Associations of household factors, hot water temperature, and chlorine residual with Legionella occurrence in single-family homes in New Jersey

Only 4 % of reported Legionnaires' disease (LD) cases are outbreak-associated and the remaining 96 % are sporadic, for which no known source of Legionella is identified. Although outbreaks of LD are linked to cooling towers, decorative fountains, spas and hot tubs, and other sources, the drivers of sporadic LD are less known. Residential premise plumbing is likely an important source of aerosol exposure and there are unique features of premise plumbing which could lead to proliferation of Legionella. A sampling study of Legionella in single-family homes was undertaken in NJ from 2020 to 2021 which included a household characteristic survey and collection of hot water temperature and chlorine residual during sampling. A total of 94 homeowners residing in owner-occupied, single-family units with individual hot water systems were recruited to participate through two mechanisms (1) Legionnaire's disease case-patients and (2) non-case volunteers from each NJ county. Among the 94 single-family homes sampled, 15 % had least one sample positive for Legionella by culture and 57 % had at least one sample with detection of Legionella DNA markers by PCR. Chlorine residual, hot water temperature, and season were independently associated with increased detection of Legionella in home water samples. There was limited or inconsistent evidence of the role of household characteristic factors in Legionella detection. This study identified season, insufficient chlorine residual and hot water temperature as risk factors for Legionella detection in single-family homes. Findings from this work can promote additional partnership between public health and water utilities in improving chlorine residuals in residential communities and educating homeowners on best practices for home water management.

Legionella monitoring results by water quality characteristics in a large public water system

Legionella, the causative agent of Legionnaires' disease, is an emerging concern for water utilities. Passaic Valley Water Commission (PVWC) is a public drinking water supplier, which provides treated surface water to approximately 800,000 customers in New Jersey. To evaluate the occurrence of Legionella in the PVWC distribution system, swab, first draw, and flushed cold water samples were collected from total coliform sites (n = 58) during a summer and winter sampling event. Endpoint PCR detection methods were combined with culture for Legionella detection. Among 58 total coliform sites during the summer, 17.2% (10/58) of first draw samples were positive for 16S and mip Legionella DNA markers and 15.5% (9/58) in flushed samples. Across both summer and winter sampling, a total of four out of 58 sites had low-level culture detection of Legionella spp. (0.5-1.6 CFU/mL) among first draw samples. Only one site had both a first and flush draw detection (8.5 CFU/mL and 1.1 CFU/mL) for an estimated culture detection frequency of 0% in the summer and 1.7% in the winter among flushed draw samples. No L. pneumophila was detected by culture. Legionella DNA detection was significantly greater in the summer than in the winter, and detection was greater in samples collected from areas treated with phosphate. No statistical difference was found between first draw and flush sample detection. Total organic carbon, copper, and nitrate were significantly associated with Legionella DNA detection.

Targeted education and outreach to neighbors of homes with high gross alpha radioactivity in domestic well water

Gross alpha, a measurement of radioactivity in drinking water, is the most frequent laboratory test to exceed primary drinking water standards among wells tested under the New Jersey Private Well Testing Act (NJ PWTA). Certain geological factors prevalent in New Jersey (NJ) are primarily responsible for the presence of radioactivity in private well drinking water and thus, many of the estimated one million private well users in NJ may be at-risk of water contamination from naturally occurring radionuclides. Neighbor-based private well outreach methodology was utilized to identify high risk wells in both northern and southern NJ regions and offer free private well testing for radionuclides. Previously tested wells with gross alpha exceeding or equal to 3.7 becquerels per liter (Bq L^-1; 100 pCi/L) were selected (n = 49) to identify neighbors (n = 406) within 152.4 m (500 feet). Invitation letters were mailed to selected neighbors and some of the previously tested high wells (n = 12) offering free water sampling for the following parameters: gross alpha (48-hour rapid test), combined radium-226 and radium-228 (Ra-226 + Ra-228), uranium-238 (U-238), radon-222 (Rn-222) and iron. Overall, 70 neighbors and 5 high PWTA wells participated in this free water testing opportunity. For neighboring wells, gross alpha results revealed 47 (67.1%) wells exceeding the gross alpha MCL of 0.555 Bq L^-1 (15 pCi/L) mainly due to radium activity in the raw/untreated water. Of those with water treatment (n = 62), 12 (19.4%) treated water samples exceeded the gross alpha MCL. Targeting neighbors of known highly radioactive wells for private well testing is an effective public health outreach method and can also provide useful insight of regional contaminant variations.

