Comparison of Tuberculin Skin Testing and Interferon-γ Release Assays in Predicting Tuberculosis Disease

Importance

Elimination of tuberculosis (TB) disease in the US hinges on the ability of tests to detect individual risk of developing disease to inform prevention. The relative performance of 3 available TB tests-the tuberculin skin test (TST) and 2 interferon-γ release assays (IGRAs; QuantiFERON-TB Gold In-Tube [QFT-GIT] and SPOT.TB [TSPOT])-in predicting TB disease development in the US remains unknown.

Objective

To compare the performance of the TST with the QFT-GIT and TSPOT IGRAs in predicting TB disease in high-risk populations.

Design, Setting, and Participants

This prospective diagnostic study included participants at high risk of TB infection (TBI) or progression to TB disease at 10 US sites between 2012 and 2020. Participants of any age who had close contact with a case patient with infectious TB, were born in a country with medium or high TB incidence, had traveled recently to a high-incidence country, were living with HIV infection, or were from a population with a high local prevalence were enrolled from July 12, 2012, through May 5, 2017. Participants were assessed for 2 years after enrollment and through registry matches until the study end date (November 15, 2020). Data analysis was performed in June 2023.

Exposures

At enrollment, participants were concurrently tested with 2 IGRAs (QFT-GIT from Qiagen and TSPOT from Oxford Immunotec) and the TST. Participants were classified as case patients with incident TB disease when diagnosed more than 30 days from enrollment.

Main Outcomes and Measures

Estimated positive predictive value (PPV) ratios from generalized estimating equation models were used to compare test performance in predicting incident TB. Incremental changes in PPV were estimated to determine whether predictive performance significantly improved with the addition of a second test. Case patients with prevalent TB were examined in sensitivity analysis.

Results

A total of 22 020 eligible participants were included in this study. Their median age was 32 (range, 0-102) years, more than half (51.2%) were male, and the median follow-up was 6.4 (range, 0.2-8.3) years. Most participants (82.0%) were born outside the US, and 9.6% were close contacts. Tuberculosis disease was identified in 129 case patients (0.6%): 42 (0.2%) had incident TB and 87 (0.4%) had prevalent TB. The TSPOT and QFT-GIT assays performed significantly better than the TST (PPV ratio, 1.65 [95% CI, 1.35-2.02] and 1.47 [95% CI, 1.22-1.77], respectively). The incremental gain in PPV, given a positive TST result, was statistically significant for positive QFT-GIT and TSPOT results (1.64 [95% CI, 1.40-1.93] and 1.94 [95% CI, 1.65-2.27], respectively).

Conclusions and Relevance

In this diagnostic study assessing predictive value, IGRAs demonstrated superior performance for predicting incident TB compared with the TST. Interferon-γ release assays provided a statistically significant incremental improvement in PPV when a positive TST result was known. These findings suggest that IGRA performance may enhance decisions to treat TBI and prevent TB.

Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

Using Electronic Health Record Data to Measure the Latent Tuberculosis Infection Care Cascade in Safety-Net Primary Care Clinics

Introduction

Prevention of tuberculosis disease through diagnosis and treatment of latent tuberculosis infection is critical for achieving tuberculosis elimination in the U.S. Diagnosis and treatment of latent tuberculosis infection in safety-net primary care settings that serve patients at risk for tuberculosis may increase uptake of this prevention effort and accelerate progress toward elimination. Optimizing tuberculosis prevention in these settings requires measuring the latent tuberculosis infection care cascade (testing, diagnosis, and treatment) and identifying gaps to develop solutions to overcome barriers. We used electronic health record data to describe the latent tuberculosis infection care cascade and identify gaps among a network of safety-net primary care clinics.

Methods

Electronic health record data for patients seen in the OCHIN Clinical Network, the largest network of safety-net clinics in the U.S., between 2012 and 2019 were extracted. electronic health record data were used to measure the latent tuberculosis infection care cascade: patients who met tuberculosis screening criteria on the basis of current recommendations were tested for tuberculosis infection, diagnosed with latent tuberculosis infection, and prescribed treatment for latent tuberculosis infection. Outcomes were stratified by diagnostic test and treatment regimen.

Results

Among 1.9 million patients in the analytic cohort, 43.5% met tuberculosis screening criteria, but only 21.4% were tested for latent tuberculosis infection; less than half (40.4%) were tested using an interferon-gamma release assay. Among those with a valid result, 10.5% were diagnosed with latent tuberculosis infection, 29.1% of those were prescribed latent tuberculosis infection treatment, and only 33.6% were prescribed a recommended rifamycin-based regimen.

Conclusions

Electronic health record data can be used to measure the latent tuberculosis infection care cascade. A large proportion of patients in this safety-net clinical network are at high risk for tuberculosis infection. Addressing identified gaps in latent tuberculosis infection testing and treatment may have a direct impact on improving tuberculosis prevention in primary care clinics and accelerate progress toward elimination.

Mumps vaccine effectiveness of a 3rd dose of measles, mumps, rubella vaccine in school settings during a mumps outbreak -- Arkansas, 2016-2017

Objectives

The largest mumps outbreak in the United States since 2006 occurred in Arkansas during the 2016-17 school year. An additional dose (third dose) of measles-mumps-rubella vaccine (MMR3) was offered to school children. We evaluated the vaccine effectiveness (VE) of MMR3 compared with two doses of MMR for preventing mumps among school-aged children during the outbreak.

Study design

A generalized linear mixed effects model was used to estimate the incremental vaccine effectiveness (VE) of a third dose of MMR compared with two doses of MMR for preventing mumps.

Methods

We obtained school enrollment, immunization status and mumps case status from school registries, Arkansas's immunization registry, and Arkansas's mumps surveillance system, respectively. We included students who previously received 2 doses of MMR in schools with ≥1 mumps case after the MMR3 clinic. We used a generalized linear mixed model to estimate VE of MMR3 compared with two doses of MMR.

Results

Sixteen schools with 9272 students were included in the analysis. Incremental VE of MMR3 versus a two-dose MMR regimen was 52.7% (95% confidence interval [CI]: -3.6%‒78.4%) overall and in 8 schools with high mumps transmission it was 64.0% (95% CI: 1.2%‒86.9%). MMR3 VE was higher among middle compared with elementary school students (68.5% [95% CI: -30.2%‒92.4%] vs 37.6% [95% CI: -62.5%‒76.1%]); these differences were not statistically significant.

Conclusion

Our findings suggest MMR3 provided additional protection from mumps compared with two MMR doses in elementary and middle school settings during a mumps outbreak.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

1665. Using Electronic Health Records to Describe TB in Community Health Settings: a Cohort Analysis in a Large Safety-Net Population

Background

Over 80% of tuberculosis (TB) cases in the United States are attributed to reactivation of latent TB infection (LTBI). Eliminating TB in the United States requires expanding identification and treatment of LTBI. Centralized electronic health records (EHRs) are an unexplored data source to identify persons with LTBI. We explored EHR data to evaluate TB and LTBI screening and diagnoses within OCHIN, Inc., a U.S. practice-based research network with a high proportion of Federally Qualified Health Centers.

Methods

From the EHRs of patients who had an encounter at an OCHIN member clinic between January 1, 2012 and December 31, 2016, we extracted demographic variables, TB risk factors, TB screening tests, International Classification of Diseases (ICD) 9 and 10 codes, and treatment regimens. Based on test results, ICD codes, and treatment regimens, we developed a novel algorithm to classify patient records into LTBI categories: definite, probable or possible. We used multivariable logistic regression, with a referent group of all cohort patients not classified as having LTBI or TB, to identify associations between TB risk factors and LTBI.

