Estimated number of symptomatic Lyme borreliosis cases in Germany in 2021 after adjusting for under-ascertainment

BACKGROUND

Although nine of 16 federal states in Germany conduct public health surveillance for Lyme borreliosis (LB), the extent of under-ascertainment is unknown.

OBJECTIVE

As a model for European countries that conduct LB surveillance, we sought to estimate the population-based incidence of symptomatic LB after adjusting for under-ascertainment.

METHODS

Estimating seroprevalence-derived under-ascertainment relies on data from seroprevalence studies, public health surveillance, and published literature. The number of symptomatic LB cases in states that conduct LB surveillance was estimated from studies reporting the seroprevalence of antibodies against Borrelia burgdorferi sensu lato, the proportion of LB cases that are asymptomatic, and the duration of antibody detection. The number of estimated incident symptomatic LB cases was compared with the number of surveillance-reported LB cases to derive under-ascertainment multipliers. The multipliers were applied to the number of 2021 surveillance-reported LB cases to estimate the population-based incidence of symptomatic LB in Germany.

RESULTS

Adjusting for seroprevalence-based under-ascertainment multipliers, the estimated number of symptomatic LB cases in states that conducted surveillance was 129,870 (408 per 100,000 population) in 2021. As there were 11,051 surveillance-reported cases in 2021 in these states, these data indicate there were 12 symptomatic LB cases for every surveillance-reported LB case.

CONCLUSIONS

We demonstrate that symptomatic LB is underdetected in Germany and that this seroprevalence-based approach can be applied elsewhere in Europe where requisite data are available. Nationwide expansion of LB surveillance would further elucidate the true LB disease burden in Germany and could support targeted disease prevention efforts to address the high LB disease burden.

A population-based estimate of the substantial burden of diarrhoeal disease in the United States; FoodNet, 1996-2003

From 1996 to 2003, four 12-month population-based surveys were performed in FoodNet sites to determine the burden of diarrhoeal disease in the population. Acute diarrhoeal illness (ADI) was defined as > or =3 loose stools in 24 hours with impairment of daily activities or duration of diarrhoea >1 day. A total of 52840 interviews were completed. The overall weighted prevalence of ADI in the previous month was 5.1% (95% CI+/-0.3%), corresponding to 0.6 episodes of ADI per person per year. The average monthly prevalence of ADI was similar in each of the four survey cycles (range 4.5-5.2%). Rates of ADI were highest in those age <5 years. Of those with ADI, 33.8% (95% CI+/-2.7%) reported vomiting, 19.5% (95% CI+/-2.1%) visited a medical provider, and 7.8% (95% CI+/-1.4%) took antibiotics. Rates of ADI were remarkably consistent over time, and demonstrate the substantial burden placed on the health-care system.

Re-assessment of risk factors for sporadic Salmonella serotype Enteritidis infections: a case-control study in five FoodNet Sites, 2002-2003

Active surveillance for laboratory-confirmed Salmonella serotype Enteritidis (SE) infection revealed a decline in incidence in the 1990s, followed by an increase starting in 2000. We sought to determine if the fluctuation in SE incidence could be explained by changes in foodborne sources of infection. We conducted a population-based case-control study of sporadic SE infection in five of the Foodborne Diseases Active Surveillance Network (FoodNet) sites during a 12-month period in 2002-2003. A total of 218 cases and 742 controls were enrolled. Sixty-seven (31%) of the 218 case-patients and six (1%) of the 742 controls reported travel outside the United States during the 5 days before the case's illness onset (OR 53, 95% CI 23-125). Eighty-one percent of cases with SE phage type 4 travelled internationally. Among persons who did not travel internationally, eating chicken prepared outside the home and undercooked eggs inside the home were associated with SE infections. Contact with birds and reptiles was also associated with SE infections. This study supports the findings of previous case-control studies and identifies risk factors associated with specific phage types and molecular subtypes.

Quinupristin-dalfopristin resistance in Enterococcus faecium isolates from humans, farm animals, and grocery store meat in the United States

Three hundred sixty-one quinupristin-dalfopristin (Q-D)-resistant Enterococcus faecium (QDREF) isolates were isolated from humans, turkeys, chickens, swine, dairy and beef cattle from farms, chicken carcasses, and ground pork from grocery stores in the United States from 1995 to 2003. These isolates were evaluated by pulsed-field gel electrophoresis (PFGE) to determine possible commonality between QDREF isolates from human and animal sources. PCR was performed to detect the streptogramin resistance genes vatD, vatE, and vgbA and the macrolide resistance gene ermB to determine the genetic mechanism of resistance in these isolates. QDREF from humans did not have PFGE patterns similar to those from animal sources. vatE was found in 35%, 26%, and 2% of QDREF isolates from turkeys, chickens, and humans, respectively, and was not found in QDREF isolates from other sources. ermB was commonly found in QDREF isolates from all sources. Known streptogramin resistance genes were absent in the majority of isolates, suggesting the presence of other, as-yet-undetermined, mechanisms of Q-D resistance.

Use of Stool Collection Kits Delivered to Patients Can Improve Confirmation of Etiology in Foodborne Disease Outbreaks

BACKGROUND

In 68% of foodborne disease outbreaks, no etiologic pathogen is identified. In two-thirds of outbreaks with no identified etiology, no stool specimens are submitted for testing.

METHODS

From April 2001 to March 2003, we pilot-tested use of prepackaged, self-contained stool specimen collection kits in 3 states, delivered to and from patients by courier or mail, to improve rates of specimen collection in the outbreak setting. Specimens were tested for bacterial and viral pathogens at health department laboratories, and results were correlated with epidemiological investigation data.

RESULTS

Specimens were returned by > or =1 person in 52 (96%) of 54 outbreaks in which kits were deployed; in total, 263 (76%) of 347 persons who received kits returned specimens. Resolution of symptoms was the most commonly cited reason for nonsubmission of kits. An etiology was confirmed in 37 (71%) of 52 outbreaks with specimens returned; 28 (76%) were attributable to norovirus, and 9 (24%) were attributed to bacterial pathogens. Stool kits were well received and cost an average of approximately 43 dollars per specimen returned.

CONCLUSIONS

In two-thirds of foodborne disease outbreaks in which delivered stool collection kits were successfully deployed, an etiologic organism was identified. Delivery of kits to and from patients to improve rates of stool collection in outbreaks in which specimens might otherwise not be submitted could substantially reduce the number of outbreaks with an unknown etiology.

