Amblyomma americanum: a potential vector of Lyme disease in New Jersey.

Amblyomma americanum is a likely secondary vector of Lyme disease in New Jersey. Ticks of this species were removed from the site of the characteristic skin lesion known as erythema chronicum migrans on two patients with the disease, and the Lyme disease spirochete was isolated from nymphs and adults of this species. That A. americanum is a potential vector is supported by its similarities to Ixodes dammini, the known tick vector, in seasonal distribution and host utilization. The extensive range of A. americanum may have great implications for potential Lyme disease transmission outside known endemic areas.

Vector tick populations and Lyme disease. A summary of control strategies.

Although many aspects of Lyme disease have been intensely studied for over a decade, little research has been directed toward control of the principal tick vector, Ixodes dammini. Ecological and epidemiological investigations have provided not only an ample understanding of tick biology and behavior, they have also identified the types of areas at risk for disease transmission. The advantages and limitations of previous attempts to control I. dammini by host reduction, habitat modification, and acaricide applications have been discussed in relation to overall control strategies for high-risk areas, and an integrated approach to control proposed.

Outbreak of adenoviral infections in a long-term paediatric facility, New Jersey, 1986/87.

During an 8-week period in the winter of 1986-87, there were 11 deaths from an adenovirus infection (case fatality rate = 39%, 11/28) in a long-term care paediatric facility in southern New Jersey. Among the 61 resident children, all with severe congenital and/or acquired disabilities, 28 developed a febrile respiratory illness compatible with adenovirus infection [attack rate (AR) = 46%]. Patients with tracheostomies were three times as likely to become ill [relative risk (RR) = 3.2, 95% confidence intervals (CI) = 1.8-5.6]. Twenty-three members of the staff had a similar febrile illness (AR = 22%, 23/106); nurses were more likely to be ill than other staff (RR = 3.0, 95% CI = 1.1-11.4). Adenovirus 7 was isolated from four of the case patients and adenovirus 1 from one. The findings suggest prolonged transmission between patients and nursing staff with lack of cohorting of ill patients probably contributing to the prolongation of the outbreak. This investigation indicates that adenoviral outbreaks, although rare, can have a high mortality in severely disabled children, and that future outbreak investigations should examine the use of vaccines or antiviral agents to reduce mortality and for outbreak control.

Lyme disease in New Jersey.

Lyme disease is a spirochetal infection endemic throughout New Jersey. Case reports from 1984 through 1986 suggest different high-risk groups and different disease severity than had been observed in earlier cases in the state. Both sexes now appear equally at risk, while younger age groups, particularly children less than ten years old, appear to be at increased risk. Mild disease is usual, although classic rheumatologic and neurologic complications can occur. Informal surveys suggest Lyme disease is under-reported by a factor of five- to tenfold in New Jersey. Early recognition by physician and patient is necessary for prompt treatment to reduce complications.

Epidemiology of congenital syphilis.

Between 1984 and 1987, the number of reported cases of congenital syphilis in New Jersey tripled. Findings indicate an increase in early syphilis among females of childbearing age living in areas of high syphilis morbidity, reflecting, possibly, lifestyle changes within populations already at risk for the disease. Future studies and interventions are needed.

Salmonella typhimurium. Transmission by fiberoptic upper gastrointestinal endoscopy.

During a four-month period, Salmonella typhimurium developed in seven persons within five days of fiberoptic upper gastrointestinal (GI) endoscopy. A retrospective cohort study confirmed the association between S typhimurium infection and fiberoptic upper GI endoscopy. Salmonella typhimurium was cultured from the endoscopic equipment and the accessory suction equipment. The Salmonella isolated from the endoscopic and accessory suction equipment was identical to that recovered from the seven patients with salmonellosis by serotype, antimicrobial susceptibility pattern, and bacteriophage lysis pattern. Salmonella transmission was attributed to inadequate disinfection of the endoscope and accessory equipment between procedures. The original source of the contamination was not discovered.

Hepatitis B outbreak traced to an oral surgeon.

Over a four-year period in a five-county area, 71 patients with clinical hepatitis B had dental work performed in the two to six months before their illness. Fifty-five cases were traced to a single oral surgeon. Seventy-nine per cent of these patients were positive for hepatitis B surface antigen (HBsAg) and most had no other recognized source of hepatitis. An investigation of the implicated dentist uncovered no gross inadequacies in instrument sterilization or general dental procedures; however, the dentist was found to be an asymptomatic carrier of HBsAg of the same subtype (ay) as nine of 11 of his patients who had hepatitis and whose serums were available for testing. Since no HBSAg was found in the dentist's saliva, urine or feces, and since he admitted to having frequent cuts on his fingers, it is possible that a "hemoral" transmission of HBs Ag produced hepatitis in his patients.

A focus of Lyme disease in Monmouth County, New Jersey.

An endemic focus of Lyme disease is present in Colt's Neck, Howell, Freehold, and Wall Townships in Monmouth County, New Jersey. Cases of Lyme disease have occurred in this area from 1978 to 1982. Fifty-seven of the 117 persons (49%) who acquired their infection in New Jersey from 1978 to 1982 live or work in these four townships, whose population of 82,491 is only 1.1% of the population of the entire state. Thirty persons who contracted Lyme disease were exposed to ticks at the Naval Weapons Station, Earle, which is located within Colt's Neck and Howell Townships. The annual incidence rate for persons stationed at or working on this military facility in 1981 and 1982 was about 1%. At Naval Weapons Station, Earle, persons working outdoors in 1981-1982 were at higher risk than those working indoors.

