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Morbidity and Mortality Weekly Report
Weekly / Vol. 66 / No. 32 August 18, 2017
U.S. Department of Health and Human Services
Centers for Disease Control and Prevention
INSIDE
846 Hypertension Prevalence, Awareness, Treatment,
and Control Among Adults Aged ≥18 Years —
Los Angeles County, 1999–2006 and 2007–2014
850 Occupational Distribution of Campylobacteriosis
and Salmonellosis Cases — Maryland, Ohio, and
Virginia, 2014
854 Progress Toward Poliomyelitis Eradication —
Afghanistan, January 2016–June 2017
859 Effects of Antiretroviral Therapy to Prevent HIV
Transmission to Women in Couples Attempting
Conception When the Man Has HIV Infection —
United States, 2017
861 Notes from the Field: Death of a Farm Worker After
Exposure to Manure Gas in an Open Air
Environment — Wisconsin, August 2016
864 QuickStats
Continuing Education examination available at
https://www.cdc.gov/mmwr/cme/conted_info.html#weekly.
Contact Lens Health Week —
August 21–25, 2017
August 21–25, 2017, marks the fourth annual Contact
Lens Health Week. In collaboration with partners from the
clinical, public health, industry, and regulatory sectors, CDC
is promoting healthy wear and care practices to reduce the risk
for eye infections among the approximately 45 million persons
in the United States who wear contact lenses. Research after
outbreaks of rare but serious eye infections in the United States
has indicated that these infections occur most often in contact
lens wearers who do not take proper care of their contact lenses,
indicating a need to promote safer wear and care (1,2).
A report in this issue of MMWR describes CDC’s first-
ever population-based estimates of contact lens–related risk
behaviors in persons aged 12–17 years (referred to here as
adolescents) in the United States. Approximately six in seven
adolescents reported at least one behavior (e.g., sleeping in
lenses, swimming, or not replacing lenses and storage cases
as recommended) putting them at risk for a serious contact
lens–related eye infection. Encouraging adolescents to adopt
healthy contact lens wear and care habits might help them
maintain healthy habits into adulthood.
Although most contact lens wearers receive the benefits of
vision correction, contact lenses can pose an infection risk,
especially if they are not worn and cared for properly. Practicing
proper contact lens hygiene and regularly visiting an eye care
provider are important behaviors for keeping contact lens
wearers’ eyes healthy. Additional information on Contact Lens
Health Week and the proper wear and care of contact lenses is
available at https://www.cdc.gov/contactlenses.
References
1. Verani JR, Lorick SA, Yoder JS, et al.; Acanthamoeba Keratitis
Investigation Team. National outbreak of Acanthamoeba keratitis
associated with use of a contact lens solution, United States. Emerg
Infect Dis 2009;15:1236–42. https://doi.org/10.3201/eid1508.090225.
2. Chang DC, Grant GB, O’Donnell K, et al.; Fusarium Keratitis
Investigation Team. Multistate outbreak of Fusarium keratitis
associated with use of a contact lens solution. JAMA 2006;296:953–63.
https://doi.org/10.1001/jama.296.8.953.
Risk Behaviors for Contact
Lens–Related Eye Infections Among
Adults and Adolescents —
United States, 2016
Jennifer R. Cope, MD1; Sarah A. Collier, MPH1;
Hannah Nethercut, MPH1; Jefferson M. Jones, MD1;
Kirsten Yates, MPH1; Jonathan S. Yoder, MSW, MPH1
Contact lens–related eye infections, which can lead to serious
outcomes, including blindness, are associated with several risk
factors, including sleeping in lenses, exposing lenses to water,
not adhering to replacement schedules, and reusing disinfect-
ing solution (1). In some studies, adolescent and young adult
contact lens wearers have been reported to be more likely than
older adult contact lens wearers to develop eye infections (2,3)
and more likely to have poor contact lens hygiene practices (2).
