@article{fdi:010068908,
  title = {{H}ydrological regime and water shortage as drivers of the seasonal incidence of diarrheal diseases in a tropical montane environment},
  author = {{B}oithias, {L}aurie and {C}hoisy, {M}arc and {S}ouliyaseng, {N}. and {J}ourdren, {M}. and {Q}uet, {F}. and {B}uisson, {Y}. and {T}hammahacksa, {C}hanthamousone and {S}ilvera, {N}orbert and {L}atsachack, {K}eooudone and {S}engtaheuanghoung, {O}. and {P}ierret, {A}lain and {R}ochelle {N}ewall, {E}mma and {B}ecerra, {S}. and {R}ibolzi, {O}livier},
  editor = {},
  language = {{ENG}},
  abstract = {{B}ackground {T}he global burden of diarrhea is a leading cause of morbidity and mortality worldwide. {I}n montane areas of {S}outh-{E}ast {A}sia such as northern {L}aos, recent changes in land use have induced increased runoff, soil erosion and in-stream suspended sediment loads, and potential pathogen dissemination. {T}o our knowledge, few studies have related diarrhea incidences to catchment scale hydrological factors such as river discharge, and loads of suspended sediment and of {F}ecal {I}ndicator {B}acteria ({FIB}) such as {E}scherichia coli, together with sociological factors such as hygiene practices. {W}e hypothesized that climate factors combined with human behavior control diarrhea incidence, either because higher rainfall, leading to higher stream discharges, suspended sediment loads and {FIB} counts, are associated with higher numbers of reported diarrhea cases during the rainy season, or because water shortage leads to the use of less safe water sources during the dry season. {U}sing {E}. coli as a {FIB}, the objectives of this study were thus (1) to characterize the epidemiological dynamics of diarrhea in {N}orthern {L}aos, and (2) to identify which hydro-meteorological and sociological risk factors were associated with diarrhea epidemics. {M}ethods {C}onsidering two unconnected river catchments of 22 and 7,448 km(2), respectively, we conducted a retrospective time series analysis of meteorological variables (rainfall, air temperature), hydrological variables (discharge, suspended sediments, {FIB} counts, water temperature), and the number of diarrheal disease cases reported at 6 health centers located in the 5 southern districts of the {L}uang {P}rabang {P}rovince, {L}ao {PDR}. {W}e also examined the socio-demographic factors potentially affecting vulnerability to the effect of the climate factors, such as drinking water sources, hygiene habits, and recreational water exposure. {R}esults {U}sing thus a mixed methods approach, we found {E}. coli to be present all year long (100-1,000 {M}ost {P}robable {N}umber or {MPN} 100 m{L}(-1)) indicating that fecal contamination is ubiquitous and constant. {W}e found that populations switch their water supply from wells to surface water during drought periods, the latter of which appear to be at higher risk of bacterial contamination than municipal water fountains. {W}e thus found that water shortage in the {L}uang {P}rabang area triggers diarrhea peaks during the dry and hot season and that rainfall and aquifer refill ends the epidemic during the wet season. {T}he temporal trends of reported daily diarrhea cases were generally bimodal with hospital admissions peaking in {F}ebruary-{M}arch and later in {M}ay-{J}uly. {A}nnual incidence rates were higher in more densely populated areas and mostly concerned the 0-4 age group and male patients. {C}onclusions {W}e found that anthropogenic drivers, such as hygiene practices, were at least as important as environmental drivers in determining the seasonal pattern of a diarrhea epidemic. {F}or diarrheal disease risk monitoring, discharge or groundwater level can be considered as relevant proxies. {T}hese variables should be monitored in the framework of an early warning system provided that a tradeoff is found between the size of the monitored catchment and the frequency of the measurement.},
  keywords = {{LAOS} ; {ZONE} {TROPICALE}},
  booktitle = {},
  journal = {{P}los {N}eglected {T}ropical {D}iseases},
  volume = {10},
  numero = {12},
  pages = {e0005195 [27 p.]},
  ISSN = {1935-2735},
  year = {2016},
  DOI = {10.1371/journal.pntd.0005195},
  URL = {https://www.documentation.ird.fr/hor/fdi:010068908},
}