Targeted Private Well Outreach Following a Change in Drinking Water Standard: Arsenic and the New Jersey Private Well Testing Act

CONTEXT

When the New Jersey Private Well Testing Act (PWTA) became effective in 2002, the maximum contaminant level (MCL) for arsenic in the United States was 50 μg/L. In 2006, the federal and New Jersey MCLs were lowered to 10 μg/L and 5 μg/L, respectively.

OBJECTIVE

To notify and provide free arsenic water testing for homeowners who had a PWTA arsenic result that passed for the MCL in 2006 or earlier but would exceed under the more health protective MCL enacted in 2006, which is still in effect as of this publication date.

DESIGN

About 1200 homeowners with PWTA arsenic results between 5 μg/L and 50 μg/L were offered free arsenic water testing. More than 400 homeowners requested tests and 292 returned samples.

SETTING

New Jersey, United States.

PARTICIPANTS

Homeowners with a passing PWTA arsenic result before 2006 that would have failed under the New Jersey arsenic MCL enacted in 2006.

MAIN OUTCOME MEASURES

Return rate of testing kits; number of tests exceeding arsenic MCL; and participant survey results.

RESULTS

Untreated well water samples (n = 279) were collected and 62.4% exceeded the New Jersey MCL. Treated well water samples (n = 102) were collected and 11.8% exceeded the current New Jersey MCL. In all, about 40% of drinking water samples from the tap, including those with or with no arsenic treatment, exceeded the New Jersey MCL. A survey of participants (n = 69) found that although many (67%) respondents reported that they at least had some idea that wells in their area are vulnerable to naturally occurring contaminants, such as arsenic, many (68%) reported that they had little or no idea that the New Jersey arsenic MCL had been lowered from 50 μg/L to 5 μg/L in 2006.

CONCLUSIONS

This effort further illuminates the necessity and significance of public health outreach for private well water users, especially after drinking water standards change.

Evaluating the impact of free private well testing outreach on participants' private well stewardship in New Jersey

Over 1 million people in New Jersey (NJ) are estimated to receive drinking water from private wells. The most commonly detected contaminants in NJ private well water are naturally occurring arsenic and gross alpha (8.3 and 10.9%, respectively). Between 2015 and 2018, three free and voluntary private well testing events tested a total of 571 at-risk wells and 226 (40%) were identified as having one or more contaminants exceeding drinking water standards. Participants were invited to complete a survey to evaluate household characteristics, participant experience, and private well stewardship behavior patterns. Of 529 delivered surveys, 211 (40%) participants completed surveys. Among respondents, 63% reported plans to test their private wells in the future. Among failed wells, 45% of households reported performing mitigative action in response to the event, either through the installation of water treatment system or switching to bottled water. The survey evaluation identified previous knowledge of well contamination risks and discussing test results with a third party as important factors for promoting self-reported stewardship behavior. The evaluation provides guidance for outreach organizers to develop effective testing events and further considers the private well owners' experience of the outreach events to identify information for 'best practices' and improvements of future programs.

A review of legionnaires' disease and public water systems - Scientific considerations, uncertainties and recommendations

Legionella is an opportunistic premise plumbing pathogen and causative agent of a severe pneumonia called Legionnaires' Disease (LD). Cases of LD have been on the rise in the U.S. and globally. Although Legionella was first identified 45 years ago, it remains an 'emerging pathogen." Legionella is part of the normal ecology of a public water system and is frequently detected in regulatory-compliant drinking water. Drinking water utilities, regulators and public health alike are increasingly required to have a productive understanding of the evolving issues and complex discussions of the contribution of the public water utility to Legionella exposure and LD risk. This review provides a brief overview of scientific considerations important for understanding this complex topic, a review of findings from investigations of public water and LD, including data gaps, and recommendations for professionals interested in investigating public water utilities. Although the current literature is inconclusive in identifying a public water utility as a sole source of an LD outbreak, the evidence is clear that minimizing growth of Legionella in public water utilities through proper maintenance and sustained disinfectant residuals, throughout all sections of the water utility, will lead to a less conducive environment for growth of the bacteria in the system and the buildings they serve.