Evidence of an Association Between Use of Anti-microbial Agents in Food Animals and Anti-microbial Resistance Among Bacteria Isolated from Humans and the Human Health Consequences of Such Resistance

Several lines of evidence indicate that the use of anti-microbial agents in food animals is associated with anti-microbial resistance among bacteria isolated from humans. The use of anti-microbial agents in food animals is most clearly associated with anti-microbial resistance among Salmonella and Campylobacter isolated from humans, but also appears likely among enterococci, Escherichia coli and other bacteria. Evidence is also accumulating that the anti-microbial resistance among bacteria isolated from humans could be the result of using anti-microbial agents in food animals and is leading to human health consequences. These human health consequences include: (i) infections that would not have otherwise occurred and (ii) increased frequency of treatment failures and increased severity of infection. Increased severity of infection includes longer duration of illness, increased frequency of bloodstream infections, increased hospitalization and increased mortality. Continued work and research efforts will provide more evidence to explain the connection between the use of anti-microbial agents in food animals and anti-microbial-resistant infections in humans. One particular focus, which would solidify this connection, is to understand the factors that dictate spread of resistance determinants, especially resistant genes. With continued efforts on the part of the medical, veterinary and public health community, such research may contribute to more precise guidelines on the use of anti-microbials in food animals.

Antimicrobial resistance in zoonotic enteric pathogens

Antimicrobial resistance is a zoonotic health threat. As in humans, the use of antimicrobial agents in animals results in the emergence and spread of resistant bacteria. Resistant bacteria from animals may be passed to humans via the food chain or direct animal contact, and may result in resistant infections. Increasing prevalence of resistance to antimicrobial agents such as fluoroquinolones and third-generation cephalosporins, which are important for the treatment of infections caused by enteric pathogens, has significant public health implications. Controlling the spread of resistance requires the collaboration of several partners, including the farming, veterinary, medical, and public health communities.

A population-based estimate of the burden of diarrhoeal illness in the United States: FoodNet, 1996-7

This study was performed to better understand and more precisely quantify the amount and burden of illness caused by acute diarrhoea in the United States today. A telephone-based population survey was conducted between 1 July, 1996, and 31 June, 1997, in sites of the Foodborne Diseases Active Surveillance Network (FoodNet). The overall prevalence of acute diarrhoea in the 4 weeks before interview was 11%, giving a rate of 1.4 episodes of diarrhoea per person per year. The rate of diarrhoeal illness defined as a diarrhoeal episode lasting longer than 1 day or which resulted in significant impairment of daily activities was 0.7 per person per year. It can be concluded that acute diarrhoea is common and represents a significant burden of illness in the United States. Our data on self-reported diarrhoea, when generalized to the entire nation, suggests 375 million episodes of acute diarrhoea each year in the United States. Many of these episodes are mild. However, our data also indicate that there are approximately 200 million episodes of diarrhoeal illness each year in the United States.

Foodborne disease in our global village: a multinational investigation of an outbreak of Salmonella serotype Enteritidis phage type 4 infection in Puerto Vallarta, Mexico

OBJECTIVES

In late 1996, a multinational investigation was launched following an outbreak of diarrheal illness that caused the disruption of an international scientific conference at a first-class hotel in Puerto Vallarta, Mexico.

METHODS

A questionnaire was mailed to all American and to selected international attendees. Additional copies of the questionnaire were provided for any family members who may have attended the conference. A case was defined as an illness with three or more loose stools during a 24-h period in a conference attendee or accompanying family member, with illness lasting 2 or more days and onset between 6 and 9 November 1996.

RESULTS

Questionnaires were returned by 81% (232/288) of American attendees, 47% (18/38) of selected international attendees, and 25 family members; 30% (83/275) of respondents met the case definition. Ill persons resided in at least seven countries. Salmonella serotype Enteritidis phage type 4 was isolated from stool specimens from patients residing in Canada, the UK, and the USA. Attending a hotel banquet on 6 November was associated with illness; 42% (82/194) of banquet attendees became ill versus 3% (1/37) of non-attendees (relative risk (RR)515.6, 95% confidence interval (CI)52.3-108.9). The only banquet food item associated with illness was chili rellenos; 53% (58/109) of persons who ate chili rellenos were ill versus 22% (12/55) of those who did not (RR52.4, 95% CI51.4-4.1). Chili rellenos ingredients included shelled eggs and cheese; Salmonella was isolated from the leftover cheese but the isolate was not serotyped.

CONCLUSIONS

Salmonella may be a cause of traveler's diarrhea and can result in outbreaks even among travelers who follow routine precautions (i.e. staying in a first-class hotel and eating hot foods). International collaboration in investigating similar outbreaks, including sharing subtyping results, will be necessary for long-term prevention. Global Salm-Surv, an international network of Salmonella reference laboratories coordinated by the World Health Organization, may facilitate such collaboration.

Characterization of plasmids carrying CMY-2 from expanded-spectrum cephalosporin-resistant Salmonella strains isolated in the United States between 1996 and 1998

Sequencing of DNA from 15 expanded-spectrum cephalosporin (e.g., ceftriaxone)-resistant Salmonella isolates obtained in the United States revealed that resistance to ceftriaxone in all isolates was mediated by cmy-2. Hybridization patterns revealed three plasmid structures containing cmy-2 in these 15 isolates. These data suggest that the spread of cmy-2 among Salmonella strains is occurring through mobilization of the cmy-2 gene into different plasmid backbones and consequent horizontal transfer by conjugation.

Quinupristin-dalfopristin-resistant Enterococcus faecium on chicken and in human stool specimens

BACKGROUND

The combination of the streptogramins quinupristin and dalfopristin was approved in the United States in late 1999 for the treatment of vancomycin-resistant Enterococcus faecium infections. Since 1974, another streptogramin, virginiamycin, has been used at subtherapeutic concentrations to promote the growth of farm animals, including chickens.

METHODS

To determine the frequency of quinupristin-dalfopristin-resistant E. faecium, we used selective medium to culture samples from chickens purchased in supermarkets in Georgia, Maryland, Minnesota, and Oregon and stool samples from outpatients.

RESULTS

Between July 1998 and June 1999, samples from 407 chickens from 26 stores in four states were cultured, as were 334 stool samples from outpatients. Quinupristin-dalfopristin-resistant E. faecium was isolated from 237 chicken carcasses and 3 stool specimens. The resistant isolates from stool had low-level resistance (minimal inhibitory concentration [MIC], 4 microg per milliliter; resistance was defined as a MIC of at least 4 microg per milliliter). The resistant isolates from chickens in general had higher levels of resistance (MICs ranging from 4 to 32 microg per milliliter; MIC required to inhibit 50 percent of isolates, 8 microg per milliliter).

