The following was excerpted from the CDC MMWR 2002 Pertussis—United States, 1997—2000/51(04);73-6

Pertussis was a major cause of morbidity and mortality among infants and children in the United States during the prevaccine era (i.e., before the mid-1940s). Following the introduction and widespread use of whole-cell pertussis vaccine combined with diphtheria and tetanus toxoids (DTP) among infants and children in the late 1940s, the incidence of reported pertussis declined to a historic low of 1,010 cases in 1976. However, since the early 1980s, reported pertussis incidence has increased cyclically with peaks occurring every 3 -4 years. In 1996, less reactogenic acellular pertussis vaccines (DTaP) were licensed and recommended for routine use among infants. This report summarizes national surveillance data for pertussis during 1997-2000 and assesses the effectiveness of pertussis vaccination in the United States during this period. The findings indicate that pertussis incidence continues to increase in infants too young to receive 3 doses of pertussis-containing vaccine and in adolescents and adults. Prevention efforts should be directed at maintaining high vaccination rates and managing pertussis cases and outbreaks.

Pertussis should be suspected in a patient presenting with an acute cough illness lasting =14 days. Pertussis can be confirmed by isolation of Bordetella pertussis, polymerase chain reaction (PCR) or by epidemiologic linkage to a laboratory-confirmed case.

The increase in reported pertussis first noted in the 1980s continued throughout the 1990s. Compared with surveillance data for 1994-1996, the pertussis incidence rate among adolescents and adults has increased, 62% and 60%, respectively. The rate increased 11% among infants. In comparison, the incidence rate decreased 8% among children aged 1-4 years and remained stable among children aged 5-9 years. These increases could reflect a change in reporting or a true increase in incidence. In 1995, criteria for reporting a pertussis case changed in two ways: PCR became a method of confirmation, and data collection began for pertussis cases epidemiologically linked to another pertussis case. These changes primarily affected the reporting among patients aged >10 years. Although underreporting of mild or atypical disease is common, increased recognition and diagnosis of pertussis among older age groups probably contributed to the large increase of reported cases among adolescents and adults. Conversely, an increase in pertussis among infants too young to receive 3 doses of pertussis-containing vaccine suggests a true increase in pertussis circulation. Infants have been a well-recognized high-risk group; changes in diagnosis or reporting patterns in this age group are unlikely. Despite recent changes in pertussis diagnostic methods, the proportion of culture-confirmed cases among infants has increased.

The screening vaccine efficacy (VE) estimate of 88% reflects the effectiveness of the overall vaccination program that, according to NIS, used approximately two thirds DTaP and one third DTP in children aged 7-18 months. This estimate is similar to the VE of 77% - 90% previously estimated using the screening method for whole cell vaccine during 1992-1994 and to VEs observed in clinical trials for acellular pertussis vaccines. The incidence of pertussis among children aged 6 months-4 years has remained stable throughout the 1990s, suggesting that protection offered by vaccination has continued with the introduction of DTaP. Thus, the increase in reported pertussis cases is not related to low VE or the introduction of acellular pertussis vaccines.

Despite the effectiveness of vaccination, pertussis continues to occur in the United States among all age groups. The burden of disease remains highest in infants, who also have the highest rates for complications and death. In addition to maintaining high vaccination rates among preschool-aged children, prevention efforts should be directed at treatment of pertussis cases to prevent further spread of disease, use of antimicrobial prophylaxis in contacts of pertussis cases, and minimizing infant exposures to children and adults with cough illnesses. Studies among older children, adolescents, and adults examining pertussis disease burden and transmission of disease to infants might guide future policy decisions on the use of acellular pertussis vaccines among persons aged >7 years.

Editorial Note:

During the year 2001, a total of 23 cases of Pertussis were confirmed in Maine, with 3 additional probable cases. Of the 23 laboratory-confirmed cases, 3 (13%) were = 1 year of age, 1 case (4%) aged 1-4 years, 4 cases (17%) aged 5-9 years, 3 (13%) cases aged 10-19 years, and 12 cases (52%) = 20 years. 14 (61%) of the confirmed cases were female, compared to 9 (39%) male. The majority of confirmed cases, 70% (n=16), were from Waldo county, while 5 (22%) occurred in Aroostook county, and 1 (4%) in each of Kennebec and Penobscot counties.

