Efficacy of an oral vaccinia-rabies glycoprotein recombinant vaccine in controlling epidemic raccoon rabies in New Jersey.

A field trial to evaluate the efficacy of an oral vaccinia-rabies glycoprotein recombinant virus vaccine in controlling epidemic raccoon (Procyon lotor) rabies was conducted by distributing 180,816 doses (10(8.2)TCID50/ml) of vaccine in wax ampules within fish-meal polymer baits at a rate of 64 doses/km2/treatment throughout a 552 km2 area, forming an 18 km wide band across the northern Cape May Peninsula of New Jersey (USA). Vaccination treatments were conducted in the spring and fall between May 1992 and October 1994 from a helicopter along ecotones and from motor vehicles along roads. Vaccine-laden baits were removed by animals from tracking stations within 3 wk and 61% of the identifiable tracks were those of raccoons. Tetracycline incorporated in the baits as a biomarker was detected in 155 (73%) of the vaccination area raccoons following the fall 1993 and spring 1994 vaccinations. Eleven (61%) of the raccoons sampled in the same time period seroconverted (> or = 0.5 IU) in response to rabies virus glycoprotein. A raccoon diagnosed with rabies from the northern border of the vaccination area on 30 April 1993 provided the first evidence that the barrier was being challenged by the rabies epidemic. The prevalence of rabies in raccoons from the vaccination area for the first year (10%, n = 96) and second year (8%, n = 61) of challenge was reduced more than six-fold by vaccination compared to unvaccinated raccoons from northern adjacent surveillance areas during the corresponding first (65%, n = 189) and second years (53%, n = 43). Vaccination also effectively reduced by three-fold the rate at which the epidemic moved through the raccoon population (15 km/yr). The breach of the vaccination area resulted in a resumption of the high rate (43 km/yr) of epidemic movement and a significant nine-fold increase in rabies prevalence (77%, n = 47). The maximum linear movement (12.9 km) among five ear-tagged rabid raccoons in the study area was significantly greater than that of 19 normal radio-collared raccoons (2.58 km) in the area. These large movements of rabid raccoons, together with relocation of nuisance raccoons, spillover of raccoon rabies in skunks (Mephitis mephitis) and other species, insufficient funding and a decision to discontinue the program in 1994 (which could have resulted in insufficient population immunity among raccoons in the vaccination area) may have contributed to the eventual breach of the barrier.

First reported outbreak in the United States of cryptosporidiosis associated with a recreational lake.

In the summer of 1994, an outbreak of cryptosporidiosis occurred among visitors to a state park in New Jersey. We enrolled 185 persons in a cohort study, 38 (20.5%) of whom had laboratory-confirmed cryptosporidiosis or gastrointestinal illness that met our clinical case definition. Having any exposure to lake water (e.g., swimming) was strongly associated with illness (P < .001). The outbreak lasted 4 weeks and affected an estimated 2,070 persons. The most likely sources of the outbreak were contaminated runoff of rainwater and infected bathers. This outbreak of cryptosporidiosis is the first reported to be associated with recreational exposure to lake water. Our investigation shows that even a large and ongoing outbreak may not be detected for several weeks. Health professionals and persons at high risk for severe cryptosporidiosis should be aware that recreational water can be a source of cryptosporidium infection.

Boilerbaisse: an outbreak of methemoglobinemia in New Jersey in 1992.

