Strategic restoration planning for land birds in the Colorado River Delta, Mexico.

Ecological restoration is an essential strategy for mitigating the current biodiversity crisis, yet restoration actions are costly. We used systematic conservation planning principles to design an approach that prioritizes restoration sites for birds and tested it in a riparian forest restoration program in the Colorado River Delta. Restoration goals were to maximize the abundance and diversity of 15 priority birds with a variety of habitat preferences. We built abundance models for priority birds based on the current landscape, and predicted bird distributions and relative abundances under a scenario of complete riparian forest restoration throughout our study area. Then, we used Zonation conservation planning software to rank this restored landscape based on core areas for all priority birds. The locations with the highest ranks represented the highest priorities for restoration and were located throughout the river reach. We optimized how much of the available landscape to restore by simulating restoration of the top 10-90% of ranked sites in 10% intervals. We found that total diversity was maximized when 40% of the landscape was restored, and mean relative abundance was maximized when 80% of the landscape was restored. The results suggest that complete restoration is not optimal for this community of priority birds and restoration of approximately 60% of the landscape would provide a balance between maximum relative abundance and diversity. Subsequent planning efforts will combine our results with an assessment of restoration costs to provide further decision support for the restoration-siting process. Our approach can be applied to any landscape-scale restoration program to improve the return on investment of limited economic resources for restoration.

HIV testing rates and outcomes in a South African community, 2001-2006: implications for expanded screening policies.

BACKGROUND: Revised World Health Organization recommendations seek to increase HIV testing. We assessed the need for expanded testing in South Africa by examining current testing and treatment trends among a high prevalence population. METHODS: We determined the numbers of adults receiving HIV testing and antiretroviral treatment (ART) during 2001-2006 using testing registers linked to patient records from 2 health care facilities believed responsible for virtually all HIV services available to the population. We evaluated annual population testing rates using census population counts; proportions of clients testing seropositive (yield); CD4 counts and World Health Organization stage at diagnosis; and ART initiation rates. RESULTS: HIV testing rates rose from 4% in 2001 to 20% in 2006 (P < 0.001) and were highest among pregnant females receiving provider-initiated testing. Yield for first-time testers decreased from 47% in 2001 to 28% in 2006; annual incidence of seroconversion among initially HIV-negative retesters was 1.9%. Median CD4 counts and World Health Organization stage distributions for newly diagnosed clients remained stable. HIV-infected clients receiving ART within 6 months of eligibility increased from 0% in 2001 to 68% in 2006 (P < 0.001). CONCLUSIONS: Population testing and ART initiation rates rose dramatically during 2001-2006. Yet, yield remained high, and HIV-infected persons continued to receive late diagnoses. These findings highlight the continuing need for expanded testing and linkage to care.

HIV type-1 clade C resistance genotypes in treatment-naive patients and after first virological failure in a large community antiretroviral therapy programme.

BACKGROUND: This study aimed to evaluate HIV type-1 (HIV-1) drug resistance pretreatment and in those failing first-line non-nucleoside reverse transcriptase inhibitor (NNRTI)-based antiretroviral therapy (ART) in South Africa. METHODS: This was an observational cohort. Genotypic resistance testing was performed on treatment-naive individuals and those failing first-line ART (confirmed HIV-1 RNA>1,000 copies/ml) from public sector clinics in Cape Town (2002-2007). Resistance profiles and mutations relative to timing of known virological failure were examined. RESULTS: In total, 230 patients (120 treatment-naive and 110 with virological failure) were included: 98% had clade C virus. Among treatment-naive patients, prevalence of primary resistance was 2.5% (95% confidence interval 0.0-5.3). Three patients had one significant reverse transcriptase mutation: K65R, Y181C and G190A. Among treatment-experienced patients, 95 (86%) individuals had therapy-limiting NNRTI mutations, including K103N (55%), V106M (31%) and Y181C (9%). The M184V mutation was the most common mutation, found in 86 (78%) patients. In total, 10 (9%) patients had the K65R mutation. More individuals tended to develop thymidine analogue mutations when sampling occurred after 6 months of detected therapy failure (10/31 [32%] individuals) compared with those who had genotyping before 6 months (15/79 [19%] patients; P=0.246). CONCLUSIONS: Prevalence of primary resistance in a sample of ART-naive clade C HIV-1-infected individuals in South Africa was low during the study period. Patients failing first-line ART most often developed resistance to NNRTIs and nucleoside reverse transcriptase inhibitors, the two drug classes used in first-line therapy. Viral load monitoring in this setting is crucial and individual genotypes in those failing first-line therapy should be considered.

