Rotavirus infection in Tanzania: a virological, epidemiological and clinical study among young children.

Rotavirus infection in the Dar es Salaam area of Tanzania was studied in 99 hospitalized children with acute diarrhoea and 99 hospitalized non-diarrhoea referents matched for sex and age. Of the diarrhoea cases 43.4% had rotavirus in the stools as opposed to 15.2% of the referents. The high carrier rate among the referents represents a serious risk of nosocomial transmission. More referents than cases had serum IgG antibodies to rotavirus, 52.5% and 35.4%, respectively (P < 0.02), while there was no correlation with serum IgM and IgA or faecal IgA antibodies. The latex agglutination test had a sensitivity comparable to that of electron microscopy (100%) and a specificity of 93.8%. The Slidex test appeared to be superior to the Rotalex test in that it gives very few false-positive reactions. The SDS-PAGE patterns of 11 RNA segments were compatible with the presence of group A strains with considerable heterogeneity among the strains. Symptoms and signs and some environmental data were recorded. None of them was clearly associated with rotavirus infection among the diarrhoea cases. It is concluded that rotavirus is a major cause of acute infectious diarrhoea in Tanzania.     

Determining virological, serological and immunological parameters of EBV infection in the development of PTLD

Post-transplant lymphoproliferative disease (PTLD) in Epstein-Barr virus (EBV) seronegative solid organ transplant recipients remains a significant problem, particularly in the first year post-transplant. Immune monitoring of a cohort of high-risk patients indicated that four EBV seronegative transplant recipients developed early-onset PTLD prior to evidence of an EBV humoral response. EBV status has been classically defined serologically, however these patients demonstrated multiple parameters of EBV infection, including the generation of EBV-specific CTL, outgrowth of spontaneous lymphoblastoid cell lines, and elevated EBV DNA levels, despite the absence of a classic EBV antibody response. As EBV serology is influenced by both immunosuppression and cytomegalovirus immunoglobulin treatment, both the EBV-specific CTL response and elevated EBV levels are more reliable indicators of EBV infection post-transplant.     

Trichophyton violaceum infection occurring in a nursing home]

Six cases of Trichophyton (T.) violaceum infection seen in a nursing home are reported. A 66-year-old female (case 1) was found with tinea corporis on her face, chest and shoulder, associated with black dot ringworm. A KOH examination of hair showed endothrix parasitism. Reddish purple colonies were isolated from the patient on Sabouraud's dextrose agar, and intercalary and terminal chlamydospores were observed on slide culture. PCR-RFLP analysis of the microorganism showed a pattern of T. violaceum type. Therefore, the isolated fungus was identified as T. violaceum, a typical anthropophilic dermatophyte which had spread among residents and staffs easily. Using a mycological method, we examined 59 persons (21 residents and 38 staff members) who had had contact with case 1. The results were as follows. An 85-year-old female (case 2) and an 83-year-old female (case 3) were carriers of T. violaceum. A 23-year-old male (case 4) had tinea corporis on his right forearm due to T. violaceum. A 24-year-old male (case 5) probably had tinea corporis on his right forearm due to T. violaceum. One year after case 1's first visit to our clinic, we observed an 88-year-old female (case 6) of tinea capitis by T. violaceum. It seems that the organism was preserved in surroundings and members of the nursing home. The contagion in our cases could either have been caused by directly touching the person or by sharing their comb. PCR-RFLP analysis was performed within a short time, so that we managed effectively to select a way of treatment and to prevent the infection from spreading.     

Rotavirus infection in a small community

Serial titres of rotavirus specific IgG and IgM have been measured in children and adults living in a small community over a 2 1/4-year period. In all age groups the mean titres of rotavirus specific IgG and IgM rose and fell in parallel with the changes in frequency of gastroenteritis symptoms in the community but after the time when respiratory symptoms reached their peak. Gastroenteritis symptoms were seen most commonly in the children but were also frequent in adults, especially the women. Titres of rotavirus specific IgG changed with age, increasing through childhood into early adult life, but decreased thereafter only to increase again in those over the age of 50 years. Females had higher levels of IgG in all age groups but especially among the children and 30-49-year-old women. The high levels of IgG did not protect the young adults from symptomatic gastroenteritis. Detectable levels of rotavirus specific IgM occurred in all age groups but more commonly in children aged under 10 years and in young adults. Raised levels of IgM were uncommon in the elderly, who rarely suffered gastroenteritis symptoms. An epidemiological model is proposed in which the older members of the community act as a reservoir of rotavirus, passing the infection to the children, who then infect the young adults.     

