Chronic kidney disease mortality trends in selected Central America countries, 1997-2013: clues to an epidemic of chronic interstitial nephritis of agricultural communities.

BACKGROUND: In Central America, chronic interstitial nephritis of agricultural communities (CINAC) has reached epidemic proportions. Clusters of cases have been described in several farming communities. Its aetiology remains uncertain and a controversy exists on its key triggers, among them the heat stress-dehydration mechanism and the toxic exposure to agrochemicals. METHODS: This study analysed the mortality pattern and trend of chronic kidney disease code N18 (CKD-N18) according to the International Statistical Classification of Diseases and Related Health Problems-10th Revision, the proxy and the underlying cause of death, in four selected Central American countries from 1997 to 2013. In addition, we used exponential regression to retrospectively model the likely onset and prior trajectory of the epidemic. RESULTS: Between 1997 and 2013, CKD-N18 mortality accounting 47 885 deaths (31% were female), 19 533 of which occurred below 60 years of age (26% female). The excess of mortality starts as early as 10-14 years of age for both boys and girls. El Salvador and Nicaragua, with mortality rates between 9-fold and 12-fold higher than reference countries, were the most affected. Statistical modelling suggests that the epidemic commenced around the mid-1970s, coinciding with important changes in modes of agricultural production. CONCLUSIONS: This study provides the most comprehensive mortality analysis of this epidemic published to date and confirms an excess of CKD-N18 mortality and its relation with the epidemic of CINAC. The overall trends and the mortality pattern among women, children and adolescents suggest that the heat stress-dehydration hypothesis cannot fully explain this epidemic and that other environmental factors, more likely agricultural practices and agrochemicals, may be causally involved.

Transformation of mortality in a remote Australian Aboriginal community: a retrospective observational study.

OBJECTIVES: To describe trends in ages and causes of death in a remote-living Australian Aboriginal group over a recent 50-year period. DESIGN: A retrospective observational study, from 1960 to 2010, of deaths and people starting dialysis, using data from local clinic, parish, dialysis and birthweight registers. SETTING: A remote island community in the Top End of Australia's Northern Territory, where a Catholic mission was established in 1911. The estimated Aboriginal population was about 800 in 1960 and 2260 in 2011. PARTICIPANTS: All Aboriginal residents of this community whose deaths had been recorded. OUTCOME MEASURES: Annual frequencies and rates of terminal events (deaths and dialysis starts) by age group and cause of death. RESULTS: Against a background of high rates of low birth weight, 223 deaths in infants and children and 934 deaths in adults (age > 15 years) were recorded; 88% were of natural causes. Most deaths in the 1960s were in infants and children. However, over time these fell dramatically, across the birthweight spectrum, while adult deaths progressively increased. The leading causes of adult natural deaths were chronic lung disease, cardiovascular disease and, more recently, renal failure, and rates were increased twofold in those of low birth weight. However, rates of natural adult deaths have been falling briskly since 1986, most markedly among people of age ≥45 years. The population is increasing and its age structure is maturing. CONCLUSIONS: The changes in death profiles, the expression of the Barker hypothesis and the ongoing increases in adult life expectancy reflect epidemiological and health transitions of astonishing rapidity. These probably flow from advances in public health policy and healthcare delivery, as well as improved inter-sectoral services, which are all to be celebrated. Other remote communities in Australia are experiencing the same phenomena, and similar events are well advanced in many developing countries.