Quality of life and the impact of drug toxicities in a South African community-based antiretroviral programme.

BACKGROUND: The impact of highly active antiretroviral therapy (HAART) on health-related quality of life has been widely researched in the developed world, but there are few data from sub-Saharan Africa, where the vast majority of HIV-infected individuals live. This study examined health-related quality of life among HIV-positive individuals initiating HAART in Cape Town, South Africa, and explored the impact of HAART-related drug toxicities on quality of life. METHODS: Health-related quality of life was assessed using a standardised questionnaire, the Medical Outcomes Survey Short Form 36. Physical health summary scores and mental health summary scores were compared pre-HAART and at regular intervals during the first 48 weeks of HAART. The relationships between socio-demographic, baseline and on-treatment variables and decline in health-related quality of life, as well as the impact of drug toxicities on quality of life, were assessed in unadjusted bivariate and adjusted multivariate analyses. RESULTS: Two hundred and ninety-five patients were enrolled into the study. There was a significant increase in health-related quality of life during the first 48 weeks on HAART. The median physical health summary score increased from 45 to 53 units (p < 0.001) and median mental health summary score increased from 45 to 50 units (p < 0.001).The bulk of this increase occurred during the first 16 weeks. Overall, 23% of participants experienced a decline in their physical health summary score, while 34% showed a decline in the mental health summary score. Average drops in median physical and mental health summary scores were 8.4 units (SD 9.31) and 9.9 (SD 11.4) units respectively. Participants with drug toxicity had lower physical health summary scores than participants without drug toxicity at all time points. However, only three participants with toxicity (27%) reported an actual decline in health-related quality of life by week 48. Drug toxicities had little impact on mental health summary scores. CONCLUSION: These results confirm the health-related quality of life benefits of HAART. While the majority of patients experienced a significant improvement in health-related quality of life on HAART, up to a third of patients reported declines in this quality of life. This was largely related to better baseline clinical state. HAART-related drug toxicities did not have a significant impact on health-related quality of life during the first year of HAART, which supports the ongoing use of the current national first-line regimen.

Occurrence of pharmaceuticals and personal care products in fish: results of a national pilot study in the United States.

Pharmaceuticals and personal care products are being increasingly reported in a variety of biological matrices, including fish tissue; however, screening studies have presently not encompassed broad geographical areas. A national pilot study was initiated in the United States to assess the accumulation of pharmaceuticals and personal care products in fish sampled from five effluent-dominated rivers that receive direct discharge from wastewater treatment facilities in Chicago, Illinois; Dallas, Texas; Orlando, Florida; Phoenix, Arizona; and West Chester, Pennsylvania, USA. Fish were also collected from the Gila River, New Mexico, USA, as a reference condition expected to be minimally impacted by anthropogenic influence. High performance liquid chromatography-tandem mass spectrometry analysis of pharmaceuticals revealed the presence of norfluoxetine, sertraline, diphenhydramine, diltiazem, and carbamazepine at nanogram-per-gram concentrations in fillet composites from effluent-dominated sampling locations; the additional presence of fluoxetine and gemfibrozil was confirmed in liver tissue. Sertraline was detected at concentrations as high as 19 and 545 ng/g in fillet and liver tissue, respectively. Gas chromatography-tandem mass spectrometry analysis of personal care products in fillet composites revealed the presence of galaxolide and tonalide at maximum concentrations of 2,100 and 290 ng/g, respectively, and trace levels of triclosan. In general, more pharmaceuticals were detected at higher concentrations and with greater frequency in liver than in fillet tissues. Higher lipid content in liver tissue could not account for this discrepancy as no significant positive correlations were found between accumulated pharmaceutical concentrations and lipid content for either tissue type from any sampling site. In contrast, accumulation of the personal care products galaxolide and tonalide was significantly related to lipid content. Results suggest that the detection of pharmaceuticals and personal care products was dependent on the degree of wastewater treatment employed.