Rotavirus infection in adults. Results of a prospective family study.

To study the epidemiologic and clinical features of rotavirus infections, we enrolled 98 families in a prospective study of diarrhea in households with newborn children. Families were seen at three-month intervals and whenever ill. The mean follow-up period was 16.4 months. Rotavirus infections were documented by electron microscopy of feces, indirect fluorescent-antibody assays in serum or both. The 43 infections identified in adults represented an attack rate of 0.17 per adult per year. Ninety-three per cent of these infections occurred from November through May. Seventeen adults had gastrointestinal symptoms, most often diarrhea (in 14) or abdominal cramps (in 11). Rotavirus infections occurred in 36 of 102 adults whose children had rotavirus infection, as compared with four of 86 without infected children (P less than 0.001). Serum rotavirus antibody did not correlate with a reduced risk of infection or symptomatic disease. Rotavirus is a mild but common infection in parents of young children.     

Persistent viruses in serological diagnosis of HIV infection]

Specific antibodies to persistent viruses (CMV, EBV, HBV) were detected by ELISA in groups of HIV-infected patients and persons showing indefinite results of the immunoblotting test for HIV-1 antigens, on the one hand, and in HIV-seronegative donors and patients with clinical manifestations of viral infection (CMVI) on the other. The findings indicate that the persons with indefinite immunoblotting test results show elevated blood CMV and HBV antigen levels than in the matched group of seronegative donors. This fact suggests that persistent viral infections might involve in the formation of an indefinite pattern when the sera were tested for HIV. The patients whose sera behaved in such a way represent a clinical risk group for HIV infection and call for further follow-up.     

A longitudinal study of the serological and virological status of 18 women infected with cytomegalovirus

Summary 18 women, of known seropositivity, have been followed for between 18 and 66 months (mean 50.2 months) for viral excretion and serological changes. CMV was isolated from 58/146 (39.7 per cent) cultures from various sites, mostly cervix. A total of 129 sera were obtained and each was titrated in the late antigen, early antigen and anti-complement immunofluorescence assays, as well as the complement fixation and microneutralisation tests.From 3 women virus was consistently re-isolated, from 3 others virus was never re-isolated and the remaining 12 women excreted virus intermittently during the period of study.No significant changes in antibody titres could be detected by any of the 5 serological assays in any woman during periods of viral excretion. This suggests that local reactivation of latent CMV infection is not associated with a demonstrable systemic antibody response.Inter-assay correlations were sought for each of the 10 possible combinations of pairs of tests. Significant correlations were found for most pairs of tests, with the notable exception of those involving the early antigen test. This confirms that antibodies detected in this assay are distinct from those detected by the other 4 serological assays.With 3 Figures     

广东省登革热原学和血清学检测

目的 了解１９７８－１９９５年广东省多次发生登革热Ⅰ－Ⅳ型流行的病学原学。方法 在流行区捕捉９种蚊媒，进行病毒分离。结果 阳性率白纹伊蚊为２０．６９％，埃及伊蚊为１８．９５％，致乏库蚊为１０．２９％，其余６种蚊媒为阴性。这三种蚊媒间的病毒分离阳性率无显著性差异。在海南岛和湛江地区，埃及伊蚊是主要的传播媒介，其他的流行区是白纹伊蚊。患者发病３天内病毒分离的阳性率在７３．５８－８２．０５％之间，发病第     

An antigen in normal avian cells which confuses virological and serological tests

A cytoplasmic antigen was detected by fluorescent antibody tests in normal lymphoid and fibroblastic cells from chickens and other avian species when explanted and grown in culture. Cells of the bursa of Fabricius were consistently positive but cells of a proportion of thymus, spleen, bone marrow, buffy coat and embryo fibroblast cultures also were positive. Eight of 19 fluorescein-conjugated chicken sera prepared for other studies on a variety of avian pathogens had antibody against the antigen. Uncultured tissues or cultured but unfixed tissues were always negative, and selective blocking and absorption tests confirmed that the fluorescence was due to an antigen-antibody reaction. The antigen was associated with cells transformed by any of 8 strains of Rous sarcoma virus (RSV) but not with cells infected by other avian pathogens, including avian leukosis virus. Tests showed that the antigen was not coded for by RSV or by endogenous (subgroup E) avian leukosis virus genome. It may be coded for by normally non-functional genes which are derepressed in some cells by in vitro cultivation or RSV infection. In vivo derepression in some birds may account for the presence of antibody in sera.     