Morbidity and Mortality Weekly Report
842 MMWR / August 18, 2017 / Vol. 66 / No. 32 US Department of Health and Human Services/Centers for Disease Control and Prevention
The MMWR series of publications is published by the Center for Surveillance, Epidemiology, and Laboratory Services, Centers for Disease Control and Prevention (CDC),
U.S. Department of Health and Human Services, Atlanta, GA 30329-4027.
Suggested citation: [Author names; first three, then et al., if more than six.] [Report title]. MMWR Morb Mortal Wkly Rep 2017;66:[inclusive page numbers].
Centers for Disease Control and Prevention
Brenda Fitzgerald, MD, Director
William R. Mac Kenzie, MD, Acting Associate Director for Science
Joanne Cono, MD, ScM, Director, Office of Science Quality
Chesley L. Richards, MD, MPH, Deputy Director for Public Health Scientific Services
Michael F. Iademarco, MD, MPH, Director, Center for Surveillance, Epidemiology, and Laboratory Services
MMWR Editorial and Production Staff (Weekly)
Sonja A. Rasmussen, MD, MS, Editor-in-Chief
Charlotte K. Kent, PhD, MPH, Executive Editor
Jacqueline Gindler, MD, Editor
Teresa F. Rutledge, Managing Editor
Douglas W. Weatherwax, Lead Technical Writer-Editor
Soumya Dunworth, PhD, Kristy Gerdes, MPH, Teresa M. Hood, MS,
Technical Writer-Editors
Martha F. Boyd, Lead Visual Information Specialist
Maureen A. Leahy, Julia C. Martinroe,
Stephen R. Spriggs, Tong Yang,
Visual Information Specialists
Quang M. Doan, MBA, Phyllis H. King,
Paul D. Maitland, Terraye M. Starr, Moua Yang,
Information Technology Specialists
MMWR Editorial Board
Timothy F. Jones, MD, Chairman
Matthew L. Boulton, MD, MPH
Virginia A. Caine, MD
Katherine Lyon Daniel, PhD
Jonathan E. Fielding, MD, MPH, MBA
David W. Fleming, MD
William E. Halperin, MD, DrPH, MPH
King K. Holmes, MD, PhD
Robin Ikeda, MD, MPH
Rima F. Khabbaz, MD
Phyllis Meadows, PhD, MSN, RN
Jewel Mullen, MD, MPH, MPA
Jeff Niederdeppe, PhD
Patricia Quinlisk, MD, MPH
Patrick L. Remington, MD, MPH
Carlos Roig, MS, MA
William L. Roper, MD, MPH
William Schaffner, MD
In 2015, CDC reported the number and demographics of
adult contact lens wearers in the United States to define the
population at risk for contact lens–related eye infections (4);
however, this estimate did not include adolescents. To better
understand this group of younger contact lens wearers and
guide prevention efforts, a population-based survey was used
to assess contact lens wear, care behaviors, risk factors, and
demographics among persons aged 12–17 years (referred to as
adolescents in this report), young adults aged 18–24 years, and
older adults aged ≥25 years in the United States. In 2016, an
estimated 3.6 million adolescents (14.5%) wore contact lenses.
Of the adolescents who wore contact lenses, 85% reported at
least one behavior that put them at risk for a contact lens–
related eye infection, compared with 81% of young adults, and
88% of older adults. These findings can inform the creation of
age-specific targeted prevention messages aimed at contact lens
wearers and establish a baseline for evaluating trends in contact
lens wear, care habits, and contact lens–related risk behaviors.