Giardia transmission in a swimming pool.

In the fall of 1985, an outbreak of giardiasis occurred among several swimming groups at an indoor pool in northeast New Jersey. Nine clinical cases were identified, eight of whom had Giardia positive stool specimens. All were female; seven were adults (greater than 18 years) and two were children. The attack rate was highest (39 per cent, 5/13) for the ladies lap group who had exposure on one day. These cases had no direct contact with children or other risk factors for acquiring Giardia. Infection most likely occurred following the ingestion of swimming pool water contaminated with Giardia cysts. The source of Giardia contamination was a handicapped child who had a fecal accident in the pool. He was a member of a group that swam at the same time as the ladies lap group. A stool survey of the handicapped group showed that of the 20 persons tested, nine were positive for Giardia, including the specimen from this child. Examination of the pool records showed that no chlorine levels had been taken on the day of the fecal accident and that on the following day the chlorine level was zero. This is the second report of Giardia transmission among swimming pool attendees. It emphasizes the need to maintain appropriate chlorine levels in swimming pools and to institute measures to clear pools after a fecal accident.

Evolution of a focus of Lyme disease.

Epidemiological investigations were initiated in 1984 when significant Lyme disease activity was observed within a 5-km radius of an area previously used as a non-endemic control site for Lyme disease research in New Jersey. Through 1983, collections of Ixodes dammini from vegetation and feral rodents were infrequent and no human cases were identified within a 16-km radius of the control site. In 1984, 4 human cases and 3 serologically reactive canines (greater than or equal to 1:512) were recognized within the area and adult I. dammini populations were over 3-fold greater than those at our primary study location where Lyme disease has been endemic since 1981. Using darkfield microscopy, 53.4% of adult I. dammini were infected with Borrelia burgdorferi as compared to 50.0% of adults collected during the same period at the known endemic study site. These data indicate that a focus of Lyme disease has recently become established at the previously non-endemic control site and that the establishment of new foci may occur more rapidly than once thought.

Comparison of rates of infection by the Lyme disease spirochete in selected populations of Ixodes dammini and Amblyomma americanum (Acari: Ixodidae).

At a major endemic focus in New Jersey, 50% of 290 adult Ixodes dammini collected in the fall of 1984 were infected with the Lyme disease spirochete (Borrelia burgdorferi), which was statistically higher than the rate found in the 202 adult ticks (39.6%) examined during the spring. Neither sex nor site of collection within the focus significantly affected the infection rate. The observed infection rates were similar to those reported in endemic areas of New York and Connecticut. Borrelia burgdorferi also infected all active stages of Amblyomma americanum ticks. Rates of infection were 5.4% in adults (n = 467) and 3.4% in nymphs (n = 289); 15.6% of clusters of unengorged larvae harbored B. burgdorferi, suggesting transovarial passage of the spirochete. Comparison of the rates of infection in I. dammini and A. americanum and their potential impact on Lyme disease transmission is discussed.

Prevalence of canine Lyme disease from an endemic area as determined by serosurvey.

From August 1984 through February 1985, 423 dogs from 43 municipalities in 7 New Jersey counties were evaluated for the presence of antibodies to the Lyme disease spirochete (Borrelia burgdorferi). Of these dogs, 34.7% with no apparent clinical symptoms were serologically reactive (IFA greater than or equal to 1:64); titers in this study ranged from non-reactive to 1:2048. Ninety percent of the dogs surveyed had a current vaccination status to Leptospira interrogans serovars canicola and icterohaemorhagiae. Dogs vaccinated to leptospirosis elicited homologous antibody titers of less than or equal to 1:16 and, therefore, did not interfere with interpretation of antibody levels to B. burgdorferi. Effects of age, degree of outdoor activity, travel history, and location of residence were evaluated. The use of serosurveys of dogs as a tool for Lyme disease surveillance is discussed.

Geographical distribution and density of Ixodes dammini (Acari: Ixodidae) and relationship to Lyme disease transmission in New Jersey.

As part of continuing studies of Lyme disease, deer were surveyed during three hunting seasons in 1981 to obtain information on geographic distribution and density of I. dammini in New Jersey. I. dammini occurred throughout central and southern New Jersey. Four deer management zones (DMZs) were shown to have high tick densities. Geographical distribution and density data were independently regressed against 25 environmental and physical factors. Elevation was shown to be the most important factor in explaining the variability in both I. dammini distribution and density. Lyme disease cases were closely associated with the distribution of I. dammini and 57.3 percent of 117 Lyme disease cases occurred in the four DMZs previously identified as having the highest tick density.

Foodborne Norwalk virus.

On December 6, 1979, three luncheon banquets were served in a New Jersey restaurant. Thirty-eight of 41 members (92.7%) of the first group became ill as did 25 of 31 members (80.6%) of the second group. None of 12 members of the third group were ill. Illness consisted primarily of diarrhea (76%), nausea, (73%), vomiting (67%), cramps (46%) and fever (18%); the median incubation period was 31 hours and median duration 24 hours. The same foods were served to all three groups, except that cole slaw was substituted for a green salad and mixed vegetables for lima beans for the third group. Consumption of green salad was associated with illness (p less than 0.0001). A total of 118 other persons who ate at the restaurant on the same day were interviewed, 60% of whom reported being ill. Green salad was significantly associated with illness for this group at lunch (p = 0.005) and dinner (p = 0.00007). Serologic studies on seven of 12 patients and on one of four exposed controls showed a fourfold or greater rise in antibody titer to Norwalk virus.