Rotavirus nosocomial infection in pediatric units. A multicentric observation study

OBJECTIVE: Rotavirus nosocomial infection (RNI) is frequent in pediatric units. This study was designed to determine the incidence and the main risk factors of RNI in children aged 3 months-3 years and admitted for at least 48 hours days during the epidemic period. PATIENTS AND METHODS: A stool sample was obtained within the 24 hours of admission. An additional sample was collected from rotavirus-negative children either the day of discharge, or when they developed abnormal clinical signs. Parents were contacted by phone after discharge. Children initially rotavirus-negative and positive 2 days or more after admission were considered as certain nosocomial cases. In the absence of the second sample, possible nosocomial cases were considered if new symptoms (i.e.; fever and or digestive symptoms) occurred 2 days or more after the first negative sample. RESULTS: One hundred and seventeen children were included. The incidence was 11.1% for certain NRI, 16.8% for possible hospital-acquired cases and 19.4% for the whole cases. Possible risk factors were the low number of nurses during the weekend, the great number of medicine students in the unit, and no use of individual material. CONCLUSION: NRI have a high incidence, whose reality can only be approximated by taking into account the possible NRI occurring at home after hospital-discharge.     

Occult HBV infection in patients with autoimmune hepatitis: A virological and clinical study

Background/PurposeOccult HBV infection (OBI) could have serious clinical consequences in patients receiving immunosuppressive therapy. We aimed to investigate the prevalence of OBI in Chinese patients with autoimmune hepatitis (AIH) and to analyze its clinical and virological features.Methods103 AIH cases were enrolled. Hepatitis B virus (HBV) serological markers were screened by chemiluminescence. HBV-DNA were detected by nest-PCR and real-time PCR. HBV genotyping and mutation analysis were performed by Sanger sequencing.ResultsTwenty-four out of 103 (23.30%) AIH patients had OBI as evidenced by positive HBV-DNA and negative hepatitis B surface antigen (HBsAg). HBV genotype C is the predominant genotype (57.89%), which had more amino acid (AA) substitutions in S region than that of B-genotype group (P = 0.001). The distribution of AA substitution in the ‘α’ determinant region between genotype C and B were significantly different (P = 0.042). In addition to those already reported OBI-associated AA substitutions (e.g., sG145R and sV184A), some new OBI-associated AA substitutions (e.g., sV106A, sC137* and sL176P) were found in AIH patients in our study. Three out of 24 (12.50%) OBI patients were diagnosed as decompensated cirrhosis, one patient with S deletion mutation and two patients with HBV extensive AA substitutions.ConclusionsThere was a higher proportion of AIH patients with OBI than the general population in China, which can be either seropositive or seronegative-OBI in AIH patients is associated with some specific AA substitutions. The presence of deletion mutations and the extent of AA substitutions in the HBV S region may have predictive clinical implications.     

Rotavirus infection in lambs: Studies on passive protection

Summary Gnotobiotic lambs were protected against rotavirus infection by the presence in the gut at the time of infection of colostrum or serum containing antibodies to rotavirus. This protection was observed even when passively-acquired antibody was not present in the serum of the infectod lamb. Infection under these conditions may have conferred immunity to subsequent challenge.     