To describe contact lens wear and care behaviors, risk fac-
tors, and demographics for adolescents and adults in the
United States, the Porter Novelli 2016 summer HealthStyles
and YouthStyles survey, an online survey of 4,548 U.S. adults
(aged ≥18 years) and 1,618 U.S. adolescents (aged 12–17 years)
was used. Adolescent participants lived in the households of
the adult participants.* The 2016 Porter Novelli Styles survey
* Porter Novelli Public Services. Summer HealthStyles and YouthStyles 2016
methodology; Washington, DC.
participants were part of the GfK KnowledgePanel, a nationally
representative online panel with members recruited through
probability-based sampling by postal address. Computer and
Internet access were provided to complete the survey where
needed. For completing this survey and others, households
received rewards points, which they could redeem for prizes
generally worth less than $500. The sample was weighted
on nine factors (sex, age, household income, race/ethnicity,
household size, education, census region, metropolitan status,
and prior Internet access) to match the Current Population
Survey conducted by the U.S. Census Bureau. Participants
were asked to provide demographic and contact lens wearing
information. If they wore contact lenses, they were asked about
contact lens hygiene behaviors and risk factors associated with
contact lens–related eye infections. The question regarding
contact lens hygiene behaviors was “When you wear contact
lenses, which of these actions do you do on a regular basis
(sometimes, most of the time, or always)?”
In 2016, an estimated 3.6 million adolescents aged
12–17 years (14.5% of adolescents), 7.5 million young adults
aged 18–24 years (24.4% of young adults), and 33.9 million
older adults aged ≥25 years (15.5% of adults) in the United
States wore contact lenses. Among lens wearers, 90.4% of
adults and 87.8% of adolescents reported wearing soft contact
lenses (lenses made of soft, flexible plastics that allow oxygen
to pass through to the cornea). No significant demographic
differences between adolescent contact lens wearers and adoles-
cent nonwearers were observed (Table 1). By race, older adult
Morbidity and Mortality Weekly Report
MMWR / August 18, 2017 / Vol. 66 / No. 32 843
US Department of Health and Human Services/Centers for Disease Control and Prevention
TABLE 1. Demographic characteristics of adolescent contact lens wearers (aged 12–17 years), by type of contact lens, compared with adolescent
nonwearers, young adult lens wearers (aged 18–24 years), and older adult lens wearers (aged ≥25 years) — United States, 2016*
Characteristic
% (95% CI)
Adolescent soft CL
wearers
(n = 119)
Adolescent gas
permeable or other†
CL wearers
(n = 16)
All adolescent
CL wearers§
(n = 135)
Adolescent
nonwearers
(n = 810)
Young adult
CL wearers
(n = 124)
Older adult
CL wearers
(n = 571)
Sex
Female 52.6 (41.6–63.5) 48.2 (11.8–84.5) 52.3 (41.6–62.9) 48.8 (44.7–52.8) 69.3 (56.8–81.8) 65.2 (60.4–70.0)
Male 47.4 (36.5–58.4) 51.8 (15.5–88.2) 47.7 (37.1–58.4) 51.2 (47.2–55.3) 30.7 (18.2–43.2) 34.8 (30.0–39.6)
Race/Ethnicity
White, non-Hispanic 49.9 (39.0–60.7) 42.3 (6.7–77.9) 48.4 (37.9–58.9) 55.0 (50.9–59.2) 56.7 (42.7–70.6) 66.9 (61.8–71.9)
Hispanic 26.6 (16.1–37.1) 15.7 (0.0–34.4) 25.6 (15.8–35.4) 22.4 (18.5–26.2) 21.1 (9.2–33.0) 11.4 (8.3–14.5)
Black, non-Hispanic 12.0 (3.4–20.6) 42.0 (4.9–79.2) 15.8 (6.4–25.2) 13.5 (10.4–16.6) 7.1 (0.6–13.6) 10.3 (7.2–13.4)
Other or multiracial 11.5 (3.9–19.2) — 10.3 (3.4–17.2) 9.1 (6.7–11.5) 15.2 (3.3–27.0) 10.7 (6.5–14.9)
Metropolitan living area
Metro 90.5 (84.8–96.3) 56.9 (18.5–95.3) 86.3 (78.1–94.5) 85.0 (81.8–88.1) 93.6 (86.2–100.0) 86.2 (82.7–89.7)
Nonmetro 9.5 (3.7–15.2) 43.1 (4.7–81.5) 13.7 (5.5–21.9) 15.0 (11.9–18.2) 6.4 (0.0–13.8) 13.8 (10.3–17.3)
Geographic region
Northeast 16.2 (8.0–24.5) 11.6 (0.0–28.7) 15.9 (8.2–23.5) 16.9 (13.9–19.8) 27.5 (15.7–39.2) 17.7 (14.0–21.3)
Midwest 27.4 (18.9–35.9) 22.5 (0.0–50.8) 26.8 (18.5–35.1) 20.4 (17.3–23.4) 24.3 (12.7–35.9) 23.5 (19.4–27.5)
South 36.5 (25.8–47.2) 54.7 (19.8–89.7) 38.3 (27.6–48.9) 37.7 (33.7–41.7) 33.8 (20.6–47.0) 35.6 (30.9–40.4)
West 19.9 (10.5–29.3) 11.2 (0.0–27.1) 19.1 (10.4–27.7) 25.0 (21.3–28.7) 14.4 (4.3–24.6) 23.2 (18.9–27.5)
Abbreviations: CI=confidence interval; CL=contact lens.
