Notifiable Diseases Surveillance Research Articles

Strengthening National Disease Surveillance and Response-Haiti, 2010-2015.

.Haiti’s health system has faced many challenges over the years, with competing health priorities in the context of chronic financial and human resource limitations. As a result, the existing notifiable disease surveillance system was unable to provide the most basic epidemiologic data for public health decision-making and action. In the wake of the January 2010 earthquake, the Haitian Ministry of Public Health and Population collaborated with the U.S. Centers for Disease Control and Prevention, the Pan American Health Organization, and other local and international partners to implement a functional national surveillance system. More than 7 years later, it is important to take the opportunity to reflect on progress made on surveillance and response in Haiti, including disease detection, reporting, outbreak investigation, and response. The national epidemiologic surveillance network that started with 51 sites in 2010 has been expanded to 357 sites as of December 2015. Disease outbreaks identified via the surveillance system, or other surveillance approaches, are investigated by epidemiologists trained by the Ministry of Health’s Field Epidemiology Training Program. Other related surveillance modules have been developed on the same model and electronic platform, allowing the country to document the impact of interventions, track progress, and monitor health problems. Sustainability remains the greatest challenge since most of the funding for surveillance come from external sources.

Comparing the historical limits method with regression models for weekly monitoring of national notifiable diseases reports

To compare the performance of the standard Historical Limits Method (HLM), with a modified HLM (MHLM), the Farrington-like Method (FLM), and the Serfling-like Method (SLM) in detecting simulated outbreak signals. We used weekly time series data from 12 infectious diseases from the U.S. Centers for Disease Control and Prevention’s National Notifiable Diseases Surveillance System (NNDSS). Data from 2006 to 2010 were used as baseline and from 2011 to 2014 were used to test the four detection methods. MHLM outperformed HLM in terms of background alert rate, sensitivity, and alerting delay. On average, SLM and FLM had higher sensitivity than MHLM. Among the four methods, the FLM had the highest sensitivity and lowest background alert rate and alerting delay. Revising or replacing the standard HLM may improve the performance of aberration detection for NNDSS standard weekly reports.

Socio-demographic, ecological factors and dengue infection trends in Australia.

Dengue has been a major public health concern in Australia. This study has explored the spatio-temporal trends of dengue and potential socio- demographic and ecological determinants in Australia. Data on dengue cases, socio-demographic, climatic and land use types for the period January 1999 to December 2010 were collected from Australian National Notifiable Diseases Surveillance System, Australian Bureau of Statistics, Australian Bureau of Meteorology, and Australian Bureau of Agricultural and Resource Economics and Sciences, respectively. Descriptive and linear regression analyses were performed to observe the spatio-temporal trends of dengue, socio-demographic and ecological factors in Australia. A total of 5,853 dengue cases (both local and overseas acquired) were recorded across Australia between January 1999 and December 2010. Most the cases (53.0%) were reported from Queensland, followed by New South Wales (16.5%). Dengue outbreak was highest (54.2%) during 2008–2010. A highest percentage of overseas arrivals (29.9%), households having rainwater tanks (33.9%), Indigenous population (27.2%), separate houses (26.5%), terrace house types (26.9%) and economically advantage people (42.8%) were also observed during 2008–2010. Regression analyses demonstrate that there was an increasing trend of dengue incidence, potential socio-ecological factors such as overseas arrivals, number of households having rainwater tanks, housing types and land use types (e.g. intensive uses and production from dryland agriculture). Spatial variation of socio-demographic factors was also observed in this study. In near future, significant increase of temperature was also projected across Australia. The projected increased temperature as well as increased socio-ecological trend may pose a future threat to the local transmission of dengue in other parts of Australia if Aedes mosquitoes are being established. Therefore, upgraded mosquito and disease surveillance at different ports should be in place to reduce the chance of mosquitoes and dengue cases being imported into all over Australia.