CONCLUSIONS

Quinupristin-dalfopristin-resistant E. faecium contaminates a large proportion of chickens sold in U.S. supermarkets. However, the low prevalence and low level of resistance of these strains in human stool specimens suggest that the use of virginiamycin in animals has not yet had a substantial influence. Foodborne dissemination of resistance may increase, however, as the clinical use of quinupristin-dalfopristin increases.

Complaints of foodborne illness in San Francisco, California, 1998

Foodborne diseases are an important public problem affecting millions of Americans each year and resulting in substantial morbidity and mortality. Many foodborne infections occur in outbreak settings. Outbreaks are often detected by complaints from the public to health authorities. This report reviews complaints received by the San Francisco Department of Public Health involving suspected foodborne illness in 1998. Although such foodborne complaints are commonly received by health officials, we provide the first review of population-based data describing such complaints. We use a broad definition of a foodborne disease outbreak. We judged a complaint to be a "likely foodborne disease outbreak" if it involved more than one person and more than one family; no other common meals were shared recently by ill persons; diarrhea, vomiting, or both was reported; and the incubation period was more than one hour. In 1998, 326 complaints of foodborne illness, involving a total of 599 ill people, were received by the Communicable Disease Control Unit in San Francisco. The complaints involved from 1 to 36 ill persons, with 61% involving one ill person and 25% involving two ill persons. Of the 126 reports involving illness in more than one person, 77 (61%) were judged to be likely foodborne disease outbreaks. Three of these 77 outbreaks had been investigated prior to our review. This project confirms that more foodborne disease outbreaks occur than are reported to state and national outbreak surveillance systems. Our review of the San Francisco system highlights opportunities for gleaning valuable information from the foodborne disease complaint systems in place in most jurisdictions.

A nosocomial outbreak of fluoroquinolone-resistant salmonella infection

BACKGROUND

Infection with fluoroquinolone-resistant strains of salmonella is rare, as is nosocomial salmonella infection. We describe the first recognized outbreak of fluoroquinolone-resistant salmonella infections in the United States, which occurred in two nursing homes and one hospital in Oregon.

METHODS

We interviewed medical staff and reviewed patients' charts and death certificates. In Nursing Home A we conducted a case-control study. Patients were defined as residents of the nursing home from whom fluoroquinolone-resistant Salmonella enterica serotype Schwarzengrund was isolated between February 1996 and December 1998. Controls were residents with similar medical conditions whose cultures did not yield salmonella. We compared isolates using pulsed-field gel electrophoresis and sequence analysis. We reviewed pharmacy records to compare the use of fluoroquinolone among several nursing homes.

RESULTS

Eleven patients with fluoroquinolone-resistant salmonellosis were identified at two nursing homes. The index patient had been hospitalized in the Philippines and had probably acquired the infection there. Transmission was probably direct (from patient to patient) or through contact with contaminated surfaces. Treatment with fluoroquinolones during the six months before a culture was obtained was associated with a significant risk of salmonella infection (4 of 5 patients had taken fluoroquinolones, as compared with 2 of 13 controls; odds ratio, 22.0; 95 percent confidence interval, 1.06 to 1177). The patients were not significantly more likely than the controls to have taken other antibiotics. More fluoroquinolones were used at Nursing Home A than at similar nursing homes in Oregon. The isolates from the outbreak had similar patterns on pulsed-field gel electrophoresis and the same gyrA mutations. The isolates from the outbreak were also similar to the only previous isolate of fluoroquinolone-resistant salmonella in the United States, which came from a patient in New York who had been transferred from a hospital in the Philippines.

CONCLUSIONS

We describe a prolonged nosocomial outbreak of infection with fluoroquinolone-resistant S. enterica serotype Schwarzengrund. More such outbreaks are likely in institutional settings, particularly those in which there is heavy use of antimicrobial agents.

Emergence of domestically acquired ceftriaxone-resistant Salmonella infections associated with AmpC beta-lactamase

CONTEXT

Ceftriaxone, an expanded-spectrum cephalosporin, is an antimicrobial agent commonly used to treat severe Salmonella infections, especially in children. Ceftriaxone-resistant Salmonella infections have recently been reported in the United States, but the extent of the problem is unknown.

OBJECTIVES

To summarize national surveillance data for ceftriaxone-resistant Salmonella infections in the United States and to describe mechanisms of resistance.

DESIGN AND SETTING

Case series and laboratory evaluation of human isolates submitted to the Centers for Disease Control and Prevention from 17 state and community health departments participating in the National Antimicrobial Resistance Monitoring System (NARMS) for enteric bacteria between 1996 and 1998.

PATIENTS

Patients with ceftriaxone-resistant Salmonella infections between 1996 and 1998 were interviewed and isolates with decreased ceftriaxone susceptibility were further characterized.

MAIN OUTCOME MEASURES

Exposures and illness outcomes, mechanisms of resistance.

RESULTS

The prevalence of ceftriaxone-resistant Salmonella was 0.1% (1 of 1326) in 1996, 0.4% (5 of 1301) in 1997, and 0.5% (7 of 1466) in 1998. Ten (77%) of the 13 patients with ceftriaxone-resistant infections were aged 18 years or younger. The patients lived in 8 states (California, Colorado, Kansas, Massachusetts, Maryland, Minnesota, New York, and Oregon). Nine (82%) of 11 patients interviewed did not take antimicrobial agents and 10 (91%) did not travel outside the United States before illness onset. Twelve of the 15 Salmonella isolates with ceftriaxone minimum inhibitory concentrations of 16 microg/mL or higher were serotype Typhimurium but these isolates had different pulsed-field gel electrophoresis patterns. Thirteen of these 15 isolates collected between 1996 and 1998 were positive for a 631-base pair polymerase chain reaction product obtained by using primers specific for the ampC gene of Citrobacter freundii.

CONCLUSIONS

Domestically acquired ceftriaxone-resistant Salmonella has emerged in the United States. Most ceftriaxone-resistant Salmonella isolates had similar AmpC plasmid-mediated resistance.

