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Biomedical subjects

B A Perkins

Publications and source records attributed to B A Perkins.

At least 55 records · Page 3Linked to original sources
PubMed1997

Clinical signs for the recognition of children with moderate or severe anaemia in western Kenya.

Optimal treatment of Plasmodium falciparum-related paediatric anaemia can result in improved haematological recovery and survival. Clinical predictors are needed to identify children with anaemia in settings where laboratory measurements are not available. The use of conjunctival (eyelid), palmar, nailbed, and tongue pallor to detect children with moderate anaemia (haemoglobin, 5.0-7.9 g/dl) or severe anaemia (haemoglobin, < 5.0 g/dl) was evaluated among children seen at an outpatient and inpatient setting in a hospital in western Kenya. Severe nailbed or severe palmar pallor had the highest sensitivity (62% and 60%, resp.), compared with severe conjunctival pallor (sensitivity = 31%), to detect children with severe anaemia in the outpatient setting. Children with moderate anaemia were best identified by the presence of nailbed or palmar pallor (sensitivity = 90% for both signs), compared with conjunctival pallor (sensitivity = 81%). Clinical signs of respiratory distress, in addition to the presence of severe pallor, did not increase the recognition of children requiring hospitalization for severe anaemia. Among inpatients, the sensitivity of severe nailbed pallor (59%) was highest for detecting children with severe anaemia, although the sensitivity of severe conjunctival pallor and severe palmar pallor was the same (53% for both signs). Presence of conjunctival pallor (sensitivity = 74%) was similar in sensitivity to both nailbed and palmar pallor (70% for both signs) among children with moderate anaemia. The sensitivity of tongue pallor was low among all children evaluated. Low haemoglobin levels were significantly associated with the likelihood of being smear-positive for P. falciparum. This study demonstrates that clinical criteria can be used to identify children with moderate and severe anaemia, thus enabling implementation of treatment algorithms. Children aged < 36 months who live in an area with P. falciparum malaria should receive treatment with an effective antimalarial drug if they have pallor.

Anemia↗
PubMed1996

Non-insulin-dependent diabetes mellitus among First Nations children. New entity among First Nations people of north western Ontario.

OBJECTIVE: To describe the emergence of a new clinical form of non-insulin-dependent diabetes mellitus (NIDDM) among First Nations children. DESIGN: Case series developed through retrospective review of a computerized diabetes registry and of records from a hospital and clinic. SETTING: Sioux Lookout Zone Hospital, a secondary care referral hospital for 28 remote First Nations communities in northwestern Ontario, affiliated with the University of Toronto's Sioux Lookout Program. PARTICIPANTS: Eighteen First Nations youths younger than 16 years identified via the Sioux Lookout Diabetes Program registry and via hospital discharge records from 1978 to 1994. Three of the 18 subjects were excluded because data essential to the study were missing from their records. MAIN OUTCOME MEASURES: Prevalence of NIDDM in this population, clinical presentation at diagnosis, and associated risk factors (including family history, obesity, and clinical management). RESULTS: Age-adjusted prevalence was 2.5/1000 in this population, the highest yet reported for NIDDM in this age group. Ratio of female to male subjects was 6:1. Typical patients were asymptomatic, obese adolescents who were not prone to ketosis and whose families had a strong history of NIDDM. CONCLUSIONS: Non-insulin-dependent diabetes mellitus can occur during childhood, particularly among First Nations people.

Adolescent↗
PubMed1995

A rapid dot immunoassay for detecting the Brazilian purpuric fever clone of Haemophilus influenzae biogroup aegyptius with a "flow through" device.

Brazilian purpuric fever (BPF) is a highly fatal pediatric disease that may follow an episode of purulent conjunctivitis caused by a virulent clone of Haemophilus influenzae biogroup aegyptius (Hae). Oral rifampin prophylaxis, by eliminating carriage of the BPF clone in children with conjunctivitis, may prevent onset of the systemic disease. A test to detect the BPF clone directly from eye swabs could identify those in need of prophylaxis. This is a preliminary report of a rapid dot immunoassay performed on a "flow-through" cartridge that was developed for use under field conditions. The test is based upon recognition of a unique epitope of the 25-kDa pilin protein on the surface of BPF clone cells by a monoclonal antibody. With 36 laboratory-maintained cultures of Hae (15 clone isolates and 21 others), sensitivity of the assay was 67% and specificity was 95%. When fimbrial-enriched (25-kDa+) phenotypes of five false-negative clone strains were prepared for use as test antigens, sensitivity rose to 100%. Evaluation of the immunoassay under field conditions is necessary to prove its efficacy.

Conjunctivitis, Bacterial↗
PubMed1995

Brazilian purpuric fever caused by Haemophilus influenzae biogroup aegyptius strains lacking the 3031 plasmid.