* Based on responses to Porter Novelli 2016 summer HealthStyles and YouthStyles surveys with questions on contact lens use and wearer/nonwearer demographics.
† Other indicates contact lens wearers who said they wore a type of contact lens not included among the survey choices.
§ Some individual columns do not sum to 100.0 because of rounding.
lens wearers were more likely to be white than were adolescent
lens wearers. No significant geographic region or metropolitan
residency differences were observed for either adolescents or
adults, regardless of lens-wearing status.
At least one contact lens hygiene risk behavior was reported
by older adult (87.5%), young adult (80.9%), and adolescent
(85.3%) lens wearers (Table 2). The most frequently reported
risk behaviors in adolescents were not visiting an eye doctor as
least annually, sleeping or napping in lenses, and swimming
in lenses (Table 2). Among young adults and older adults, the
most frequently reported risk behaviors were replacing lenses
at intervals longer than those prescribed, replacing lens stor-
age cases at intervals longer than those recommended, swim-
ming in lenses, and sleeping or napping in lenses. Adolescents
were significantly less likely to report replacing lenses at
intervals longer than prescribed and replacing lens storage
cases at intervals longer than recommended. Although both
adults and adolescents most commonly reported purchasing
contact lenses through their eye care provider, both young
adults and older adults were more likely than adolescents
to purchase lenses on the Internet. A higher percentage of
young adults (14.6%, 1.1 million) and older adults (11.4%,
3.9 million) than adolescents (4.2%, 152,000) reported ever
experiencing a red or painful eye that required an eye care
provider visit.
Discussion
An estimated one in seven adolescents and one in six adults in
the United States wore contact lenses in 2016, and approximately
six of seven lens wearers reported at least one behavior putting
them at risk for a serious contact lens–related eye infection. Lens
wearers most commonly reported sleeping or napping in lenses,
swimming in lenses, and replacing both lenses and lens storage
cases at intervals longer than those recommended.
A previous study suggested that adolescents and young
adults have lower compliance with contact lens hygiene recom-
mendations and have a greater risk for corneal inflammatory
events, a category of eye problems that includes serious eye
infections (3). Young adults in this survey were significantly
more likely to replace lenses and cases at intervals longer than
those recommended than were adolescents. These findings
might reflect the fact that most adolescents are still living with
their parents who might help to reinforce good contact lens
hygiene practices whereas young adults might have recently
left home and are no longer subject to parental reminders (2).