Results

Among 2,190,686 patients, 6.9% (n=151,195) had a TB screening test; among those, 8% tested positive. Non-U.S. –born or non-English–speaking persons comprised 24% of our cohort; 11% were tested for TB infection, and 14% had a positive test. Risk factors in the multivariable model significantly associated with being classified as having LTBI included preferring non-English language (adjusted odds ratio [aOR] 4.20, 95% confidence interval [CI] 4.09–4.32); non-Hispanic Asian (aOR 5.17, 95% CI 4.94–5.40), non-Hispanic black (aOR 3.02, 95% CI 2.91–3.13), or Native Hawaiian/other Pacific Islander (aOR 3.35, 95% CI 2.92–3.84) race; and HIV infection (aOR 3.09, 95% CI 2.84–3.35).

Conclusion

This study demonstrates the utility of EHR data for understanding TB screening practices and as an important data source that can be used to enhance public health surveillance of LTBI prevalence. Increasing screening among high-risk populations remains an important step toward eliminating TB in the United States. These results underscore the importance of offering TB screening in non-U.S.–born populations.

Disclosures

All Authors: No reported disclosures

1651. Describing the Tuberculosis Infection Cascade of Care Based on Electronic Health Record Data

Background

Appropriate screening of individuals to detect latent tuberculosis infection (LTBI) is a critical step for achieving tuberculosis (TB) elimination in the US; >80% of TB cases are attributed to LTBI reactivation. TB infection testing and treatment must engage community health clinics where populations at risk seek care. However, there are significant data knowledge gaps in the current LTBI cascade of care (CoC) in this setting. We used an electronic health record (EHR) database from OCHIN, Inc., to characterize the LTBI CoC and identify potential future interventions.

Methods

We extracted a cohort of patients from 2012–2016 EHR data; we stratified by whether patients were at risk for TB based on meeting at least one of the following criteria: non-US born or non-English language preference, homelessness, encounter at correctional facility, history of close contact with a TB case, or being immunocompromised. Along each step of the LTBI CoC, we determined the proportions with a test for TB infection, with available test results, with a positive test, with an LTBI diagnosis, and with LTBI treatment prescribed. We used Χ ² tests to compare the LTBI CoCs among patients at risk with those classified as not at risk.

Results

Of nearly 2.2 million patient records, 701,467 (32.0%) met criteria for being at risk for TB; 84,422 at risk (12.0%) were tested; 65,562 (77.7%) had available results, of whom 9,624 (14.7%) were positive. Among those with positive results, 6,958 (72.3%) had an LTBI diagnosis, of whom 1,732 (24.9%) were prescribed treatment. Among those classified as not at risk, fewer were tested (66,773 [4.5%], p< 0.001) and had positive results (2,500 [3.7%], p< 0.0001). Among those with positive results, 1,998 (80.0%) had an LTBI diagnosis, of whom 395 (19.8%) initiated treatment.

Conclusion

This study highlights gaps in the LTBI CoC, and where interventions are most needed. The largest gaps were in testing patients at risk, as 88% were not tested, and treatment, as 75% diagnosed with LTBI were not treated. Just under half (44%) of all TB tests appeared to be performed in persons with little risk for TB; this is a substantial amount of testing given very few begin treatment. Resources could be redirected to increase screening and treatment among populations at risk.

Disclosures

All Authors: No reported disclosures

A Cluster Randomized Trial of the Impact of Education through Listening (a Novel Behavior Change Technique) on Household Water Treatment with Chlorine in Vihiga District, Kenya, 2010-2011

Despite multiple studies demonstrating the effectiveness of household water treatment with chlorine in disinfecting water and preventing diarrhea, social marketing of this intervention in low- and middle-income countries has resulted in only modest uptake. In a cluster randomized trial in Vihiga district, western Kenya, we compared uptake of household water treatment with chlorine among six villages served by community vendors trained in standard social marketing plus education through listening (ETL), an innovative behavior change method, and six villages served by community vendors trained in standard social marketing only. Water treatment uptake, water quality, and childhood diarrhea were measured over 6 months and compared between the two groups of villages. During the 6-month period, we found no association between ETL exposure and reported and confirmed household water treatment with chlorine. In both groups (ETL and comparison), reported use of water treatment was low and did not change during our 6-month follow-up. However, persons confirmed to have chlorinated water had improved bacteriologic water quality. Study findings suggest that ETL implementation was suboptimal, which, along with unexpected changes in the supply and price of chlorine, may have prevented an accurate assessment of the potential impact of ETL on water treatment behavior. Taken together, these observations exemplify the complexities of habits, practices, attitudes, and external factors that can create challenging conditions for implementing behavioral interventions. As a consequence, in this trial, ETL had no measurable impact on water treatment behavior.

Prevalence of Latent Tuberculosis Infection among Non-U.S.-Born Persons by Country of Birth - United States, 2012-2017

BACKGROUND

Most tuberculosis (TB) disease in the U.S. is attributed to reactivation of remotely acquired latent TB infection (LTBI) in non-U.S.-born persons who were likely infected with Mycobacterium tuberculosis in their countries of birth. Information on LTBI prevalence by country of birth could help guide local providers and health departments to scale up the LTBI screening and preventive treatment needed to advance progress towards TB elimination.

METHODS

13 805 non-U.S.-born persons at high risk of TB infection or progression to TB disease were screened for LTBI at 16 clinical sites located across the United States with a tuberculin skin test, QuantiFERON ® Gold In-Tube test, and T-SPOT ®.TB test. Bayesian latent class analysis was applied to test results to estimate LTBI prevalence and associated credible intervals (CRI) for each country or world region of birth.

RESULTS

Among the study population, the estimated LTBI prevalence was 31% (95% CRI 26% - 35%). Country-of-birth-level LTBI prevalence estimates were highest for persons born in Haiti, Peru, Somalia, Ethiopia, Vietnam, and Bhutan, ranging from 42%-55%. LTBI prevalence estimates were lowest for persons born in Colombia, Malaysia, and Thailand, ranging from 8%-13%.

CONCLUSIONS

LTBI prevalence in persons born outside the United States varies widely by country. These estimates can help target community outreach efforts to the highest risk groups.

Efficacy of a solar concentrator to Inactivate E. coli and C. perfringens spores in latrine waste in Kenya

Alternative sanitation options are needed for effective waste management in low-income countries where centralized, large-scale waste treatment is not easily achievable. A newly designed solar concentrator technology utilizes solar thermal energy to treat feces contained in drums. This pilot study assessed the efficacy of the new design to inactivate microbes in 13 treatment drums under field conditions in Kenya. Three-quarters of the drums contained <1000 E. coli/g of total solids following 6 h of solar thermal treatment and inactivation of thermotolerant C. perfringens spores ranged from <1.8 to >5.0 log₁₀. Nearly all (94%) samples collected from treatment drums achieved thermophilic temperatures (>50 °C) during the treatment period, however this alone did not ensure samples met the WHO E. coli guideline; higher, sustained thermophilic temperatures tended to be more effective in reaching this guideline. The newly designed solar concentrator was capable of inactivating thermotolerant, environmentally-stable microorganisms as, or possibly more, efficiently than a previous design. Additional data are needed to better characterize how temperature, time, and other parameters affect the ability of the solar concentrator to inactivate microbes in feces.

