetes who have at least an annual clinical foot examination. Six communities reached the HP 2010 objective of increasing to 76% the proportion of adults with diabetes who have an annual dilated eye examination; 20 communities reached the HP 2010 objective of increasing to 65% the proportion of adults who have a glycosylated hemoglobin measurement (A1c) at least once a year. In 2007, the estimated prevalence of diagnosed diabetes (excluding gestational diabetes) ranged from 4.4% to 17.9%. None of the communities achieved the HP 2010 objective of increasing to 91% the proportion of adults with diabetes who have at least an annual clinical foot examination, eight communities achieved the HP 2010 objective of increasing to 76% the proportion of adults with diabetes who have an annual dilated eye examination, and 16 communities achieved the HP 2010 objective of increasing to 65% the proportion of adults who have an A1c at least once a year. In 2006, the prevalence of reported asthma ranged from 6.5% to 18.9%. Among those who reported having asthma, the prevalence of having no symptoms of asthma during the preceding 30 days ranged from 11.5% to 29.5% for five communities with sufficient data for estimates. In 2007, the estimated prevalence of reported asthma ranged from 7.5% to 18.9%. Among those who reported having asthma, the prevalence of having no symptoms of asthma during the preceding 30 days ranged from 10.3% to 36.1% for 12 communities with sufficient data for estimates. In 2006, the prevalence of respondents who engaged in moderate physical activity for ≥30 minutes at least five times a week or who reported vigorous physical activity for ≥20 minutes at least three times a week ranged from 42.3% to 59.9%. The prevalence of consumption of fruits and vegetables at least five times/day ranged from 11.1% to 30.2%. In 2007, the prevalence of moderate or vigorous physical activity ranged from 40.6% to 69.8%; 25 communities reached the HP 2010 objective to increase the proportion of adults who engage in physical activity to 50%. The prevalence of consumption of fruits and vegetables ≥5 times/day ranged from 14.6% to 37.6%. In 2006, the estimated prevalence among respondents aged >18 years who reported having smoked >100 cigarettes in their lifetime and who were current smokers on every day or some days at the time of the survey ranged from 12.5% to 48.0%. Among smokers, the prevalence of having stopped smoking for ≥1 day because of trying to quit smoking during the previous 12 months ranged from 48.4% to 67.9% for 31 communities. No communities reached the HP 2010 target of increasing to 75% smoking cessation attempts by adult smokers. In 2007, the estimated prevalence of current smokers ranged from 11.2% to 33.7%. Two communities reached the HP 2010 objective to reduce the proportion of adults who smoke. Among smokers, the prevalence of having stopped smoking for ≥1 day because of trying to quit smoking during the preceding 12 months ranged from 50.8% to 69.6% for 26 communities. No communities reached the HP 2010 objective of increasing to 75% smoking cessation attempts by adult smokers. INTERPRETATION: The findings in this report indicate variations in health risk behaviors, chronic diseases and conditions, and use of preventive health screenings and health services among Steps communities. These findings underscore the continued need to evaluate prevention interventions at the community level and to design and implement policies to promote and encourage healthy behaviors. PUBLIC HEALTH ACTION: Steps BRFSS data monitored the prevalence of health behaviors, conditions, and use of preventive health services. CDC (at the national level), and Steps staff at state, local, and tribal levels can use BRFSS data to demonstrate accountability to stakeholders; monitor progress in meeting objectives; focus activities on policy, systems and environmental change strategies with the greatest promise of results; identify collaboration opportunities; and identify and disseminate successes and lessons learned.

Youth risk behavior surveillance--selected Steps communities, United States, 2007.

PROBLEM: Priority health-risk behaviors, including tobacco use, unhealthy dietary behaviors, and physical inactivity often are established during childhood and adolescence, extend into adulthood, are interrelated, and are preventable. These behaviors contribute to chronic disease and other health conditions, including asthma. REPORTING PERIOD COVERED: January--May 2007. DESCRIPTION OF SYSTEM: The Youth Risk Behavior Surveillance System (YRBSS) monitors priority health-risk behaviors and the prevalence of obesity and asthma among youth and young adults. YRBSS includes a national school-based survey conducted by CDC and state and local school-based surveys conducted by state and local education and health agencies. In 2007, as a component of YRBSS, communities participating in the Steps Cooperative Agreement Program (Steps Program) also conducted school-based surveys of students in grades 9--12 in their program intervention areas. These communities used a standard questionnaire that measured tobacco use, dietary behaviors, and physical activity and monitored the prevalence of obesity and asthma. This report summarizes results from surveys of students in 26 Steps communities that conducted surveys in 2007. RESULTS: Results from the 26 Steps communities indicated that a substantial proportion of adolescents engaged in health-risk behaviors that increased their likelihood of becoming obese. During 2007, across surveys, the percentage of high school students who had ever smoked at least one cigarette every day for 30 days ranged from 3.7% to 20.1% (median: 9.0%), the percentage who had eaten fruits and vegetables five or more times per day during the 7 days before the survey ranged from 13.9% to 23.9% (median: 17.9%), and the percentage who met recommended levels of physical activity ranged from 27.7% to 55.5% (median: 40.1%). Across surveys, the percentage of students who were obese ranged from 4.6% to 20.2% (median: 13.6%), and the percentage of students who had ever been told by a doctor or nurse that they had asthma ranged from 16.8% to 28.5% (median: 21.6%). INTERPRETATION: Although the prevalence of many health-risk behaviors and health conditions related to obesity and asthma varies across Steps communities, a substantial proportion of high school students engage in behaviors that place them at risk for chronic disease. PUBLIC HEALTH ACTION: Steps Program staff at the national, tribal, state, and local levels will use YRBSS data for decision making, program planning, and enhancing technical assistance to reduce tobacco use and exposure and to increase healthy eating and physical activity. These data will be used to help focus existing programs on activities that have shown the greatest promise of results, as well as identify populations of greatest need and opportunities for strategic collaboration to identify and disseminate lessons learned.

