A Scoping Review of Strategies for the Prevention of Hip Fracture in Elderly Nursing Home Residents

Background

Elderly nursing home residents are at increased risk of hip fracture; however, the efficacy of fracture prevention strategies in this population is unclear.

Objective

We performed a scoping review of randomized controlled trials of interventions tested in the long-term care (LTC) setting, examining hip fracture outcomes.

Methods

We searched for citations in 6 respective electronic searches, supplemented by hand searches. Two reviewers independently reviewed all citations and full-text papers; consensus was achieved on final inclusion. Data was abstracted in duplicate.

Findings

We reviewed 22,349 abstracts or citations and 949 full-text papers. Data from 20 trials were included: 7 - vitamin D (n = 12,875 participants), 2 - sunlight exposure (n = 522), 1 - alendronate (n = 327), 1 - fluoride (n = 460), 4 – exercise or multimodal interventions (n = 8,165), and 5 - hip protectors (n = 2,594). Vitamin D, particularly vitamin D₃ ≥800 IU orally daily, reduced hip fracture risk. Hip protectors reduced hip fractures in included studies, although a recent large study not meeting inclusion criteria was negative. Fluoride and sunlight exposure did not significantly reduce hip fractures. Falls were reduced in three studies of exercise or multimodal interventions, with one study suggesting reduced hip fractures in a secondary analysis. A staff education and risk assessment strategy did not significantly reduce falls or hip fractures. In a study underpowered for fracture outcomes, alendronate did not significantly reduce hip fractures in LTC.

Conclusions

The intervention with the strongest evidence for reduction of hip fractures in LTC is Vitamin D supplementation; more research on other interventions is needed.     

Brain type carnosinase in dementia: a pilot study

Background  

The pathological processes underlying dementia are poorly understood and so are the markers which identify them. Carnosinase is a dipeptidase found almost exclusively in brain and serum. Carnosinase and its substrate carnosine have been linked to neuropathophysiological processes.     

Low Seroprevalence of Brucellosis in Humans and Small Ruminants in the Gambia

BackgroundBrucellosis is a worldwide zoonosis with significant impact on rural livelihoods and a potentially underestimated contributor to febrile illnesses. The aim of this study was to estimate the seroprevalence of brucellosis in humans and small ruminants in The Gambia.MethodsThe study was carried out in rural and urban areas. In 12 rural villages in Kiang West district, sera were collected from humans (n = 599) and small ruminants (n = 623) from the same compounds. From lactating small ruminants, milk samples and vaginal swabs were obtained. At the urban study sites, sera were collected from small ruminants (n = 500) from slaughterhouses and livestock markets. Information on possible risk factors for seropositivity was collected through questionnaires. Sera were screened for antibodies against Brucella spp. with the Rose Bengal Test, ELISA and Micro Agglutination Test (human sera only). PCR was performed on 10 percent of the milk samples and vaginal swabs from small ruminants.ResultsOne human and 14 sheep sera were positive by the Rose Bengal Test. The rest were negative in all serological tests used. The PCR results were all negative.ConclusionsThe results suggest that brucellosis is currently not a generalized problem in humans or small ruminants in The Gambia.     

Reader reaction to “Outcome-adaptive lasso: Variable selection for causal inference” by Shortreed and Ertefaie (2017)

Shortreed and Ertefaie introduced a clever propensity score variable selection approach for estimating average causal effects, namely, the outcome adaptive lasso (OAL). OAL aims to select desirable covariates, confounders, and predictors of outcome, to build an unbiased and statistically efficient propensity score estimator. Due to its design, a potential limitation of OAL is how it handles the collinearity problem, which is often encountered in high-dimensional data. As seen in Shortreed and Ertefaie, OAL's performance degraded with increased correlation between covariates. In this note, we propose the generalized OAL (GOAL) that combines the strengths of the adaptively weighted L₁ penalty and the elastic net to better handle the selection of correlated covariates. Two different versions of GOAL, which differ in their procedure (algorithm), are proposed. We compared OAL and GOAL in simulation scenarios that mimic those examined by Shortreed and Ertefaie. Although all approaches performed equivalently with independent covariates, we found that both GOAL versions were more performant than OAL in low and high dimensions with correlated covariates.     

