Epidemiologic, clinical, and laboratory features of Coxsackie B1-B5 infections in the United States, 1970-79.

In the period 1970 through 1979, the Coxsackie B1, B2, B3, B4, and B5 viruses constituted 24 percent of more than 18,000 enteroviruses isolated and reported through national surveillance. Young children, especially males, were most frequently affected: 48 percent of the national surveillance population were less than 5 years of age, including 30 percent who were less than 1 year old. Among the most frequently reported clinical syndromes associated with B infection were meningitis (in 56 percent of patients with B1-B5 infections), encephalitis (in 15 percent), and respiratory tract disease (in 14 percent). Carditis, a well-known B syndrome, was reported with only 2 percent of B1-B5 infections. Like most enteroviral agents, Group B viruses were isolated primarily during the summer: 87 percent of all these isolations were made during the 5 months from June through October. Although B2, B3, and B4 viruses were isolated at relatively uniform levels each year, B1 and B5 viral illnesses occurred nationwide as explosive epidemics only in certain years. A separate population of B-infected patients, identified by the Nassau County Medical Center (NCMC) Virus Laboratory, East Meadow, N.Y., during the same 10-year period, was studied to compare epidemiologic characteristics and to evaluate in greater detail clinical and laboratory features of B infections. Because of more active solicitation of specimens for testing, ascertainment in the NCMC system was more complete. The most frequently reported clinical findings at NCMC included fever (97 percent of cases), which was biphasic in 27 percent; pharyngitis (85 percent); vomiting (56 percent); headache (49 percent); other respiratory signs and symptoms (44 percent); diarrhea (40 percent); abdominal pain (33 percent); rash (31 percent); and otitis (28 percent). Rash was more frequently associated with younger than with older age groups (P < .01) for all B agents. Overall, throat (T) and rectal (R) swabs had the highest B-positivity rates among known infected patients(83 percent for T and 78 percent for R). Only for T was the positivity rate correlated with the interval between onset of illness and obtaining the specimen (P < .05). B agents grew most quickly from T specimens, but most reliably from R specimens. On the basis of these data,the authors recommend that both T and R specimens be obtained from every patient for whom prompt and reliable laboratory diagnosis of B infection is sought.To the authors' knowledge, these results from 10 years of national surveillance represent the largest surveillance summary of Coxsackie B viruses to date in the literature. Comparison of these results with those reported over the same 10 years by NCMC reflects differences that arise mostly because of differences in ascertainment systems.