Multiple Infection Sites Research Articles

Pathogenesis of the hyphomycete Tolypocladium cylindrosporum in the mosquito Aedes aegypti

A series of experiments were carried out to determine the pathogenesis of Tolypocladium cylindrosporum in larvae of Aedes aegypti. Host death in relation to larval feeding, molting, and fungal colonization of the hemocoel, and the principle sites of infection were determined. In addition, observations were made on conidial germination, fungal growth, and sporulation on surface or in submerged culture using scanning electron and light microscopy. The host-pathogen relationships are complex: Multiple infection sites occur which differ according to the host's growth stage; larvae seem most susceptible during their molting period; and conidia germinate and produce blastoconidia in the mosquito rearing medium. Molting larvae succumb to the fungus prior to fungal colonization of the hemocoel, primary infection sites being through the alimentary canal and the exocuticle. Intermolt larvae succumb to the fungus after fungal colonization of the hemocoel with primary infection sites at the base of the mandibles and maxillae and in the region of the anus.

Cytomegalovirus: import of sexual transmission.

This article reviews available evidence regarding the transmission of cytomegalovirus (CMV) and concludes that sexual transmission--if it occurs at all--is medically and epidemiologically insignificant. The great majority of CMV infections, primary or recurrent, are completely asymptomatic and must be regarded as clinically inapparent entities. The virus does cause overt illness in some well-defined clinical situations, including heterophil-negative mononucleosis, after renal and cardiac transplants, in interstitial pneumonitis of early childhood, late neonatal sepsis, and congenital infection. Infections without concomitant disease, multiple sites of infection including oropharynx, urine, cervix, spermatic fluid, breast milk, and blood, and persistence of excretion over years have enabled CMV to parasitize human populations. Between .5% and 2.5% of the infant population is infected in utero, another 3-5% of live born infants become infected at delivery, in some areas of the world 90-100% of the population acquires the virus in early childhood by respiratory spread, and in the US and other developed countries 40-80% of the population is infected by puberty. By the 6th decade of life virtually the entire population is infected. Several lines of evidence suggest that sexual transmission is not important: the amply documented major role of alternative modes of transmission, the insignificant role of hygiene per se as a determinant of CMV prevalence in a population, the influence of hormonal status independent of sexual activity on active infection and presumably transmission, and the fact that CMV is not excreted from the human cervix beyond the age of 30. A possible exception to the general conclusion is the recent suggestion of clinical disease caused by sexually transmitted CMV in homosexual men, in which other factors however also appear to play a role.

Changing Patterns of Hospital Infections and Antibiotic Use

The results of a physician-performed prevalence survey of infections and antibiotic use at the Salt Lake City LDS Hospital in 1979 were compared with those from a previous survey in 1971. The overall prevalences and types of infections found in the two surveys were similar. Although Gram-negative bacilli accounted for 60% or more of all bacterial isolates from hospital-acquired infections in both surveys, Gram-negative bacilli other than Escherichia coli were more prevalent in the 1979 survey. An anticipated increase in numbers of critically ill patients resulting from our hospital's evolution as a regional tertiary care center was reflected by more patients with multiple sites of infection, with vascular or urinary catheters, and who were receiving multiple antibiotics. Use of antimicrobial agents increased from 23% to 37% of all surveyed patients and was attributed mainly to wide use of cephalosporins for prophylaxis in surgical patients.

Bilateral Deep Brachial Vein Thrombophlebitis Due to Vibrio fetus

A patient had bilateral deep brachial vein thrombophlebitis in which Vibrio fetus was recovered from six blood cultures of the six drawn. Fever and phlebitis continued with treatment with intravenous doses of heparin and oxacillin but rapidly improved with treatment change of oxacillin to clindamycin. In vitro antibiotic disk susceptibility testing confirmed resistance to oxacillin and susceptibility to clindamycin. Vibrio fetus infection is associated with the vascular endothelium in this and previously reported cases

Lethal postoperative infections following cardiac surgery. Review of four years' experience.

Seventeen of 1,494 patients (1.1%) succumbed to infection following open-heart operations at New York University Hospital between January, 1968 and December, 1971. All but two of these patients had Starr-Edwards ball-valve prostheses inserted. One had repair of a tetralogy of Fallot, and one had aortic commissurotomy and a double coronary bypass graft. The sites of infection were pulmonary (15 patients), urinary tract (14), mediastinum or pleura (10), and blood (15). Pulmonary infection appeared as the source of endocarditis in 13 patients and as a source of pleural or mediastinal infection in nine. Candida species infection was directly responsible for the deaths of 10 of the 17 patients, being the sole organism isolated in 5 of the 10. Predisposing factors to infection were preoperative bacterial endocarditis 2 patients, prolonged cardiopulmonary bypass (>3½ hours) 6 patients, a "low output" state following operation 12 patients, postoperative cerebral dysfunction 6 patients, and postoperative disseminated intravascular coagulation 4 patients. The debilitated state of the patients, multiple sites of infection, degree of tissue destruction, and the variety and resistance of the organisms involved all combined to produce treatment failure. Removal of the infected valvular prosthesis coupled with antimicrobial therapy is considered the treatment of choice in instances of bacterial endocarditis when chemotherapy fails and in all cases of established fungal endocarditis.