Climate change will have far reaching effects on how

Climate change will have far-reaching effects on how we build, organise, and manage health systems as complex institutions. Yet, to date, these challenges have largely been ignored by the research community. Despite substantial work by WHO on the interface between climate and health, two major conferences on health systems, failed to consider climate-related issues. On the eve of WHO\'s third Health Systems Global conference (Sept 29–Oct 3), we highlight some key implications of climate change for health systems to form the basis of an agenda for research and action. First, disease surveillance, and the development and maintenance of early-warning mechanisms of climate change, will need to become a key function of health systems, if they Estradiol Cypionate are to be able to forecast and adequately prepare to meet changing disease-patterns and health needs. Developed countries have initiated surveillance and early-warning systems and planning tools, but initiatives elsewhere are ad-hoc, and the capacity to translate complex scientific data (from different specialist fields) into planning goals and implementation plans is often weak.
In their article in , Quentin Vincent and colleagues (July issue) analysed 1227 laboratory-confirmed cases of Buruli ulcer and provided clinically relevant results such as an operational classification of lesions. They reported unbalanced age and sex groups, as previously noted, and an over-representation of Buruli ulcer cases in children. Quantification of this over-representation is challenging—proper comparisons between age groups need estimation of age-specific incidence rates, which are rarely reported. Furthermore, most studies of risk factors rely on age-matched and sex-matched case-control designs, precluding comparative analysis by age and sex. Here we report incidence rates for men and women by 5 year age-groups for 814 laboratory-confirmed cases in the Nyong River region in Cameroon (). Estimates were obtained using Buruli ulcer surveillance data from the Centre Pasteur du Cameroun (National Reference Laboratory for Mycobacteria, Yaoundé, Cameroon) from 2002 to 2012, and detailed 2010 population census data. Incidence rate was twice as high for children aged 5–14 years (165 per 100 000 person-years) as for adults older than 15 years (87 per 100 000 person-years). Incidence rate was stable among adults, suggesting lifelong exposure and possibly increasing susceptibility to disease development among older individuals. The overall women–men incidence rate ratio was 1·01 (95% CI 0·88–1·15). Incidence rate ratio was 0·81 (0·67–0·98) for children aged 0–14 years, 1·55 (1·22–1·98) for adults aged 15–49 years, and 0·85 (0·57–1·28) for adults older than 50 years. Vincent and colleagues defined age-specific and sex-specific subgroups relevant for clinical considerations. We define three subgroups—boys younger than 15 years, women aged 15–50 years, and elderly people—which are likely to have different exposures, behaviours, immunity, and treatment-seeking attitudes. We advocate that this risk categorisation is relevant for epidemiological studies and public health programmes such as prevention or case-detection campaigns.
We thank Jordi Landier and colleagues for their comments about our recent Article in . In their work, Landier and coworkers generalise some of our observations on Buruli ulcer in Benin to those for Cameroon, the country that has the fifth highest prevalence of Buruli ulcer worldwide. Briefly, they make use of age and sex distribution from the Cameroon national census to show that patients aged 5–14 years were twice as likely to be affected by Buruli ulcer as older individuals; and that boys were over-represented in individuals younger than 15 years, women were over-represented in patients aged 15–50 years, and that men and women were equally represented in patients older than 50 years. They advocate the use of national census references to produce incidence rates and incidence rate ratios (IRRs), which they believe to be the proper way to draw valid conclusions.