Improving rural health care reduces illegal logging and conserves carbon in a tropical forest.

Tropical forest loss currently exceeds forest gain, leading to a net greenhouse gas emission that exacerbates global climate change. This has sparked scientific debate on how to achieve natural climate solutions. Central to this debate is whether sustainably managing forests and protected areas will deliver global climate mitigation benefits, while ensuring local peoples' health and well-being. Here, we evaluate the 10-y impact of a human-centered solution to achieve natural climate mitigation through reductions in illegal logging in rural Borneo: an intervention aimed at expanding health care access and use for communities living near a national park, with clinic discounts offsetting costs historically met through illegal logging. Conservation, education, and alternative livelihood programs were also offered. We hypothesized that this would lead to improved health and well-being, while also alleviating illegal logging activity within the protected forest. We estimated that 27.4 km2 of deforestation was averted in the national park over a decade (∼70% reduction in deforestation compared to a synthetic control, permuted P = 0.038). Concurrently, the intervention provided health care access to more than 28,400 unique patients, with clinic usage and patient visitation frequency highest in communities participating in the intervention. Finally, we observed a dose-response in forest change rate to intervention engagement (person-contacts with intervention activities) across communities bordering the park: The greatest logging reductions were adjacent to the most highly engaged villages. Results suggest that this community-derived solution simultaneously improved health care access for local and indigenous communities and sustainably conserved carbon stocks in a protected tropical forest.

Addressing Family Planning Access Barriers Using an Integrated Population Health Environment Approach in Rural Uganda.

Recent studies recommend FP initiatives in rural sub-Saharan Africa operate in more context-specific ways to reduce inequities. In 2011 such a project, HoPE-LVB, was implemented by Pathfinder International and local partners among Ugandan Lake Victoria fishing communities using a Population, Health and Environment approach. Among other objectives, the project aimed to increase support for FP and women's involvement in decision-making by linking FP benefits to community needs including income generation from nature-based livelihoods. Improved FP access was measured by the project using qualitative methods and the project's indicator database in terms of five barriers: service quality, community knowledge, physical access, finances, and social acceptability. Through coordinated interventions representing multiple sectors, the project helped communities move more towards a -tipping point‖ whereby FP use has now become more an acceptable and accepted social norm. Central to this has been improving service quality and physical access as well as facilitating women's involvement in income-generation, thereby increasing their agency and contribution to decision-making including pregnancy timing.

Family planning as a contributor to environmental sustainability: weighing the evidence.

PURPOSE OF REVIEW: To highlight recent evidence that family planning, readily accessible to all who seek it and exercised as a human right, can contribute to environmental sustainability. As global concern increases about the health of our planet, better understanding of the role family planning programs play in maintaining a sustainable environment could bolster public and policymaker support for access to family planning. RECENT FINDINGS: A recent Worldwatch Institute review of scientific literature (FPESA) exploring this relationship covered two potential cause-effect pathways: one demographic, one personal. Although nonconfirmatory, a decade of reviewed studies overwhelmingly supported the hypothesis that family planning benefits environmental sustainability. A complementary review by the Evidence Project of population, health and environment projects over a similar time period strongly suggests that transdisciplinary efforts including family planning can yield multiple benefits - health, empowerment, economic and environmental. SUMMARY: Cumulative research generally supports but cannot confirm the thesis that family planning contributes to efforts to achieve environmental sustainability. This does not equate to no relationship but rather a lack of adequate methodologies. For research on complex relationships like this, novel research designs may prove more effective.

Effects of land use on plague (Yersinia pestis) activity in rodents in Tanzania.

Understanding the effects of land-use change on zoonotic disease risk is a pressing global health concern. Here, we compare prevalence of Yersinia pestis, the etiologic agent of plague, in rodents across two land-use types-agricultural and conserved-in northern Tanzania. Estimated abundance of seropositive rodents nearly doubled in agricultural sites compared with conserved sites. This relationship between land-use type and abundance of seropositive rodents is likely mediated by changes in rodent and flea community composition, particularly via an increase in the abundance of the commensal species, Mastomys natalensis, in agricultural habitats. There was mixed support for rodent species diversity negatively impacting Y. pestis seroprevalence. Together, these results suggest that land-use change could affect the risk of local transmission of plague, and raise critical questions about transmission dynamics at the interface of conserved and agricultural habitats. These findings emphasize the importance of understanding disease ecology in the context of rapidly proceeding landscape change.

