Multiple Modes Of Transmission Research Articles

An Outbreak ofMycobacterium terraein Clinical Specimens Associated with a Hospital Potable Water Supply

We investigated an increase in the number of patient specimens yielding Mycobacterium terrae in 1986, isolation of M. terrae was associated with specimens obtained from inpatients at our new hospital, but not with specimens referred from other hospitals [37(+)/144 inpatient specimens versus 2(+)/26 referred specimens, p less than 0.05]. By October 31, 1987, we had identified 163 positive specimens from 131 patients. All M. terrae were isolated from specimens obtained from non-sterile sites, i.e., respiratory, gastrointestinal, or urine. No clinical disease related to M. terrae occurred. Review of procedures and cultures of solutions used in the Microbiology Laboratory suggested the source of M. terrae was not in the Microbiology Laboratory. An analysis of case location showed an association with hospital tier (p less than 0.05), a pattern matching the design of the potable water system of the hospital. M. terrae was cultured from multiple outlets of this system. There appeared to be multiple modes of transmission of M. terrae from this reservoir. Control measures included avoidance of water sources during specimen collection and hyperchlorination of the potable water system. These measures appeared to result in the disappearance of M. terrae from subsequent clinical specimens. We believe this to be the first report defining the epidemiologic aspects of M. terrae contaminating clinical specimens.

An outbreak of giardiasis in a nursing home with evidence for multiple modes of transmission.

During a 6-w period from 20 April through 7 June 1986, an outbreak of giardiasis occurred in residents and employees of a nursing home and children participating in day care at the nursing home. Eighty-eight cases of giardiasis (defined by presence of clinical symptoms or results of stool examination) were identified from groups associated with the nursing home including 35 in nursing home residents, 15 in children in day care, and 38 in employees (including kitchen staff and child care providers). Multiple modes of transmission of Giardia lamblia, including food-borne and person-to-person transmission, occurred for these groups. Evidence of transmission by food included a significant association between sandwich consumption and illness in nursing home staff (P = .04) and a significant lack of illness among nursing home residents who consumed only a pureed diet (P = .007), where all food items are cooked before serving. The primary case among the food handlers, whose illness began in mid-April, had an infected child in the day care center. Person-to-person transmission is supported by a significant association between illness and physical contact with children from the day care facility through an "adopted grandparent" program (P = .03). This is the first reported outbreak of giardiasis in a nursing home, and these findings have implications for disease control in other facilities that combine child day care and care of the elderly.

EFFECTS EVOKED IN AN AXON BY THE ACTIVITY OF A CONTIGUOUS ONE

EFFECTS EVOKED IN AN AXON BY THE ACTIVITY OF A CONTIGUOUS ONE