Xenotransplantation and xenogeneic infections.
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Acquired Immunodeficiency Syndrome↗
Biomedical subjects
L E Chapman
Publications and source records attributed to L E Chapman.
Guidelines for the prevention and treatment of B-virus infections in exposed persons. The B virus Working Group.
Cercopithecine herpesvirus 1 (B virus), enzootic among monkeys of the genus Macaca, causes minimal morbidity in its natural host. In contrast, human B-virus infection presents as rapidly ascending encephalomyelitis with a fatality rate of approximately 70%. This infection remains an uncommon result of macaque-related injuries, although the increase in the use of macaques for research on simian retrovirus infection and hepatitis has expanded the number of opportunities for human exposure. In response to this situation, Emory University and the Centers for Disease Control and Prevention jointly sponsored a B Virus Working Group to formulate a rational approach to the detection and management of human B-virus infection. The resulting guidelines are presented herein and are based upon information from published cases, unpublished cases managed by working-group members, knowledge of the behavior of herpes simplex virus, and--in the absence of hard data--the collective judgment of the group. Although consensus among the co-authors existed on the major points covered by these guidelines, opinions varied widely regarding specific recommendations.
Animals↗
Lack of evidence for infection with known human and animal retroviruses in patients with chronic fatigue syndrome.
We investigated 21 patients with chronic fatigue syndrome who were identified through the surveillance system of the Centers for Disease Control and Prevention (CDC) in Atlanta for the presence of several human and animal retroviruses. In addition, we evaluated 21 CDC employee controls matched with the patients for age (+/- 5 years), gender, and race. The viruses tested included human T-lymphotropic viruses types I and II; human spuma retrovirus; simian T-lymphotropic virus type I; simian retroviruses types 1, 2, and 3; bovine leukemia virus; feline leukemia virus; and gibbon ape leukemia virus. Samples of peripheral blood lymphocytes and leukocytes from patients and controls were analyzed in a blinded fashion for retroviral sequences; polymerase chain reaction (PCR) amplification assays and Southern blot hybridization to 32P-labeled internal oligoprobes were used. All PCR assays were optimized for maximal sensitivity on respective infected cell lines or plasmids, and sensitivity controls were included in each experiment. All samples from patients and controls were negative for the tested retroviral sequences. Our data indicate that none of these retroviruses plays an etiologic role or is a cofactor in the chronic fatigue syndrome illnesses of our study population.
Animals↗
Norwalk virus-associated gastroenteritis traced to ice consumption aboard a cruise ship in Hawaii: comparison and application of molecular method-based assays.
Investigation of an outbreak of acute nonbacterial gastroenteritis on a cruise ship provided an opportunity to assess new molecular method-based diagnostic methods for Norwalk virus (NV) and the antibody response to NV infection. The outbreak began within 36 h of embarkation and affected 30% of 672 passengers and crew. No single meal, seating, or food item was implicated in the transmission of NV, but a passenger's risk of illness was associated with the amount of ice (but not water) consumed (chi-square for trend, P = 0.009). Of 19 fecal specimens examined, 7 were found to contain 27-nm NV-like particles by electron microscopy and 16 were positive by PCR with very sensitive NV-specific primers, but only 5 were positive by a new highly specific antigen enzyme immunoassay for NV. Ten of 12 serum specimen pairs demonstrated a fourfold or greater rise in antibody titer to recombinant baculovirus-expressed NV antigen. The amplified PCR band shared only 81% nucleotide sequence homology with the reference NV strain, which may explain the lack of utility of the fecal specimen enzyme immunoassay. This report, the first to document the use of these molecular method-based assays for investigation of an outbreak, demonstrates the importance of highly sensitive viral diagnostics such as PCR and serodiagnosis for the epidemiologic investigation of NV gastroenteritis.
Antibodies, Viral↗
Rift Valley fever in rural northern Senegal: human risk factors and potential vectors.
