In 1994 the Indiana State Department of Health (ISDH) set goals for elimination of measles, rubella, polio, diphtheria, tetanus in persons under 15 years of age, and Haemophilus influenzae type b disease in children under 5 years of age by 1996 and future years. These goals (zero cases) were met in 1997 for all targeted diseases except for Haemophilus influenzae type b. Indiana established a goal of no more than 10 cases of mumps in 1997. A specific goal was not established for pertussis.

For the second consecutive year there were over 100 cases of pertussis reported. This is the third time since 1993 that over 100 cases have been reported. In the seven years prior to 1993, 100 cases or more had been reported in only one year (1990). In the past five years (1993-97), 583 (mean=117) cases of pertussis have been reported in Indiana. In the five years previous to that period (1988-92), 458 (mean=92) cases were reported. This increased incidence in Indiana follows a national trend in pertussis occurrence. Over 6,000 cases of pertussis were reported nationally in 1996 and 1993; these two years represent the highest incidence of pertussis since 1967. Figure 1 depicts the annual incidence of pertussis for the past ten years.

Over half (53%) of Indiana's 1996 cases were in infants under the age of one; 16% occurred in children between the ages of 1-4; 18% of the cases were in the 5-17 year old group; and 13% were 18 years and older. Eighty-seven percent of the cases were white, 9% were African-American, 1% were biracial and 3% were of unknown race.

Fifty-six percent (58/104) of the all cases were hospitalized. Sixty-four percent (39/64) of the cases under the age of two were hospitalized. The average hospital stay for all cases was 2.9 days.

The vaccination status of cases 6 years and younger is shown in Table 1.

Twenty-four cases of invasive Haemophilus influenzae disease were reported to the ISDH in 1997, six of which were in children under five years of age. All six of the isolates from children under the age of five were serotyped. Of those six cases, one was type b (a seven month old female with documentation of two doses of Hib vaccine). Of the remaining 18 cases, nine were serotyped. Of those nine, one was type b (a 55 year old female).

Mumps incidence remains at a low level in the state, with only fifteen cases being reported in 1997. (The five-year mean for mumps in Indiana is 10 cases per year.) Twelve of the fifteen (80%) cases were laboratory confirmed. Nine of the cases were in children of school or preschool age and were eligible for vaccination with at least one dose of MMR. Of those nine cases, five had one dose of mumps containing vaccine and four were not vaccinated.

In 1997, for the third consecutive year, there were no cases of measles and for the fourth year there were no cases of rubella confirmed in Indiana.

There were no cases of polio (vaccine-associated or wild type virus), diphtheria or tetanus in 1997. The last case of tetanus in Indiana occurred in Indiana in 1994.

The continuing low or decreasing levels of vaccine-preventable disease cases in Indiana demonstrates the effectiveness of vaccination of appropriate populations as a preventive strategy. To continue at zero level for the five diseases and to reduce the levels of other vaccine-preventable diseases continued emphasis must be placed on reaching the goal of having 90% of two year olds complete the primary vaccination series by their second birthday. In addition, a surveillance system that ensures the identification, control, and elimination of vaccine-preventable diseases must include prompt case reporting, rapid confirmation of cases, expanded case finding and timely implementation of control measures. Table 2 compares 1996 and 1997 incidence of vaccine-preventable diseases in all ages and in children less than five years of age.

* Goals have not been established for these diseases.

Zero cases in 1997 was the goal for all diseases listed in this table with the exception of hepatitis b, mumps and pertussis. For Haemophilus influenzae type b, the goal is set for children under five years of age and for tetanus the goal is for children less than fifteen years of age. Ten cases or less was the goal set for mumps. Goals have not been set for pertussis or hepatitis B.