Nasopharyngeal colonization by potentially pathogenic bacteria found in healthy semi-captive wild-born chimpanzees in Uganda.

Information on the chimpanzee nasopharygeal colonization in captive sanctuaries and in the wild is rare. This study was undertaken to establish the nasopharygeal colonization and potential bacterial pathogens in sanctuary chimpanzees as a basis for improving chimpanzee and employee health. Nasopharygeal colonization of 39 healthy chimpanzees were analyzed by microbiological cultivation method and polymerase chain reaction (PCR) targeting the bacterial 16S rRNA gene. We report four major phyla dominated by Proteobacteria (50%), Fermicutes (35.7%), Bacteriodes (7.1%), and Cynobacteria (7.1%) in healthy semi-captive chimpanzees. Further classification based on 7-base oligomers revealed the following genera: Streptococcus, Veillonella, Neisseria, Prevotella, Kingella and unclassified Cynobacteria, Actinobacillus, Bacteriodes and Pasteurellaceae. On microbiological cultivation we were able to identify and characterize some of the bacteria to species level as Klebsiella pneumonie and Pseudomonas aeruginosa being dominant bacteria with 54.7% and 50% colonization, respectively. Of these, Streptococcus, Neisseria, Klebsiella, and Haemophillus have representatives known to potentially cause severe respiratory disease. Our data present important information on chimpanzee nasopharygeal colonization as a guide to understanding disease processes and pharmaceutical therapies required for improving the health of chimpanzees. The results from this study will guide the processes to improve procedures for routine management of sanctuary chimpanzees and use it as a basis for evaluation of future reintroduction possibilities.

Human health impacts of ecosystem alteration.

Human activity is rapidly transforming most of Earth's natural systems. How this transformation is impacting human health, whose health is at greatest risk, and the magnitude of the associated disease burden are relatively new subjects within the field of environmental health. We discuss what is known about the human health implications of changes in the structure and function of natural systems and propose that these changes are affecting human health in a variety of important ways. We identify several gaps and limitations in the research that has been done to date and propose a more systematic and comprehensive approach to applied research in this field. Such efforts could lead to a more robust understanding of the human health impacts of accelerating environmental change and inform decision making in the land-use planning, environmental conservation, and public health policy realms.

The environment as a strategic healthcare partner.

PURPOSE OF REVIEW: To describe the growing-consensus opinion regarding the contribution of natural processes - 'nature' - to human health. Globally, natural environments are becoming smaller and critically degraded because of various human-related factors. Consequently, some of the 'free' health benefits nature confers are being lost. This is especially problematic for people in rural areas with limited access to clinical services whose lives depend closely upon nature. RECENT FINDINGS: In 2001, an assessment of the world's 'ecosystems' was initiated - the Millennium Ecosystem Assessment. It explored ecosystem changes and their subsequent effects in various locales on human well being, including health. Global Burden of Disease studies have also revealed the importance of environmental factors to health, in some countries in particular. Not coincidentally, geographic areas in the two research efforts overlap. Despite this, convincing research describing how conserving healthy environments may positively affect human health remains lacking. SUMMARY: Establishing ecosystem-human health causal linkages via traditional epidemiological approaches is challenging. Innovative research initiatives are beginning to increase our understanding and appreciation of nature's role as a provider of health, rendering conservation potentially a healthcare strategy. Transdisciplinary university teaching is also playing a role in broadening the awareness of these important linkages and developing research skills to meet the challenge.

Avoiding verification bias in screening test evaluation in resource poor settings: a case study from Zimbabwe.