To investigate past infection in and transmission of Rift Valley fever (RVF) virus to humans within an endemic focus, we undertook a retrospective cohort study of the seminomadic Peul people living in sub-Saharan northcentral Senegal. Residents of the rural settlement of Yonofere five years of age or older were studied during February-May 1989. Anti-RVF virus IgG was found in blood samples of 22.3% of 273 persons who responded to a standard questionnaire; none had IgM antibodies. Seropositivity was similar for males (25.4%) and females (21.1%), increased markedly with age for both sexes, and varied considerably among compounds (groups of huts) (0-37.5%). Risk factors for past RVF virus infection were nursing sick people, assisting animals during abortions/births, and treating sick animals. In all age groups, odds ratios (ORs) for RVF viral antibody among females who reported treating sick animals were three to six times greater than for those who did not. The ORs for males who reported assisting with animal births/abortions and nursing sick people were approximately five times those for males who did not. Serologic prevalence of RVF viral antibody among sheep averaged 30.1% overall (0.8% IgM), but varied among compounds (0-66.7%) in a manner different from that of humans. The seasonal abundance and relative density of potential mosquito vectors were estimated by monthly samples captured in Centers for Disease Control and Prevention-type traps. Mosquito abundance varied seasonally with rainfall (> 90% captures during four months). Species diversity was large (28 spp.), dominated by Aedes and Culex. Rift Valley fever virus was not isolated from 142 pools of 2,956 unengorged mosquitoes tested, although three other arboviruses were found. Results indicate that RVF is endemic in this region, people are at considerable risk of infection, and that a heretofore unrecognized mode of human infection under nonepizootic conditions may be transmission via contact with infected animals or humans.
Adolescent↗
Etiology and epidemiology of the Four Corners hantavirus outbreak.
In May and June 1993, a handful of previously healthy residents of rural areas in the Four Corners region of the southwestern United States died of acute unexplained respiratory distress, later diagnosed as hantavirus pulmonary syndrome. Their illnesses were characterized most prominently by a prodrome of fever and myalgias, followed by thrombocytopenia, the presence of immature white blood cells on the peripheral smear, and catastrophic respiratory decline associated with the sudden onset of noncardiogenic pulmonary edema and hypotensive shock. Although the primary care doctors who treated these patients were spread over a relatively wide rural geographic area, this cluster was recognized in large part because these patients belonged to a defined cohort receiving medical care from a unified system of interconsulting physicians, the Indian Health Service. By just over 2 weeks after receiving laboratory diagnostic specimens, Public Health Service scientists had identified a newly recognized hantavirus as the cause of this disease cluster and Peromyscus maniculatus (the deer mouse) as the rodent reservoir for this zoonotic virus. The oral history of local American Indian healers describes clusters of similar deaths occurring over three cycles during the twentieth century in association with identifiable ecological markers. The abrupt introduction to Western medical practitioners of a disease long recognized by indigenous healers through illness occurring among a cohort of patients seeking care from medical officers of the U.S. Uniformed Services parallels the initial Western medical recognition of previous human illnesses associated with hantaviral infections through disease outbreaks among military troops. The remarkable speed with which the etiology of this disease was elucidated is attributable to both the power of modern genetic investigational techniques and the scientific groundwork laid by nearly half a century of systematic research on hantaviruses.
Animals↗
Influenza--United States, 1988-89.
PROBLEM/CONDITION: CDC monitors the emergence and spread of new influenza virus variants and the impact of influenza on morbidity and mortality annually from October through May. REPORTING PERIOD COVERED: This report covers United States influenza surveillance conducted from October 1988 through May 1989. DESCRIPTION OF SYSTEM: Weekly reports from the vital statistics offices of 121 cities provided an index of influenza's impact on mortality; 58 WHO collaborating laboratories reported weekly identification of influenza viruses; weekly morbidity reports were received both from the state and territorial epidemiologists and from 153 sentinel family practice physicians. Nonsystematic reports of outbreaks and unusual illnesses were received throughout the year. RESULTS: During the 1988-89 influenza season, influenza A (H1N1) and B viruses were identified in the United States with essentially equal frequency overall, although both regional and temporal patterns of predominance shifted over the course of the season. Throughout the season increases in the indices of influenza morbidity in regions where influenza B predominated. Only 7% of identified viruses were influenza A (H3N2), but not isolations of this subtype increased as the season waned and it subsequently predominated during the 1989-90 season. During the 1988-89 season outbreaks in nursing homes were reported in association with influenza B and A (H3N2), but not influenza A (H1N1). INTERPRETATION: The alternating temporal and geographic predominance of influenza strains A (H1N1) and B during the 1988-89 season emphasizes the importance of continual attention to regional viral strain surveillance, since amantadine is effective only for treatment and prophylaxis of influenza A. ACTIONS TAKEN: Weekly interim analyses of surveillance data produced throughout the season allow physicians and public health officials to make informed choices regarding appropriate use of amantadine. CDC's annual surveillance allows the observed viral variants to be assessed as candidates for inclusion as components in vaccines used in subsequent influenza seasons.