Characteristics and Behaviors Among a Representative Sample of New Jersey Adults Practicing Environmental Risk-Reduction Behaviors

CONTEXT

Environmental exposure to groundwater contamination from agricultural runoff, chemical pollution, or geology and indoor air hazards from misuse of consumer products or naturally occurring radon contributes to adverse health outcomes. Individuals can reduce exposure to environmental hazards by practicing risk-reduction behaviors.

OBJECTIVE

To characterize the demographic and behavioral characteristics of the population practicing environmental risk-reduction behaviors in order to identify gaps in current prevention outreach efforts.

DESIGN

The New Jersey Behavioral Risk Factor Survey captures data on self-reported environmental risk-reduction behaviors and health-promoting behaviors (cancer screenings, vaccinations, smoking). To account for complex survey data, weighted analyses were performed in SAS v9.4.

SETTING

New Jersey, 2014-2015.

PARTICIPANTS

The New Jersey Behavioral Risk Factor Survey is an ongoing telephone health survey of NJ residents. About 1000 NJ residents are selected randomly each month to derive statewide representative prevalence estimates.

MAIN OUTCOME MEASURES

Self-reported private well testing, radon screening, and carbon monoxide (CO) detector ownership.

RESULTS

Statewide prevalence of the practice of environmental risk-reduction practices includes 56.6% for private well testing, 44.3% for radon screening, and 86.1% for CO detector ownership. A larger percentage of individuals who are white or Asian, college-educated, earn more than $50 000, and own their homes reported CO detector ownership and radon screening. Age was the only demographic factor associated with private well testing. Screening for radon and CO detector ownership was positively associated with receiving an influenza shot, colonoscopy, aerobic exercise, and positive self-reported health and not smoking.

CONCLUSIONS

There is a need to improve rates of environmental risk-reduction behaviors and reduce disparities in the practice of these behaviors through efforts to increase awareness. Public health officials should target outreach to specific populations that do not practice risk-reduction behaviors.

Improve private well testing outreach efficiency by targeting households based on proximity to a high arsenic well

Research into precautionary action suggests outreach with personally-relevant risk information may help overcome optimistic biases, which have been shown to impede voluntary testing for arsenic by at-risk private well households. Since 2002, New Jersey's Private Well Testing Act (PWTA) has required testing for arsenic during real estate transactions. The PWTA database of over 35,000 geocoded well arsenic tests offers a unique opportunity to evaluate the efficacy of targeted outreach to neighbors living in proximity to a known high arsenic well with variable risk messaging to motivate testing. In this study, residents of properties (n = 1743) located within 500 ft and between 500 and 1000 ft of a known high arsenic well (>5 μg/L, New Jersey's drinking water arsenic standard) were mailed a notice of the high arsenic result in their neighborhood and offered a free water test. Overall 274 households (16%) requested a test kit and 230 (13%) ultimately submitted a water sample; with significantly higher participation rates among those told their neighborhood well had an arsenic concentration "over 5 times higher" than the standard, compared to those told the concentration was "above." Overall, 25% of wells tested (n = 230), and 47% (n = 66) of non-treated wells located within 500 ft of a well with >25 μg/L arsenic, exceeded the standard for arsenic. Both the arsenic concentration and distance to the neighboring well were significant predictors of exceedance. Given the high proportion of previously untested wells (70%) and their owners' lack of awareness of arsenic in their area (80%), this targeting approach succeeded not only in identifying a much higher proportion of at risk wells than blanket testing by town or county, but also in motivating testing among households unreached by prior awareness-raising activities. In conclusion, geographically and personally-relevant risk targeted messaging and outreach are both efficient and effective.

Drinking water lead and socioeconomic factors as predictors of blood lead levels in New Jersey's children between two time periods

As blood lead levels have decreased over time, the relative contributions of alternative lead sources warrant further examination. Much attention has been paid to the relative contribution of lead in drinking water, particularly after the discovery of contaminated drinking water in Flint, Michigan which has also renewed interest in the persistent socioeconomic and racial disparities in children's exposure to lead. As the environmental sources of lead exposure are shifting in importance over time, we decided to examine how demographic, socioeconomic, and environmental factors may confound or interact with each other, and whether these relationships have changed over time. The study population included all New Jersey resident children aged 6-26 months with at least one blood lead specimen collected between 2000 and 2004 (n = 288,758) or 2010 and 2014 (n = 326,530). Reported 90th percentile water lead data (in parts per billion) was summarized annually for each water system statewide. Children's blood lead levels have decreased over time from a statewide geometric mean of 2.47 µg/dL (95% CI 2.46, 2.48) between 2000 and 2004 to 1.57 µg/dL (95% CI 1.57, 1.57) between 2010 and 2014. Individual-level factors of child's age and season of blood draw and area-based measures of race, older housing, and poverty were predictors of children's blood lead levels. Conclusions regarding area-based measure of Hispanic ethnicity are limited and require further research. The narrow range and low levels of area-based lead concentrations in drinking water limits the ability to detect associations with blood lead levels. Racial disparities in blood lead continue to persist but economic disparities may be narrowing as blood lead concentrations continue to decline.