Origins and consequences of antimicrobial-resistant nontyphoidal Salmonella: implications for the use of fluoroquinolones in food animals

Human Salmonella infections are common; most infections are self-limiting, however severe disease may occur. Antimicrobial agents, while not essential for the treatment of Salmonella gastroenteritis, are essential for the treatment of thousands of patients each year with invasive infections. Fluoroquinolones and third-generation cephalosporins are the drugs-of-choice for invasive Salmonella infections in humans; alternative antimicrobial choices are limited by increasing antimicrobial resistance, limited efficacy, and less desirable pharmacodynamic properties. Antimicrobial-resistant Salmonella results from the use of antimicrobial agents in food animals, and these antimicrobial resistant Salmonella are subsequently transmitted to humans, usually through the food supply. The antimicrobial resistance patterns of isolates collected from persons with Salmonella infections show more resistance to antimicrobial agents used in agriculture than to antimicrobial agents used for the treatment of Salmonella infections in humans. Because of the adverse health consequences in humans and animals associated with the increasing prevalence of antimicrobial-resistant Salmonella, there is an urgent need to emphasize non-antimicrobial infection control strategies, such as improved sanitation and hygiene, to develop guidelines for the prudent usage of antimicrobial agents, and establishment of adequate public health safeguards to minimize the development and dissemination of antimicrobial resistance and dissemination of Salmonella resistant to these agents.

Evaluation of safe food-handling instructions on raw meat and poultry products

Every year in the United States, millions of people become ill, thousands of people die, and substantial economic costs are incurred from foodborne diseases. As a measure to prevent foodborne diseases, since July 1994, the U.S. Department of Agriculture has required that safe food-handling labels be placed on retail packages of raw or partially cooked meat and poultry products. Through selected states' Behavioral Risk Factor Surveillance System (BRFSS) interviews, survey data were collected to determine the proportion of adults aware of the label and adults who reported changing their raw meat-handling practices because of the label. Fifty-one percent of the 14,262 respondents reported that they had seen the label. Of these, 79% remembered reading the label, and 37% of persons who reported that they had seen and read the label reported changing their raw meat preparation methods because of the label. Women were more likely than men to have read the label, as were persons who are at least 30 years of age compared to younger adults (P < 0.05). Both label awareness and risky food-handling behaviors increased with education and income, suggesting that safe food-handling labels have limited influence on consumer practices. Our results also suggest that the labels might be more effective in discouraging cross-contamination than in promoting thorough cooking practices. We suggest that the label is only one component among many food safety education programs that are needed to inform consumers about proper food-handling and preparation practices and to motivate persons who have risky food-handling and preparation behaviors to change these behaviors.

Emergence of a new Vibrio parahaemolyticus serotype in raw oysters: A prevention quandary

CONTEXT

In May and June 1998, reported Vibrio parahaemolyticus infections increased sharply in Texas.

OBJECTIVE

To determine factors that contributed to the increase in V parahaemolyticus infections.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional survey of persons reporting gastroenteritis after eating seafood in Texas; survey of environmental conditions in Galveston Bay.

MAIN OUTCOME MEASURES

Traceback of oysters, water quality measures in harvest areas, presence of V parahaemolyticus in stool cultures; comparison of median values for environmental conditions before and during the outbreak compared with during the previous 5 years.

RESULTS

Between May 31 and July 10, 1998, 416 persons in 13 states reported having gastroenteritis after eating oysters harvested from Galveston Bay. All 28 available stool specimens from affected persons yielded V parahaemolyticus serotype O3:K6 isolates. Oyster beds met current bacteriologic standards during harvest and fecal coliform counts in water samples were within acceptable limits. Median water temperature and salinity during May and June 1998 were 30.0 degrees C and 29.6 parts per thousand (ppt) compared with 28.9 degrees C and 15.6 ppt for the previous 5 years (P<.001).

CONCLUSIONS

This is the first reported outbreak of V parahaemolyticus serotype O3:K6 infection in the United States. The emergence of a virulent serotype and elevated seawater temperatures and salinity levels may have contributed to this large multistate outbreak of V parahaemolyticus. Bacteriologic monitoring at harvest sites did not prevent this outbreak, suggesting that current policy and regulations regarding the safety of raw oysters require reevaluation. Consumers and physicians should understand that raw or undercooked oysters can cause illness even if harvested from monitored beds. In patients who develop acute gastroenteritis within 4 days of consuming raw or undercooked oysters, a stool specimen should be tested for Vibrio species using specific media. JAMA. 2000;284:1541-1545.

Incidence of foodborne illnesses reported by the foodborne diseases active surveillance network (FoodNet)-1997. FoodNet Working Group

In 1997, the Foodborne Diseases Active Surveillance Program (FoodNet) conducted active surveillance for culture-confirmed cases of Campylobacter, Escherichia coli O157, Listeria, Salmonella, Shigella, Vibrio, Yersinia, Cyclospora, and Cryptosporidium in five Emerging Infections Program sites. FoodNet is a collaborative effort of the Centers for Disease Control and Prevention's National Center for Infectious Diseases, the United States Department of Agriculture's Food Safety and Inspection Service, the Food and Drug Administration's Center for Food Safety and Applied Nutrition, and state health departments in California, Connecticut, Georgia, Minnesota, and Oregon. The population under active surveillance for foodborne infections was approximately 16.1 million persons or roughly 6% of the United States Population. Through weekly or monthly contact with all clinical laboratories in these sites, 8,576 total isolations were recorded: 2,205 cases of salmonellosis, 1,273 cases of shigellosis, 468 cases of cryptosporidiosis, 340 of E. coli O157:H7 infections, 139 of yersiniosis, 77 of listeriosis, 51 of Vibrio infections, and 49 of cyclosporiasis. Results from 1997 demonstrate that while there are regional and seasonal differences in reported incidence rates of certain bacterial and parasitic diseases, and that some pathogens showed a change in incidence from 1996, the overall incidence of illness caused by pathogens under surveillance was stable. More data over more years are needed to assess if observed variations in incidence reflect yearly fluctuations or true changes in the burden of foodborne illness.

A survey of stool culturing practices for vibrio species at clinical laboratories in Gulf Coast states

Non-cholera Vibrio infections are an important public health problem. Non-cholera Vibrio species usually cause sporadic infections, often in coastal states, and have also caused several recent nationwide outbreaks of gastroenteritis in the United States. We report a survey of laboratory stool culturing practices for Vibrio among randomly selected clinical laboratories in Gulf Coast states (Alabama, Florida, Louisiana, Mississippi, and Texas). Interviews conducted with the microbiology supervisors of 201 clinical laboratories found that 164 (82%) received stool specimens for culture. Of these, 102 (62%) of 164 processed stool specimens on site, and 20 (20%) of these 102 laboratories cultured all stool specimens for Vibrio, indicating that at least 34,463 (22%) of 152, 797 stool specimens were cultured for Vibrio. This survey suggests that despite an increased incidence of non-cholera Vibrio infections in Gulf Coast states, a low percentage of clinical laboratories routinely screen all stool specimens, and fewer than 25% of stool specimens collected are routinely screened for non-cholera Vibrio.