Rotavirus infection in lambs: Pathogenesis and pathology

Summary Experimental lamb rotavirus infections were studied by immunofluorescence, histopathology and electron microscopy of tissues from infected gnotobiotic lambs killed at intervals from the incubation period to recovery. The rotavirus was demonstrated by immunofluorescence only in epithelial cells of villi in the small and large intestine, and virus antigen was most abundant during the incubation period. An increased enterocyte turnover rate was suggested by the rapid movement of virus-infected cells to the villus tip, and this increase may be one of the basic pathogenic mechanisms of rotavirus infection. Principal histopathological changes were shortening of villi and sloughing of epithelial cells. These were greatest in the middle and posterior small intestine at the onset of diarrhoea, but regeneration occurred within a few hours. Virus morphology in tissues was similar to that reported in other species, and virus presence correlated well with histopathological change.With 11 Figures     

Evidence of Rickettsia spp. infection in Sweden: a clinical, ultrastructural and serological study

Sweden is an area potentially endemic for spotted fever rickettsioses. Rickettsia helvetica has been isolated from its tick vector Ixodes ricinus, and in a handful of cases linked to human disease. This study demonstrates for the first time in Sweden the transmission of rickettsial infection after a tick bite and the attack rate in an endemic area. We present three cases of documented rickettsial infection and a prospective serological study of Swedish recruits who were trained in the area where the patients lived and showed seroconversion to spotted fever rickettsiae. All patients showed a four-fold increase in antibody titer to the spotted fever rickettsia, R. helvetica, and immunohistochemical examination revealed rickettsia-like organisms in the walls of skin capillaries and veins. Electron microscopy showed organisms resembling R. helvetica and immunogold labeling with two anti-rickettsial antibodies demonstrated specific labeling of the rickettsial organisms in the skin biopsy specimens. Eight of the thirty-five recruits showed a four-fold increase in IgG titer reflecting a high rate of exposure. The results of this study demonstrate that spotted fever rickettsioses should be taken into consideration in the diagnosis of tick-transmitted infections in Sweden.     

Cytomegalovirus infection in infancy: virological and immunological studies

Immunological and virological studies on 18 infants with cytomegalovirus (CMV) infection were performed. Eleven of these infants were studied on multiple occasions over a period of 1 year. The patients were divided into three clinical groups based on the probable time of infection and the resulting variation in clinical presentation. General parameters of cell-mediated immunity as determined by E-rosette formation and lymphocyte proliferative responses to mitogens and antigens were found to be normal. Quantitation of CMV excretion in urine, CMV-specific immunofluorescent (IF) and complement-fixing (CF) antibody titres and CMV-specific cell-mediated immune responses were done on all patients at approximately monthly intervals. Throughout the study period all patients continued to excrete CMV despite the presence of high antibody titres to the virus. CMV-specific lymphocyte proliferative responses were absent or diminished in 15 of the 18 patients. The immunological and virological status of all patients was similar regardless of the clinical manifestation of infection.     

Home deliveries in Holland: Dutch maternity care and home confinements *

In the Netherlands a majority of all deliveries take place at home. The perinatal mortality rate is better than that reported from the United ffiingdom, probably because obstetric care in hospital is more active and aggressive. Dutch midwives play an important role and the specially trained home helps are most successful. I believe that, provided case selection is rigorous, many women are best delivered at home.     

Cryoglobulinemia in Japanese patients with chronic hepatitis C virus infection: host genetic and virological study

Essential cryoglobulinemia is associated closely with hepatitis C virus (HCV) infection. The mechanism responsible for occurrence of the disease is unclear. The aim of this study was to investigate pathogenetic roles of HCV in cryoglobulinemia. One hundred sixty-seven consecutive patients with HCV were studied clinically by HCV grouping, HCV RNA levels, GBV-C/HGV, HCV quasispecies (target region was hypervariable region-1) and HLA polymorphism. The quasispecies in cryoprecipitate were compared with those in supernatant. The results of HLA polymorphism of patients with cryoglobulinemia were compared with those without cryoglobulinemia and healthy controls. The frequency of HCV-related cryoglobulinemia was 71 of 167 (42.5%). Patients with cirrhosis (36 of 63, 57.1%) had cryoglobulinemia more frequently than those with chronic hepatitis (35 of 104, 33.7%, P < 0.01). No significant differences were not found between the two groups (patients with and without cryoglobulinemia) in age, gender, HCV grouping, HCV RNA level and frequency of GBV-C/HGV. HCV was found quantitatively and clonally more frequently in the cryoprecipitate than in the supernatant. HLA polymorphism presented no significant differences among three groups. The stage of liver disease is one of pathogenetic factors. The greater the presence of HCV quasispecies in cryoprecipitate than in the supernatant indicates that various antigen presentations play an important role in the formation of cryoglobulin, whereas HLA typing dose not seem to contribute to the development of cryoglobulinemia.