Epidemiology and Trends of Pertussis among Infants: United States, 2000–2015

BackgroundPertussis, a cyclic respiratory disease, causes the greatest morbidity and mortality among infants, particularly those too young to be vaccinated. Following a resurgence of pertussis in the 1990s, a recommendation was made in 2012 to vaccinate during every pregnancy in order to prevent infant disease. We describe pertussis trends from 2000–2015 among U.S. infants aged <1 year.MethodsWe analyzed infant pertussis cases reported through the National Notifiable Diseases Surveillance System from 2000 to 2015. Incidence rates (cases per 100,000 population) among various age groups (<2, 2– <4, 4– <6, and 6–<12 months) were calculated using National Center for Health Statistics population estimates as denominators. Negative binomial regression was used to estimate the annual average percent change with a linear trend; P < 0.05 was significant.ResultsFrom 2000 to 2015, 48,909 infant pertussis cases and 255 deaths were reported; infants aged <2 months accounted for 38.7% of cases. The age distribution of infant cases was stable from 2000 to 2009 but changed from 2010 to 2015 (Fig. 1), as the proportion of cases aged 4–<12 months increased annually on average by 4.7% (P < 0.001). Annual incidence was highest among <2 month olds; however, rates increased among older infants (Fig. 2): 7% average annual increase among infants aged 4–<6 months and 11% among infants aged 6–<12 months (P < 0.001 for each). The proportion of infants hospitalized decreased over time in each age group (P < 0.001 for all) with the largest annual average declines among 4–<6 (−5.1%) and 6–<12 month (−5.9%) olds. For all age groups, hospitalization rates were relatively stable, but non-hospitalization rates increased (P < 0.05 for all). The case–fatality ratio (CFR) was highest among <2 month olds (1.6%); CFRs decreased over time among <2 and 2–< 4 month olds (P < 0.05 for each).ConclusionPertussis incidence remains highest among infants aged <4 months, although the age distribution appears to be changing. Decreasing proportions of infants hospitalized may suggest a true decline in disease severity or an increase in reporting of less severe disease. Ongoing monitoring of infant pertussis is needed to better understand the impact of vaccinating pregnant women to prevent pertussis in young infants.Disclosures All authors: No reported disclosures.

Current Epidemiology of Serogroup W Meningococcal Disease—United States, 2010–2015

BackgroundSerogroup W (NmW) meningococcal disease is a rare but severe infection. Following an NmW outbreak after the Hajj in 2000, NmW disease, predominantly caused by sequence type (ST)-11 clonal complex (cc), rapidly increased in South Africa, South America, and the UK. We describe NmW meningococcal disease epidemiology in the USA during 2010–2015.MethodsData were collected from the National Notifiable Diseases Surveillance System, Active Bacterial Core surveillance, and state health departments. Isolates were serogrouped via slide agglutination and real-time polymerase chain reaction. For cases lacking a serogroup result at CDC, the state result was used. Case-fatality ratios (CFR) were calculated using the proportion of cases with known outcomes as the denominator. cc and ST were determined using multilocus sequence typing (MLST).ResultsFrom 2010 to 2015, 3,504 meningococcal disease cases were reported to CDC; 2,976 (85%) had a serogroup result, of which 290 (10%) were NmW. Although the number of NmW cases reported annually remained fairly stable (range: 40–57), the total number of reported meningococcal disease cases decreased by 60%, and the proportion of cases due to NmW increased from 6% (42/830) in 2010 to 12% (40/332) in 2015. The majority of NmW cases were reported from five states: Florida (n = 106), California (n = 31), New York (n = 25), Georgia (n = 19), and Oregon (n = 11). Half of people with NmW disease were male, 185 (64%) were white, and 84 (29%) were Hispanic. The median age was 51 years (interquartile range: 26–70). Overall, 20% (52/259) of NmW cases were fatal, compared with CFRs for serogroups B (15%), Y (18%), or C (24%). NmW CFR was highest among adults aged 50–59 years (38%). MLST results were available for 119 (41%) of NmW cases: 76 (64%) were cc11, 40 (34%) were cc22, and 1 each were cc23, cc32, and an unassigned cc. cc appeared to be geographically associated: cc11 was concentrated in Florida and Georgia, while cc22 predominated on the West coast. Within cc11, the majority of isolates (86%) were ST-11, and within cc22 the majority (73%) were ST-22.ConclusionA rapid increase in NmW disease has not been observed in the USA. Most NmW cases were reported in a limited number of states, with geographic differences in clonal complex.Disclosures All authors: No reported disclosures.