Public health aspects of antibiotic resistance monitoring in the USA

Treatment of food-producing animals with antimicrobial agents that are important in human therapy may present a public health risk by the transfer of resistant zoonotic pathogens or resistant genes from animals to humans via consumption of contaminated food. Resistant bacteria can diminish the effectiveness of antibiotics and demand the use of more expensive or less safe alternatives. In 1996, the U. S. Food and Drug Administration (FDA), the Centers for Disease Control and Prevention (CDC), and the Department of Agriculture (USDA) established the National Antimicrobial Resistance Monitoring Program to prospectively monitor changes in antimicrobial susceptibilities of zoonotic enteric pathogens from human and animal clinical specimens, from healthy farm animals, and from carcasses of food-producing animals at slaughter plants. Data resulting from the monitoring program will be used to redirect antimicrobial drug use, primarily through educational initiatives directed at health practitioners, in order to diminish the development and spread of resistance. Veterinary testing is conducted at USDA's Agricultural Research Service and CDC's Foodborne Disease Laboratory is testing human isolates under contract to FDA. Both the CDC and USDA laboratories are using a semi-automated system (Sensititre, Accumed, Westlake, Ohio) for testing susceptibilities of the isolates to 17 antimicrobial agents on a minimum inhibitory concentration plate. Comparable methods for isolate handling are used in both laboratories. This paper describes the development, implementation, and objectives of the National Antimicrobial Resistance Monitoring Program, presents initial data generated by the program, and discusses future plans.

Ceftriaxone-resistant salmonella infection acquired by a child from cattle

BACKGROUND

The emergence of resistance to antimicrobial agents within the salmonellae is a worldwide problem that has been associated with the use of antibiotics in livestock. Resistance to ceftriaxone and the fluoroquinolones, which are used to treat invasive salmonella infections, is rare in the United States. We analyzed the molecular characteristics of a ceftriaxone-resistant strain of Salmonella enterica serotype typhimurium isolated from a 12-year-old boy with fever, abdominal pain, and diarrhea.

METHODS

We used pulsed-field gel electrophoresis and analysis of plasmids and beta-lactamases to compare the ceftriaxone-resistant S. enterica serotype typhimurium from the child with four isolates of this strain obtained from cattle during a local outbreak of salmonellosis.

RESULTS

The ceftriaxone-resistant isolate from the child was indistinguishable from one of the isolates from cattle, which was also resistant to ceftriaxone. Both ceftriaxone-resistant isolates were resistant to 13 antimicrobial agents; all but one of the resistance determinants were on a conjugative plasmid of 160 kb that encoded the functional group 1 beta-lactamase CMY-2. Both ceftriaxone-resistant isolates were closely related to the three other salmonella isolates obtained from cattle, all of which were susceptible to ceftriaxone.

CONCLUSIONS

This study provides additional evidence that antibiotic-resistant strains of salmonella in the United States evolve primarily in livestock. Resistance to ceftriaxone, the drug of choice for invasive salmonella disease, is a public health concern, especially with respect to children, since fluoroquinolones, which can also be used to treat this disease, are not approved for use in children.

Epidemic cholera in Guinea-Bissau: the challenge of preventing deaths in rural West Africa

OBJECTIVES

An epidemiologic investigation was conducted to identify factors associated with cholera mortality in a rural African setting and interventions likely to prevent deaths in future epidemics.

METHODS

The authors reviewed surveillance data from rural Biombo, Guinea-Bissau, interviewed family members of persons who died of cholera, and conducted a case-control study in the catchment area of a health center with a high case:fatality ratio (CFR).

RESULTS

Forty-three deaths occurred among the 1169 persons who reported to health centers with cholera during the epidemic (CFR = 3.7%). Delayed rehydration and over-hydration probably contributed to 10 of these deaths. An additional 19 cholera deaths occurred outside health centers. In the case-control study, persons with cholera who died were 5.4 times (95% CI = 1.0-53.4) more likely to be in poor health or intoxicated at illness onset than persons with cholera who survived. Fatal cases were 6.0 times (95% CI = 1.1-60.8) more likely to not attend the health center than survivors.

CONCLUSIONS

The low overall CFR in Biombo, compared to CFRs reported during other epidemics in sub-Saharan Africa, suggests that medical care provided at rudimentary rural health centers prevented numerous deaths. Additional deaths may be prevented by strengthening the infrastructure of health services in the rural areas and by enhanced public education regarding the need for persons with cholera to promptly seek medical care.

Outbreaks of salmonellosis associated with eating uncooked tomatoes: implications for public health. The Investigation Team

Laboratory-based surveillance of salmonella isolates serotyped at four state health departments (Illinois, Michigan, Minnesota and Wisconsin) led to the identification of multistate outbreaks of salmonella infections during 1990 (176 cases of S. javiana) and 1993 (100 cases of S. montevideo). Community-based case-control studies and product traceback implicated consumption of tomatoes from a single South Carolina tomato packer (Packer A) MOR 16.0; 95% CI2.1, 120.6; P < 0.0001 in 1990 and again in 1993 (MOR 5.7; 95 % CI 1.5, 21.9; P = 0.01) as the likely vehicle. Contamination likely occurred at the packing shed, where field grown tomatoes were dumped into a common water bath. These outbreaks represent part of a growing trend of large geographically dispersed outbreaks caused by sporadic or low-level contamination of widely distributed food items. Controlling contamination of agricultural commodities that are also ready-to-eat foods, particularly fruits and vegetables, presents a major challenge to industry, regulators and public health officials.

A multi-state survey of consumer food-handling and food-consumption practices

INTRODUCTION

In the United States, foodborne infections cause an estimated 6.5-33 million illnesses a year. Also included in the burden of foodborne illnesses are sequelae such as hemolytic uremic syndrome, Guillain-Barré syndrome, and reactive arthritis. Surveillance for risky food-handling and food-consumption practices can be used to identify high-risk populations, develop educational efforts, and evaluate progress toward risk reduction.

