Population Structure of the South West Indian Ocean Islands: Implications for Precision Medicine.

Precision medicine has brought new hopes for patients around the world with the applications of novel technologies for understanding genetics of complex diseases and their translation into clinical services. Such applications however require a foundation of skills, knowledge and infrastructure to translate genetics for health care. The crucial element is no doubt the availability of genomics data for the target populations, which is seriously lacking for most parts of Africa. We discuss here why it is vital to prioritize genomics data for the South West Indian Ocean region where a mosaic of ethnicities co-exist. The islands of the SWIO, which comprise Madagascar, La Reunion, Mauritius, Seychelles and Comoros, have been the scene for major explorations and trade since the 17th century being on the route to Asia. This part of the world has lived through active passage of slaves from East Africa to Arabia and further. Today's demography of the islands is a diverse mix of ancestries including European, African and Asian. The extent of admixtures has yet to be resolved. Except for a few studies in Madagascar, there is very little published data on human genetics for these countries. Isolation and small population sizes have likely resulted in reduced genetic variation and possible founder effects. There is a significant prevalence of diabetes, particularly in individuals of Indian descent, while breast and prostate cancers are on the rise. The island of La Reunion is a French overseas territory with a high standard of health care and close ties to Mauritius. Its demography is comparable to that of Mauritius but with a predominantly mixed population and a smaller proportion of people of Indian descent. On the other hand, Madagascar's African descendants inhabit mostly the lower coastal zones of the West and South regions, while the upper highlands are occupied by peoples of mixed African-Indonesian ancestries. Historical records confirm the Austronesian contribution to the Madagascar genomes. With the rapid progress in genomic medicine, there is a growing demand for sequencing services in the clinical settings to explore the incidence of variants in candidate disease genes and other markers. Genome sequence data has become a priority in order to understand the population sub-structures and to identify specific pathogenic variants among the different groups of inhabitants on the islands. Genomic data is increasingly being used to advise families at risk and propose diagnostic screening measures to enhance the success of therapies. This paper discusses the complexity of the islands' populations and argues for the needs for genotyping and understanding the genetic factors associated with disease risks. The benefits to patients and improvement in health services through a concerted regional effort are depicted. Some private patients are having recourse to external facilities for molecular profiling with no return of data for research. Evidence of disease variants through sequencing represents a valuable source of medical data that can guide policy decisions at the national level. There are presently no such records for future implementation of strategies for genomic medicine.

Exploring the Perceived Risks and Benefits of Heroin Use among Young People (18-24 Years) in Mauritius: Economic Insights from an Exploratory Qualitative Study.

The decreasing age of young people injecting illicit drugs is an under-reported challenge for the prevention of HIV transmission worldwide. Young people aged 15-24 years represent 1 in 5 persons living with HIV in Mauritius where the epidemic is driven by injecting drug use and risky sexual behaviours. We recruited 22 heroin users aged 18-24 and 5 service providers working in harm reduction (HR) for the present study. Qualitative data were collected through unstructured interviews. We adopted an economic framework and an inductive approach to the analysis, which implied revising codes and themes. The risks heroin users described as consumers of illicit drugs and as clients of HR services could not be analyzed in isolation. Polydrug use emerged as a recurrent coping mechanism resulting from the changing dynamics within the heroin market. The risks faced by women went beyond addiction and infection with HIV. How participants viewed the risks and benefits linked to using heroin was greatly influenced by gaps in knowledge that left room for uncertainty and reinforcing mechanisms such as peer influence. The study shows that qualitative research can produce in-depth socio-behavioural insights required to produce more effective services for young people.

Prevalence of and risk factors for chronic arthralgia and rheumatoid-like polyarthritis more than 2 years after infection with chikungunya virus.

OBJECTIVES: Chikungunya virus (CHIKV), transmitted to humans from infected mosquitoes, causes acute fever, arthralgia and rash. There is increasing evidence that it also causes longer-term rheumatic symptoms. In a circumscribed part of Mauritius where infectivity was high, a cohort of inhabitants was surveyed with the objectives of assessing the prevalence of and risk factors for chronic musculoskeletal symptoms and for a rheumatoid arthritis-like condition at 27.5 months after initial infection. METHODS: Participants were recruited May-November 2008 and invited to complete a questionnaire. CHIKV was diagnosed clinically. The primary outcomes for the analyses were (a) self-reported ongoing musculoskeletal symptoms and (b) fulfilment of modified diagnostic criteria for rheumatoid arthritis. Risk factors for these outcomes were explored in univariate analyses using logistic regression. Subsequently, multivariate logistic regression was used to identify factors that were independently associated with the outcomes. RESULTS: 173 individuals were identified with CHIKV, of whom 136 (78.6%) reported persisting musculoskeletal symptoms 27.5 months after infection. Persistent symptoms were associated with older age at time of infection, female gender and baseline symmetrical distribution of joint symptoms. We found that 5% of those infected with CHIKV fulfilled a modified version of the American College of Rheumatology criteria for rheumatoid arthritis 27.5 months after infection. CONCLUSIONS: CHIKV is associated with a high prevalence of persistent rheumatic symptoms. Physicians need to be aware of CHIKV as a cause of acute and chronic rheumatic symptoms.

The health impact of nonhazardous solid waste disposal in a community: the case of the Mare Chicose landfill in mauritius.

The disposal of nonhazardous solid waste on the island of Mauritius is centered on the Mare Chicose landfill. Because of health concerns in the community, the authors conducted a health impact survey, took measurements of height and weight, and compared the results with a control locality. After adjusting for confounding factors, the authors observed that numerous complaints were significantly higher in the target population. After elimination of reporting bias, however, nausea and vomiting remained as the only significant self-reported outcomes. The mean body mass index (BMI) of target men was significantly lower when compared with the control. This result was not observed in the populations of women and children, and suggests a gender difference in the health impact of the landfill.