Acute Flaccid Myelitis in the United States: 2015-2017

BACKGROUND

Acute flaccid myelitis (AFM) is a neurologic condition characterized by flaccid limb weakness. After a large number of reports of AFM in 2014, the Centers for Disease Control and Prevention began standardized surveillance in the United States to characterize the disease burden and explore potential etiologies and epidemiologic associations.

METHODS

Persons meeting the clinical case criteria of acute flaccid limb weakness from January 1, 2015, through December 31, 2017, were classified as confirmed (spinal cord gray matter lesions on MRI) or probable (white blood cell count >5 cells per mm³ in cerebrospinal fluid [CSF]). We describe clinical, radiologic, laboratory, and epidemiologic findings of pediatric patients (age ≤21 years) confirmed with AFM.

RESULTS

Of 305 children reported from 43 states, 193 were confirmed and 25 were probable. Of confirmed patients, 61% were male, with a median age of 6 years (range: 3 months to 21 years; interquartile range: 3 to 10 years). An antecedent respiratory or febrile illness was reported in 79% with a median of 5 days (interquartile range: 2 to 7 days) before limb weakness. Among 153 sterile-site specimens (CSF and serum) submitted to the Centers for Disease Control and Prevention, coxsackievirus A16 was detected in CSF and serum of one case patient and enterovirus D68 was detected in serum of another. Of 167 nonsterile site (respiratory and stool) specimens, 28% tested positive for enterovirus or rhinovirus.

CONCLUSIONS

AFM surveillance data suggest a viral etiology, including enteroviruses. Further study is ongoing to better characterize the etiology, pathogenesis, and risk factors of this rare condition.

Water, Sanitation, and Hygiene Characteristics among HIV-Positive Households Participating in the Global Enteric Multicenter Study in Rural Western Kenya, 2008-2012

Diarrheal illness, a common occurrence among people living with human immunodeficiency virus (PLHIV), is largely preventable through access to safe drinking water quality, sanitation, and hygiene (WASH) facilities. We examined WASH characteristics among households with and without HIV-positive residents enrolled in the Global Enteric Multicenter Study (GEMS) in rural Western Kenya. Using univariable logistic regression, we examined differences between HIV-positive and HIV-negative households in regard to WASH practices. Among HIV-positive households, we explored the relationship between the length of time knowing their HIV status and GEMS enrollment. No statistically significant differences were apparent in the WASH characteristics among HIV-positive and HIV-negative households. However, we found differences in the WASH characteristics among HIV-positive households who were aware of their HIV status ≥ 30 days before enrollment compared with HIV-positive households who found out their status < 30 days before enrollment or thereafter. Significantly more households aware of their HIV-positive status before enrollment reported treating their drinking water (odds ratio [OR] confidence interval [CI]: 2.34 [1.12, 4.86]) and using effective water treatment methods (OR [CI]: 9.6 [3.09, 29.86]), and had better drinking water storage practices. This suggests that within this region of Kenya, HIV programs are effective in promoting the importance of practicing positive WASH-related behaviors among PLHIV.

1723. Mumps Attack Rates Following Administration of a Third Dose of MMR Vaccine to School-Aged Children, Arkansas, 2016–2017

Background

During the 2016–2017 school year, the largest mumps outbreak in the United States since 2006 occurred in Arkansas with nearly 3,000 cases. As part of outbreak response, a third dose of measles–mumps–rubella vaccine (MMR3) was offered at 27 schools with mumps attack rates ≥5 cases/1,000 students. We compared attack rates after vaccination clinics among students who received MMR3 and students with 2 MMR vaccine doses.

Methods

We obtained information on school enrollment and student immunization status from school registries, and mumps case status from Arkansas’s National Electronic Disease Surveillance System database. We included students aged 6–21 years who had previously received ≥2 doses of MMR vaccine. We used Arkansas’s Immunization Information System to identify students who received MMR3.

We included schools with at least 1 mumps case after their vaccination clinic. We calculated mumps attack rates by 2- and 3-dose MMR vaccine recipients. Observation time started 14 days after each clinic to allow for development of an immune response to MMR3, and continued to the end of the 2016–2017 school year. Observation time varied by school as schools held clinics on different dates.

Results

A total of 18 schools (10 elementary, 8 middle/junior high) with 10,275 students who had previously received ≥2 doses of MMR (85% of total enrolled) met inclusion criteria. Median number of students per school was 553. Median student age was 11 years (range, 6–18) and 1,525 students received MMR3. MMR3 uptake varied by school (median, 12%; range, 2–33%; interquartile range, 7–22%). A total of 12 mumps cases occurred among MMR3 recipients and 122 cases among 2-dose recipients. School-specific attack rates ranged from 0 to 23 cases/1,000 students among 3-dose recipients, and 2–41 cases/1,000 students among 2-dose recipients. Mumps attack rates within each school were lower for 3-dose recipients vs. 2-dose recipients in all but one school (P < .05). The differences in attack rates between 2- and 2-dose recipients ranged from −5 to 23 cases/1,000 students (median, 5/1,000).

Conclusion

Mumps attack rates were lower in 3-dose vs. 2-dose MMR vaccine recipients after MMR3 vaccination clinics, supporting a benefit of MMR3 for persons in outbreak settings. Further analysis is needed to determine impact of MMR3 on duration and size of mumps outbreaks.

Disclosures

All authors: No reported disclosures.

Diffusion of Handwashing Knowledge and Water Treatment Practices From Mothers in an Antenatal Hygiene Promotion Program to Nonpregnant Friends and Relatives, Machinga District, Malawi

Access to safe drinking water and improved hygiene are essential for preventing diarrheal diseases in low- and middle-income countries. Integrating water treatment and hygiene products into antenatal clinic care can motivate water treatment and handwashing among pregnant women. Free water hygiene kits (water storage containers, sodium hypochlorite water treatment solution, and soap) and refills of water treatment solution and soap were integrated into antenatal care and delivery services in Machinga District, Malawi, resulting in improved water treatment and hygiene practices in the home and increased maternal health service use. To determine whether water treatment and hygiene practices diffused from maternal health program participants to friends and relatives households in the same communities, we assessed the practices of 106 nonpregnant friends and relatives of these new mothers at baseline and 1-year follow-up. At follow-up, friends and relatives were more likely than at baseline to have water treatment products observable in the home (33.3% vs. 1.2%, p < 0.00001) and detectable free chlorine residual in their water, confirming water treatment (35.7% vs. 1.4%; p < 0.00001). Qualitative data from in-depth interviews also suggested that program participants helped motivate adoption of water treatment and hygiene behaviors among their friends and relatives.

Water treatment and handwashing practices in rural Kenyan health care facilities and households six years after the installation of portable water stations and hygiene training

Many health care facilities (HCFs) and households in low-and-middle-income countries have inadequate access to water for hygiene and consumption. To address these problems, handwashing and drinking water stations were installed in 53 HCFs with prevention-of-mother-to-child-transmission of HIV programs in Kenya in 2005, and hygiene education was provided to health workers and clinic clients. To assess this program, we selected a random sample of 30 HCFs, observed the percentage of handwashing and drinking water stations that were functional and in use, and after that interviewed health providers and clients about hygiene and water treatment. Results indicated that, six years after implementation, 80.0% of HCFs had at least one functional handwashing station and 83.3% had at least one functional drinking water station. In addition, 60% of HCFs had soap at ≥ one handwashing stations, and 23.3% had ≥ one container with detectable free chlorine. Of 299 clients (mothers with ≥ one child under five), 57.2% demonstrated proper water treatment knowledge, 93.3% reported ever using water treatment products, 16.4% had detectable chlorine residual in stored water, and 89.0% demonstrated proper handwashing technique. Six years after program implementation, although most HCFs had water stations and most clients could demonstrate proper handwashing technique, water stored in most clinics and homes was not treated.