BACKGROUND: On October 20, 1992, > 40 children from one elementary school visited the school nurse due to the acute onset of blue lips and hands, vomiting, and headache during and after the school lunch periods. Forty-nine children were seen by physicians that day and 14 were hospitalized. Laboratory analysis revealed methemoglobinemia in many of the children. All recovered in 36 hours. OBJECTIVE: A case-control study was supplemented by environmental and laboratory investigations to determine the outbreak source. METHODS: Cases were selected based on the laboratory diagnosis of methemoglobinemia (methemoglobin level > 2%). Children whose methemoglobin levels were missing or < 2% were excluded from analysis. Controls were obtained by selecting every third name from a school roster. The parents of 29 students who met the case definition and 52 controls were interviewed. RESULTS: All 29 cases and 33% (17/52) of the controls ate soup during the school lunch (odds ratio undefined, lower 95% confidence limit 16.1). Two pots of soup were prepared from ready-to-serve cans, which were diluted with water and enriched with a commercially prepared flavor enhancer. The school's boiler, dormant during the previous 5 months, was restarted on the morning of the outbreak. The boiler also served as a tankless hot water heater. Laboratory analysis of the soup identified abnormally high quantities of nitrite (459 ppm) and sodium metaborate, major components of the boiler water treatment solution. Undiluted soup from the same lot had 2.0 ppm nitrites; the flavor enhancer had 2.2 ppm nitrites. Nitrites were present in the hot potable water system (4 to 10 ppm) and absent in the cold potable water system. CONCLUSIONS: This outbreak of methemoglobinemia due to nitrite poisoning was traced to soup contaminated by nitrites in a boiler additive. Nitrites are ubiquitous and potentially hazardous inorganic ions. Extreme caution should be used when the possibility for toxic human exposure to nitrites exists.

Guide to pre- and postexposure rabies treatment. New Jersey State Department of Health.

Physicians are required by law to report all animal bites and human rabies postexposure treatments to a local health department. This information is extremely important to physicians and to New Jersey residents. The authors present recommendations for rabies pre- and postexposure treatment.

Benefits and costs of using an orally absorbed vaccine to control rabies in raccoons.

In November 1989, the epizootic of rabies affecting raccoons in the mid-Atlantic states reached New Jersey. An economic evaluation was conducted in 2 counties first affected by the epizootic to estimate the costs of the epizootic and to assess the costs and benefits of orally administering a newly developed recombinant rabies vaccine to prevent further spread of the disease. Data on expenditures associated with prevention of rabies in human beings and domestic animals and laboratory testing of suspect animals were collected and analyzed for 1988 (before the epizootic) and 1990 (first full year of the epizootic). Benefit-cost ratios were calculated and used to evaluate the economic advisability of the vaccine at various vaccination program alternatives. Two indices of capital investment analysis, payback period and net present value, were used to evaluate the economic benefits of the rabies vaccine. Expenditures were estimated to be $1,952,014 in 1990 (primarily for pet animal vaccinations), compared with $768,488 in 1988. Benefit-cost ratios ranged from 2.21 for the most expensive vaccination program alternative to 6.80 for the least expensive alternative. The payback period varied from 0.69 to 2.11 years, and the net present value ranged from $2,105,453 to $4,877,452. The high costs of this epizootic necessitated the reallocation of scarce public health resources to various rabies prevention activities, particularly the vaccination of dogs. This study also demonstrated the usefulness of benefit-cost analysis in developing public health strategies. Although the mass application of this recombinant vaccine was found to be economically beneficial, other qualitative considerations must be used to supplement these findings.

A cluster of unexplained deaths in a nursing home in Florida.

In the two-week period November 13-27, 1984, 12 patients died in a 54-bed nursing home in Florida; based on previous mortality patterns, 2.5 deaths would have been expected for the whole month. There was no similar increase in deaths in November 1984 and no comparable monthly death rate for any of 69 nursing homes in the same county from 1976-84. Comparison of the 12 deaths in November with 28 deaths that occurred during the previous 10 months and with 31 surviving patients who were continuously present in the nursing home between November 12-28, 1984 revealed that the patients who died in November were more likely to have had onset of the terminal event during the night shift, had a recent visitor, and had an admitting diagnosis of organic brain syndrome. The abrupt increase in the death rate for November 1984 was not associated with a measurable change in population characteristics, an outbreak of infectious disease, or changes in procedures or the environment. Reviews of employee schedules revealed a consistent and strong association between the duty times of two nurses and the onsets of the terminal episode and the times of patient deaths. Continuing epidemiologic surveillance of adverse outcomes in nursing homes is recommended.