Young adults also might have fewer resources (e.g., money
and transportation) to regularly visit eye care providers and
obtain hygiene education or regularly replace contact lenses,
lens storage cases, and solution (3). Young adults have been
reported to have poor planning and a more impulsive lifestyle
in relation to contact lens hygiene, possibly related to crowded
Morbidity and Mortality Weekly Report
844 MMWR / August 18, 2017 / Vol. 66 / No. 32 US Department of Health and Human Services/Centers for Disease Control and Prevention
living conditions (e.g., dormitories, living with roommates,
and sharing bathrooms), alcohol consumption, and attitudes
conducive to taking greater risks (2). A higher percentage of
young adults also reported ever having a red or painful eye
while wearing contact lenses, suggesting that poor hygiene
practices might lead to complications.
Engaging in risky contact lens behaviors can lead to poten-
tially serious eye infections (1). Substantial percentages of
adults and adolescents reported noncompliance with recom-
mended contact lens storage case and lens replacement sched-
ules. Infrequent contact lens storage case replacement has been
associated with microbial keratitis (5), and lens wearers who
do not replace their lenses as often as recommended report
more complications and eye discomfort (6). Not replacing
contact lenses and contact lens storage cases as often as recom-
mended increases the risk for contact lens–related eye infections
because recurrent handling of the contact lenses and storage
cases presents the opportunity to introduce microorganisms;
in addition, the moist surfaces of the lens and storage case
provide an environment favorable to microbial growth (7).
Exposing contact lenses to water through swimming or show-
ering increases the risk for infection because microorganisms
living in water can be transferred to the eye. Even household
tap water, although safe for drinking, contains microorganisms
that can contaminate lens cases and contact lenses and cause
eye infections, especially when not replaced at recommended
intervals (8). Sleeping in contact lenses was another commonly
reported risk behavior. Although some soft and rigid contact
lenses have Food and Drug Administration approval for over-
night wear, sleeping in any type of contact lens increases the
risk for eye infections (9).
The findings in this report are subject to at least five limita-
tions. First, respondents were part of a larger survey that was
not specifically focused on contact lens behaviors. Therefore,
participants might not have been representative of contact lens
wearers in the United States. Second, adolescents were sampled
through convenience sampling, specifically those living in the
household of an adult taking the larger survey. This sampling
method led to a small sample size of adolescent respondents.
In addition, the number of young adults in the sample was
small. Third, the sampling method differed from a sample in
a previous report (4) that also asked risk behavior questions
in a different manner (i.e., “ever” versus “regular” behaviors)
and produced differences in the percentage of respondents
reporting outcomes and behaviors. Fourth, because data were
self-reported, respondents might have been reluctant to report
risk behaviors because of social desirability bias. Finally, for
the contact lens hygiene and outcomes questions, no period
was stipulated; this might affect the comparison among age
groups because the duration of contact lens use might differ
and individual practices can change over time.
Although adolescent contact lens wearers reported engag-
ing in some healthier contact lens hygiene behaviors than
their adult counterparts, there is still room for improvement
to prevent potentially serious outcomes, including blindness.
Prevention efforts should focus on encouraging contact lens
TABLE 2. Prevalence of risk behaviors* for contact lens–related eye infections and outcomes among adolescent (aged 12–17 years), young
adult (aged 18–24 years), and older adult (aged ≥25 years) contact lens wearers — United States, 2016
Characteristic
% (95% CI)
Adolescent CL wearers Young adult CL wearers Older adult CL wearers
Risk factor/Behavior
Sleeping or napping in CLs 29.8 (19.7–40.0) 33.3 (20.9–45.7) 32.9 (28.3–37.5)
Topping off solution†10.6 (4.9–16.2) 19.1 (8.4–29.8) 11.0 (7.8–14.3)
Replacing lenses at intervals longer than prescribed 23.7§,¶ (14.7–32.6) 52.4 (38.8–66.1) 44.5 (39.7–49.4)
Did not visit eye doctor at least annually 43.9 (33.1–54.6) 24.0 (11.8–36.1) 29.6 (25.0–34.3)
Replacing CL case at interval longer than recommended 22.8§,¶ (14.5–31.2) 40.5 (27.2–53.7) 41.7 (36.9–46.5)
Storing lenses in tap water 9.5¶ (3.3–15.7) 11.0 (2.1–19.9) 2.3 (0.8–3.8)
Rinsing lenses in tap water 7.1 (2.7–11.5) 12.1 (3.2–21.0) 6.2 (4.2–8.2)
Swimming in CLs 27.2 (18.4–36.0) 28.1 (16.3–40.0) 33.2 (28.7–37.7)
Any risk behavior 85.3 (78.7–91.9) 80.9 (70.0–91.8) 87.5 (84.2–90.7)
Source of purchase
Eye care provider office 68.0 (58.2–77.9) 65.5 (52.7–78.4) 65.4 (60.6–70.2)
Retail store without eye exam 15.8 (9.4–22.2) 22.5 (11.4–33.7) 21.3 (17.1–25.5)
Internet 10.5 (5.1–15.8) 20.6 (9.6–31.5) 18.8 (14.9–22.6)
Other 3.6 (0.0–7.4) — 1.7 (0.5–3.0)
Ever had a red/painful eye while wearing CLs that required a doctor visit 4.2 (0.7–7.8) 14.6 (5.1–24.1) 11.4 (8.1–14.8)
Abbreviations: CI=confidence intervals; CL=contact lens.
