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At least 19 recordsLinked to original sources
PubMed1978

Bovine respiratory syncytial virus infection of bovine embryonic lung cultures: enhancement of infectivity with diethylaminoethyl-dextran and virus-infected cells.

The effects of incorporating diethylaminoethyl-dextran (DEAE-D) in the inoculum with bovine respiratory syncytial virus (BRSV) on the infectivity of BRSV was evaluated. A concentration of 40 microgram DEAE-D/ml provided maximal enhancement of infection as determined by the time of onset of cytopathic effect (CPE), the percentage of cells infected by the inoculum, and the amount of virus produced. When DEAE-D was used in the inoculum, the CPE appeared a day earlier, the percentage of cells infected by the inoculum, as determined by the fluorescent antibody test, was increased 11 times, and the viral titer was increased 2 times as compared to results obtained without DEAE-D. Bovine respiratory syncytial virus-infected cultures contained much cell-associated virus which could be liberated by sonication to increase the titer of virus stocks. The use of BRSV-infected cells rather than supernates from BRSV-infected cells increased the rate at which a cytopathic effect developed, although it did not substantially increase the titer of virus which was harvested. The use of DEAE-D in the inoculum and the passage of BRSV-infected cells instead of viral suspensions was found to be the quickest and most effective method of consistently obtaining BRSV with a titer of about 10(5.5) TCID50/ml.

Animals↗
PubMed1976

Studies on the infectivity of Fasciola hepatica miracidia to Lymnaea truncatula. Attachment and penetration of miracidia into non-infected and infected snails.

Fasciola hepatica miracidia labelled in vivo with radioselenium have been used in studies on the capacity of the miracidia to attach to and penetrate the tegument of infected compared with non-infected host snails (Lymnaea truncatula). The results show that the penetration of the larvae into the snail tissue is not influenced by an already existing infection, regardless of its developmental stage.

Animals↗
PubMed1978

Ocular histopathology in animals experimentally infected with Mycobacterium leprae and M. lepraemurium. 1. Mycobacterium leprae and M. lepraemurium infections in the mouse. 2. Mycobacterium leprae infections in the 9-banded armadillo (Dasypus novemcinctus L.).

At varying periods of time following the successful establishment of systemic infections with Mycobacterium leprae or M. lepraemurium in the mouse and the nine-banded armadillo eyes were examined by light microscopy. Inoculation of bacilli was by the intravenous or intraperitoneal route or directly into the hind footpads; eyes were not directly inoculated in this study. During periods of up to 3 years under laboratory conditions no animal showed evidence of impaired vision or blindness, and the external appearance of both eyes was normal. The ocular histopathology and the sites of accumulation of bacilli are described. In immunologically normal mice infected with M. lepraemurium bacilli were much commoner in extraorbital tissues, but they were, nevertheless, found in various tissues within the orbit, including the ciliary body and sclera. In immunologically normal mice (and one rat) injected with M. leprae of human origin no bacilli were found in the eye, but in mice immunologically depressed by thymectomy and total body irradiation considerable numbers of bacilli were present in the iris and ciliary body and also in the limbal cornea. In the armadillo bacilli were found in large numbers in virtually all tissues except the lens, retina, optic nerve, and aqueous and vitreous humours, but the uveal tract was heavily involved. Findings are discussed in relation to the great frequency of ocular involvement and the importance of immune-complex disease in patients with lepromatous leprosy, and to factors wihch may favour the localisation and multiplication of Mycobacterium leprae in the eye.

Animals↗
PubMed1977

Long term variations in trypanosome infection rates in highly infected tsetse flies on a cattle route in south-western Nigeria.

One thousand, nine hundred and ninety-seven male and 1988 female Glossina morsitans submorsitans were dissected at Ogbomosho, on a trade cattle route in south-western Nigeria, from June 1970 to August 1973. Of male flies, 1307 (65-45%) were infected by Trypanosoma vivax trypanosomes, 66 (3-31%) by the subgenus Nannomonas (congolense group) and three (0.15%) by the subgenus Trypanozoon (brucei group). Of flies, 1236 (62-17%) had T. vivax infections, 80 (4-02%) had infections of the subgenus Nannomonas and two (0.10%) had infections of the subgenus Trypanozoon, The great majority of T. vivax infections were mature, while a high proportion (10% in males and 22% in females) of infections of the subgenus Nannomonas were immature. No infection with the subgenus Trypanozoon was found after October 1971. Overall infection rates, for male and female flies respectively, rose from 77% and 80% in June 1970 to peak values of 91% ad 90% in April and June 1971 and thereafter declined to lowest values of 37% and 43% in 1973. The incidence of T. vivax infections was the major component of the rises and falls in overall infection rate. During the period of peak infection rates (April-June 1971), all female flies over about 40 days old were infected. It was assumed that all these had T. vivax infections; some also had subgenus Nannomonas infections and one also had an infection of the subgenus Trypanozoon. Of 72 specimens of G. tachinoides dissected at Ogbomosho from June 1970 to August 1972, 20 (27-8%) were infected by trypanosomes, 19 with T. vivax and one with immature subgenus Nannomonas. In this species, also, infection rate was related to the age of the fly. Of 43 specimens of G. m. submorsitans dissected at Ilorin, north of Ogbomosho on the same cattle route, in February 1975, seven (16-3%) had T. vivax infections. One of two specimens of G. tachinoides dissected here at the same time had an immature infection of the subgenus Nannomonas. In G. m. submorsitans, variations in age structure of the population did not account for the temporal fluctuations in infection rates. It appeared that since 1970 events further north, especially tsetse eradication and the natural decline of tsetse populations (due probably to drought) reduced the trypanosomiasis risk to cattle proceeding southwards. The declining infection rates at Ogbomosho, after 1971, reflected this.

