Adam Karpati

Antimicrobial residues in animal waste and water resources proximal to large-scale swine and poultry feeding operations

Expansion and intensification of large-scale animal feeding operations (AFOs) in the United States has resulted in concern about environmental contamination and its potential public health impacts. The objective of this investigation was to obtain background data on a broad profile of antimicrobial residues in animal wastes and surface water and groundwater proximal to large-scale swine and poultry operations. The samples were measured for antimicrobial compounds using both radioimmunoassay and liquid chromatography/electrospray ionization-mass spectrometry (LC/ESI-MS) techniques. Multiple classes of antimicrobial compounds (commonly at concentrations of > 100 microg/l) were detected in swine waste storage lagoons. In addition, multiple classes of antimicrobial compounds were detected in surface and groundwater samples collected proximal to the swine and poultry farms. This information indicates that animal waste used as fertilizer for crops may serve as a source of antimicrobial residues for the environment. Further research is required to determine if the levels of antimicrobials detected in this study are of consequence to human and/or environmental ecosystems. A comparison of the radioimmunoassay and LC/ESI-MS analytical methods documented that radioimmunoassay techniques were only appropriate for measuring residues in animal waste samples likely to contain high levels of antimicrobials. More sensitive LC/ESI-MS techniques are required in environmental samples, where low levels of antimicrobial residues are more likely.

An Outbreak of Rift Valley Fever in Northeastern Kenya, 1997-98

In December 1997, 170 hemorrhagic fever-associated deaths were reported in Carissa District, Kenya. Laboratory testing identified evidence of acute Rift Valley fever virus (RVFV). Of the 171 persons enrolled in a cross-sectional study, 31(18%) were anti-RVFV immunoglobulin (Ig) M positive. An age-adjusted IgM antibody prevalence of 14% was estimated for the district. We estimate approximately 27,500 infections occurred in Garissa District, making this the largest recorded outbreak of RVFV in East Africa. In multivariate analysis, contact with sheep body fluids and sheltering livestock in one’s home were significantly associated with infection. Direct contact with animals, particularly contact with sheep body fluids, was the most important modifiable risk factor for RVFV infection. Public education during epizootics may reduce human illness and deaths associated with future outbreaks.

Outbreak of Leptospirosis among Triathlon Participants and Community Residents in Springfield, Illinois, 1998

We investigated an outbreak of leptospirosis among athletes and community residents after a triathlon was held in Springfield, Illinois. A telephone survey was conducted to collect clinical information and data on possible risk factors, community surveillance was established, and animal specimens and lake water samples were collected to determine the source of the leptospiral contamination. A total of 834 of 876 triathletes were contacted; 98 (12%) reported being ill. Serum samples obtained from 474 athletes were tested; 52 of these samples (11%) tested positive for leptospirosis. Fourteen (6%) of 248 symptomatic community residents tested positive for leptospirosis. Heavy rains that preceded the triathlon are likely to have increased leptospiral contamination of Lake Springfield. Among athletes, ingestion of 1 or more swallows of lake water was a predominant risk factor for illness. This is the largest outbreak of leptospirosis that has been reported in the United States. Health care providers and occupational and recreational users of bodies of freshwater in the United States should be aware of the risk of contracting leptospirosis, particularly after heavy rains.

Stature and pubertal stage assessment in American boys: the 1988-1994 Third National Health and Nutrition Examination Survey.

PURPOSE To describe current stature and pubertal development in North American boys, and to compare these measures with measures observed approximately 30 years ago. METHODS We analyzed data (i.e., height, weight, and Tanner Stage) from the Third National Health and Nutrition Examination Survey (NHANES III), conducted between 1988-1994, and compared it to the National Health Examination Survey, Cycles II and III (HES II/III), conducted from 1963-1965 and 1966-1970. The surveys included physical examination and questionnaire components, employed cross-sectional designs, and are nationally representative. We used logistic regression to calculate median age at onset of pubertal stages. RESULTS NHANES III included 2481 boys aged 8 to 18 years. HES II comprised 3010 boys aged 8-11 years and HES III comprised 3514 boys aged 12-17 years. The mean heights of the oldest boys in both surveys did not differ significantly; however, at younger ages, boys in the more recent survey were taller (average height difference among those aged 8-14 years was 2.0 cm). Boys in NHANES III were also heavier and had higher body mass index than those in HES II/III. The median estimated ages of onset of pubertal stages in NHANES III were 9.9, 12.2, 13.6, and 15.8 years for genital stages 2-5, respectively, and 11.9, 12.6, 13.6, and 15.7 years for pubic hair stages 2-5, respectively. For some stages, the median estimated age of onset of puberty was earlier among boys in NHANES III than among those in HES III. CONCLUSIONS Differences in mean height at young ages, but not at older ages, suggest that the rate of growth among boys in NHANES III was faster than that of boys in the earlier surveys. This finding, coupled with the finding of earlier ages of onset of some pubertal stages, suggests that boys of this generation may be maturing more rapidly than did boys in the past.