Prevalence of selected risk behaviors and chronic diseases--Behavioral Risk Factor Surveillance System (BRFSS), 39 steps communities, United States, 2005.

PROBLEM: Behavioral risk factors (e.g., tobacco use, poor diet, and physical inactivity) can lead to chronic diseases. In 2005, of the 10 leading causes of death in the United States, seven (heart disease, cancer, stroke, chronic lower respiratory diseases, diabetes, Alzheimer's disease, and kidney disease) were attributable to chronic disease. Chronic diseases also adversely affect the quality of life of an estimated 90 million persons in the United States, resulting in illness, disability, extended pain and suffering, and major limitations in daily living. REPORTING PERIOD COVERED: 2005. DESCRIPTION OF THE SYSTEM: CDC's Steps Program funds 40 selected U.S. communities to address six leading causes of death and disability and rising health-care costs in the United States: obesity, diabetes, asthma, physical inactivity, poor nutrition, and tobacco use. In 2005, a total of 39 Steps communities conducted a survey to collect adult health outcome data. The survey instrument was a modified version of the Behavioral Risk Factor Surveillance System (BRFSS) survey, a community-based, random-digit--dialing telephone survey with a multistage cluster design. The survey instrument collected information on health risk behaviors and preventive health practices among noninstitutionalized adults aged >/=18 years. RESULTS: Prevalence estimates of risk behaviors and chronic conditions varied among the 39 Steps communities that reported data for 2005. The proportion of the population that achieved Healthy People 2010 (HP 2010) objectives also varied among the communities. The estimated prevalence of obesity (defined as having a body mass index [BMI] of >/=30.0 kg/m(2) as calculated from self-reported weight and height) ranged from 15.6% to 44.0%. No communities reached the HP2010 objective of reducing the proportion of adults who are obese to 15.0%. The prevalence of diagnosed diabetes (excluding gestational diabetes) ranged from 4.3% to 16.6%. Eighteen communities achieved the HP2010 objective to increase the proportion of adults with diabetes who have at least an annual foot examination to 75.0%; five communities achieved the HP2010 objective to increase the proportion of adults with diabetes who have an annual dilated eye examination to 75.0%. The prevalence of reported asthma ranged from 7.0% to 17.6%. Among those who reported having asthma, the prevalence of having no symptoms of asthma during the preceding 30 days ranged from 15.4% to 40.3% for 10 communities with sufficient data for estimates. The prevalence of respondents who engaged in moderate physical activity for >/=30 minutes at least five times a week or who reported vigorous physical activity for >/=20 minutes at least three times a week ranged from 42.0% to 62.2%. The prevalence of consumption of fruits and vegetables at least five times a day ranged from 15.6% to 30.3%. The estimated prevalence among respondents aged >/=18 years who reported having smoked >/=100 cigarettes in their lifetime and who were current smokers on every day or some days at the time of the survey ranged from 11.0% to 39.7%. One community achieved the HP2010 objective to reduce the proportion of adults who smoke to 12.0%. Among smokers, the prevalence of having stopped smoking for >/=1 day as a result of trying to quit smoking during the previous 12 months ranged from 47.8% to 63.3% for 31 communities. No communities reached the HP2010 objective of increasing smoking cessation attempts by adult smokers to 75%. INTERPRETATION: The findings in this report indicate variations in health risk behaviors, chronic conditions, and use of preventive health screenings and health services. These findings underscore the continued need to evaluate intervention programs at the community level and to design and implement policies to reduce morbidity and mortality caused by chronic disease. PUBLIC HEALTH ACTION: Steps BRFSS data can be used to monitor the prevalence of specific health behaviors, diseases, conditions, and use of preventive health services. Steps Program staff at the national, state, local, and tribal levels can use BRFSS data to demonstrate accountability to stakeholders, monitor progress in meeting program objectives, focus programs on activities with the greatest promise of results, identify opportunities for strategic collaboration, and identify and disseminate successes and lessons learned.