Health protective behavior following required arsenic testing under the New Jersey Private Well Testing Act

Exposure to naturally occurring arsenic in groundwater is a public health concern, particularly for households served by unregulated private wells. At present, one of the greatest barriers to exposure reduction is a lack of private well testing due to difficulties in motivating individual private well owners to take protective actions. Policy and regulations requiring testing could make a significant contribution towards universal screening of private well water and arsenic exposure reduction. New Jersey's Private Well Testing Act (PWTA) requires tests for arsenic during real estate transactions; however, the regulations do not require remedial action when maximum contaminant levels (MCLs) are exceeded. A follow-up survey sent to residents of homes where arsenic was measured above the state MCL in PWTA-required tests reveals a range of mitigation behavior among respondents (n = 486), from taking no action to reduce exposure (28%), to reporting both treatment use and appropriate maintenance and monitoring behavior (15%). Although 86% of respondents recall their well was tested during their real estate transaction, only 60% report their test showed an arsenic problem. Treatment systems are used by 63% of households, although half were installed by a previous owner. Among those treating their water (n = 308), 57% report that maintenance is being performed as recommended, although only 31% have tested the treated water within the past year. Perceived susceptibility and perceived barriers are strong predictors of mitigation action. Among those treating for arsenic, perceived severity is associated with recent monitoring, and level of commitment is associated with proper maintenance. Mention of a treatment service agreement is a strong predictor of appropriate monitoring and maintenance behavior, while treatment installed by a previous owner is less likely to be maintained. Though the PWTA requires that wells be tested, this study finds that not all current well owners are aware the test occurred or understood the implications of their arsenic results. Among those that have treatment installed to remove arsenic, poor monitoring and maintenance behaviors threaten to undermine intentions to reduce exposure. Findings suggest that additional effort, resources, and support to ensure home buyers pay attention to, understand, and act on test results at the time they are performed may help improve management of arsenic water problems over the long term and thus the PWTA's public health impact.

Key scientific issues in developing drinking water guidelines for perfluoroalkyl acids: Contaminants of emerging concern

Perfluoroalkyl acids (PFAAs), a group of synthetic organic chemicals with industrial and commercial uses, are of current concern because of increasing awareness of their presence in drinking water and their potential to cause adverse health effects. PFAAs are distinctive among persistent, bioaccumulative, and toxic (PBT) contaminants because they are water soluble and do not break down in the environment. This commentary discusses scientific and risk assessment issues that impact the development of drinking water guidelines for PFAAs, including choice of toxicological endpoints, uncertainty factors, and exposure assumptions used as their basis. In experimental animals, PFAAs cause toxicity to the liver, the immune, endocrine, and male reproductive systems, and the developing fetus and neonate. Low-dose effects include persistent delays in mammary gland development (perfluorooctanoic acid; PFOA) and suppression of immune response (perfluorooctane sulfonate; PFOS). In humans, even general population level exposures to some PFAAs are associated with health effects such as increased serum lipids and liver enzymes, decreased vaccine response, and decreased birth weight. Ongoing exposures to even relatively low drinking water concentrations of long-chain PFAAs substantially increase human body burdens, which remain elevated for many years after exposure ends. Notably, infants are a sensitive subpopulation for PFAA’s developmental effects and receive higher exposures than adults from the same drinking water source. This information, as well as emerging data from future studies, should be considered in the development of health-protective and scientifically sound guidelines for PFAAs in drinking water.

Analysis of population-level determinants of legionellosis: spatial and geovisual methods for enhancing classification of high-risk areas

Background

Although the incidence of legionellosis throughout North America and Europe continues to increase, public health investigations have not been able to identify a common exposure in most cases. Over 80% of cases are sporadic with no known source. To better understand the role of the macro-environment in legionellosis risk, a retrospective ecological study assessed associations between population-level measures of demographic, socioeconomic, and environmental factors and high-risk areas.