Safe Water and Hygiene Integration with Human Immunodeficiency Virus and Antenatal Services: Leveraging Opportunities for Public Health Interventions and Improved Service Uptake

Integrating public health interventions with antenatal clinic (ANC) visits may motivate women to attend ANC, thereby improving maternal and neonatal health, particularly for human immunodeficiency virus (HIV)-infected persons. In 2009, in an integrated ANC/Preventing Mother-to-Child Transmission program, we provided free hygiene kits (safe storage containers, WaterGuard water treatment solution, soap, and oral rehydration salts) to women at their first ANC visit and refills at subsequent visits. To increase fathers' participation, we required partners' presence for women to receive hygiene kits. We surveyed pregnant women at baseline and at 12-month follow-up to assess ANC service utilization, HIV counseling and testing (HCT), test drinking water for residual chlorine, and observe handwashing. We conducted in-depth interviews with pregnant women, partners, and health workers. We enrolled 106 participants; 97 (92%) were found at follow-up. During the program, 99% of pregnant women and their partners received HCT, and 99% mutually disclosed. Fifty-six percent of respondents had ≥ 4 ANC visits and 90% delivered at health facilities. From baseline to follow-up, the percentage of women who knew how to use WaterGuard (23% versus 80%, P < 0.0001), had residual chlorine in stored water (0% versus 73%, P < 0.0001), had confirmed WaterGuard use (0% versus 70%, P < 0.0003), and demonstrated proper handwashing technique (21% versus 64% P < 0.0001) increased. Program participants showed significant improvements in water treatment and hygiene, and high use of ANC services and HCT. This evaluation suggests that integration of hygiene kits, refills, and HIV testing during ANC is feasible and may help improve household hygiene and increase use of health services.

An evaluation of a bucket chlorination campaign during a cholera outbreak in rural Cameroon

Bucket chlorination (where workers stationed at water sources manually add chlorine solution to recipients' water containers during collection) is a common emergency response intervention with little evidence to support its effectiveness in preventing waterborne disease. We evaluated a bucket chlorination intervention implemented during a cholera outbreak by visiting 234 recipients' homes across five intervention villages to conduct an unannounced survey and test stored household drinking water for free chlorine residual (FCR). Overall, 89 per cent of survey respondents reported receiving bucket chlorination, and 80 per cent reported receiving the intervention in the previous 24 hours. However, only 8 per cent of stored household water samples that were reportedly treated only with bucket chlorination in the previous 24 hours had FCR ≥0.2 mg/l. Current international guidelines for bucket chlorination recommend an empirically derived dosage determined 30 minutes after chlorine addition, and do not account for water storage in the home. In controlled investigations we conducted, an initial FCR of 1.5 mg/l resulted in FCR ≥0.5 mg/l for 24 hours in representative household plastic and clay storage containers. To ensure reduction of the risk of waterborne disease, we recommend revising bucket chlorination protocols to recommend a chlorine dosage sufficient to maintain FCR ≥0.2 mg/l for 24 hours in recipients' household stored drinking water.

Recurrence of Guinea Worm Disease in Chad after a 10-Year Absence: Risk Factors for Human Cases Identified in 2010-2011

A decade after reporting its last case of Guinea worm disease (GWD), a waterborne parasitic disease targeted for eradication, Chad reported 20 confirmed human cases from 17 villages-10 cases in 2010 and 10 cases in 2011. In 2012, the first GWD dog infections were diagnosed. We conducted a case-control study during April-May 2012 to identify human transmission risk factors and epidemiologic links. We recruited 19 cases and 45 controls matched by age, sex, time, and location of exposure based on the case patients' periods of infection 10-14 months earlier. Data were analyzed with simple conditional logistic regression models using Firth penalized likelihood methods. Unusually, GWD did not appear to be associated with household primary water sources. Instead, secondary water sources, used outside the village or other nonprimary sources used at home, were risk factors (matched odds ratio = 38.1, 95% confidence interval = 1.6-728.2). This study highlights the changing epidemiology of GWD in Chad-household primary water sources were not identified as risk factors and few epidemiologic links were identified between the handfuls of sporadic cases per year, a trend that continues. Since this investigation, annual dog infections have increased, far surpassing human cases. An aquatic paratenic host is a postulated mode of transmission for both dogs and humans, although fish could not be assessed in this case-control study due to their near-universal consumption. GWD's evolving nature in Chad underscores the continued need for interventions to prevent both waterborne and potential foodborne transmission until the true mechanism is established.

Factors Associated with the Duration of Moderate-to-Severe Diarrhea among Children in Rural Western Kenya Enrolled in the Global Enteric Multicenter Study, 2008-2012

Diarrheal disease is a leading cause of death among young children worldwide. As rates of acute diarrhea (AD; 1-6 days duration) have decreased, persistent diarrhea (PD; > 14 days duration) accounts for a greater proportion of the diarrheal disease burden. We describe factors associated with the duration of moderate-to-severe diarrhea in Kenyan children < 5 years old enrolled in the Global Enteric Multicenter Study. We found 587 (58%) children experienced AD, 360 (35%) had prolonged acute diarrhea (ProAD; 7-13 days duration), and 73 (7%) had PD. We constructed a Cox proportional hazards model to identify factors associated with diarrheal duration. Risk factors independently associated with longer diarrheal duration included infection with Cryptosporidium (hazard ratio [HR]: 0.868, P = 0.035), using an unimproved drinking water source (HR: 0.87, P = 0.035), and being stunted at enrollment (HR: 0.026, P < 0.0001). Diarrheal illness of extended duration appears to be multifactorial; given its association with adverse health and development outcomes, effective strategies should be implemented to reduce the duration and severity of diarrheal illness. Effective treatments for Cryptosporidium should be identified, interventions to improve drinking water are imperative, and nutrition should be improved through exclusive breastfeeding in infants ≤ 6 months and appropriate continued feeding practices for ill children.

Integrating Water Treatment into Antenatal Care: Impact on Use of Maternal Health Services and Household Water Treatment by Mothers-Rural Uganda, 2013

To increase maternal health service use and household water treatment (HWT), free water treatment kits were provided at first antenatal care (ANC) visits and free water treatment sachet refills were provided at follow-up ANC visits, delivery, and postnatal visits in 46 health facilities in rural Uganda. We evaluated the impact by surveying 226 women in the initiative (intervention group) and 207 women who received ANC before the initiative began (comparison group). There was no differences in the percentages of intervention and comparison group women with ≥ 4 ANC visits; however, a higher percentage of intervention group women reported treating their drinking water (31.7% versus 19.7%, P = 0.01), and had free chlorine residual in stored water (13.5% versus 3.4%, P = 0.02) than comparison group women. The intervention did not appear to motivate increased maternal health service use, but demonstrated improvements in HWT.