Compendium of Measures to ControlChlamydia psittaciInfection Among Humans (Psittacosis) and Pet Birds (Avian Chlamydiosis), 2017

Psittacosis, also known as parrot fever and ornithosis, is a bacterial infection that can cause severe pneumonia and other serious health problems in humans. It is caused by Chlamydia psittaci. Reclassification of the order Chlamydiales in 1999 into 2 genera (Chlamydia and Chlamydophila) was not wholly accepted or adopted. This resulted in a reversion to the single, original genus Chlamydia, which now encompasses all 9 species including Chlamydia psittaci. During 2003-2014, 112 human cases of psittacosis were reported to the Centers for Disease Control and Prevention through the Nationally Notifiable Diseases Surveillance System. While many types of birds can be infected by C psittaci, in general, the literature suggests that human cases can most often occur after exposure to infected parrot-type birds kept as pets, especially cockatiels, parakeets, and conures. In birds, C psittaci infection is referred to as avian chlamydiosis. Infected birds shed the bacteria through feces and nasal discharges, and humans become infected from exposure to these materials. This compendium provides information about psittacosis and avian chlamydiosis to public health officials, physicians, veterinarians, the pet bird industry, and others concerned with controlling these diseases and protecting public health. The recommendations in this compendium provide standardized procedures to control C psittaci infections. This document will be reviewed and revised as necessary, and the most current version replaces all previous versions. This document was last revised in 2010. Major changes in this version include a recommendation for a shorter treatment time for birds with avian chlamydiosis, additional information about diagnostic testing, including genotyping, clearer language associated with personal protective equipment recommended for those caring for confirmed or exposed birds, and incorporating a grading scale with recommendations generally based on the United States Preventive Services Task Force's methods.

Importation of travel-related infectious diseases is increasing in South Korea: An analysis of salmonellosis, shigellosis, malaria, and dengue surveillance data.

BackgroundInternational travel has an important role in transmission of emerging infectious diseases. We described the imported infectious diseases in Korea from 2003 to 2012, and to analyze association of travels with the change in the incidences.MethodsWe used National Notifiable Disease Surveillance System to investigate the incidence of salmonellosis, shigellosis, malaria, and dengue. Data from Korea Tourism Organization was used to describe the inbound and outbound travelers by their age group, gender, and purpose of travel. We assessed association between international travel and the incidence of the infectious diseases, and seasonal variability.ResultsAmong 1849 imported cases, dengue comprised the largest number with 631 cases. The proportion of imported cases among total cases gradually increased from 4.1% in 2003 to 30.3% in 2012 (P < 0.001). There was a positive correlation between the number of travelers and the number of imported cases of shigellosis, dengue (P < 0.001), but not for malaria. Seasonal variability was observed for importation of salmonellosis, shigellosis and dengue fever (P = 0.005).ConclusionInternational travel was associated with the incidence of imported infectious diseases in Korea. Pre-travel consultation for international travelers planned to visit endemic area should be recommended strongly.

Effectiveness of different vaccine schedules for heptavalent and 13-valent conjugate vaccines against pneumococcal disease in the Community of Madrid.

The heptavalent pneumococcal conjugate vaccine (PCV-7) was added to the childhood routine vaccination program in the Community of Madrid in November of 2006 with 3+1 recommended doses and a catch-up for those under 2years old. In June 2010, PCV-7 was replaced by 13-valent vaccine (PCV-13) with 2+1 recommended doses. In July of 2012, the PCV-13 was removed from the funded program and reintroduced again (2+1 recommended doses) in December 2014. In between, children were vaccinated privately with 3+1 recommended doses of PCV-13. The aim of this study was to evaluate the effectiveness of each vaccination schedule used in the Community of Madrid. We included all cases of invasive pneumococcal disease (IPD) reported between 2007 and 2015 to the Notifiable Diseases Surveillance System. Vaccination information was obtained from the Immunization Registry. Vaccine effectiveness (VE) was estimated using the indirect cohort design for cases with serotype information. A total 779 cases were included in the study. Among them 47.6% of the cases were primo-vaccinated with booster, 20% primo-vaccinated, 15.9% incompletely primo-vaccinated and 16.5% not vaccinated. The VE for ≥1 doses of any PCV was 82% (CI 95%: 67.8-89.9%): 91.9% (CI 95%: 76.5-97.2%) for PCV-7 and 77.2% (48.6-89.9%) for PCV-13. VE in those receiving the full 2+1 or 3+1 schedules was 100% for both vaccines. A high number of vaccine failures were reported in children before they had the opportunity to receive the booster dose, especially due to PCV-13-non-PCV-7 serotypes. VE was higher for PCV-7 compared to PCV-13, except for those that received the complete schedule with booster that achieved 100% of VE, which shows the relevance of the vaccines and complying with all doses scheduled.