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Audience: Clinicians and other health professionals interested

in adolescent or adult infectious disease issues.

Date: May 23, 2002

Time: 8:00 a.m. to 4:30 p.m.

Fee: $40, scholarships available

Location: Bangor Civic Center

Look for brochure with registration form in April.

Questions: Anne Littlejohn at 622-7566 x231

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MAINE RABIES SUMMARY - 2001

Table 1.

Rabid Animals Identified by Species and County
January 1, 2001 through December 31, 2001

A total of 85 animals were tested positive for rabies in 2001 as illustrated in Table 1. While 15 of 16 counties are endemic for the raccoon strain of rabies, only 12 counties had any rabid animals identified in 2001. This is not an indication of a lack of rabid animals but a lack of animals submitted for testing.. Maine only tests animals which have had contact with people, pets or agricultural animals. Aroostook County is the only county where the raccoon strain of rabies has not been found in any of the animals tested thus far.

The raccoon strain of rabies entered the state from the south in 1994. Although the fox and bat strains of rabies were already present in the state, the raccoon strain has accounted for a great majority of the infected animals tested since that time. The number of rabid animals identified in Maine has decreased since the peak in 1998 when 248 animals tested positive for rabies (see Table 2).

A total of 98 persons were treated prophylactically following contact with a rabid or suspect rabid animal in 2001. Thirty-nine persons were treated following contact with a bat, 19 had contact with a stray cat, 13 had contact with an unknown fur-bearing mammal, 9 with a raccoon, 7 had contact with other various mammals not listed, and 4 had contact with a skunk. Of the 98 persons treated with rabies post exposure prophylaxis (PEP), only 76 (78%) were recommended to be so treated following the Centers for Disease Control’s guidelines for determining exposure. Comparatively, in 1997, the first year that PEP was reportable to the Bureau of Health, only 50% of persons who received PEP were treated per the guidelines.

Types of exposure which warrant treatment for rabies prophylaxis are:

For each animal tested for rabies at the Health and Environmental Testing Laboratories (HETL) , an exposure history is obtained. There were 97 domesticated or agricultural animal exposures to a confirmed rabid animal recorded. Of these, 73 (75%) were up to date on their rabies vaccination and only required a booster dose of vaccine as well as 45 days of observation for symptoms of rabies. Twenty-four animals were not up to date on their rabies vaccination. Their owners were required to quarantine the animal for six months or euthanize the animal. Of these, fourteen animals were quarantined for six months and ten animals were euthanized.

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The Maine Bureau of Health is investigating an outbreak of Salmonella enteritidis (SE) among Maine residents who became ill between 13 January and 26 January 2002. The outbreak was first detected in late January when an unexpectedly large number of Salmonella isolates were reported by clinical laboratorians and were sent to the Maine Health and Environmental Testing Laboratory (HETL) for serotyping.

During 2001, 8 cases of Salmonella were reported between January 1 and February 15, 2001, one of which was S. enteritidis. During the same period in 2002, a total of 22 cases were reported, 16 of which were S. enteritidis. Subsequent molecular testing at the Maine HETL determined that 15 of 16 isolates shared a single Pulsed Field Gel Electrophoresis (PFGE) pattern on one enzyme testing, and that 4 of 5 tested isolates also had a common pattern on testing with a second enzyme. Testing at the Centers for Disease Control’s Foodborne and Diarrheal Diseases Laboratory identified 13 of 15 isolates as sharing the same uncommon phage type (Type 913). These similarities strongly suggest a common source for the illness.

Individual telephone interviews were conducted with all 16 SE cases or with the appropriate parent or guardian, and studies were performed on all SE isolates. One case, in a hospitalized child, was excluded from cluster analysis after interviews revealed that the bulk of his incubation period occurred during overseas travel and that the PFGE pattern did not match the 15 others. The remaining 15 cases were included in the outbreak investigation. Eleven cases reside in southern Maine (York and Cumberland counties) and 4 in the mid coast region (Waldo, Sagadahoc, and Lincoln counties) . Case age range is 5-88 years with a mean of 31 and a median of 25 years. Seventy three percent of cases are female. Dates of illness onset range from January 13–January 26, with 11 cases clustered during the week of January 20-26.