Disease Outbreaks↗
Assessment of a retrovirus sequence and other possible risk factors for the chronic fatigue syndrome in adults.
OBJECTIVE: To assess whether the human T-lymphotropic virus type II (HTLV-II) gag gene sequence, a purportedly new laboratory marker of the chronic fatigue syndrome (CFS), and other possible risk factors for CFS, particularly those associated with retroviral transmission, are associated with well-characterized CFS. DESIGN: Two matched case-control studies. SETTING: The metropolitan Atlanta area. PATIENTS: Twenty-one patients with CFS who were identified by the Centers for Disease Control and Prevention CFS surveillance system; 21 CDC employee controls (laboratory study) and 42 neighborhood controls (risk-factor study) who were matched to patients by age, race, and gender. MEASUREMENTS: Peripheral blood lymphocytes and leukocytes were assayed for the HTLV-II gag gene sequence by polymerase chain reaction and specific Southern blot hybridization. Questionnaires elicited demographic and clinical information and a history of exposures associated with retrovirus transmission (for example, blood transfusions, sexual practices, intravenous drug use). RESULTS: All patients were white and 86% were female. The median age at illness onset was 34 years (range, 16 to 51 years). The HTLV-II gag gene sequence was not identified in the blood of any patient or control under conditions in which the appropriate assay controls were positive. No statistical differences were observed between patients and controls in frequency of blood transfusions (10% compared with 7%), median number of sex partners before illness (3 compared with 3), bisexual or homosexual behavior (14% compared with 7%), intravenous drug use (0% compared with 0%), and other factors associated with retroviral infection. CONCLUSIONS: The HTLV-II gag gene sequence was not a marker for CFS in this small study of well-defined patients, nor did other characteristics of the patients and controls support the hypothesis that a retrovirus, transmitted by usual modes, was a cause of CFS.
Adult↗
Do family physicians make good sentinels for influenza?
OBJECTIVE: To determine whether volunteer family physician reports of the frequency of influenza-like illness (ILI) usefully supplement information from other influenza surveillance systems conducted by the Centers for Disease Control and Prevention. DESIGN: Evaluation of physician reports from five influenza surveillance seasons (1987-88 through 1991-92). SETTING: Family physician office practices in all regions of the United States. PARTICIPANTS: An average of 140 physicians during each of five influenza seasons. INTERVENTIONS: None. OUTCOME MEASURES: An office visit or hospitalization of a patient for ILI, defined as presence of fever (temperature > or = 37.8 degrees C) and cough, sore throat, or myalgia, along with the physician's clinical judgment of influenza. A subset of physicians collected specimens for confirmation of influenza virus by culture. RESULTS: Physicians attributed 81,408 (5%) of 1,672,542 office visits to ILI; 2754 (3%) patients with ILI were hospitalized. Persons 65 years of age and older accounted for 11% of visits for ILI and 43% of hospitalizations for ILI. In three of five seasons, physicians obtained influenza virus isolates from a greater proportion of specimens compared with those processed by World Health Organization laboratories (36% vs 12%). Influenza virus isolates from sentinel physicians peaked from 1 to 4 weeks earlier than those reported by World Health Organization laboratories. Physicians reported peak morbidity 1 to 4 weeks earlier than state and territorial health departments in four of five seasons and 2 to 5 weeks earlier than peak mortality reported by 121 cities during seasons with excess mortality associated with pneumonia and influenza. CONCLUSIONS: Family physicians provide sensitive, timely, and accurate community influenza morbidity data that complement data from other surveillance systems. This information enables monitoring of the type, timing, and intensity of influenza activity and can help health care workers implement prevention or control measures.
Adolescent↗
Coxsackievirus B2 infection and aseptic meningitis: a focal outbreak among members of a high school football team.
In an investigation of a school outbreak of enterovirus-like illness and aseptic meningitis, an IgM antibody assay was used to identify persons with evidence of recent coxsackie virus B2 infection. During September and October 1989, 81 (25%) of 319 students and staff reported an enterovirus-like illness; of these, 17 (21%) also had aseptic meningitis. Attack rates for enterovirus-like illness were highest among varsity football team members (53%), and most of this illness occurred between 6 and 15 October. Coxsackie virus B2 was isolated from 2 varsity football players. IgM antibody studies confirmed that coxsackie virus B2 was the cause of the outbreak in the varsity football team and suggested it was not responsible for much of the disease in other students and staff: 63% of football team members were seropositive compared with 12% for other students in grades 6-12. This report illustrates the value of an IgM antibody assay in the investigation of enterovirus outbreaks to distinguish infection from illness.