Summary of Notifiable Infectious Diseases and Conditions - United States, 2015.

The Summary of Notifiable Infectious Diseases and Conditions - United States, 2015 (hereafter referred to as the summary) contains the official statistics, in tabular and graphical form, for the reported occurrence of nationally notifiable infectious diseases and conditions in the United States for 2015. Unless otherwise noted, data are final totals for 2015 reported as of June 30, 2016. These statistics are collected and compiled from reports sent by U.S. state and territories, New York City, and District of Columbia health departments to the National Notifiable Diseases Surveillance System (NNDSS), which is operated by CDC in collaboration with the Council of State and Territorial Epidemiologists (CSTE). This summary is available at https://www.cdc.gov/MMWR/MMWR_nd/index.html. This site also includes summary publications from previous years.

Increasing Campylobacter Infections, Outbreaks, and Antimicrobial Resistance in the United States, 2004-2012.

Campylobacteriosis, a leading cause of foodborne illness in the United States, was not nationally notifiable until 2015. Data describing national patterns and trends are limited. We describe the epidemiology of Campylobacter infections in the United States during 2004-2012. We summarized laboratory-confirmed campylobacteriosis data from the Nationally Notifiable Disease Surveillance System, National Outbreak Reporting System, National Antimicrobial Resistance Monitoring System, and Foodborne Diseases Active Surveillance Network. During 2004-2012, 303520 culture-confirmed campylobacteriosis cases were reported. Average annual incidence rate (IR) was 11.4 cases/100000 persons, with substantial variation by state (range, 3.1-47.6 cases/100000 persons). IRs among patients aged 0-4 years were more than double overall IRs. IRs were highest among males in all age groups. IRs in western states and rural counties were higher (16.2/100000 and 14.2/100000, respectively) than southern states and metropolitan counties (6.8/100000 and 11.0/100000, respectively). Annual IRs increased 21% from 10.5/100000 during 2004-2006 to 12.7/100000 during 2010-2012, with the greatest increases among persons aged >60 years (40%) and in southern states (32%). The annual median number of Campylobacter outbreaks increased from 28 in 2004-2006 to 56 in 2010-2012; in total, 347 were reported. Antimicrobial susceptibility testing of isolates from 4793 domestic and 1070 travel-associated infections revealed that, comparing 2004-2009 to 2010-2012, ciprofloxacin resistance increased among domestic infections (12.8% vs 16.1%). During 2004-2012, incidence of campylobacteriosis, outbreaks, and clinically significant antimicrobial resistance increased. Marked demographic and geographic differences exist. Our findings underscore the importance of national surveillance and understanding of risk factors to guide and target control measures.

State HCV Incidence and Policies Related to HCV Preventive and Treatment Services For Persons Who Inject Drugs — United States, 2015–2016

Hepatitis C is associated with more deaths in the United States than 60 other infectious diseases reported to CDC combined. Despite curative hepatitis C virus (HCV) therapies and known preventive measures to interrupt transmission, new HCV infections have increased in recent years (1,2). Injection drug use is the primary risk factor for new HCV infections (2). One potential strategy to decrease the prevalence of HCV is to create and strengthen public health laws and policies aimed specifically at reducing transmission risks among persons who inject drugs. To evaluate factors affecting access to HCV preventive and treatment services, CDC assessed state laws governing access to safe injection equipment and Medicaid policies related to sobriety requirements for approval of HCV treatment for persons who inject drugs. Acute HCV incidence rates were obtained from CDC's National Notifiable Disease Surveillance System (NNDSS). States were categorized based on analysis of laws related to access to clean needles and syringes and Medicaid HCV treatment policies associated with sobriety requirements. In 2015, HCV incidence remained high in the United States, with rates in 17 states exceeding the national average. Three states were determined to have state laws and Medicaid policies capable of comprehensively preventing and treating HCV among persons who inject drugs. Opportunities exist for states to adopt laws and policies that could help increase access to HCV preventive and treatment services reducing the number of persons at risk for HCV transmission and disease.