DESIGN

In 1995 and 1996, Behavioral Risk Factor Surveillance System interviews of 19,356 adults in eight states (1995: Colorado, Florida, Missouri, New York, and Tennessee; 1996: Indiana, New Jersey, and South Dakota) included questions related to food-handling and/or food-consumption practices. Risky food-handling and food-consumption practices were not uncommon. Overall, 19% of respondents did not adequately wash hands or cutting boards after contact with raw meat or chicken. During the previous year, 20% ate pink hamburgers, 50% ate undercooked eggs, 8% ate raw oysters, and 1% drank raw milk. Men were more likely to report risky practices than women. The prevalence of most risky behaviors increased with increasing socioeconomic status.

CONCLUSION

Targeted education efforts may reduce the frequency of these behaviors. Periodic surveillance can be used to assess effectiveness. In addition to consumer education, prevention efforts are needed throughout the food chain including on the farm, in processing, distribution, and at retail.

AIDS diagnosis and depression in the Multicenter AIDS Cohort Study: the ameliorating impact of pet ownership

The impact of pet ownership on depression was tested among a sample of gay and bisexual men (n = 1,872). Multivariate analyses, controlling for demographics and baseline depressive symptomatology, showed that neither pet ownership nor the presence of HIV infection was associated with depression. Depression was influenced by the presence of AIDS and by having relatively few confidants. Analyses among HIV-infected men only showed that persons with AIDS who owned pets reported less depression than persons with AIDS who did not own pets. This beneficial effect of pet ownership occurred principally among persons who reported fewer confidants. These results suggest that by enhancing companionship for some HIV-infected persons, pets may buffer the stressful impact of AIDS.

HIV infection as a risk factor for shigellosis

We investigated cases of shigellosis in San Francisco and Alameda Counties identified during 1996 by active laboratory surveillance to assess the role of HIV infection as a risk factor for shigellosis. Dramatically elevated rates of shigellosis in HIV-infected persons implicate HIV infection as an important risk factor for shigellosis in San Francisco.

Multistate surveillance for food-handling, preparation, and consumption behaviors associated with foodborne diseases: 1995 and 1996 BRFSS food-safety questions

PROBLEM/CONDITION

In 1995, CDC, the Food and Drug Administration (FDA), and several state health departments collaboratively developed questions regarding food safety. This set of questions was used to collect data about food-handling, preparation, and consumption behaviors that have been associated with foodborne diseases in adults. These data will help characterize persons at high risk for foodborne illness and assist in developing food-safety education strategies for consumers and foodhandlers that are intended to reduce foodborne illness.

REPORTING PERIOD COVERED

January 1995-December 1996.

DESCRIPTION OF SYSTEM

Data were collected by using the 12 food-safety questions, which were administered with the 1995 Behavioral Risk Factor Surveillance Systems (BRFSS) in Colorado, Florida, Missouri, New York, and Tennessee, and the 1996 BRFSS in Indiana and New Jersey. In addition, data were collected in South Dakota from two of the standardized questions that deal with consumption of undercooked eggs and pink hamburgers. The BRFSS is a state-based system that surveys noninstitutionalized adults by telephone about their health behaviors and practices.

RESULTS

This study included 19,356 completed questionnaires (2,461 in Colorado; 3,335 in Florida; 2,212 in Indiana; 1,572 in Missouri; 3,149 in New Jersey; 2,477 in New York; 2,110 in South Dakota; and 2,040 in Tennessee). During the previous 12 months, 50.2% of respondents reported eating undercooked eggs (95% confidence interval [CI] = 49.2-51.2); 23.8% reported eating home-canned vegetables (95% CI = 22.5-24.5); 19.7% reported eating pink hamburgers (95% CI = 18.9-20.5); 8.0% reported eating raw oysters (95% CI = 7.5-8.5); and 1.4% reported drinking raw milk (95% CI = 1.2-1.6). The prevalence of not washing hands with soap after handling raw meat or chicken and not washing a cutting board with soap or bleach after using it for cutting raw meat or chicken were 18.6% (95% CI = 17.8-19.4) and 19.5% (95% CI = 18.6-20.4), respectively. Less than half of respondents (45.4%, 95% CI = 44.2-46.6) reported seeing safe food-handling label information on raw meat products. In addition, among those persons who reported they remembered seeing the label information, 77.2% (95% CI = 76.0-78.4) remembered reading the label information, and 36.7% reported changing their meat and poultry preparation habits because of the labels (95% CI = 35.2-38.2). When population characteristics were considered in the analysis, all high-risk food-handling, preparation, and consumption behaviors were more prevalent in men than in women. Eating pink hamburgers during the previous 12 months was more commonly reported by whites (22.3%) than by blacks (6.5%). The prevalence of reported consumption of pink hamburgers during the previous. 12 months decreased with age (18-29 years: 21.8%, 30-59 years: 21.9%, and 60-99 years: 13.2%); increased with education (less than grade 12: 12.0%, high school graduate: 16.5%, and any college education: 24.0%); and increased with income (< $15,000: 11.8%, $15,000-$34,999: 17.6%, $35,000-$49,999: 22.0%, and > or = $50,000: 28.6%).

INTERPRETATION

During 1995-1996, several high-risk food-handling, preparation, and consumption behaviors were common, and some were particular to specific population groups. Based on this analysis, interventions are needed to reduce the prevalence of these risky behaviors. All consumers and foodhandlers could benefit from food-safety education.

ACTIONS TAKEN

Behavioral surveillance systems can provide data that identify persons or groups in which behaviors associated with foodborne diseases are more common and who are at higher risk for foodborne illness. State-specific data can assist in developing food-safety education programs and, if collected periodically, can be used to evaluate program effectiveness.

The epidemiology of raw milk-associated foodborne disease outbreaks reported in the United States, 1973 through 1992

OBJECTIVES

This study describes the epidemiology of raw milk-associated outbreaks reported to the Centers for Disease Control and Prevention from 1973 through 1992.

METHODS

Surveillance data for each reported raw milk-associated outbreak were reviewed. A national survey was conducted to determine the legal status of intrastate raw milk sales for the period 1973 through 1995.

RESULTS

Forty-six raw milk-associated outbreaks were reported during the study period; 40 outbreaks (87%) occurred in states where the intrastate sale of raw milk was legal.

CONCLUSIONS

Consumption of raw milk remains a preventable cause of foodborne disease outbreaks.

Prevalence of fecal shedding of Salmonella organisms among captive green iguanas and potential public health implications

OBJECTIVE

To determine prevalence of fecal shedding of Salmonella organisms among captive green iguanas (Iguana iguana).

DESIGN

Cohort study.

