HIV-associated mortality in the era of antiretroviral therapy scale-up – Nairobi, Kenya, 2015

<div><p>Background</p><p>Declines in HIV prevalence and increases in antiretroviral treatment coverage have been documented in Kenya, but population-level mortality associated with HIV has not been directly measured. In urban areas where a majority of deaths pass through mortuaries, mortuary-based studies have the potential to contribute to our understanding of excess mortality among HIV-infected persons. We used results from a cross-sectional mortuary-based HIV surveillance study to estimate the association between HIV and mortality for Nairobi, the capital city of Kenya.</p><p>Methods and findings</p><p>HIV seropositivity in cadavers measured at the two largest mortuaries in Nairobi was used to estimate HIV prevalence in adult deaths. Model-based estimates of the HIV-infected and uninfected population for Nairobi were used to calculate a standardized mortality ratio and population-attributable fraction for mortality among the infected versus uninfected population. Monte Carlo simulation was used to assess sensitivity to epidemiological assumptions. When standardized to the age and sex distribution of expected deaths, the estimated HIV positivity among adult deaths aged 15 years and above in Nairobi was 20.9% (95% CI 17.7–24.6%). The standardized mortality ratio of deaths among HIV-infected versus uninfected adults was 4.35 (95% CI 3.67–5.15), while the risk difference was 0.016 (95% CI 0.013–0.019). The HIV population attributable mortality fraction was 0.161 (95% CI 0.131–0.190). Sensitivity analyses demonstrated robustness of results.</p><p>Conclusions</p><p>Although 73.6% of adult PLHIV receive antiretrovirals in Nairobi, their risk of death is four-fold greater than in the uninfected, while 16.1% of all adult deaths in the city can be attributed to HIV infection. In order to further reduce HIV-associated mortality, high-burden countries may need to reach very high levels of diagnosis, treatment coverage, retention in care, and viral suppression.</p></div

Annualized and coverage-adjusted surveillance deaths, Nairobi 2015.

<p>Annualized and coverage-adjusted surveillance deaths, Nairobi 2015.</p

Risk difference (RD), standardized mortality rate (SMR) and population attributable fraction (PAF) due to HIV, Nairobi 2015.

<p>Risk difference (RD), standardized mortality rate (SMR) and population attributable fraction (PAF) due to HIV, Nairobi 2015.</p

Percent HIV positivity among cadavers at City and KNH mortuaries, Nairobi 2015.

<p>Percent HIV positivity among cadavers at City and KNH mortuaries, Nairobi 2015.</p

Data from: Admixture increases performance of an invasive plant beyond first generation heterosis

1. Through its potential to enhance progeny performance, admixture (between-population crossing) may promote invasiveness of alien plants. The few studies that tested this idea found evidence for heterosis (positive effects of admixture) in the first generation (F1), but have not considered further generations. In this paper, we test whether admixture-benefits can be maintained in subsequent generations of an invasive plant. 2. We follow up on a previous study, in which we made crosses between plants of Mimulus guttatus from native- (western North America) and invaded-range populations (New Zealand and Scotland), and showed that admixture increases F1 performance. Here, we performed further crosses to create non-admixed progeny, F1 progeny resulting from within- and between-range admixture, and subsequent F2 progeny both through outcrossing and through self-fertilization. As heterosis, out- and inbreeding depression may depend on the environment, we assessed progeny-performance under benign (well-watered) and drought-stress conditions in a greenhouse experiment. 3. We found that non-admixed progeny of M. guttatus were outperformed by admixed progeny (averaged across F1 and F2), particularly by progeny from between-range admixture. However, the benefit of admixture was stronger in F1 than in F2 progeny, especially when the F2 was produced by self-fertilisation. The benefit of admixture also depended on the range of origin and the test environment. 4. Synthesis Our findings indicate that increased performance of admixed F1 progeny is partly maintained in the F2 progeny. Admixture might thus significantly boost performance of an invasive plant across multiple generations