Editing Leptospirosis (section)

==Epidemiology==
[[File:Global burden of leptospirosis in DALY per 100,000 per year.png|thumb|upright=1.3|alt=Disability-adjusted life year world map | Global burden of leptospirosis calculated as [[Disability-adjusted life year]] (DALY) lost per 100,000 people per year.]]
It is estimated that one million severe cases of leptospirosis occur annually, with 58,900 deaths. Severe cases account for 5-15% of all leptospirosis cases.<ref name=Costa2015/> Leptospirosis is found in both urban and rural areas in [[tropical]], [[subtropical]], and [[temperate]] regions.<ref name="Evangelista2010">{{cite journal | vauthors = Evangelista KV, Coburn J | title = Leptospira as an emerging pathogen: a review of its biology, pathogenesis and host immune responses | journal = Future Microbiology | volume = 5 | issue = 9 | pages = 1413–25 | date = September 2010 | pmid = 20860485 | pmc = 3037011 | doi = 10.2217/fmb.10.102 }}</ref> The global health burden for leptospirosis can be measured by [[disability-adjusted life year]] (DALY). The score is 42&nbsp;per 100,000 people per year, which is more than other diseases such as [[rabies]] and [[filariasis]].<ref name="Karpagm2020"/>

The disease is observed persistently in parts of Asia, Oceania, the Caribbean, Latin America and Africa.<ref name="Spickler 2013"/> [[Antarctica]] is the only place not affected by leptospirosis.<ref name="Spickler 2013">{{cite web | vauthors = Spickler AR, Leedom Larson KR |title=Leptospirosis (Fact sheet) |date=October 2013 |access-date=15 March 2019 |publisher=The Center for Food Security and Public Health |url=http://www.cfsph.iastate.edu/Factsheets/pdfs/leptospirosis.pdf |archive-url=https://web.archive.org/web/20141124082710/http://www.cfsph.iastate.edu/Factsheets/pdfs/leptospirosis.pdf |archive-date=24 November 2014 |url-status=live }}</ref> In the United States, there were 100&nbsp;to 150 leptospirosis cases annually.<ref name="CDC 2017">{{cite web |title=Healthcare Workers – Technical Information for Leptospirosis |url=https://www.cdc.gov/leptospirosis/health_care_workers/index.html |publisher=[[Centers for Disease Control and Prevention]] (CDC) |access-date=28 April 2019 |archive-url=https://web.archive.org/web/20190111230629/https://www.cdc.gov/leptospirosis/health_care_workers/index.html |archive-date=11 January 2019 |date=9 November 2017}}</ref> In 1994, leptospirosis ceased to be a notifiable disease in the United States except in 36&nbsp;states/territories where it is prevalent such as Hawaii, Texas, California, and Puerto Rico.<ref>{{cite journal | vauthors = Guerra MA | title = Leptospirosis: public health perspectives | journal = Biologicals | volume = 41 | issue = 5 | pages = 295–7 | date = September 2013 | pmid = 23850378 | pmc = 4629849 | doi = 10.1016/j.biologicals.2013.06.010 }}</ref> About 50%&nbsp;of the reported cases occurred in Puerto Rico. In January 2013, leptosprirosis was reinstated as a nationally notifiable disease in the United States.<ref name="CDC 2017"/>

The global rates of leptospirosis have been underestimated because most affected countries lack notification or notification is not mandatory.<ref name="Haake 2015"/> Distinguishing clinical signs of leptospirosis from other diseases and lack of laboratory diagnostic services are other problems.<ref name=":0">{{Cite web|url=https://www.who.int/zoonoses/diseases/lerg/en/index2.html|title=WHO {{!}} Leptospirosis Burden Epidemiology Reference Group (LERG)|website=www.who.int|access-date=30 November 2017|archive-url=https://web.archive.org/web/20171117150425/http://www.who.int/zoonoses/diseases/lerg/en/index2.html|archive-date=17 November 2017|url-status=live}}</ref> The socioeconomic status of many of the world's population is closely tied to malnutrition; subsequent lack of [[micronutrients]] may lead to increased risk of infection and death due to leptospirosis infection.<ref name=":1" /> Micronutrients such as [[iron]], [[calcium]], and [[magnesium]] represent important areas for future research.<ref name=":1">{{cite journal | vauthors = Herman HS, Mehta S, Cárdenas WB, Stewart-Ibarra AM, Finkelstein JL | title = Micronutrients and Leptospirosis: A Review of the Current Evidence | journal = PLOS Neglected Tropical Diseases | volume = 10 | issue = 7 | pages = e0004652 | date = July 2016 | pmid = 27387046 | pmc = 4936698 | doi = 10.1371/journal.pntd.0004652 }}</ref>

[[File:Working at aaddy rice field without a footwear, is a risk factor for leptospirosis.png|thumb|upright=1.3|alt=Workers in a rice paddy field | Working in a paddy field barefoot is a risk factor for leptospirosis.]]
The number of cases of leptospirosis is directly related to the amount of rainfall, making the disease seasonal in temperate climates and year-round in tropical climates.<ref name="Karpagm2020"/> The risk of contracting leptospirosis depends upon the risk of disease carriage in the community and the frequency of exposure.<ref name="Haake 2015"/> In rural areas, farming and animal husbandry are the major risk factors for contracting leptospirosis.<ref name="Zoey2020"/> Poor housing and inadequate sanitation also increase the risk of infection.<ref name="Haake 2015"/> In tropical and semi-tropical areas, the disease often becomes [[Epidemic|widespread]] after heavy rains or after flooding.<ref name="Karpagm2020"/>