Methods

Geographic variability and clustering of legionellosis was explored in our study setting using the following methods: unadjusted and standardized incidence rate and SaTScan™ cluster detection methods using default scanning window of 1 and 50% as well as a reliability score methodology. Methods for classification of “high-risk” census tracts (areas roughly equivalent to a neighborhood with average population of 4000) for each of the spatial methods are presented. Univariate and multivariate logistic regression analyses were used to estimate associations with sociodemographic factors: population ≥ 65 years of age, non-white race, Hispanic ethnicity, poverty, less than or some high school education; housing factors: housing vacant, renter-occupied, and built pre-1950 and pre-1970; and whether drinking water is groundwater or surface water source.

Results

Census tracts with high percentages of poverty, Hispanic population, and non-white population were more likely to be classified as high-risk for legionellosis versus a low-risk census tract. Vacant housing, renter-occupied housing, and homes built pre-1970 were also important positively associated risk factors. Drinking water source was not found to be associated with legionellosis incidence.

Discussion

Census tract level demographic, socioeconomic, and environmental characteristics are important risk factors of legionellosis and add to our understanding of the macro-environment for legionellosis occurrence. Our findings can be used by public health professionals to target disease prevention communication to vulnerable populations. Future studies are needed to explore the exact mechanisms by which these risk factors may influence legionellosis clustering.

Under the Weather: Legionellosis and Meteorological Factors

The incidence of legionellosis, caused by the bacteria Legionella which are commonly found in the environment, has been increasing in New Jersey (NJ) over the last decade. The majority of cases are sporadic with no known source of exposure. Meteorological factors may be associated with increases in legionellosis. Time series and case-crossover study designs were used to evaluate associations of legionellosis and meteorological factors (temperature (daily minimum, maximum, and mean), precipitation, dew point, relative humidity, sea level pressure, wind speed (daily maximum and mean), gust, and visibility). Time series analyses of multi-factor models indicated increases in monthly relative humidity and precipitation were positively associated with monthly legionellosis rate, while maximum temperature and visibility were inversely associated. Case-crossover analyses of multi-factor models indicated increases in relative humidity occurring likely before incubation period was positively associated, while sea level pressure and visibility, also likely preceding incubation period, were inversely associated. It is possible that meteorological factors, such as wet, humid weather with low barometric pressure, allow proliferation of Legionella in natural environments, increasing the rate of legionellosis.

Associations of daily pediatric asthma emergency department visits with air pollution in Newark, NJ: utilizing time-series and case-crossover study designs

OBJECTIVE

Asthma is one of the most common chronic diseases affecting children. This study assesses the associations of ozone and fine particulate matter (PM2.5) with pediatric emergency department visits in the urban environment of Newark, NJ. Two study designs were utilized and evaluated for usability.

METHODS

We obtained daily emergency department visits among children aged 3-17 years with a primary diagnosis of asthma during April to September for 2004-2007. Both a time-stratified case-crossover study design with bi-directional control sampling and a time-series study design were utilized. Lagged effects (1-d through 5-d lag, 3-d average, and 5-d average) of ozone and PM2.5 were explored and a dose-response analysis comparing the bottom 5th percentile of 3-d average lag ozone with each 5 percentile increase was performed.

RESULTS

Associations of interquartile range increase in same-day ozone were similar between the time-series and case-crossover study designs (RR = 1.08, 95% CI 1.04-1.12) and (OR = 1.10, 95% CI 1.06-1.14), respectively. Similar associations were seen for 1-day lag and 3-day average lag ozone levels. PM2.5 was not associated with the outcome in either study design. Dose-response assessment indicated a statistically significant and increasing association around 50-55 ppb consistent for both study designs.

CONCLUSIONS

Ozone was statistically positively associated with pediatric asthma ED visits in Newark, NJ. Our results were generally comparable across the time-series and case-crossover study designs, indicating both are useful to assess local air pollution impacts.

Associations of perfluorinated chemical serum concentrations and biomarkers of liver function and uric acid in the US population (NHANES), 2007-2010

BACKGROUND

Perfluorinated chemicals (PFCs) are a group of manmade compounds that are not broken down in the body. Four PFCs (PFHxS, PFOS, PFOA, and PFNA) have been found in the blood of more than 98% of the United States population.