Animals↗
PubMed1976

The epidemiology of 2056 remote site infections and 1966 surgical wound infections occurring in 1865 patients: a four year study of 40,923 operations at Rush-Presbyterian-St. Luke's Hospital, Chicago.

Over a 4-year period 40,923 operations and 44,716 surgical admissions were monitored for both community and hospital onset infections. One thousand eight hundred sixty-five patients had 1966 surgical wound infections and 2056 remote infections including 1652 hospital onset and 404 community onset infections. One thousand one hudnred forty-four patients with multiple infections averaged 40 days in the hospital contrasted with 24 days for 721 patients with a single wound infection. The total excess cost of hospitalization for these patients was $951,150. A statistically significant reduction occurred for urinary tract infections, lower respiratory infections and clean and contaminated surgical wound infections. It is suggested that these are all inter-related and a significant reduction in surgical wound infections can be achieved through control of infections at remote sites, particularly those associated with medical devices. The coagulase positive staphylococcus is still the most important single bacterial species in the primary etiology of surgical wound infections. When the gastrointestinal tract is entered or "supra" infecting organisms appear, gram negative bacteria and mixed gram negative and gram positive infections are dominant. Reduction in remote site infections occurring in surgical patients is necessary to reduce the incidence of surgical wound infections, suggest preventive and control measures, and document the effectiveness of such measures.

Adolescent↗
PubMed1979

Experimental infections with Cooperia oncophora (Railliet, 1918) in calves. Results of single infections with two graded dose levels of larvae.

Two experiments were carried out in which calves reared parasite-free were infected with a single dose of 3rd-stage larvae of Cooperia oncophora. In the first experiment the calves received 20 000 or 200 000 infective larvae and they were autopsied 28 or 56 days after the infection. In the second experiment the doses were the same but the animals were killed 14, 84 or 140 days after infection. If a dose of 20 000 was given, clinical signs were never observed, while at a dose level of 200 000 the weight gain was less on 56 and 84 days after the infection compared with the low-infected groups or the control animals. After 170 days the differences in weight gain were compensated. Faecal egg output was higher in the 200 000 groups only in the first period of patency, thereafter the calves in the 20 000 groups produced more. No obvious differences between the two infection levels were observed with regard to the haematological data. In the low-infected groups worm counts were only slightly lower when the results after 28 days were compared with those after 56 days. Also, the worm numbers after 14 days were almost equal to those after 84 days, while at 140 days 1 animal still had the same number, the other one had lost its worm burden. In the high-infected groups the worm loss was much quicker. After 28 days a great part of the population had already been lost. Obviously, at the 200 000 level the reaction of the host against the parasite was much stronger. Adult worms were expelled at a higher rate than early 4th-larval stages. In the first experiment worm measurements revealed differences between the length of females, males and spicules of males, these being significantly longer in the low-infected groups. Analysis of the distribution of worms over the small intestine showed that in the low-infected groups worms were mainly restricted to the first 6 metres. In the high-infected groups the worm population was distributed more evenly over the whole small intestine.

Animals↗
PubMed1978

Plasmodium falciparum and Plasmodium vivax infections in the owl monkey (Aotus trivirgatus). I. The courses of untreated infections.