Probabilistic forecasting in infectious disease epidemiology: the 13th Armitage lecture.

Routine surveillance of notifiable infectious diseases gives rise to daily or weekly counts of reported cases stratified by region and age group. From a public health perspective, forecasts of infectious disease spread are of central importance. We argue that such forecasts need to properly incorporate the attached uncertainty, so they should be probabilistic in nature. However, forecasts also need to take into account temporal dependencies inherent to communicable diseases, spatial dynamics through human travel and social contact patterns between age groups. We describe a multivariate time series model for weekly surveillance counts on norovirus gastroenteritis from the 12 city districts of Berlin, in six age groups, from week 2011/27 to week 2015/26. The following year (2015/27 to 2016/26) is used to assess the quality of the predictions. Probabilistic forecasts of the total number of cases can be derived through Monte Carlo simulation, but first and second moments are also available analytically. Final size forecasts as well as multivariate forecasts of the total number of cases by age group, by district and by week are compared across different models of varying complexity. This leads to a more general discussion of issues regarding modelling, prediction and evaluation of public health surveillance data. Copyright © 2017 John Wiley & Sons, Ltd.

Epidemiological characteristics of human brucellosis in Hamadan Province during 2009–2015: results from the National Notifiable Diseases Surveillance System

BackgroundHuman brucellosis and recurrent brucellosis is an ever-increasing public health concern, especially in endemic areas like Iran. Nevertheless, little is known regarding the epidemiology and determinants of recurrent brucellosis. Therefore, the objective of this study was to investigate epidemiological patterns and potential determinants of recurrent brucellosis in Hamadan Province during the years 2009–2015. MethodsData on reported cases of new and recurrent brucellosis from 2009 to 2015 were obtained from the provincial Notifiable Diseases Surveillance System at Hamadan University of Medical Sciences. Incidence rates per 100000 were estimated at the county level. Binary logistic regression was used to estimate the effects of background characteristics and recurrent brucellosis. The power of discrimination of the model for recurrent brucellosis was assessed using the area under the curve (AUC). ResultsAmong 7318 brucellosis cases, the total frequency (%) of recurrent cases was 472 (6.45%). The rate of recurrent brucellosis was higher in females, people aged 50 years and over, people with a history of consuming unpasteurized dairy products with no history of contact with animals, and in the winter season. Multivariable logistic regression analysis showed that female sex (adjusted odds ratio (AOR) 1.36, 95% confidence interval (CI) 1.13–1.65), age ≥55 years (AOR 4.15, 95% CI 2.32–7.42), consumption of unpasteurized dairy products (AOR 1.16, 95% CI 0.96–1.40), and winter season (AOR 1.32, 95% CI 1.03–1.71) are potential risk factors for recurrent brucellosis. The final model that involved all the determinants showed moderate discrimination (AUC 0.61). ConclusionsFemale sex, older age, and winter months were found to be significant determinants of recurrent human brucellosis. Enhanced surveillance systems with an emphasis on these population characteristics will allow effective preventive and protective measures to be implemented and might alleviate the recurrence of brucellosis in the country.

Malaria Surveillance - United States, 2014.

Malaria Surveillance - United States, 2014.