Adolescent↗
Epidemic keratoconjunctivitis in a chronic care facility: risk factors and measures for control.
OBJECTIVE: To study patterns of transmission of epidemic keratoconjunctivitis (EKC) in a chronic care facility and to assess control measures and prevent future outbreaks in this setting. DESIGN: A retrospective cohort study. SETTING: A 120-bed, four-unit, skilled nursing facility. PATIENTS: Residents and employees of the above facility. INTERVENTIONS: Increased frequency of cleaning; use of bleach disinfectant; universal precautions in handling eye secretions from residents with conjunctivitis; cohorting residents by unit; suspension of new admissions; closure of common gathering areas. MEASUREMENTS: Resident demographics; possible risk factors for infection among residents (including mobility, underlying illness, medications, involvement in social activity, level of confusion) and among employees (including co-morbid illnesses and eye conditions, exposures to persons with conjunctivitis, visits to eye care specialists, use of contact lenses or glasses); testing of conjunctival specimens from symptomatic persons for viral and bacterial agents. RESULTS: Of 95 residents on three chronic care units, 47 (attack rate 49%) had onset of eye symptoms consistent with EKC between September 14 and December 7, 1990. Thirty-eight (81%) of these had onset following the onset of symptoms in a resident with dementia who, despite habitual eye-rubbing and wandering into other residents' rooms, was not isolated or restricted in any way. Attack rates were higher (though not statistically significant) among more mobile residents (60% for ambulatory residents) and among those considered by staff to be confused (56%). Rapid antigen detection and culture confirmed adenovirus type 37 as the etiologic agent. CONCLUSIONS: Transmission of infection with adenovirus type 37 was successfully interrupted following strict infection control, suspension of new admissions, cohorting of residents by unit, and change to a disinfectant that inactivates adenovirus. Recognition of conjunctivitis as an appropriate reason for restricting movement of an infected resident may have prevented extensive viral transmission in this outbreak.
Activities of Daily Living↗
Influenza surveillance--United States, 1991-92.
During the 1991-92 influenza season, sustained regional influenza activity began to be reported by state and territorial epidemiologists in the United States in mid-October 1991. Sustained reporting of widespread influenza activity began in early November 1991, 5-10 weeks earlier than in any of the previous nine influenza seasons. Influenza caused substantial morbidity among school-age children and excess mortality among the elderly. Regional outbreaks of influenza ended 2-6 weeks earlier than in the previous nine influenza seasons, based on the last sustained state and territorial epidemiologists' reports. Nationally, > 99% of isolates were influenza A. Influenza A(H3N2) predominated in all regions of the country, but isolation of influenza A(H1N1) increased proportionally as the season progressed. Isolation of influenza B (< 1% of total isolates) clustered after February. The majority of isolates characterized were antigenically similar to components in the 1991-92 influenza vaccine. However, an influenza A(H1N1) strain that had undergone antigenic drift was detected in many regions of the country; this strain will be included in the 1992-93 influenza vaccine.
Aged↗
Influenza--United States, 1989-90 and 1990-91 seasons.
During the 1989-90 influenza season, 98% of all influenza viruses isolated in the United States and reported to CDC were influenza A. Almost all those that were antigenically characterized were similar to influenza A/Shanghai/11/87(H3N2), a component of the 1989-90 influenza vaccine. Regional and widespread influenza activity began to be reported in late December 1989, peaked in mid-January 1990, and declined rapidly through early April 1990. Most of the outbreaks reported to CDC were among nursing-home residents. Considerable influenza-associated mortality was reflected in the percentage of deaths due to pneumonia and influenza (P&I) reported through the CDC 121 Cities Surveillance System from early January through early April. More than 80% of all reported P&I deaths were among persons greater than or equal to 65 years. In contrast to the predominance of influenza A during 1989-90, during the 1990-91 influenza season 86% of all influenza virus isolations reported were influenza B. Widespread influenza activity was reported from mid-January through April 1991, with regional activity extending into May. Outbreaks were reported primarily among schoolchildren, and no evidence of excess influenza-associated mortality was found. Almost all the influenza B isolates tested were related to influenza B/Yamagata/16/88, a component of the 1990-91 influenza vaccine, but were antigenically closer to B/Panama/45/90, a minor variant.