A Multistate Investigation of Antibiotic-Resistant Salmonella enterica Serotype I 4,[5],12:i:- Infections as Part of an International Outbreak Associated with Frozen Feeder Rodents

While most human Salmonella infections result from exposure to contaminated foods, an estimated 11% of all Salmonella infections are attributed to animal exposures, including both direct animal handling and indirect exposures such as cleaning cages and handling contaminated pet food. This report describes the epidemiologic, environmental and laboratory investigations conducted in the United States as part of the response to an international outbreak of tetracycline-resistant Salmonella enterica serotype I 4,[5],12:i:- infections with over 500 illnesses occurring from 2008 to 2010. This investigation found that illness due to the outbreak strain was significantly associated with exposure to pet reptiles and frozen feeder rodents used as food for pet reptiles. Salmonella isolates indistinguishable from the outbreak strain were isolated from a frozen feeder mice-fed reptile owned by a case patient, as well as from frozen feeder mice and environmental samples collected from a rodent producing facility (Company A). An international voluntary recall of all Company A produced frozen feeder animals sold between May 2009 and July 2010 occurred. Only 13% of cases in our investigation were aware of the association between Salmonella infection and mice or rats. Consumers, the pet industry, healthcare providers and veterinarians need to be aware of the potential health risk posed by feeder rodents, whether live or frozen. Frozen feeder rodent producers, suppliers and distributors should follow the animal food labelling requirements as described in 21 CFR §501.5, and all packages of frozen feeder rodents should include safe handling instructions. Persons should wash their hands thoroughly with soap and water after handling live or frozen feeder rodents, as well as reptiles or anything in the area where the animals live. Continued opportunities exist for public health officials, the pet industry, veterinarians and consumers to work together to prevent salmonellosis associated with pet food, pets and other animals.

Associations between Self-Reported Gastrointestinal Illness and Water System Characteristics in Community Water Supplies in Rural Alabama: A Cross-Sectional Study

BACKGROUND

Community water supplies in underserved areas of the United States may be associated with increased microbiological contamination and risk of gastrointestinal disease. Microbial and health risks affecting such systems have not been systematically characterized outside outbreak investigations. The objective of the study was to evaluate associations between self-reported gastrointestinal illnesses (GII) and household-level water supply characteristics.

METHODS

We conducted a cross-sectional study of water quality, water supply characteristics, and GII in 906 households served by 14 small and medium-sized community water supplies in Alabama's underserved Black Belt region.

RESULTS

We identified associations between respondent-reported water supply interruption and any symptoms of GII (adjusted odds ratio (aOR): 3.01, 95% confidence interval (CI) = 1.65-5.49), as well as low water pressure and any symptoms of GII (aOR: 4.51, 95% CI = 2.55-7.97). We also identified associations between measured water quality such as lack of total chlorine and any symptoms of GII (aOR: 5.73, 95% CI = 1.09-30.1), and detection of E. coli in water samples and increased reports of vomiting (aOR: 5.01, 95% CI = 1.62-15.52) or diarrhea (aOR: 7.75, 95% CI = 2.06-29.15).

CONCLUSIONS

Increased self-reported GII was associated with key water system characteristics as measured at the point of sampling in a cross-sectional study of small and medium water systems in rural Alabama in 2012 suggesting that these water supplies can contribute to endemic gastro-intestinal disease risks. Future studies should focus on further characterizing and managing microbial risks in systems facing similar challenges.

A Cluster Randomized Controlled Evaluation of the Health Impact of a Novel Antimicrobial Hand Towel on the Health of Children Under 2 Years Old in Rural Communities in Nyanza Province, Kenya

To assess the health impact of reusable, antimicrobial hand towels, we conducted a cluster randomized, yearlong field trial. At baseline, we surveyed mothers, and gave four towels plus hygiene education to intervention households and education alone to controls. At biweekly home visits, we asked about infections in children < 2 years old and tested post-handwashing hand rinse samples of 20% of mothers for Escherichia coli. At study's conclusion, we tested 50% of towels for E. coli. Baseline characteristics between 188 intervention and 181 control households were similar. Intervention and control children had similar rates of diarrhea (1.47 versus 1.48, P = 0.99), respiratory infections (1.38 versus 1.48, P = 0.92), skin infections (1.76 versus 1.79, P = 0.81), and subjective fever (2.62 versus 3.40, P = 0.04) per 100 person-visits. Post-handwashing hand contamination was similar; 67% of towels exhibited E. coli contamination. Antimicrobial hand towels became contaminated over time, did not improve hand hygiene, or prevent diarrhea, respiratory infections, or skin infections.

Note: Thermally stable thin-film filters for high-power extreme-ultraviolet applications

We investigated several types of thin-film filters for high intensity work in the extreme-ultraviolet (EUV) spectral range. In our application, with a peak EUV intensity of 2.7 W cm(-2), Ni-mesh-backed Zr filters have a typical lifetime of 20 h, at which point they suffer from pinholes and a 50% loss of transmission. Initial trials with Si filters on Ni meshes resulted in rupture of the filters in less than an hour. A simple thermal calculation showed that the temperature rise in those filters to be about 634 K. A similar calculation indicated that using a finer mesh with thicker wires and made of Cu reduces the temperature increase to about 60 K. We have exposed a Si filter backed by such a mesh for more than 60 h with little loss of transmission and no leaks.

A rapid assessment of drinking water quality in informal settlements after a cholera outbreak in Nairobi, Kenya

Populations living in informal settlements with inadequate water and sanitation infrastructure are at risk of epidemic disease. In 2010, we conducted 398 household surveys in two informal settlements in Nairobi, Kenya with isolated cholera cases. We tested source and household water for free chlorine residual (FCR) and Escherichia coli in approximately 200 households. International guidelines are ≥0.5 mg/L FCR at source, ≥0.2 mg/L at household, and <1 E. coli/100 mL. In these two settlements, 82% and 38% of water sources met FCR guidelines; and 7% and 8% were contaminated with E. coli, respectively. In household stored water, 82% and 35% met FCR guidelines and 11% and 32% were contaminated with E. coli, respectively. Source water FCR≥0.5 mg/L (p=0.003) and reported purchase of a household water treatment product (p=0.002) were associated with increases in likelihood that household stored water had ≥0.2 mg/L FCR, which was associated with a lower likelihood of E. coli contamination (p<0.001). These results challenge the assumption that water quality in informal settlements is universally poor and the route of disease transmission, and highlight that providing centralized water with ≥0.5 mg/L FCR or (if not feasible) household water treatment technologies reduces the risk of waterborne cholera transmission in informal settlements.

Recurrence of Helicobacter pylori infection in Bolivian children and adults after a population-based "screen and treat" strategy

BACKGROUND

Strategies to prevent gastric cancer by decreasing Helicobacter pylori infections in high-prevalence, low-income countries could include a population-based "screen and treat" eradication program.

METHODS

We tested residents of two rural villages for H. pylori infection using urea breath test (UBT), treated infected persons using directly observed therapy (DOT), retested for cure, and retested after 1 year later for H. pylori infection.

FINDINGS

We tested 1,065 (92%) of 1153 residents from two villages in rural Bolivia. Baseline H. pylori prevalence was 80% (95% confidence interval [CI]: 78-84). Age-specific cure rates were similar (≥92%) after DOT. Among those cured, 12% (95% CI: 8-15) had recurrent infection. Age-specific annual H. pylori recurrence rates for combined villages were 20% (95% CI: 10-29) in persons <5 years, 20% (95% CI: 10-29) in 5-9 years, 8% (95% CI: 1-15) in 10-14 years, and 8% (95% CI: 4-12) in persons ≥15 years. Compared with the referent population, those ≥15 years, recurrent infections were significantly more likely in children <5 years (odds ratios [OR] 2.7, 95% CI: 1.2-5.8) and 5-9 years (OR 2.7, 95% CI: 1.4-5.1).