Evolutionary Dynamics of Multiple Sublineages of H5N1 Influenza Viruses in Nigeria from 2006 to 2008

Highly pathogenic A/H5N1 avian influenza (HPAI H5N1) viruses have seriously affected the Nigerian poultry industry since early 2006. Previous studies have identified multiple introductions of the virus into Nigeria and several reassortment events between cocirculating lineages. To determine the spatial, evolutionary, and population dynamics of the multiple H5N1 lineages cocirculating in Nigeria, we conducted a phylogenetic analysis of whole-genome sequences from 106 HPAI H5N1 viruses isolated between 2006 and 2008 and representing all 25 Nigerian states and the Federal Capital Territory (FCT) reporting outbreaks. We identified a major new subclade in Nigeria that is phylogenetically distinguishable from all previously identified sublineages, as well as two novel reassortment events. A detailed analysis of viral phylogeography identified two major source populations for the HPAI H5N1 virus in Nigeria, one in a major commercial poultry area (southwest region) and one in northern Nigeria, where contact between wild birds and backyard poultry is frequent. These findings suggested that migratory birds from Eastern Europe or Russia may serve an important role in the introduction of HPAI H5N1 viruses into Nigeria, although virus spread through the movement of poultry and poultry products cannot be excluded. Our study provides new insight into the genesis and evolution of H5N1 influenza viruses in Nigeria and has important implications for targeting surveillance efforts to rapidly identify the spread of the virus into and within Nigeria.Since its emergence in 1996 in Guangdong, China, highly pathogenic avian influenza virus of the H5N1 subtype (HPAI H5N1 virus) has disseminated widely across Asia, Europe, and Africa, infecting a range of domestic and wild avian species and sporadically spilling over into humans and other mammals (4, 35). Over time, the HPAI H5N1 virus has diversified into multiple phylogenetically distinct lineages, classified as clades 0 to 9 according to the unified nomenclature system (33). The H5N1 lineage currently circulating in central Asia, the Middle East, Europe, and Africa is referred to as clade 2.2 (33) and has also been described as “EMA” or Qinghai-like in previous publications (4, 17, 27). This clade originated in April 2005 during a large outbreak of a phylogenetically distinct H5N1 virus among wild bird populations at Qinghai Lake in western China (4, 17) and rapidly spread west through central Asia and Europe, eventually reaching Africa in 2006 (27). Clade 2.2 has further diversified, forming the genetic third-order clade 2.2.1 (32) and three genetically distinct sublineages (I, II, and III) (2, 19, 28), all of which are found in Africa.Since 2006 HPAI H5N1 viruses belonging to clade 2.2 have disseminated across multiple countries in western, eastern, and northern Africa: Egypt, Niger, Cameroon, Sudan, Burkina Faso, Djibouti, Ivory Coast, Ghana, Togo, Benin, and Nigeria (2). With a large poultry industry, estimated at 140 million birds (11), Nigeria has experienced several major outbreaks of HPAI H5N1 virus, posing a serious threat to food security and public health in Africa. The first case of HPAI H5N1 virus in Nigeria (sublineage I) occurred in January 2006 in the state of Kaduna, and the virus subsequently was detected in Ghana, Burkina Faso, Ivory Coast, and Sudan (2). In February 2006 sublineage II was reported in Nigeria, and it disseminated widely across the country during 2006 and 2007, also appearing in Togo (2). Clade 2.2.1, which has been prevalent in Egypt, Israel, and the Gaza Strip from 2006 to 2008, was also detected in Nigeria in 2006 (10).By the end of 2007, outbreaks of HPAI H5N1 virus in Nigeria appeared to have been successfully controlled by measures such as “stamping out with compensation,” restrictions on movement of poultry, and enhanced surveillance (13). However, in July 2008 new cases of HPAI H5N1 from a sublineage never previously detected in Africa (sublineage III) were registered in the Nigerian states of Kano and Katsina and in live bird markets in Gombe and Kebbi states (13, 21). Hence, Nigeria is the only African country where viruses belonging to clade 2.2.1 and to three different sublineages (I, II, and III) of clade 2.2 have all been detected. At least three different reassortment events between sublineages have been documented in Nigeria. Salzberg et al. identified the first reassortant strain (which we refer to as “R1”), in which four genome segments (hemagglutinin [HA], NP, NS, and PB1) belong to sublineage I and the other four segments (NA, MP, PA, and PB2) are derived from sublineage II (27). Subsequently, phylogenetic analysis showed that a 2007 reassortant strain (which we refer to as “R3”) contained the HA and NS segments from sublineage I and the other six segments from sublineage II (19, 22). Another reassortant virus (which we refer to as “R5”) contained only the NS gene segment from sublineage I, while the other seven segments were derived from sublineage II (22).Although the genetic diversity of the Nigerian HPAI H5N1 virus population has been well characterized, including multiple introductions of the virus into Nigeria and several reassortment events, little is known about the evolutionary and population growth dynamics of the virus within Nigeria. Particularly understudied are the spatial movements of individual sublineages among Nigeria''s vast poultry population. To explore the spatial, evolutionary, and population dynamics of the multiple H5N1 lineages cocirculating in Nigeria, we conducted a phylogenetic analysis of whole-genome sequences from 106 HPAI H5N1 viruses isolated between 2006 and 2008 and representing all 25 Nigerian states and the Federal Capital Territory (FCT) reporting outbreaks. Using the exact date and location of collection for each viral isolate, we inferred from their phylogenetic relationships the directionality of viral gene flow among Nigerian states and identified critical regions that are likely to serve as key sources for the H5N1 virus in Nigeria.