ANIMALS

12 captive green iguanas.

PROCEDURE

Iguanas were isolated in an environmental chamber, and fecal samples were collected weekly for 10 consecutive weeks. Samples were incubated aerobically in tetrathionate broth for 18 to 24 hours. Aliquots were then transferred to Hektoen and Salmonella-Shigella agar plates and incubated for an additional 18 to 24 hours. Isolated colonies were subcultured on nutrient agar slants, and Salmonella isolates were serogrouped and serotyped.

RESULTS

All 12 iguanas were found to be shedding Salmonella organisms at least once during the study, and multiple serotypes were isolated from 7 of the 12. Salmonella organisms were isolated from 88 of 106 (83%) fecal samples; 21 samples contained multiple Salmonella serotypes. Overall, 11 Salmonella serotypes were identified. In 74 of 100 instances, when a particular Salmonella serotype was isolated from an individual iguana, the same serotype was also isolated from a subsequent fecal sample from that iguana.

CLINICAL IMPLICATIONS

Results suggested that most iguanas have a stable mixture of Salmonella serotypes in their intestinal tracts and intermittently or continuously shed Salmonella organisms in their feces. Veterinarians should advise their clients on precautions for reducing the risk of acquiring these organisms from their pets. Public health officials trying to determine whether an iguana is the source of a specific Salmonella serotype that caused infection in human patients should submit at least 3 fecal samples collected from the iguana 1 week apart for bacterial culture.

A large outbreak of botulism: the hazardous baked potato

In April 1994, the largest outbreak of botulism in the United States since 1978 occurred in El Paso, Texas. Thirty persons were affected; 4 required mechanical ventilation. All ate food from a Greek restaurant. The attack rate among persons who ate a potato-based dip was 86% (19/22) compared with 6% (11/176) among persons who did not eat the dip (relative risk [RR] = 13.8; 95% confidence interval [CI], 7.6-25.1). The attack rate among persons who ate an eggplant-based dip was 67% (6/9) compared with 13% (241189) among persons who did not (RR = 5.2; 95% CI, 2.9-9.5). Botulism toxin type A was detected from patients and in both dips. Toxin formation resulted from holding aluminum foil-wrapped baked potatoes at room temperature, apparently for several days, before they were used in the dips. Consumers should be informed of the potential hazards caused by holding foil-wrapped potatoes at ambient temperatures after cooking.

Emergence of multidrug-resistant Salmonella enterica serotype typhimurium DT104 infections in the United States

BACKGROUND

Strains of salmonella that are resistant to antimicrobial agents have become a worldwide health problem. A distinct strain of Salmonella enterica serotype typhimurium, known as definitive type 104 (DT104), is resistant to ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline and has become a major cause of illness in humans and animals in Europe, especially the United Kingdom.

METHODS

To characterize typhimurium DT104 infections in the United States, we analyzed data collected by local and state health departments and public health laboratories between 1979 and 1996 in national surveys of the antimicrobial-drug resistance of salmonella. Selected typhimurium isolates with the five-drug pattern of resistance were phage typed.

RESULTS

The prevalence of typhimurium isolates with the five-drug pattern of resistance increased from 0.6 percent in 1979-1980 to 34 percent in 1996. In 1994-1995, such isolates were identified in samples from 36 of the 46 surveillance sites (78 percent). Thirty-nine of 43 typhimurium isolates with the five-drug pattern of resistance identified in 1994-1995 and 1996 were phage type DT104 or a closely related phage type.

CONCLUSIONS

Multidrug-resistant typhimurium DT104 has become a widespread pathogen in the United States. More prudent use of antimicrobial agents in farm animals and more effective disease prevention on farms are necessary to reduce the dissemination of multidrug-resistant typhimurium DT104 and to slow the emergence of resistance to additional agents in this and other strains of salmonella.

Determining the burden of human illness from food borne diseases. CDC's emerging infectious disease program Food Borne Diseases Active Surveillance Network (FoodNet)

Food borne diseases cause a significant burden of illness in the United States. The Food Borne Diseases Active Surveillance Network (FoodNet), established in 1995, continues to monitor the burden and causes of food borne diseases and provide much of the data to address this public health problem.

National surveillance for antibiotic resistance in zoonotic enteric pathogens

Treatment of food-producing animals with antimicrobial agents that are important in human therapy may present a public health risk by the transfer of resistant zoonotic pathogens from animals to humans. Resistant bacteria can diminish the effectiveness of antibiotics and demand the use of more expensive or less safe alternatives. In 1996, the Centers for Disease Control (CDC), United States Department of Agriculture (USDA), and Food and Drug Administration (FDA) established the National Antimicrobial Monitoring System to prospectively monitor changes in antimicrobial susceptibilities of zoonotic pathogens from human and animal clinical specimens, healthy farm animals, and carcasses of food-producing animals at slaughter plants. This article describes the development, implementation, and objectives of the monitoring system and presents initial data generated by the system.

Funerals during the 1994 cholera epidemic in Guinea-Bissau, West Africa: the need for disinfection of bodies of persons dying of cholera

The 1994 cholera epidemic in Guinea-Bissau resulted in 15,878 reported cases and 306 deaths. Early in the epidemic, although the health ministry mandated that the bodies of persons dying of cholera be disinfected, outbreaks occurred in several villages following funerals in the region of Biombo. To determine the influence of disinfection and funeral activities on cholera transmission, we analysed surveillance data and conducted a case-control study following a funeral. The attack rate during the week following funerals was higher in villages where bodies were not disinfected (risk ratio = 2.6, 95% confidence interval [CI] 1.9-3.8). Cholera was strongly associated with eating at a funeral with a non-disinfected corpse (odds ratio [OR] = 14.5, 95% CI 0.9-786) and with touching (i.e., transporting, washing) the body (OR = 36.2, 95% CI 2.6-1769). During cholera epidemics, in addition to other cholera prevention activities, health officials should inform community leaders about the risk of cholera transmission during funerals, meals should not be served at funerals, and bodies of persons dying of cholera should be disinfected.

A community waterborne outbreak of salmonellosis and the effectiveness of a boil water order

OBJECTIVES

A 1993 large water-borne outbreak of Salmonella typhimurium infections in Gideon, Mo, a city of 1100 with an unchlorinated community water supply, was investigated to determine the source of contamination and the effectiveness of an order to boil water.

METHODS

A survey of household members in Gideon and the surrounding township produced information on diarrheal illness, water consumption, and compliance with the boil water order.