OBJECTIVES

Our goal was to assess associations between PFHxS, PFOS, PFOA, and PFNA and uric acid, alanine transferase (ALT), gamma-glutamyl transferase (GGT), asparate aminotransferase (AST), alkaline phosphate (ALP), and total bilirubin in 2007-2008 and 2009-2010 combined National Health and Nutrition Examination Survey (NHANES).

METHODS

We used multivariate linear regression and logistic regression adjusted for age, gender, race/ethnicity and BMI group, poverty, smoking, and/or alcohol consumption to estimate associations. Trend analysis was performed.

RESULTS

PFHxS was associated with ALT. Each quartile of PFOS was statistically associated with total bilirubin [(Q2: OR=1.44, 95% CI 1.12-1.84), (Q3: OR=1.65, 95% CI 1.25-2.18), and (Q4: OR=1.51, 95% CI 1.06-2.15)], with evidence of an increasing trend (p-value=0.028). PFOA was associated with uric acid, ALT, GGT, and total bilirubin. PFNA was linearly associated with ALT (p-value <0.001), and there was statistically significant increasing trend (p-value=0.042).

CONCLUSIONS

Our analysis found evidence of associations of biomarkers of liver function and uric acid with PFHxS, PFOS, PFOA, and PFNA at levels found in the general U.S. population.

Associations between ozone, PM2.5, and four pollen types on emergency department pediatric asthma events during the warm season in New Jersey: a case-crossover study

BACKGROUND

Asthma is one of the most common chronic diseases among school-aged children in the United States. Environmental respiratory irritants exacerbate asthma among children. Understanding the impact of a variety of known and biologically plausible environmental irritants and triggers among children in New Jersey - ozone, fine particulate matter (PM2.5), tree pollen, weed pollen, grass pollen and ragweed - would allow for informed public health interventions.

METHODS

Time-stratified case-crossover design was used to study the transient impact of ozone, PM2.5 and pollen on the acute onset of pediatric asthma. Daily emergency department visits were obtained for children aged 3-17 years with a primary diagnosis of asthma during the warm season (April through September), 2004-2007 (inclusive). Bi-directional control sampling was used to select two control periods for each case for a total of 65,562 inclusion days. Since the period of exposure prior to emergency department visit may be the most clinically relevant, lag exposures were investigated (same day (lag0), 1, 2, 3, 4, and 5 as well as 3-day and 5-day moving averages). Multivariable conditional logistic regression controlling for holiday, school-in-session indicator, and 3-day moving average for temperature and relative humidity was used to examine the associations. Odds ratios are based on interquartile range (IQR) increases or 10 unit increases when IQR ranges were narrow. Single-pollutant models as well as multipollutant models were examined. Stratification on gender, race, ethnicity and socioeconomic status was explored.

RESULTS

The associations with ozone and PM2.5 were strongest on the same day (lag0) of the emergency department visit (RR IQR=1.05, 95% CI 1.04-1.06) and (RR IQR=1.03, 95% CI 1.02-1.04), respectively, with a decreasing lag effect. Tree and weed pollen were associated with pediatric ED visits; the largest magnitudes of association was with the 5-day average (RR IQR=1.23, 95% CI 1.21-1.25) and (RR 10=1.13, 95% CI 1.12-1.14), respectively. Grass pollen was only minimally associated with the outcome while ragweed had a negative association.

CONCLUSIONS

The ambient air pollutant ozone is associated with increases in pediatric emergency department asthma visits during the warm weather season. The different pollen types showed different associations with the outcome. High levels of tree pollen appear to be an important risk factor in asthma exacerbations.

Aggressive gastric peripheral T-cell lymphoma of CD8+ type associated with lymphomatous meningitis

Most gastric lymphomas are of B-cell origin, and many are either low-grade or high-grade B-cell lymphomas of mucosa-associated lymphoid tissue type. Gastric T-cell lymphomas are very rare, usually of CD4+ type, and few have had genotypic studies. We report the case of a gastric peripheral T-cell lymphoma of CD8+ type. Genotypic studies demonstrated partial deletion with rearrangement of the T-cell receptor beta-chain gene. Lymphomatous meningitis developed, and the patient died after only 2 months despite chemotherapy. The case is compared with the other gastric T-cell lymphomas that have been reported.