BACKGROUND: Verification bias occurs when the percentage of subjects receiving disease verification differs according to the test result. Statistical adjustment yields unbiased sensitivity and specificity under a missing at random (MAR) assumption. PURPOSE: To use an example from an international study to show how the assumptions needed for unbiased statistical adjustment for verification bias can be undermined by conditions on the ground, and that accuracy of estimates is also compromised by too low a sampling fraction of subjects who test negative. METHODS: A study in Zimbabwe assessed the accuracy of a screening test for cervical cancer screening, visual inspection with acetic acid (VIA). The study was conducted in two phases, Phase I, where only 10% of subjects with negative tests received verification, and Phase II, in which nearly all subjects were verified. Unadjusted, simple- and covariate-adjusted estimates were compared to investigate factors affecting differences. Bootstrap simulations were used to illustrate the effect of varying test negative sampling fractions. RESULTS: Phase I unadjusted sensitivity and specificity were 0.66 (0.61-0.70) and 0.34 (0.31-0.36), respectively. Simple-weighted adjusted estimators accounting only for VIA status were 0.20 (0.17-0.23) and 0.80 (0.78-0.81), respectively, suggesting the test to be useless. It was found that verification (colposcopy) capacity in-country had been exceeded, and that random selection of test negative patients for colposcopy had been compromised. Phase II estimates of sensitivity and specificity were 0.77 and 0.64, respectively. With 9% disease prevalence, a VIA test-negative sampling fraction >50% was necessary for the confidence intervals for sensitivity to have more than a 90% probability of including the true value. LIMITATIONS: Phase I statistical adjustment was not made for MAR deviations unexplained by the two auxiliary factors, Pap results and STD history. Adjustment was not possible for other unmeasured co-factors. CONCLUSIONS: While there are standard formulae for correcting for verification bias, these will be biased if the MAR assumption is not met, which can occur through the actions of study personnel or subjects. Design of such studies in low resource environments needs to either require 100% verification, or employ procedures ensuring that the sample of test negatives who receive verification is indeed random. In addition, required test negative sampling fractions need to incorporate information on both disease prevalence and overall sample size.

Visual inspection with acetic acid as a cervical cancer test: accuracy validated using latent class analysis.

BACKGROUND: The purpose of this study was to validate the accuracy of an alternative cervical cancer test - visual inspection with acetic acid (VIA) - by addressing possible imperfections in the gold standard through latent class analysis (LCA). The data were originally collected at peri-urban health clinics in Zimbabwe. METHODS: Conventional accuracy (sensitivity/specificity) estimates for VIA and two other screening tests using colposcopy/biopsy as the reference standard were compared to LCA estimates based on results from all four tests. For conventional analysis, negative colposcopy was accepted as a negative outcome when biopsy was not available as the reference standard. With LCA, local dependencies between tests were handled through adding direct effect parameters or additional latent classes to the model. RESULTS: Two models yielded good fit to the data, a 2-class model with two adjustments and a 3-class model with one adjustment. The definition of latent disease associated with the latter was more stringent, backed by three of the four tests. Under that model, sensitivity for VIA (abnormal+) was 0.74 compared to 0.78 with conventional analyses. Specificity was 0.639 versus 0.568, respectively. By contrast, the LCA-derived sensitivity for colposcopy/biopsy was 0.63. CONCLUSION: VIA sensitivity and specificity with the 3-class LCA model were within the range of published data and relatively consistent with conventional analyses, thus validating the original assessment of test accuracy. LCA probably yielded more likely estimates of the true accuracy than did conventional analysis with in-country colposcopy/biopsy as the reference standard. Colposcopy with biopsy can be problematic as a study reference standard and LCA offers the possibility of obtaining estimates adjusted for referent imperfections.

Cervical cancer prevention: safety, acceptability, and feasibility of a single-visit approach in Accra, Ghana.

OBJECTIVE: The purpose of this study was to assess the safety and acceptability of a single-visit approach to cervical cancer prevention combining visual inspection of the cervix with acetic acid wash (VIA) and cryotherapy. STUDY DESIGN: The study was observational. Nine clinicians were trained in VIA and cryotherapy. Over 18 months 3665 women were VIA-tested. If positive and eligible, cryotherapy was offered immediately. Treated women were followed-up at 3 months and 1 year. RESULTS: The test-positive rate was 13.2%. Of those eligible, 70.2% and 21% received immediate or delayed treatment, respectively. No major complications were recorded, and 5.6% presented for a perceived problem post-cryotherapy. Among those treated over 90% expressed satisfaction with their experience, and 96% had an indentifiable squamo-columnar junction. Only 2.6% (6/232) were test positive, 1-year posttreatment. CONCLUSION: A single-visit approach using VIA and cryotherapy proved to be safe, acceptable, and feasible in an urban African setting.

Poverty reduction and Millennium Development Goals: recognizing population, health, and environment linkages in rural Madagascar.