RESULTS

More than 650 persons were ill; 15 were hospitalized, and 7 died. Persons consuming city water were more likely to be ill (relative risk [RR] = 9.1, 95% confidence interval [CI] = 2.9, 28.4), and the attack rate increased with increased water consumption. S. typhimurium was recovered from samples taken from a city fire hydrant and a water storage tower. Persons in 31% (30/ 98) of city households had drunk unboiled water after being informed about the boil water order, including 14 individuals who subsequently became ill. Reasons for noncompliance included "not remembering" (44%) and "disbelieving" (25%) the order.

CONCLUSIONS

Communities with deteriorating water systems risk widespread illness unless water supplies are properly operated and maintained. Effective education to improve compliance during boil water orders is needed.

Iguanas and Salmonella marina infection in children: a reflection of the increasing incidence of reptile-associated salmonellosis in the United States

OBJECTIVE

To investigate clinical aspects and risk factors for Salmonella serotype Marina infection in the United States.

METHODS

We identified all isolates of S Marina reported in 1994 to the National Salmonella Surveillance System. Patients were interviewed about demographic information, clinical course, diet, travel history, and contact with reptiles before illness.

RESULTS

Twenty-six (81%) of 32 patients were infants (<1 year of age) and 24 (75%) were male. This differs from other Salmonella isolates reported to the Centers for Disease Control and Prevention in 1994, of which 14% were from infants and 49% from male patients. Eleven patients (34%) were hospitalized for a median of 3.5 days (range: 2 to 21 days), and 1 died. Of 28 patients (88%) with reported iguana exposure, only 4 (14%) touched the reptile, and only 12 respondents (43%) realized that it might have been the source of infection. Seven (32%) of 22 families who owned an iguana at the time of illness continued to own an iguana when contacted a median of 28 weeks later. Persons who thought that the iguana was the source of infection were more likely to have given away or sold the pet than those who did not. Four isolates (13%) were from blood. Bacteremia was associated with taking antibiotics during the 30 days before S Marina infection (odds ratio: 24; 95% confidence interval: 1.2-1309).

CONCLUSION

S Marina infection is a potentially serious illness associated with iguana exposure, and it reflects the larger problem of reptile-associated salmonellosis. Many parents do not know that owning an iguana puts their children at risk for Salmonella infection. Pediatricians, veterinarians, and pet store owners should inform their patients and customers of the potential risks of owning reptiles and provide appropriate preventive education.

Emerging quinolone-resistant Salmonella in the United States

We conducted a national survey of antimicrobial resistance in human clinical isolates of Salmonella between July 1, 1994, and June 30, 1995. Every tenth nontyphoidal Salmonella isolate received at state public health laboratories in the United States during this period was tested for resistance to 12 antimicrobial agents, including two quinolones, nalidixic acid, and ciprofloxacin. Emerging quinolone resistance was detected; of 4,008 isolates tested, 21 (0.5%) were resistant to nalidixic acid, and one (0.02%) was resistant to ciprofloxacin. Continued surveillance for quinolone-resistant Salmonella is necessary, particularly after the recent approval of a fluoroquinolone for use in animals intended for food in the United States.

Surveillance for foodborne-disease outbreaks--United States, 1988-1992

PROBLEM/CONDITION

Since 1973, CDC has maintained a collaborative surveillance program for collection and periodic reporting of data concerning the occurrence and causes of foodborne-disease outbreaks (FBDOs).

REPORTING PERIOD COVERED

This summary reviews data from January 1988 through December 1992.

DESCRIPTION OF SYSTEM

The surveillance system reviews data concerning FBDOs--defined as the occurrence of two or more cases of a similar illness resulting from the ingestion of a common food. Before 1992, only one case of intoxication by chemical, marine toxin, or Clostridium botulinum toxin as a result of the ingestion of food was required to constitute an FBDO. Since 1992, two or more cases have been required. State and local public health departments have primary responsibility for the identifying and investigating FBDOs. State and territorial health departments report these outbreaks to CDC on a standard form.

RESULTS

During 1988-1992, a total of 2,423 outbreaks of foodborne disease were reported (451 in 1988, 505 in 1989, 532 in 1990, 528 in 1991, and 407 in 1992). These outbreaks caused a reported 77,373 persons to become ill. Among outbreaks for which the etiology was determined, bacterial pathogens caused the largest percentage of outbreaks (79%) and the largest percentage of cases (90%). Salmonella serotype Enteritidis accounted for the largest number of outbreaks, cases, and deaths; most of these outbreaks were attributed to eating undercooked, infected eggs. Chemical agents caused 14% of outbreaks and 2% of cases; parasites, 2% of outbreaks and 1% of cases; and viruses, 4% of outbreaks and 6% of cases.

INTERPRETATION

The number of FBDOs reported per year did not change substantially during the first 4 years but declined in 1992 as a result of the revised definition of an outbreak. During this reporting period, S. Enteritidis continued to be a major cause of morbidity and mortality. In addition, multistate outbreaks caused by contaminated produce and outbreaks caused by Escherichia coli O157:H7 became more prominent.

ACTIONS TAKEN

State and local public health departments investigate FBDOs. At the regional and national level, surveillance data provide an indication of the etiologic agents, vehicles of transmission, and contributing factors associated with FBDOs and help direct public health actions.

Bartonella (Rochalimaea) antibodies, dementia, and cat ownership among men infected with human immunodeficiency virus

To determine the association between recent human immunodeficiency virus (HIV)-associated dementia and serum antibodies to Bartonella (Rochalimaea) henselae, we performed a nested case control study within the Multicenter AIDS Cohort Study in Los Angeles. We measured serum IgG and IgM antibodies to B. henselae with use of enzyme immunoassay in 369 HIV-seropositive and HIV-seronegative participants with and without recent neuropsychological deterioration. Data on pet ownership were also collected. IgM antibodies to B. henselae were strongly associated with neuropsychological decline or dementia (OR = 6.6;95% CI = 1.4-31.9;P = .02). Those participants with IgM antibodies to B. henselae were 1.7 times more likely to develop HIV-associated dementia (HAD) or neuropsychological decline over the next 5 years. At least 4% of the new cases of HAD and neuropsychological decline were due to bartonella infection. Cat ownership was associated with the presence of IgM antibodies to B. henselae (OR = 6.4;95% CI = 1.3-30.8;p = .02) and with neuropsychological decline and dementia (OR = 2.4;95% CI = 1.2-5.1;P = .02). This finding suggests that some cases of HAD and neuropsychological decline are associated with potentially treatable B. henselae infections.