Viral epidemiology: the hidden universality of infection

Enteroviruses as causative agents in type 1 diabetes: loose ends or lost cause?

Considerable evidence implies that an enteroviral infection may accelerate or precipitate type 1 diabetes (T1D) in some individuals. However, causality is not proven. We present and critically assess evidence suggesting that islet β cells can become infected with enterovirus, and argue that this may result in one of several consequences. Occasionally, a fully lytic infection may arise and this culminates in fulminant diabetes. Alternatively, an atypical persistent infection develops which can be either benign or promote islet autoimmunity. We propose a model in which the 'strength' of the β cell response to the establishment of a persistent enteroviral infection determines the final disease outcome.

Effect of respiratory infections on exacerbation of asthma in adult patients. A six-month follow-up

The peak expiratory flow values and asthma symptom scores of 92 adults with extrinsic and intrinsic asthma were recorded daily from September 1981 to April 1982 in order to study the effects of symptomatic respiratory infections (SRI) on the course of asthma. During the follow-up, 253 exacerbations of asthma were observed in 67 patients. 68 subjects had 141 episodes of SRI. 63 of 253 exacerbations (25%) were found in association with SRI. The mean duration of the exacerbations associated with SRI was 11.4 days, significantly different (P less than 0.01) from the mean duration of 8.1 days recorded for the other exacerbations. The results confirm the high incidence of asthmatic exacerbations during respiratory infections and suggest that the recovery from an exacerbation is slower in association with infection.

Viral inclusion bodies in tracheobronchial epithelium of asymptomatic subjects

During a survey conducted for the cytodiagnosis of early bronchogenic carcinoma, cytoplasmic viral inclusion bodies were found sporadically in tracheobronchial smears of asymtomatic patients of both sexes (ages ranging from 18 to 80 years) undergoing general endotracheal anesthesia for surgery. A review of 3,049 cases performed to assess the frequency of occurrence of this phenomenon showed a 1.1 percent incidence in all smears studied. There was no relationship between smoking habit, age, or sex and the presence of inclusion bodies; however, there was a marked seasonal incidence, with 60 percent of inclusion-bearing smears being found during the months of January through March.