* As assessed by the question “When you wear contact lenses, which of these actions do you do on a regular basis (sometimes, most of the time, or always)?”
† Adding new solution to existing solution in the contact lens case instead of emptying and cleaning the case before adding new solution.
§ p-value <0.05 compared with young adult CL wearers.
¶ p-value <0.05 compared with older adult CL wearers.
Morbidity and Mortality Weekly Report
MMWR / August 18, 2017 / Vol. 66 / No. 32 845
US Department of Health and Human Services/Centers for Disease Control and Prevention
Summary
What is already known about this topic?
In 2015, CDC established that there were approximately
41 million contact lens wearers aged ≥18 years in the
United States, the majority of whom engaged in behaviors
that put them at risk for serious eye infections.
What is added by this report?
In 2016, there were an estimated 3.6 million adolescents aged
12–17 years in the United States who wore contact lenses. Of
the adolescents who wore contact lenses, 85% reported at least
one behavior that put them at risk for a contact lens–related eye
infection, compared with 81% of young adults, and 88% of
older adults.
What are the implications for public health practice?
Although adolescent contact lens wearers engage in some
healthier contact lens hygiene behaviors than do their adult
counterparts, there is room for improvement in order to prevent
potentially serious outcomes including blindness. Prevention
efforts should focus on encouraging contact lens wearers to
replace their contact lens storage case regularly and to avoid
sleeping or napping in contact lenses.
wearers to replace their contact lens storage case regularly and
to avoid sleeping or napping in contact lenses. There are insuf-
ficient data regarding the appropriate frequency of lens case and
contact lens replacement, but contact lens wearers who do not
follow recommended lens replacement schedules have more
complications and self-reported discomfort than contact lens
wearers who follow the replacement recommendations (6).†
Existing health communication strategies known to influ-
ence behavior change in adolescents (e.g., appeals to vanity
and social norms marketing) can be applied to communica-
tion efforts focusing on contact lens hygiene behaviors in this
population (10). Additionally, encouraging adolescents to
adopt healthy contact lens wear and care habits early might
help them maintain these habits into young adulthood, when
the frequency of reported risk behaviors increases. Prevention
messages targeting young adults can be shaped around the
lifestyle changes known to occur in this population.
† https://www.cdc.gov/contactlenses/show-me-the-science.html.
Conict of Interest
CDC receives an annual contribution from the Contact Lens
Institute to support CDC’s Healthy Contact Lens Program. The
Contact Lens Institute had no involvement in the survey questions,
analysis, drafting, or review of this manuscript.
1Division of Foodborne, Waterborne, and Environmental Diseases, National
Center for Emerging and Zoonotic Infectious Diseases, CDC.
Corresponding author: Jennifer R. Cope, jcope@cdc.gov, 404-639-3286.
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