Comparing laboratory surveillance with the notifiable diseases surveillance system in South Africa

The aim of this study was to compare laboratory surveillance with the notifiable diseases surveillance system (NDSS) in South Africa. Data on three tracer notifiable diseases - measles, meningococcal meningitis, and typhoid - were compared to assess data quality, stability, representativeness, sensitivity and positive predictive value (PPV), using the Wilcoxon and Chi-square tests, at the 5% significance level. For all three diseases, fewer cases were notified than confirmed in the laboratory. Completeness for the laboratory system was higher for measles (63% vs. 47%, p<0.001) and meningococcal meningitis (63% vs. 57%, p<0.001), but not for typhoid (60% vs. 63%, p=0.082). Stability was higher for the laboratory (all 100%) compared to notified measles (24%, p<0.001), meningococcal meningitis (74%, p<0.001), and typhoid (36%, p<0.001). Representativeness was also higher for the laboratory (all 100%) than for notified measles (67%, p=0.058), meningococcal meningitis (56%, p=0.023), and typhoid (44%, p=0.009). The sensitivity of the NDSS was 50%, 98%, and 93%, and the PPV was 20%, 57%, and 81% for measles, meningococcal meningitis, and typhoid, respectively. Compared to laboratory surveillance, the NDSS performed poorly on most system attributes. Revitalization of the NDSS in South Africa is recommended to address the completeness, stability, and representativeness of the system.

Increased Risk for Meningococcal Disease Among Men Who Have Sex With Men in the United States, 2012-2015.

Several clusters of serogroup C meningococcal disease among men who have sex with men (MSM) have been reported in the United States in recent years. The epidemiology and risk of meningococcal disease among MSM is not well described. All meningococcal disease cases among men aged 18-64 years reported to the National Notifiable Disease Surveillance System between January 2012 and June 2015 were reviewed. Characteristics of meningococcal disease cases among MSM and men not known to be MSM (non-MSM) were described. Annualized incidence rates among MSM and non-MSM were compared through calculation of the relative risk and 95% confidence intervals. Isolates from meningococcal disease cases among MSM were characterized using standard microbiological methods and whole-genome sequencing. Seventy-four cases of meningococcal disease were reported among MSM and 453 among non-MSM. Annualized incidence of meningococcal disease among MSM was 0.56 cases per 100000 population, compared to 0.14 among non-MSM, for a relative risk of 4.0 (95% confidence interval [CI], 3.1-5.1). Among the 64 MSM with known status, 38 (59%) were infected with human immunodeficiency virus (HIV). HIV-infected MSM had 10.1 times (95% CI, 6.1-16.6) the risk of HIV-uninfected MSM. All isolates from cluster-associated cases were serogroup C sequence type 11. MSM are at increased risk for meningococcal disease, although the incidence of disease remains low. HIV infection may be an important factor for this increased risk. Routine vaccination of HIV-infected persons with a quadrivalent meningococcal conjugate vaccine in accordance with Advisory Committee on Immunization Practices recommendations should be encouraged.

State HCV Incidence and Policies Related to HCV Preventive and Treatment Services for Persons Who Inject Drugs - United States, 2015-2016.

Hepatitis C is associated with more deaths in the United States than 60 other infectious diseases reported to CDC combined. Despite curative hepatitis C virus (HCV) therapies and known preventive measures to interrupt transmission, new HCV infections have increased in recent years (1,2). Injection drug use is the primary risk factor for new HCV infections (2). One potential strategy to decrease the prevalence of HCV is to create and strengthen public health laws and policies aimed specifically at reducing transmission risks among persons who inject drugs. To evaluate factors affecting access to HCV preventive and treatment services, CDC assessed state laws governing access to safe injection equipment and Medicaid policies related to sobriety requirements for approval of HCV treatment for persons who inject drugs. Acute HCV incidence rates were obtained from CDC's National Notifiable Disease Surveillance System (NNDSS). States were categorized based on analysis of laws related to access to clean needles and syringes and Medicaid HCV treatment policies associated with sobriety requirements. In 2015, HCV incidence remained high in the United States, with rates in 17 states exceeding the national average. Three states were determined to have state laws and Medicaid policies capable of comprehensively preventing and treating HCV among persons who inject drugs. Opportunities exist for states to adopt laws and policies that could help increase access to HCV preventive and treatment services reducing the number of persons at risk for HCV transmission and disease.

Hepatitis C Virus Infection Among Reproductive-Aged Women and Children in the United States, 2006 to 2014.

