The seasonality of tuberculosis, sunlight, vitamin D, and household crowding

Schumacher, Samuel G.; Tovar, Marco A.; Wingfield, Tom; Zevallos, Karine; Gilman, Robert Hugh; Friedland, Jon S.; Montoya, Rosario; Jongkaewwattana, Chulanee; Evans, Carlton Anthony William; Ramos, Eric S.; Sandhu, Gurjinder; Lewis, James J.; Baldwin, Matthew R.

dc.contributor.author	Wingfield, Tom
dc.contributor.author	Schumacher, Samuel G.
dc.contributor.author	Sandhu, Gurjinder
dc.contributor.author	Tovar, Marco A.
dc.contributor.author	Zevallos, Karine
dc.contributor.author	Baldwin, Matthew R.
dc.contributor.author	Montoya, Rosario
dc.contributor.author	Ramos, Eric S.
dc.contributor.author	Jongkaewwattana, Chulanee
dc.contributor.author	Lewis, James J.
dc.contributor.author	Gilman, Robert Hugh
dc.contributor.author	Friedland, Jon S.
dc.contributor.author	Evans, Carlton Anthony William
dc.date.accessioned	2020-06-10T18:12:15Z
dc.date.available	2020-06-10T18:12:15Z
dc.date.issued	2014
dc.identifier.uri	https://hdl.handle.net/20.500.12866/8069
dc.description.abstract	BACKGROUND: Unlike other respiratory infections, tuberculosis diagnoses increase in summer. We performed an ecological analysis of this paradoxical seasonality in a Peruvian shantytown over 4 years. METHODS: Tuberculosis symptom-onset and diagnosis dates were recorded for 852 patients. Their tuberculosis-exposed cohabitants were tested for tuberculosis infection with the tuberculin skin test (n = 1389) and QuantiFERON assay (n = 576) and vitamin D concentrations (n = 195) quantified from randomly selected cohabitants. Crowding was calculated for all tuberculosis-affected households and daily sunlight records obtained. RESULTS: Fifty-seven percent of vitamin D measurements revealed deficiency (<50 nmol/L). Risk of deficiency was increased 2.0-fold by female sex (P < .001) and 1.4-fold by winter (P < .05). During the weeks following peak crowding and trough sunlight, there was a midwinter peak in vitamin D deficiency (P < .02). Peak vitamin D deficiency was followed 6 weeks later by a late-winter peak in tuberculin skin test positivity and 12 weeks after that by an early-summer peak in QuantiFERON positivity (both P < .04). Twelve weeks after peak QuantiFERON positivity, there was a midsummer peak in tuberculosis symptom onset (P < .05) followed after 3 weeks by a late-summer peak in tuberculosis diagnoses (P < .001). CONCLUSIONS: The intervals from midwinter peak crowding and trough sunlight to sequential peaks in vitamin D deficiency, tuberculosis infection, symptom onset, and diagnosis may explain the enigmatic late-summer peak in tuberculosis.	en_US
dc.language.iso	eng
dc.publisher	Oxford University Press
dc.relation.ispartofseries	Journal of Infectious Diseases
dc.rights	info:eu-repo/semantics/restrictedAccess
dc.rights.uri	https://creativecommons.org/licenses/by-nc-nd/4.0/deed.es
dc.subject	Crowding	en_US
dc.subject	Family Characteristics	en_US
dc.subject	Sunlight	en_US
dc.subject	Adult	en_US
dc.subject	Cohort Studies	en_US
dc.subject	crowding	en_US
dc.subject	Female	en_US
dc.subject	household	en_US
dc.subject	Humans	en_US
dc.subject	Incidence	en_US
dc.subject	Interferon-gamma Release Tests	en_US
dc.subject	Male	en_US
dc.subject	Peru/epidemiology	en_US
dc.subject	seasonality	en_US
dc.subject	Seasons	en_US
dc.subject	sunlight	en_US
dc.subject	Tuberculin Test	en_US
dc.subject	tuberculosis	en_US
dc.subject	Tuberculosis/epidemiology	en_US
dc.subject	vitamin D	en_US
dc.subject	Vitamin D/blood	en_US
dc.title	The seasonality of tuberculosis, sunlight, vitamin D, and household crowding	en_US
dc.type	info:eu-repo/semantics/article
dc.identifier.doi	https://doi.org/10.1093/infdis/jiu121
dc.subject.ocde	https://purl.org/pe-repo/ocde/ford#3.03.08
dc.relation.issn	1537-6613