Survey design for lakes and reservoirs in the United States to assess contaminants in fish tissue.

The National Lake Fish Tissue Study (NLFTS) was the first survey of fish contamination in lakes and reservoirs in the 48 conterminous states based on a probability survey design. This study included the largest set (268) of persistent, bioaccumulative, and toxic (PBT) chemicals ever studied in predator and bottom-dwelling fish species. The U.S. Environmental Protection Agency (USEPA) implemented the study in cooperation with states, tribal nations, and other federal agencies, with field collection occurring at 500 lakes and reservoirs over a four-year period (2000-2003). The sampled lakes and reservoirs were selected using a spatially balanced unequal probability survey design from 270,761 lake objects in USEPA's River Reach File Version 3 (RF3). The survey design selected 900 lake objects, with a reserve sample of 900, equally distributed across six lake area categories. A total of 1,001 lake objects were evaluated to identify 500 lake objects that met the study's definition of a lake and could be accessed for sampling. Based on the 1,001 evaluated lakes, it was estimated that a target population of 147,343 (+/-7% with 95% confidence) lakes and reservoirs met the NLFTS definition of a lake. Of the estimated 147,343 target lakes, 47% were estimated not to be sampleable either due to landowner access denial (35%) or due to physical barriers (12%). It was estimated that a sampled population of 78,664 (+/-12% with 95% confidence) lakes met the NLFTS lake definition, had either predator or bottom-dwelling fish present, and could be sampled.

Contaminants in fish tissue from US lakes and reservoirs: a national probabilistic study.

An unequal probability design was used to develop national estimates for 268 persistent, bioaccumulative, and toxic chemicals in fish tissue from lakes and reservoirs of the conterminous United States (excluding the Laurentian Great Lakes and Great Salt Lake). Predator (fillet) and bottom-dweller (whole body) composites were collected from 500 lakes selected randomly from the target population of 147,343 lakes in the lower 48 states. Each of these composite types comprised nationally representative samples whose results were extrapolated to the sampled population of an estimated 76,559 lakes for predators and 46,190 lakes for bottom dwellers. Mercury and PCBs were detected in all fish samples. Dioxins and furans were detected in 81% and 99% of predator and bottom-dweller samples, respectively. Cumulative frequency distributions showed that mercury concentrations exceeded the EPA 300 ppb mercury fish tissue criterion at nearly half of the lakes in the sampled population. Total PCB concentrations exceeded a 12 ppb human health risk-based consumption limit at nearly 17% of lakes, and dioxins and furans exceeded a 0.15 ppt (toxic equivalent or TEQ) risk-based threshold at nearly 8% of lakes in the sampled population. In contrast, 43 target chemicals were not detected in any samples. No detections were reported for nine organophosphate pesticides, one PCB congener, 16 polycyclic aromatic hydrocarbons, or 17 other semivolatile organic chemicals.

Reconciling environmental and flood control goals on an arid-zone river: case study of the limitrophe region of the lower colorado river in the United States and Mexico.

Arid zone rivers have highly variable flow rates, and flood control projects are needed to protect adjacent property from flood damage. On the other hand, riparian corridors provide important wildlife habitat, especially for birds, and riparian vegetation is adapted to the natural variability in flows on these rivers. While environmental and flood control goals might appear to be at odds, we show that both goals can be accommodated in the Limitrophe Region (the shared border between the United States and Mexico) on the Lower Colorado River. In 1999, the International Boundary and Water Commission proposed a routine maintenance project to clear vegetation and create a pilot channel within the Limitrophe Region to improve flow capacity and delineate the border. In 2000, however, Minute 306 to the international water treaty was adopted, which calls for consideration of environmental effects of IBWC actions. We conducted vegetation and bird surveys within the Limitrophe and found that this river segment is unusually rich in native cottonwood and willow trees, marsh habitat, and resident and migratory birds compared to flow-regulated segments of river. A flood-frequency analysis showed that the existing levee system can easily contain a 100 year flood even if vegetation is not removed, and the existing braided channel system has greater carrying capacity than the proposed pilot channel.