In the United States, hepatitis C virus (HCV) infection has increased among young persons who inject drugs, but the extent of this epidemic among reproductive-aged women and their children is unknown. To estimate numbers and describe characteristics of reproductive-aged women with HCV infection and of their offspring. Analysis of the National Notifiable Diseases Surveillance System (NNDSS) from 2006 to 2014 and the Quest Diagnostics Health Trends national database from 2011 to 2014. United States. 171801 women (aged 15 to 44 years) and 1859 children (aged 2 to 13 years) with HCV infection reported to the NNDSS; 2.1 million reproductive-aged women and 56684 children who had HCV testing by Quest Diagnostics. NNDSS HCV case reports and Quest laboratory data regarding unique reproductive-aged women and children who were tested for HCV infection. The number of reproductive-aged women with acute and past or present HCV infection in the NNDSS doubled, from 15550 in 2006 to 31039 in 2014. Of 581255 pregnant women tested by Quest from 2011 to 2014, 4232 (0.73% [95% CI, 0.71% to 0.75%]) had HCV infection. Of children tested by Quest, 0.76% (CI, 0.69% to 0.83%) had HCV infection, but the percentage was 3.2-fold higher among children aged 2 to 3 years (1.62% [CI, 1.34% to 1.96%]) than those aged 12 to 13 years (0.50% [CI, 0.41% to 0.62%]). Applying the Quest HCV infection rate to annual live births from 2011 to 2014 resulted in an estimated average of 29000 women (CI, 27400 to 30900 women) with HCV infection, who gave birth to 1700 infants (CI, 1200 to 2200 infants) with the infection each year. Only a fraction of HCV infections is detected and reported to the NNDSS. Quest data are potentially biased, because women who are asymptomatic, do not access health care, or have unreported risks may be less likely to be tested for HCV infection. These data suggest a recent increase in HCV infection among reproductive-aged women and may inform deliberations regarding a role for routine HCV screening during pregnancy. Centers for Disease Control and Prevention.

Spatial distribution of mumps in South Korea, 2001–2015: identifying clusters and population risk factors

In South Korea, the resurgence of mumps was noted primarily among school-aged children and adolescents since 2000. We analyzed spatial patterns in mumps incidence to give an indication to the geographical risk. We used National Notifiable Disease Surveillance System data from 2001 to 2015, classifying into three periods according to the level of endemicity. A geographic-weighted regression analysis was performed to find demographic predictors of mumps incidence according to district level. We assessed the association between the total population size, population density, percentage of children (age 0-19 years), timely vaccination rate of measles-mumps-rubella vaccines and the higher incidence rate of mumps. During low endemic periods, there were sporadic regional distributions of outbreak in the central and northern part of the country. During intermediate endemic periods, the increase of incidence was noted across the country. During high endemic period, a nationwide high incidence of mumps was noted especially concentrated in southwestern regions. A clear pattern for the mumps cluster shown through global spatial autocorrelation analysis from 2004 to 2015. The 'non-timely vaccination coverage' (P = 0·002), and 'proportion of children population' (P < 0·001) were the predictors for high mumps incidence in district levels. Our study indicates that the rate of mumps incidence according to geographic regions vary by population proportion and neighboring regions, and timeliness of vaccination, suggesting the importance of community-level surveillance and improving of timely vaccination.

Trend of measles, mumps, and rubella incidence following the measles-rubella catch up vaccination in the Republic of Korea, 2001.

Following the introduction of measles-rubella (MR) catch-up vaccination in 2001 and two dose measles-mumps-rubella (MMR2) keep-up program in 2002, the incidence of measles, mumps, and rubella was not evaluated systematically. To describe the recent changes in epidemiology, a population-based incidence study from 2001 to 2015 using national notifiable disease surveillance data was conducted. Between 2001 and 2015, there was decrease in the incidence of measles and rubella, whereas a steady increase in mump incidence was noted. The age distribution of mumps cases has shifted to the older age group, whereas rubella became more frequent in younger age group. The incidence of mumps showed an increase in every birth cohorts, except for the decrease in incidence for catch-up vaccination cohort from 131 cases in 2007-2011 to 64 cases per 100 000 in 2012-2015. Continuing in monitoring of mumps and strengthening of the high two-dose MMR vaccination coverage should be taken place in Korea.