PNEUMOCOCCAL DISEASE RATES DECLINING IN THE UNITED STATES

In early 2000, the seven-valent protein polysaccharide pneumococcal conjugate vaccine was licensed for use in infants and young children. A recent study reviewed changes in the incidence of invasive pneumococcal infection and found that the vaccine is preventing disease in both children and adults.

The study used data from the CDC’s Active Bacterial Core Surveillance system, which monitored invasive pneumococcal infection rates in seven states between 1996 and 2001. The population surveyed included 652,551 children between the ages of 2 and 4 and 433,591 younger children.

The overall incidence of invasive pneumococcal disease decreased by 59%, from an average case rate of 96/100,000 in 1998– 1999 to 40/100,000 in 2001. No change was seen in the 3- and 4-year-old children. The most striking declines occurred in the younger children. Disease rates among children 2 or younger decreased from 188/100,000 in 1998–1999 to 59/100,000 in 2001. By 2001, case rates had decreased by 69% in children younger than 1 year, by 68% in children 12 to 23 months old, and by 44% in 2-year-olds. For children younger than 2, the rate of disease caused by serotypes included in the vaccine decreased by 78%.

Disease rates also fell in groups for whom the vaccine is not recommended. A 32% decrease from baseline was found among people ages 20 to 39. Giving the vaccine to young children may be reducing carriage of vaccine-type pneumococcal strains in children, thereby protecting household contacts.

Whitney CG, Farley MM, Hadler J, et al. Decline in invasive pneumococcal disease after the introduction of protein-polysaccharide conjugate vaccine. N Engl J Med. 2003;348:1737-1746.

UNDIAGNOSED WHEEZING IN ADOLESCENTS

After evaluating data from the North Carolina School Asthma Survey (NCSAS), Yeatts et al concluded that children with undiagnosed frequent wheezing may actually have undiagnosed asthma and are not getting adequate treatment.

The NCSAS obtained surveillance data on the respiratory health of 84,405 seventh- and eighth-grade students from 499 public middle schools in North Carolina. A questionnaire was used to identify rates of wheezing, asthma, allergies, and heath care use.

Undiagnosed frequent wheezing was detected in 9% of the children; another 14% reported diagnosed asthma. The remaining children served as controls.

In comparison with the controls or the children with diagnosed asthma, those with undiagnosed frequent wheezing were more likely to be female, to come from a family of low socioeconomic status, and to have smoked cigarettes within the last month. Seventy percent of the children with undiagnosed frequent wheezing reported having allergies, as did 86% of children with diagnosed asthma and 36% of the controls. Demographic information was otherwise similar for children with undiagnosed frequent wheezing and those with diagnosed asthma.

Thirty-three percent of children with undiagnosed frequent wheezing reported having made one or more physician visits in the past year, compared with 71% of those with diagnosed asthma and 4% of controls.

The high prevalence of allergies both in asthmatic children and those with undiagnosed frequent wheezing suggests that children with undiagnosed frequent wheezing actually have asthma. The study also indicates that children with frequent wheezing may not be getting adequate treatment.

Yeatts K, Johnston Davis K, Sotir M, et al. Who gets diagnosed with asthma? Frequent wheeze among adolescents with and without a diagnosis of asthma. Pediatrics. 2003;111:1046-1054.

10-MG WARFARIN STARTING DOSE SUPERIOR FOR OUTPATIENTS

A randomized, controlled, clinical trial evaluating warfarin therapy in an outpatient setting compared a 10-mg dosing regimen with a 5-mg regimen and found that a therapeutic international normalized ratio (INR) could be achieved faster with the higher initial dose than with the lower dose.

Kovacs et al studied 210 consecutive outpatients, all of whom had acute venous thromboembolism. Patients received either 5 or 10 mg of warfarin on the first two days. INR was measured at baseline and on days 3, 4, and 5. The primary end point was time to a therapeutic INR. Secondary end points included the number of patients who had a therapeutic INR by day 5, incidence of recurrent venous thromboembolism within 90 days of diagnosis, and incidence of major bleeding events within 28 days.

Patients in the 10-mg group achieved a therapeutic INR 1.4 days sooner than did the 5-mg group. Eighty-three percent of patients in the 10-mg group had a therapeutic INR by day 5, compared with 46% of the 5-mg group. The 5-mg group required more INR assessments in the first 28 days of therapy. One major bleeding episode occurred in each group; rates of recurrent venous thromboembolism did not differ between groups.

Kovacs MJ, Rodger M, Anderson DR, et al. Comparison of 10-mg and 5-mg warfarin initiation nomograms together with low-molecular-weight heparin for outpatient treatment of acute venous thromboembolism: a randomized, double-blind, controlled trial. Ann Intern Med. 2003;138:714-719.

TREATING GER REDUCES NEED FOR ASTHMA MEDICATION IN CHILDREN

Gastroesophageal reflux (GER) can induce or exacerbate asthma. A recent study has now found that treating GER in children with asthma significantly reduces the amount of asthma medication needed.

The study, conducted by Khoshoo et al, included 46 children with moderate persistent asthma. All children underwent extended esophageal pH monitoring. Children with an abnormal pH either were given aggressive anti-GER treatment, including a proton-pump inhibitor (lansoprazole), a prokinetic agent (either cisapride or metoclopramide), and lifestyle changes, or underwent surgery. Children with normal pH levels had the option of no anti-GER therapy or empiric anti-GER treatment. Data were obtained for six months before GER work-up and for 12 months afterward.

Of the 27 patients with abnormal pH levels, 18 received anti-GER treatment and nine underwent surgery. Of the 19 children with normal pH levels, eight received anti-GER therapy and 11 received no treatment.

All patients with GER were able to reduce the amount of asthma medication used by more than 50% after treatment. In addition, two of the patients with normal pH findings who received anti-GER treatment had a 70% reduction in the need for bronchodilators and inhaled corticosteroids.

The authors concluded that an abnormal pH level is a good predictor of response to anti-GER therapy in children with asthma but added that therapy will probably have to be used for six months before a response is seen.

Khoshoo V, Le T, Haydel RM Jr, et al. Role of gastroesophageal reflux in older children with persistent asthma. Chest. 2003;123:1008-1013.