Aged↗
Risk factors for Crimean-Congo hemorrhagic fever in rural northern Senegal.
The extent of infection among 722 residents of an enzootic focus of Crimean-Congo hemorrhagic fever (CCHF) virus in rural northern Senegal and putative modes of transmission were studied by a cross-sectional seroprevalence survey done from February through May 1989. Anti-CCHF virus IgG was found in 13.1% of 283 persons who completed a standard questionnaire and provided blood samples. Seropositivity rates were similar between sexes and increased significantly with age among nomadic persons. Behavior patterns providing exposure to multifactorial risk factors were gender-based. Male risk factors, primarily associated with herding activities, included sleeping outside during seasonal migrations (also a risk factor for nomadic women), bite by a tick (adult male Hyalomma truncatum), tick bite during the cool dry season, and contact with sick animals. Human infection of CCHF occurred more frequently or with less mortality in the region studied than has been found elsewhere in Africa; however, the rate of seroconversion-associated illness is undetermined. Hyalomma ticks appear to be the primary transmission mode.
Adolescent↗
Normal differentiation of prolactin cells in neonatal rats requires a maternal signal specific to early lactation.
This laboratory has previously demonstrated that PRL-secreting cells are virtually nonexistent on day 3 but appear in appreciable numbers on day 4 of neonatal life. The purpose of the present study was to determine whether this explosive appearance of PRL cells is due to maternal influences specific to the first 4 days of lactation. Litters of 1-day-old rat pups were placed with foster mothers that had been lactating for either 1 or 4 days. Four days later (at 5 days of age), the anterior pituitaries from these pups were removed, dispersed into individual cells with trypsin, and subjected to reverse hemolytic plaque assays for PRL and GH release. We found that the proportion of PRL-releasing cells in pituitaries from pups placed with day 1 mothers (4.2 +/- 0.6%; mean +/- SE; n = 4 experiments) was similar to that in 5-day-old pups that had not been fostered (3.4 +/- 0.6%; n = 3 experiments). In contrast, placing 1-day-old pups with day 4 mothers significantly reduced (P less than 0.01) the fraction that released PRL to 0.6 +/- 0.2% of all pituitary cells (n = 4 experiments). This effect appeared to be specific to PRL cells, since the percentage of all pituitary cells that secreted GH was not different between litters fostered onto day 1 or day 4 dams (40.0 +/- 3.8% and 41.1 +/- 3.9%, respectively; n = 3 experiments). Furthermore, the suppression of PRL cell expression did not result from a gross nutritional deficit, since the rates of body wt gain during the foster period were not different between the two groups (12.4 +/- 0.5 and 12.9 +/- 0.8 g/litter.day, respectively; n = 4 experiments). In a second design, newborn pups were placed with females that had been lactating for 0, 2, 4, or 7 days and analyzed for PRL- and GH-releasing cells at 5 days of age. In two trials of this experiment, the fractions of pituitary cells that secreted PRL were 5.2, 6.3, 5.9, and 1.2%, respectively for trial 1 and 3.3, 4.1, 0.7, and 0.6%, respectively for trial 2. As in the first experiment, the proportion of GH-releasing cells and the rate of growth were not different among the four groups. Taken together, these results indicate that normal differentiation of PRL cells in neonatal rats is triggered by a maternal signal present during the first few days of lactation, and that the magnitude of this signal declines with the progression of lactation.
Aging↗
Risk factors for strongyloidiasis. A case-control study.
Although infection with Strongyloides stercoralis is usually only mildly symptomatic, it can persist for many years and occasionally progress to the hyperinfection syndrome, with a resultant high mortality rate. We studied factors associated with S stercoralis infection by comparing 28 domestic cases of S stercoralis infection with 76 controls with negative stool samples for ova and parasites. The relative risk (RR) of S stercoralis infection was increased for white patients (RR = 5.6), men (RR = 3.9), and patients who had recently used corticosteroids (RR = 3.3), had a hematologic malignancy (RR = 5.28) or had prior gastric surgery (RR = 11.5). These risk factors might be for initial infection, persistence of infection, or both. Although they are not necessarily causal, knowledge of them may lead to earlier recognition of this dangerous and treatable disease.
Adrenal Cortex Hormones↗
Some reactions of carbonyl azide: n-azidocarbonylazepine.
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Azepines↗
Xenotransplantation: the potential for xenogeneic infections.
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Animals↗