INTERPRETATION

Children <10 years had high H. pylori recurrence rates following a population-based screen and treat program; this H. pylori eradication strategy may not be feasible in high-prevalence, low-income settings.

Improved health among people living with HIV/AIDS who received packages of proven preventive health interventions, Amhara, Ethiopia

In 2009, basic care packages (BCP) containing health products were distributed to HIV-infected persons in Ethiopia who were clients of antiretroviral therapy clinics. To measure health impact, we enrolled clients from an intervention hospital and comparison hospital, and then conducted a baseline survey, and 7 bi-weekly home visits. We enrolled 405 intervention group clients and 344 comparison clients. Intervention clients were more likely than comparison clients to have detectable chlorine in stored water (40% vs. 1%, p<0.001), soap (51% vs. 36%, p<0.001), and a BCP water container (65% vs. 0%, p<0.001) at every home visit. Intervention clients were less likely than comparison clients to report illness (44% vs. 67%, p<0.001) or health facility visits for illness (74% vs. 95%, p<0.001), and had lower median illness scores (1.0 vs. 3.0, p<0.05). Participation in the BCP program appeared to improve reported health outcomes.

Household water treatment uptake during a public health response to a large typhoid fever outbreak in Harare, Zimbabwe

Locally manufactured sodium hypochlorite (chlorine) solution has been sold in Zimbabwe since 2010. During October 1, 2011-April 30, 2012, 4,181 suspected and 52 confirmed cases of typhoid fever were identified in Harare. In response to this outbreak, chlorine tablets were distributed. To evaluate household water treatment uptake, we conducted a survey and water quality testing in 458 randomly selected households in two suburbs most affected by the outbreak. Although 75% of households were aware of chlorine solution and 85% received chlorine tablets, only 18% had reportedly treated stored water and had the recommended protective level of free chlorine residuals. Water treatment was more common among households that reported water treatment before the outbreak, and those that received free tablets during the outbreak (P < 0.01), but was not associated with chlorine solution awareness or use before the outbreak (P > 0.05). Outbreak response did not build on pre-existing prevention programs.

Cholera epidemic associated with consumption of unsafe drinking water and street-vended water--Eastern Freetown, Sierra Leone, 2012

During 2012, Sierra Leone experienced a cholera epidemic with 22,815 reported cases and 296 deaths. We conducted a matched case-control study to assess risk factors, enrolling 49 cases and 98 controls. Stool specimens were analyzed by culture, polymerase chain reaction (PCR), and pulsed-field gel electrophoresis (PFGE). Conditional logistic regression found that consuming unsafe water (matched odds ratio [mOR]: 3.4; 95% confidence interval [CI]: 1.1, 11.0), street-vended water (mOR: 9.4; 95% CI: 2.0, 43.7), and crab (mOR: 3.3; 95% CI: 1.03, 10.6) were significant risk factors for cholera infection. Of 30 stool specimens, 13 (43%) showed PCR evidence of toxigenic Vibrio cholerae O1. Six specimens yielded isolates of V. cholerae O1, El Tor; PFGE identified a pattern previously observed in seven countries. We recommended ensuring the quality of improved water sources, promoting household chlorination, and educating street vendors on water handling practices.

Evaluation of a rapid cholera response activity--Nyanza Province, Kenya, 2008

BACKGROUND

In response to recurrent cholera outbreaks in Nyanza Province, Kenya, a local nongovernmental organization assisted the Ministry of Health by providing cholera education activities to some cholera-affected communities. We evaluated the impact on cholera prevention knowledge and practices.

METHODS

In November-December 2008, we conducted a cross-sectional household survey and tested stored water for chlorine in 6 cholera-affected enumeration areas (intervention-EAs) where response activities had occurred between March-September 2008, and 6 comparison-EAs with no known reports of cholera outbreaks or response activities.

RESULTS

We enrolled 358 individuals from intervention-EAs and 365 from comparison-EAs. Overall, >80% knew cholera symptoms and over 60% knew that water treatment prevented diarrhea; <20% had chlorine residual in stored water. More intervention-EA respondents than comparison-EA respondents recalled a cholera outbreak in their community (52% vs 19%, P < .0001), and of those, 51% versus 39%, respectively, had attended a cholera response event. Detectable chlorine residuals in stored water were found in a higher percentage of intervention-EA and comparison-EA event attendees (21% and 25%, respectively) than nonattendees (17% and 8%, respectively).

CONCLUSIONS

There was a gap between knowledge and practice of water treatment as a cholera preventive measure. Cholera event attendance may have modestly motivated increased household water treatment.

A national cholera epidemic with high case fatality rates--Kenya 2009

BACKGROUND

Cholera remains endemic in sub-Saharan Africa. We characterized the 2009 cholera outbreaks in Kenya and evaluated the response.

METHODS

We analyzed surveillance data and estimated case fatality rates (CFRs). Households in 2 districts, East Pokot (224 cases; CFR = 11.7%) and Turkana South (1493 cases; CFR = 1.0%), were surveyed. We randomly selected 15 villages and 8 households per village in each district. Healthcare workers at 27 health facilities (HFs) were surveyed in both districts.

RESULTS

In 2009, cholera outbreaks caused a reported 11 425 cases and 264 deaths in Kenya. Data were available from 44 districts for 6893 (60%) cases. District CFRs ranged from 0% to 14.3%. Surveyed household respondents (n = 240) were aware of cholera (97.5%) and oral rehydration solution (ORS) (87.9%). Cholera deaths were reported more frequently from East Pokot (n = 120) than Turkana South (n = 120) households (20.7% vs. 12.3%). The average travel time to a HF was 31 hours in East Pokot compared with 2 hours in Turkana South. Fewer respondents in East Pokot (9.8%) than in Turkana South (33.9%) stated that ORS was available in their village. ORS or intravenous fluid shortages occurred in 20 (76.9%) surveyed HFs.

CONCLUSIONS

High CFRs in Kenya are related to healthcare access disparities, including availability of rehydration supplies.

Attribution of foodborne illnesses, hospitalizations, and deaths to food commodities by using outbreak data, United States, 1998-2008

Each year, >9 million foodborne illnesses are estimated to be caused by major pathogens acquired in the United States. Preventing these illnesses is challenging because resources are limited and linking individual illnesses to a particular food is rarely possible except during an outbreak. We developed a method of attributing illnesses to food commodities that uses data from outbreaks associated with both simple and complex foods. Using data from outbreak-associated illnesses for 1998–2008, we estimated annual US foodborne illnesses, hospitalizations, and deaths attributable to each of 17 food commodities. We attributed 46% of illnesses to produce and found that more deaths were attributed to poultry than to any other commodity. To the extent that these estimates reflect the commodities causing all foodborne illness, they indicate that efforts are particularly needed to prevent contamination of produce and poultry. Methods to incorporate data from other sources are needed to improve attribution estimates for some commodities and agents.

Association between intensive handwashing promotion and child development in Karachi, Pakistan: a cluster randomized controlled trial

OBJECTIVE

To evaluate associations between handwashing promotion and child growth and development.

DESIGN

Cluster randomized controlled trial.

SETTING

Informal settlements in Karachi, Pakistan.