During the investigation, a history of mung bean sprout ingestion emerged in many of the cases.

Nine (60%) specifically recalled a history of eating mung bean sprouts, and one had possible, but uncertain bean sprout consumption history. Five cases did not recall any history of eating bean sprouts on specific questioning. No other food, restaurant or other exposure commonalities were identified.

For the nine cases who consumed bean sprouts, meal-to-illness intervals ranged from 12-103 hours with a mean of 47 and a median of 48 hours. Of these individuals, eight (89%) had eaten bean sprout-containing items in one of 4 Asian restaurants in southern and midcoastal Maine (Pad Thai or raw salad with bean sprouts). The ninth individual ate a chicken wrap sandwich that contained bean sprouts at a non-Asian restaurant. In all, five Maine restaurants were implicated as the source for bean sprout consumption.

Once mung bean sprouts were identified as the probable source of illness for the nine cases, Sanitarians from the Maine Department of Human Services and the City of Portland were dispatched to all implicated restaurants to determine bean sprout providers. Three of the restaurants were noted to have utilized a single bean sprout grower in Maine, designated as Grower A (note: two of the three reported more than one supplier). When a list of customers of Grower A was obtained, it was determined that he had also supplied sprouts to a fourth implicated restaurant, and also to a distributor who supplied these sprouts to the fifth implicated restaurant. Officials from the U.S. Food and Drug Administration (FDA) and the Maine Department of Agriculture were notified, and joined the investigation. Once investigators identified the likely source of seeds used to grow implicated sprouts, the grower voluntarily ceased use of sprout seeds from this stock and recalled previously distributed sprouts grown from implicated seed stock.

Epidemiologists at state health departments in Massachusetts and New Hampshire were contacted and they reported that no concomitant increases in SE incidence in their respective states.

A telephone case-control study was conducted by the Maine Department of Human Services’ Bureau of Health and CDC. Preliminary results further implicate mung bean sprout consumption as the source for Salmonella infection in the 9 cases.

This investigation is continuing with the collaboration of the US Food and Drug Administration and with assistance from the Maine Department of Agriculture. Epidemiological and laboratory assistance has been supplied by the CDC Foodborne and Diarrheal Diseases Branch.

Of note, during February and March 2001, Edmonton, Canada experienced an outbreak of Salmonella enteritidis phage type 913 (SE PT 913), the same unique phage type as this Maine outbreak. Eighty-four cases were reported. Sixty-two percent of cases in Edmonton recalled eating at Vietnamese, Chinese or Japanese style restaurants in the Edmonton area. Of those cases, 84% recalled consuming a meal with bean sprouts. Further investigation revealed that all implicated restaurants shared the same bean sprout supplier during February 2001.

The following was excerpted from CDC MMWR Outbreak of Salmonella serotype Kottbus Infections Associated with Eating Alfalfa Sprouts --- Arizona, California, Colorado, and New Mexico, February--April 2001 51(01):7-9- January 11, 2002

Since 1995, 15 outbreaks of Salmonella spp. and two outbreaks of Escherichia coli O157:H7 infections associated with sprouts have been reported to the Centers for Disease Control (CDC). Despite public health advisories about the risks for eating raw sprouts, persons at high risk for systemic infection continue to eat sprouts.

The Maine Bureau of Health, Division of Disease Control and the Health and Environmental Testing Laboratory are offering free hepatitis C EIA screening tests for high-risk patients. The Bureau will also cover specimen postage costs. Any medical or social service provider working in a setting where blood is drawn and patients are counseled is eligible to participate. Enrollment is contingent upon attendance at a one-day training. The pilot will begin on May 1, 2002.

Training topics include: HCV epidemiology, pilot program policies/procedures, and a review of hepatitis C pre/post-test counseling messages.

For more information contact: Mary Kate Appicelli, Hepatitis Coordinator at 287-3817
or mary-kate.appicelli@state.me.us.

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