The Millennium Development Goals (MDGs), committed to by all 191 United Nations member states, are rooted in the concept of sustainable development. Although 2007 (midway) reports indicated that programs are under way, unfortunately many countries are unlikely to reach their goals by 2015 due to high levels of poverty. Madagascar is one such example, although some gains are being made. Attempts of this island nation to achieve its MDGs, expressed most recently in the form of a Madagascar Action Plan, are notable in their emphasis on (1) conserving the country's natural resource base, (2) the effect of demographic trends on development, and (3) the importance of health as a prerequisite for development. Leadership in the country's struggle for economic growth comes from the president of the Republic, in part, through his "Madagascar Naturally" vision as well as his commitment to universal access to family planning, among other health and development interventions. However, for resource-limited countries, such as Madagascar, to get or stay "on track" to achieving the MDGs will require support from many sides. "Madagascar cannot do it alone and should not do it alone." This position is inherent in the eighth MDG: "Develop a global partnership for development." Apparently, it takes a village after all - a global one.

Cost-effectiveness of cervical-cancer screening in five developing countries.

BACKGROUND: Cervical-cancer screening strategies that involve the use of conventional cytology and require multiple visits have been impractical in developing countries. METHODS: We used computer-based models to assess the cost-effectiveness of a variety of cervical-cancer screening strategies in India, Kenya, Peru, South Africa, and Thailand. Primary data were combined with data from the literature to estimate age-specific incidence and mortality rates for cancer and the effectiveness of screening for and treatment of precancerous lesions. We assessed the direct medical, time, and program-related costs of strategies that differed according to screening test, targeted age and frequency, and number of clinic visits required. Single-visit strategies involved the assumption that screening and treatment could be provided in the same day. Outcomes included the lifetime risk of cancer, years of life saved, lifetime costs, and cost-effectiveness ratios (cost per year of life saved). RESULTS: The most cost-effective strategies were those that required the fewest visits, resulting in improved follow-up testing and treatment. Screening women once in their lifetime, at the age of 35 years, with a one-visit or two-visit screening strategy involving visual inspection of the cervix with acetic acid or DNA testing for human papillomavirus (HPV) in cervical cell samples, reduced the lifetime risk of cancer by approximately 25 to 36 percent, and cost less than 500 dollars per year of life saved. Relative cancer risk declined by an additional 40 percent with two screenings (at 35 and 40 years of age), resulting in a cost per year of life saved that was less than each country's per capita gross domestic product--a very cost-effective result, according to the Commission on Macroeconomics and Health. CONCLUSIONS: Cervical-cancer screening strategies incorporating visual inspection of the cervix with acetic acid or DNA testing for HPV in one or two clinical visits are cost-effective alternatives to conventional three-visit cytology-based screening programs in resource-poor settings.

Screening test accuracy studies: how valid are our conclusions? Application to visual inspection methods for cervical screening.

While the basic concepts associated with screening are simple, studying the value of new tests requires a very strict methodology. This paper summarizes lessons learned regarding appropriate methodologies to assess the value of new screening approaches using visual inspection with acetic acid (VIA), a screening test for cervical pre-cancerous lesions, as an example. In addition to being convenient to, safe for and acceptable by target community members, a screening test should be reliable and have good test characteristics (i.e. be able to discriminate well between early disease and non disease). Test reliability assesses the degree to which repeated measurements of the test yields the same result. To ensure reproducibility of study findings, test reliability should be assessed before any evaluation of test accuracy. The accuracy of a test (specificity and sensitivity) is measured using cross-sectional studies with adequate sample size. Several basic features are necessary to ensure internal validity for such studies: (a) final disease status data should be obtained for all subjects, (b) all tests results must be determined independently of previous results, (c) the reference standard used to determine the disease status should be accurate, (d) the full "spectrum" of the disease should be included in the study. The study results should also have external validity to be applicable to other populations to which the test will be applied. All these consideration are exemplified by 17 very heterogeneous studies published to date assessing VIA test accuracy. The assessment of a new screening test is the first step in researching a new cancer prevention strategy. For this reason, this step should be carefully addressed through rigorous studies.

Occupational health and gorilla conservation in Rwanda.

The design and implementation of an employee health program for people who work with mountain gorillas in Rwanda is described. This program aims to improve worker health and to reduce human-to-gorilla transmission of infectious disease. The program covered approximately 111 workers, generally healthy men and women 25-45 years old, including essentially all people in Rwanda who have regular contact with gorillas. Initial assessment included a questionnaire, medical examination, and local tests. U.S. laboratory facilities were utilized to confirm some results and for serologic testing for zoonotic (simian) viruses. Initial interventions included STD/HIV prevention health education, tetanus immunization, and anthelminthic treatment. Local physicians continue to provide health services, including follow-up testing and treatment. Mountain Gorilla Veterinary Project (MGVP) veterinarians assist in planning and implementing continuing program components in collaboration with local health authorities and the other employing organizations.