PARTICIPANTS

A total of 461 children who were enrolled in a trial of household-level handwashing promotion in 2003 and were younger than 8 years at reassessment in 2009.

INTERVENTIONS

In 2003, neighborhoods were randomized to control (n = 9), handwashing promotion (n = 9), or handwashing promotion and drinking water treatment (n = 10); intervention households received free soap and weekly handwashing promotion for 9 months.

MAIN OUTCOME MEASURES

Anthropometrics and developmental quotients measured with the Battelle Developmental Inventory II at 5 to 7 years of age.

RESULTS

Overall, 24.9% (95% CI, 20.0%-30.6%) and 22.1% (95% CI, 18.0%-26.8%) of children had z scores that were more than 2 SDs below the expected z scores for height and body mass index for age, respectively; anthropometrics did not differ significantly across study groups. Global developmental quotients averaged 104.4 (95% CI, 101.9-107.0) among intervention children and 98.3 (95% CI, 93.1-103.4) among control children (P = .04). Differences of similar magnitude were measured across adaptive, personal-social, communication, cognitive, and motor domains.

CONCLUSIONS

Although growth was similar across groups, children randomized to the handwashing promotion during their first 30 months of age attained global developmental quotients 0.4 SDs greater than those of control children at 5 to 7 years of age. These gains are comparable to those of at-risk children enrolled in publicly funded preschools in the United States and suggest that handwashing promotion could improve child well-being and societal productivity.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01538953.

Sustained improvements in handwashing indicators more than 5 years after a cluster-randomised, community-based trial of handwashing promotion in Karachi, Pakistan

OBJECTIVE

To evaluate handwashing behaviour 5 years after a handwashing intervention in Karachi, Pakistan.

METHODS

In 2003, we randomised neighbourhoods to control, handwashing promotion, or handwashing promotion and water treatment. Intervention households were given soap +/- water treatment product and weekly handwashing education for 9 months. In 2009, we re-enrolled 461 households from the three study groups: control (160), handwashing (141), and handwashing + water treatment (160) and assessed hygiene-related outcomes, accounting for clustering.

RESULTS

Intervention households were 3.4 times more likely than controls to have soap at their handwashing stations during the study visit [293/301 (97%) vs. 45/159 (28%), P < 0.0001]. While nearly all households reported handwashing after toileting, intervention households more commonly reported handwashing before cooking [relative risk (RR) 1.2 (95% confidence interval (CI) 1.0-1.4)] and before meals [RR 1.7 (95% CI, 1.3-2.1)]. Control households cited a mean of 3.87 occasions for washing hands; handwashing households, 4.74 occasions; and handwashing + water treatment households, 4.78 occasions (P < 0.0001). Households reported purchasing a mean of 0.65 (control), 0.91 (handwashing) and 1.1 (handwashing + water treatment) bars of soap/person/month (P < 0.0001).

CONCLUSIONS

Five years after receiving handwashing promotion, intervention households were more likely to have soap at the household handwashing station, know key times to wash hands and report purchasing more soap than controls, suggesting habituation of improved handwashing practices in this population. Intensive handwashing promotion may be an effective strategy for habituating hygiene behaviours and improving health.

Long-term impact of integration of household water treatment and hygiene promotion with antenatal services on maternal water treatment and hygiene practices in Malawi

A clinic-based program to integrate antenatal services with distribution of hygiene kits including safe water storage containers, water treatment solution (brand name WaterGuard), soap, and hygiene education, was implemented in Malawi in 2007 and evaluated in 2010. We surveyed 389 participants at baseline in 2007, and found and surveyed 232 (60%) participants to assess water treatment, test stored drinking water for residual chlorine (an objective measure of treatment), and observe handwashing technique at follow-up in 2010. Program participants were more likely to know correct water treatment procedures (67% versus 36%; P < 0.0001), treat drinking water with WaterGuard (24% versus 2%; P < 0.0001), purchase and use WaterGuard (21% versus 1%; P < 0.001), and demonstrate correct handwashing technique (50% versus 21%; P < 0.001) at the three-year follow-up survey than at baseline. This antenatal-clinic-based program may have contributed to sustained water treatment and proper handwashing technique among program participants.

Impact of locally-produced, ceramic cookstoves on respiratory disease in children in rural western Kenya

Household air pollution is a risk factor for pneumonia, the leading cause of death among children < 5 years of age. From 2008 to 2010, a Kenyan organization sold ≈ 2,500 ceramic cookstoves (upesi jiko) that produce less visible household smoke than 3-stone firepits. During a year-long observational study, we made 25 biweekly visits to 200 homes to determine stove use and observe signs of acute respiratory infection in children < 3 years of age. Reported stove use included 3-stone firepit only (81.8%), upesi jiko only (15.7%), and both (2.3%). Lower, but not statistically significant, percentages of children in upesi jiko-using households than 3-stone firepit-using households had observed cough (1.3% versus 2.9%, rate ratio [RR] 0.48, 95% confidence interval [CI]: 0.22-1.03), pneumonia (0.9% versus 1.7%, RR 0.60, 95% CI: 0.24-1.48), and severe pneumonia (0.3% versus 0.6%, RR 0.66, 95% CI: 0.17-2.62). Upesi jiko use did not result in significantly lower pneumonia rates. Further research on the health impact of improved cookstoves is warranted.

Nonpasteurized dairy products, disease outbreaks, and state laws-United States, 1993-2006

Most dairy-associated outbreaks occurred in states that permitted sale of these products.

Risk factors early in the 2010 cholera epidemic, Haiti

During the early weeks of the cholera outbreak that began in Haiti in October 2010, we conducted a case-control study to identify risk factors. Drinking treated water was strongly protective against illness. Our results highlight the effectiveness of safe water in cholera control.

Ground beef consumption patterns in the United States, FoodNet, 2006 through 2007

Infection resulting from foodborne pathogens, including Escherichia coli O157:H7, is often associated with consumption of raw or undercooked ground beef. However, little is known about the frequency of ground beef consumption in the general population. The objective of this study was to describe patterns of self-reported ground beef and pink ground beef consumption using data from the 2006 through 2007 FoodNet Population Survey. From 1 July 2006 until 30 June 2007, residents of 10 FoodNet sites were contacted by telephone and asked about foods consumed within the previous week. The survey included questions regarding consumption of ground beef patties both inside and outside the home, the consumption of pink ground beef patties and other types of ground beef inside the home, and consumption of ground beef outside the home. Of 8,543 survey respondents, 75.3% reported consuming some type of ground beef in the home. Of respondents who ate ground beef patties in the home, 18.0% reported consuming pink ground beef. Consumption of ground beef was reported most frequently among men, persons with incomes from $40,000 to $75,000 per year, and persons with a high school or college education. Ground beef consumption was least often reported in adults ≥65 years of age. Men and persons with a graduate level education most commonly reported eating pink ground beef in the home. Reported consumption of ground beef and pink ground beef did not differ by season. Ground beef is a frequently consumed food item in the United States, and rates of consumption of pink ground beef have changed little since previous studies. The high rate of consumption of beef that has not been cooked sufficiently to kill pathogens makes pasteurization of ground beef an important consideration, especially for those individuals at high risk of complications from foodborne illnesses such as hemolytic uremic syndrome.

Epidemic cholera in a crowded urban environment, Port-au-Prince, Haiti

We conducted a case-control study to investigate factors associated with epidemic cholera. Water treatment and handwashing may have been protective, highlighting the need for personal hygiene for cholera prevention in contaminated urban environments. We also found a diverse diet, a possible proxy for improved nutrition, was protective against cholera.