Diarrheal Illness Detected Through Syndromic Surveillance After a Massive Power Outage: New York City, August 2003

OBJECTIVES We investigated increases in diarrheal illness detected through syndromic surveillance after a power outage in New York City on August 14, 2003. METHODS The New York City Department of Health and Mental Hygiene uses emergency department, pharmacy, and absentee data to conduct syndromic surveillance for diarrhea. We conducted a case-control investigation among patients presenting during August 16 to 18, 2003, to emergency departments that participated in syndromic surveillance. We compared risk factors for diarrheal illness ascertained through structured telephone interviews for case patients presenting with diarrheal symptoms and control patients selected from a stratified random sample of nondiarrheal patients. RESULTS Increases in diarrhea were detected in all data streams. Of 758 patients selected for the investigation, 301 (40%) received the full interview. Among patients 13 years and older, consumption of meat (odds ratio [OR]=2.7, 95% confidence interval [CI]=1.2, 6.1) and seafood (OR=4.8; 95% CI=1.6, 14) between the power outage and symptom onset was associated with diarrheal illness. CONCLUSIONS Diarrhea may have resulted from consumption of meat or seafood that spoiled after the power outage. Syndromic surveillance enabled prompt detection and systematic investigation of citywide illness that would otherwise have gone undetected.

Needs assessment of the displaced population following the August 1999 earthquake in Turkey

In August 1999 a major earthquake struck north-western Turkey. An assessment followed to identify the immediate needs of the displaced population. A random cluster sample of displaced families living in temporary shelter outside of organised relief camps was designed. Representatives of 230 households from the four communities worse affected by the earthquake were interviewed. Most families lived in makeshift shelters (84 per cent), used bottled water (91 per cent), obtained food from relief organisations (61 per cent), had access to latrines (90 per cent), had a member on routine medication (53 per cent) and obtained information by word of mouth (81 per cent). Many respondents reported having family members who were over the age of 65 (32 per cent) or under age three (20 per cent), who were pregnant (6 per cent), or who had been ill since the earthquake (64 per cent). The greatest immediate need reported by most families was shelter requirements (37 per cent), followed by food (23 per cent) and hygiene requirements (19 per cent). Ten days after the earthquake, basic environmental health needs of food, shelter and hygiene still predominated in this displaced population. Significant portions may have special needs due to age or illness.

Mysterious Outbreaks of Gastrointestinal Illness Associated with Burritos Supplied through School Lunch Programs

From October 1997 through March 1998, three outbreaks of gastrointestinal illness among school children were linked to company A burritos. In September 1998, a similar outbreak occurred in three North Dakota schools following lunches that included company B burritos. We conducted an investigation to determine the source of the North Dakota outbreak, identify other similar outbreaks, characterize the illness, and gather evidence about the cause. The investigation included epidemiologic analyses, environmental investigation, and laboratory analyses. In North Dakota, a case was defined as nausea, headache, abdominal cramps, vomiting, or diarrhea after lunch on 16 September 1998. Case definitions varied in the other states. In North Dakota, 504 students and staff met the case definition; predominant symptoms were nausea (72%), headache (68%), abdominal cramps (54%), vomiting (24%), and diarrhea (16%). The median incubation period was 35 min and median duration of illness was 6 h. Eating burritos was significantly associated with illness (odds ratio, 2.6; 95% confidence interval, 1.6 to 4.2). We identified 16 outbreaks that occurred in seven states from October 1997 through October 1998, affecting more than 1,900 people who ate burritos from two unrelated companies. All tortillas were made with wheat flour, but the fillings differed, suggesting that tortillas contained the etiologic agent. Results of plant inspections, tracebacks, and laboratory investigations were unrevealing. More than two million pounds of burritos were recalled or held from distribution. The short incubation period, symptoms, and laboratory data suggest that these outbreaks were caused by an undetected toxin or an agent not previously associated with this clinical syndrome. Mass psychogenic illness is an unlikely explanation because of the large number of sites where outbreaks occurred over a short period, the similarity of symptoms, the common food item, the lack of publicity, and the link to only two companies. A network of laboratories that can rapidly identify known and screen for unknown agents in food is a critical part of protecting the food supply against natural and intentional contamination.