When to initiate highly active antiretroviral therapy in sub-Saharan Africa? A South African cost-effectiveness study.

BACKGROUND: Large-scale programmes increasing access to highly active antiretroviral therapy (HAART) are being implemented in sub-Saharan Africa. However, cost-effectiveness of initiating treatment at different CD4 count thresholds has not been explored in resource-poor settings. METHODS: A cost-effectiveness analysis was conducted from a public health perspective using primary treatment outcomes, healthcare utilisation and cost data (Jan 2004 local prices; US dollars 1=7.6 Rands) derived from the Cape Town AIDS Cohort. A Markov state-transition model was developed to estimate life-expectancy, lifetime costs, quality-adjusted life-years (QALYs), cost per life-year and QALY gained for initiating HAART at three CD4 cell count thresholds (<200/microl, 200-350/microl and >350/microl), including the no antiretroviral therapy (No-ART) alternative. Each treatment option was compared with the next most effective undominated option. RESULTS: Mean life-expectancy was 6.2, 18.8, 21.0 and 23.3 years; discounted (8%) QALYs were 3.1, 6.2, 6.7 and 7.4; and discounted lifetime costs were US dollars 5,250, US dollars 5,434, US dollars 5,740, US dollars 6,588 for No-ART, and therapy initiation at <200/microl, 200-350/microl and >350/microl scenarios respectively. Clinical benefits increased significantly with early therapy initiation. Initiating therapy at <200/microl had an incremental cost-effectiveness ratio (ICER) of US dollars 54 per QALY versus No-ART, 200-350/microl had an ICER of US dollars 616 versus therapy initiation at <200/microl, and >350/microl had an ICER of US dollars 1,137 versus therapy initiation at 200-350/microl. ICERs were sensitive to HAART cost. CONCLUSIONS: HAART is reasonably cost-effective for HIV-infected patients in South Africa, and most effective if initiated when CD4 count >200/microl. Deferring treatment to <200/microl would reduce the aggregate cost of treatment, but this should be balanced against the significant clinical benefits associated with early therapy.

Initiating highly active antiretroviral therapy in sub-Saharan Africa: an assessment of the revised World Health Organization scaling-up guidelines.

OBJECTIVES: To assess the utility of the 2003 revised World Health Organization (WHO) criteria [initiating highly active antiretroviral therapy (HAART) in stage IV, in stage III plus CD4 cell count < 350 x 10(6) cells/l, or in stage I or II plus CD4 cell count < 200 x 10 cells/l] relative to other scenarios of HAART initiation. METHODS: Progression to AIDS and death in 292 patients taking HAART and 974 not taking HAART in a South African institution in 1992-2001, stratifying patients by baseline CD4 cell count and WHO stage. RESULTS: HAART was associated with decreased AIDS [adjusted rate ratio [ARR], 0.16; 95% confidence interval (CI), 0.08-0.31) and death (ARR, 0.10; 95% CI, 0.06-0.18). Benefit of HAART was significant across all WHO stages plus CD4 cell counts. The greatest number of deaths averted was in stages IV [74.0/100 patient-years (PY); 95% CI, 50.2-84.5) and III (32.8/100 PY; 95% CI, 22.4-40.9). AIDS cases averted in stage III (22.0/100 PY; 95% CI, 6.1-26.9) were higher than in stage I and II with CD4 cell count < 200 x 10(6) cells/l (8.9/100 PY 95% CI, 5.6-13.3). Treatment initiation for symptomatic disease resulted in greater benefits than using any CD4 cell thresholds. Application of WHO criteria increased the treatment-eligible proportion from 44.5% to 56.7% (P < 0.05) but did not prevent more death (P > 0.05) than treating symptomatic disease. CONCLUSION: Implementation of the revised WHO guidelines in sub-Saharan Africa may result in a significantly increased number of individuals eligible for treatment but would not be as effective a strategy for preventing death as treating symptomatic disease.