This study, the first of three designed to determine the feasibility of using owl monkeys infected with human plasmodia in the search for new, more broadly active antimalarial drugs, dealt with the characteristics of untreated infections with eight strains of Plasmodium falciparum and two strains of P. vivax. Such infections, induced by standardized inocula of these strains in 1,733 monkeys, all Aotus trivirgatus griseimembra, were followed from day of inoculation to death of self-cure. The virulence of the various strains differed strikingly. Incidences of fatal reactions, ranging from 24.4--89.4% and 8.1--45.8%, respectively, in infections with strains of P. falciparum and P. vivax, were closely related to the rate at which parasitemia evolved, the height of parasitemia in the primary attack, and/or the time period over which a high parasite level was sustained. Antemortem symptom complexes and gross tissue and organ reactions in infections with P. falciparum varied with survival time, but within that boundary, were the same for infections with all eight strains of this plasmodium. Morbidity in both fatal and self-limited infections with both plasmodial species was related to height of parasitemia; however, at comparable parasite levels, symptoms exhibited in infections with P. vivax were more severe than in infections with P. falciparum. Overall, the characteristics of infections with these plasmodia in owl monkeys were remarkably similar to those of human infections. With respect to biological features, infections with P. falciparum and P. vivax in this simian host appear to have much to offer in the search for new antimalarial drugs.

Animals↗
PubMed2026

Serological and Molecular Prevalence of HCMV, HCV, HBV and Toxoplasma gondii Co-infection in Treatment-Naive HIV-Infected Individuals.

INTRODUCTION: Co-infections with human cytomegalovirus (HCMV), hepatitis B virus (HBV), hepatitis C virus (HCV), and Toxoplasma gondii (T. gondii) pose clinical challenges in human immunodeficiency virus-1 (HIV-1)-infected individuals by complicating disease progression and management. This study aimed to investigate the serological and molecular prevalence of HCMV, HBV, HCV, and T. gondii co-infections among treatment-naive HIV-infected individuals. METHODS: A cross-sectional study was conducted from March 2022 to August 2024 on 203 treatment- naive HIV-1-infected individuals. Plasma samples were analyzed using ELISA for serological markers and real-time PCR for molecular detection. Statistical analyses were performed to assess demographic and clinical variables associated with co-infections. RESULTS: Among the 203 participants, the prevalence of anti-HCV antibodies, HBsAg, HCMV IgM, and T. gondii IgM was 9.9%, 2.5%, 1.5%, and 0.5%, respectively. Molecular detection confirmed active HBV, HCV, and HCMV infections in 40%, 60%, and 66.7% of seropositive individuals, respectively, while T. gondii DNA was undetected. HCV genotyping revealed subtype 1a as the most common (50%), followed by 3a (37.5%) and 1b (12.5%). DISCUSSION: The findings indicate a moderate prevalence of HBV and HCV co-infections and a low prevalence of HCMV and T. gondii co-infections in treatment-naive HIV patients. CONCLUSION: These results highlight the need for targeted public health interventions, including vaccination and screening strategies, to reduce the risk of co-infections in HIV-infected individuals.

Humans↗
PubMed1976

Wound infections in general surgery. Wound contamination, rates of infection and some consequences.

Rates of wound infection have been studied in a clinic performing to an equal degree both clean surgery and potentially contaminated surgery. Included in the study were 2827 patients with 213 (7.5%) postoperative wound infections. The postoperative mortality was 2.1%. Primary illness and cardiovascular complications were the main causes of postoperative death, while infectious complications (pneumonia, peritonitis and wound infection) were associated with or caused 1/3 of all postoperative deaths. Positive cultures from the wound before closure and from the wound dressings, immediately after operation, were followed by an increased risk of wound infection compared to negative cultures. Rates of wound infection were significantly higher in potentially contaminated operations compared to clean operations. Gram negative bacteria dominated in isolates from infected wounds after the former type of surgery, while S. aureus was the most common bacteria in wound infections after clean surgery. The time interval between operation and the discovery of wound infection was in the mean 10 days for staphylococci, and 9 days for Gram negative bacteria. The average time of hospitalization for patients contracting postoperative wound infections was 9 days longer than that for non-infected patients, which means that 3.4% of all nursing days were lost owing to excess hospitalization of infected patients.

Aged↗
PubMed1978

Congenital cytomegalovirus infection in newborn infants of mothers infected before pregnancy.

The rate of congenital cytomegalovirus (CMV) infection was studied in newborn infants in an African population in which all adults had experienced primary CMV infection during childhood. Viruria within the first 12 hours after delivery was taken as evidence of prenatal CMV infection. 28 of 2032 newborn infants examined had viruria, giving a rate of 1.4% congenital CMV infection. The presence of meternal serum antibody therefore appears not to protect the fetus from intrauterine infection. Either reactivation of latent maternal CMV infection or recurrence of infection during pregnancy despite the presence of serum antibodies may explain these findings. Whether the long-term effects of CMV infection acquired in utero differ in cases of primary maternal infection from those due to reactivated or recurrent infection in seropositive mothers, remains undecided. Thus, the value of a live CMV vaccine to prevent prenatal CMV infection may be questioned.

Adolescent↗
PubMed1976

Animal model studies of genital chlamydial infections. Immunity to re-infection with guinea-pig inclusion conjunctivitis agent in the urethra and eye of male guinea-pigs.