Multistate outbreak of Escherichia coli O157:H7 infections associated with a national fast-food chain, 2006: a study incorporating epidemiological and food source traceback results

A multistate outbreak of Escherichia coli O157:H7 infections occurred in the USA in November-December 2006 in patrons of restaurant chain A. We identified 77 cases with chain A exposure in four states - Delaware, New Jersey, New York, and Pennsylvania. Fifty-one (66%) patients were hospitalized, and seven (9%) developed haemolytic uraemic syndrome; none died. In a matched analysis controlling for age in 31 cases and 55 controls, illness was associated with consumption of shredded iceberg lettuce [matched odds ratio (mOR) 8·0, 95% confidence interval (CI) 1·1-348·1] and shredded cheddar cheese (mOR 6·2, CI 1·7-33·7). Lettuce, an uncooked ingredient, was more commonly consumed (97% of patients) than cheddar cheese (84%) and a single source supplied all affected restaurants. A single source of cheese could not explain the regional distribution of outbreak cases. The outbreak highlights challenges in conducting rapid multistate investigations and the importance of incorporating epidemiological study results with other investigative findings.

Human Salmonella infections linked to contaminated dry dog and cat food, 2006-2008

OBJECTIVE

Human Salmonella infections associated with dry pet food have not been previously reported. We investigated such an outbreak of Salmonella Schwarzengrund and primarily affecting young children.

PATIENTS AND METHODS

Two multistate case-control studies were conducted to determine the source and mode of infections among case-patients with the outbreak strain. Study 1 evaluated household exposures to animals and pet foods, and study 2 examined risk factors for transmission among infant case-patients. Environmental investigations were conducted.

RESULTS

Seventy-nine case-patients in 21 states were identified; 48% were children aged 2 years or younger. Case-households were significantly more likely than control households to report dog contact (matched odds ratio [mOR]: 3.6) and to have recently purchased manufacturer X brands of dry pet food (mOR: 6.9). Illness among infant case-patients was significantly associated with feeding pets in the kitchen (OR: 4.4). The outbreak strain was isolated from opened bags of dry dog food produced at plant X, fecal specimens from dogs that ate manufacturer X dry dog food, and an environmental sample and unopened bags of dog and cat foods from plant X. More than 23 000 tons of pet foods were recalled. After additional outbreak-linked illnesses were identified during 2008, the company recalled 105 brands of dry pet food and permanently closed plant X.

CONCLUSIONS

Dry dog and cat foods manufactured at plant X were linked to human illness for a 3-year period. This outbreak highlights the importance of proper handling and storage of pet foods in the home to prevent human illness, especially among young children.

Epidemiology of seafood-associated infections in the United States

Seafood is part of a healthful diet, but seafood consumption is not risk-free. Seafood is responsible for an important proportion of food-borne illnesses and outbreaks in the United States. Seafood-associated infections are caused by a variety of bacteria, viruses, and parasites; this diverse group of pathogens results in a wide variety of clinical syndromes, each with its own epidemiology. Some seafood commodities are inherently more risky than others, owing to many factors, including the nature of the environment from which they come, their mode of feeding, the season during which they are harvested, and how they are prepared and served. Prevention of seafood-associated infections requires an understanding not only of the etiologic agents and seafood commodities associated with illness but also of the mechanisms of contamination that are amenable to control. Defining these problem areas, which relies on surveillance of seafood-associated infections through outbreak and case reporting, can lead to targeted research and help to guide control efforts. Coordinated efforts are necessary to further reduce the risk of seafood-associated illnesses. Continued surveillance will be important to assess the effectiveness of current and future prevention strategies.

Recipes for foodborne outbreaks: a scheme for categorizing and grouping implicated foods

BACKGROUND

To better understand the sources of foodborne illness, we propose a scheme for categorizing foods implicated in investigations of outbreaks of foodborne diseases. Because nearly 2000 foods have been reported as causing outbreaks in the United States, foods must be grouped for meaningful analyses.

METHODS

We defined a hierarchy of 17 mutually exclusive food commodities. We defined the following three commodity groups from which nearly all food is derived: aquatic animals, land animals, and plants. We defined three commodities in aquatic animals, six in land animals, and eight in plants. We considered each food as a set of ingredients composed of one or more commodities. We defined a simple food as one made of ingredients that are all in one commodity and a complex food as one containing ingredients in more than one commodity. We determined likely ingredients using a panel of epidemiologists and a web-based search process.

RESULTS

We assigned 1709 (95%) of the 1794 foods implicated in outbreaks of foodborne diseases reported to Centers for Disease Control and Prevention from 1973 to 2006. Of those, 987 (57%) were simple foods and 722 (43%) were complex foods.

DISCUSSION

This categorization may serve as an input for modeling the attribution of human illness to specific food commodities and could be used by policy makers, health officials, regulatory agencies, and consumer groups to evaluate the contribution of various food commodities to illness.

Attributing the human disease burden of foodborne infections to specific sources

Foodborne diseases are an important cause of human illness worldwide. Humans acquire these infections from a variety of sources and routes of transmission. Many efforts have been made in the last decades to prevent and control foodborne diseases, particularly foodborne zoonoses. However, information on the impact of these interventions is limited. To identify and prioritize successful food safety interventions, it is important to attribute the burden of human illness to the specific sources. Defining scientific concepts and harmonizing terminology for "source attribution" is essential for understanding and improving attribution methodologies and for sharing knowledge within the scientific community. We propose harmonized nomenclature, and describe the various approaches for human illness source attribution and their usefulness to address specific public health questions.

Identifying risk factors for underimmunization by using geocoding matched to census tracts: a statewide assessment of children in Hawaii

OBJECTIVE

Obtaining childhood immunization coverage data for small geographic areas is difficult and resource-intensive, especially in the absence of comprehensive immunization registries. To identify factors that are associated with delayed immunization, we collected school-entry immunization records statewide and used geocoding to link to publicly available census tract sociodemographic data.

METHODS

Immunization records were reviewed for children who were enrolled in all public and private school kindergarten programs in Hawaii in the 2002-2003 school year; immunization status at the time of the second birthday was determined. The main outcome variable was up-to-date status for the 4:3:1:3:3 vaccination series (4 doses of diphtheria-tetanus-pertussis, 3 doses of polio, 1 dose of measles-mumps-rubella, 3 doses of Haemophilus influenzae type b, and 3 doses of hepatitis B vaccines). Children's home addresses were geocoded to census tracts; coverage rates by tract were mapped, and sociodemographic data from Census 2000 files were used to identify factors that were associated with delays in immunization.

RESULTS

Records were obtained for 15,275 of 15,594 children registered in Hawaii kindergartens. Overall, 78% had completed their 4:3:1:3:3 series by their second birthday. Risk factors for delayed immunization included delayed immunization at 3 months of age, living in Maui County, living in a neighborhood where a low proportion of adults had postsecondary education, and living in a neighborhood where a high proportion of households spoke a language other than English at home. The majority (80%) of underimmunized children would have required only 1 additional visit to bring them up-to-date.

CONCLUSIONS

Retrospective review of kindergarten-entry immunization data revealed geographic areas with lower immunization coverage, and geocoding to census tracts identified associated sociodemographic risk factors. This is a practical method for state or city health departments to identify pockets of need and to direct resources appropriately.