A previous report demonstrated that male guinea-pigs could be infected in the urethra with guinea-pig inclusion conjunctivitis (GPIC) agent and that the infection was transmitted during mating from infected males to females. In the experiments reported here, inoculation of male guinea-pigs in the urethra with GPIC organisms resulted in infection which subsided spontaneously in about 2 weeks. Males were demonstrated to be completely resistant to urethral challenge with 10(3)ID50 when tested 6 weeks after urethral infection. These guinea-pigs, immune to re-infection of the urethra, remained susceptible to infection of the eye, but this ocular infection was shorter in duration than that in previously uninfected control animals. Infection in the eye resulted in immunity to both ocular and urethral infection when animals were challenged 6 weeks after the ocular infection.

Animals↗
PubMed1977

Failure of vaccine strains of Babesia bovis to regain infectivity for ticks during long-standing infections in cattle.

Two strains of Babesia bovis that were known to have lost infectivity for the normal tick vector, Boophilus microplus, due to repeated blood passaging in cattle, were studied to determine whether the strains would regain infectivity for ticks during longstanding infections. Parasitaemias were monitored in 4 chronically infected calves that were regularly infested with ticks. Two strains of ticks known to be susceptible to infection with unmodified strains of B. bovis were used. Adult female ticks that dropped from the calves on days that a parasitaemia was evident were tested for B. bovis infection. Sixty-six batches of ticks collected up to 279 days after infection of the calves produced 14 pools of larvae, none of which transmitted infection. Primary infections established from the chronic infections by subinoculation at 200, 259 and 333 days after infection of the calves were also not transmitted by ticks.

Animals↗
PubMed1977

Complement-fixing reactivity of Varicella-Zoster virus subunit antigens with sera from homotypic infections and heterotypic Herpes simplex virus infections.

Various subunit antigens of varicella-zoster (V-Z) virus were examined for complement-fixing (CF) activity with sera from homotypic infections and from herpes simplex virus (HSV) infections in which a CF antibody titer rise was demonstrated with crude V-Z antigen. The subunit antigens included nucleocapsids, envelopes, a soluble antigen produced from infected culture fluids by sucrose density gradient centrifugation, a soluble antigen produced by reducing the volume of clarified infected culture fluids, a soluble antigen derived from infected cell lysates, a "viral" antigen consisting largely of enveloped particles with a few nucleocapsids, and a cell membrane-associated antigen. None was more suitable than crude V-Z antigen for serodifferentiation of V-Z virus and HSV infections. The envelope antigen, cell membrane antigen, and the soluble antigen prepared by density gradient centrifugation showed little reactivity with sera from varicella and HSV infections, but gave high antibody titers with sera from zoster infections, suggesting that a secondary V-Z virus infection is required to produce an antibody response to these subunit antigens. Patients with varicella and zoster infections and the selected patients with HSV infections all showed significant CF antibody responses to the other V-Z subunit antigens.

Antibodies, Viral↗
PubMed1978

Surveillance, prevention and control of hospital-acquired infections. III. Nosocomial infections as cause of death: retrospective analysis of 1000 autopsy reports.

One thousand post-mortem reports were analysed retrospectively to see whether the patient had had a nosocomial or community-acquired infection and whether this led directly to or contributed to the patient's death. In 7.4% of all autopsies nosocomial infection was the direct cause of death. In 6.3% of the patients, nosocomial infection was a contributory factor leading to death. The most common hospital infections were pneumonia, septicaemia, peritonitis, meningitis, and hepatitis B. Most infections which led to or contributed to death were acquired in surgical wards. Patients with nosocomial infections, however, were more endangered by factors predisposing to infections (1.8 factors per patient) than patients without nosocomial infections (0.67 factors per patient). Sixty-three patients acquired an infection outside the hospital; in 70% of these patients, the infection was the main or contributory cause of death.

Adolescent↗
PubMed1978

Cytomegalovirus infection in guinea pigs. I. Viremia during acute primary and chronic persistent infection.

Studies on the pathogenesis of cytomegalovirus (CMV) infection in guinea pigs have revealed two distinct phases of infection, without any signs of clinical disease. During acute primary infection, viremia was easily demonstrated and infectious virus was recovered from various tissues, including lung, spleen, and kidney, of the infected animal two to 10 days after inoculation. Chronic persistent infection was readily established thereafter. In animals with chronic persistent infection with high levels of circulating antibody, infectious virus was consistently isolated from the salivary gland and pancreas. Evidence of CMV in the blood of the persistently infected animals was detected only occasionally and only when a highly sensitive method and/or a large inoculum was used. However, the anticoagulant heparin was found to inactivate CMV significantly during collection of blood. These data suggest that CMV was indeed circulating in the blood of apparently health but persistently infected animals for prolonged periods. Such infected blood could conceivably be the source of CMV infection when large quantities of blood are given to susceptible recipients.

Acute Disease↗