Brazilian purpuric fever (BPF) is a life-threatening pediatric infection caused by Haemophilus influenzae biogroup aegyptius (Hae), an organism formerly associated with only self-limited purulent conjunctivitis. Strains of Hae causing BPF have a 24-MDa plasmid with a specific AccI restriction pattern designated 3031. This plasmid was thought to code for a virulence factor because it had been detected only among Hae strains isolated from BPF cases or their contacts. From 3 typical BPF cases recently identified in São Paulo State, sterile-site Hae isolates were obtained; these isolates were similar to earlier BPF-associated Hae except they did not possess a 3031 plasmid. HindIII restricted chromosomal DNA from these strains was probed with purified 3031 plasmid DNA under high-stringency conditions. There was no evidence that 3031 plasmid DNA had become chromosomally integrated. It appears that the 3031 plasmid does not code for BPF-specific virulence factors.

Blotting, Southern↗
PubMed1995

Cutaneous manifestations of opportunistic infections in patients infected with human immunodeficiency virus.

Bacillary angiomatosis (BA) presents most commonly as a cutaneous disease and is caused by two organisms. Bartonella (Rochalimaea) henselae and Bartonella (Rochalimaea) quintana. Biopsy confirmation of cutaneous BA is essential because lesions can mimic nodular Kaposi's sarcoma in appearance. Although the vast majority of human immunodeficiency virus (HIV)-infected patients with BA have CD4 lymphocyte counts of less than 100 cells per mm3, the disease responds well to antimicrobial therapy. Staphylococcus aureus is the most common bacterial skin pathogen affecting HIV-infected patients. The prevalence of skin disease due to S. aureus may be explained by high nasal carriage rates for the organism ( > or = 50%) and altered immune function in conjunction with an impaired cutaneous barrier. Herpes simplex virus causes mucocutaneous disease early in the course HIV infection and ulcerative lesions at any site in advanced HIV infection. Herpes zoster is common early in the course of HIV infection; recurrent and disseminated herpes zoster infections are characteristic of patients with advanced HIV disease. Acyclovir resistance is usually seen in patients with large, untreated, ulcerative lesions of herpes simplex virus and in patients with chronic, verrucous lesions of varicella-zoster virus. Cutaneous cryptococcosis, histoplasmosis, and coccidiomycosis are markers of disseminated disease and require biopsy confirmation. Scabies is easily diagnosed but may be atypical in presentation and difficult to eradicate in advanced HIV disease.

AIDS-Related Opportunistic Infections↗
PubMed1995

Serologic responses to Bartonella and Afipia antigens in patients with cat scratch disease.

OBJECTIVE: To assess the serologic response to Afipia and Bartonella, previously named Rochalimaea, in patients with cat scratch disease (CSD) and a healthy control group. DESIGN: Prospective, controlled trial. SETTING: Referral clinic and hospitalized patients in a university medical center. PARTICIPANTS: Eighty patients with CSD and 57 healthy control subjects of similar age. MAIN OUTCOME MEASURES: The immune responses to Afipia felis and Bartonella henselae were evaluated by a newly developed enzyme-linked immunosorbent assay (ELISA) in patients with CSD and healthy control subjects. Responses to B henselae were also measured by indirect fluorescent antibody (IFA) tests. Antibody levels to Bartonella quintana were measured by ELISA and IFA in a limited number of patients and control subjects. RESULTS: Of the 80 patients with clinical CSD, 56 had positive results of CSD skin tests. ELISA antibody levels to A felis did not differ between patients and control subjects, but immunoglobulin M (IgM) and IgG ELISA antibodies to B henselae and B quintana were significantly higher in patients than in control subjects. IFA responses to B henselae and B quintana were also significantly higher in patients than in control subjects. CONCLUSION: Patients with CSD had significant serologic responses to B henselae and B quintana but not to A felis, suggesting that the causative agent of CSD is antigenically related to the Bartonella genus and not to Afipia. The Bartonella IgM ELISA and IFA assay were both sensitive and specific and may be used to establish the diagnosis of CSD.

Adolescent↗
PubMed1993

Cat scratch disease in Connecticut. Epidemiology, risk factors, and evaluation of a new diagnostic test.

BACKGROUND: Although cat scratch disease is commonly diagnosed in patients who have unexplained regional lymphadenopathy after encounters with cats, its epidemiology and the risk factors for disease are not clearly defined, and there is no generally accepted diagnostic test. METHODS: We conducted a physician survey to identify cases of cat scratch disease occurring over a 13-month period in cat owners in Connecticut. We interviewed both the patients (or their parents) and controls matched for age who owned cats. Serum from the patients was tested for antibodies to Rochalimaea henselae with a new, indirect fluorescent-antibody test. RESULTS: We identified 60 patients with cat scratch disease and 56 age-matched subjects. Patients were more likely than controls to have at least one pet kitten 12 months old or younger (odds ratio, 15), to have been scratched or bitten by a kitten (odds ratio, 27), and to have had at least one kitten with fleas (odds ratio, 29). A conditional logistic-regression analysis found that in kitten-owning households, patients were more likely than controls to have been scratched or bitten by a cat or kitten (odds ratio, 12.4; 95 percent confidence interval, 1.0 to 150). Of 45 patients, 38 had serum samples with titers of 1:64 or higher for antibody to R. henselae, as compared with 4 of 112 samples from controls (P < 0.001). The positive predictive value of the serologic test was 91 percent. Of 48 serum samples from patients' cats, 39 were positive for antibodies to R. henselae, as compared with positive samples from 11 of 29 control cats (P < 0.001). CONCLUSIONS: Cat scratch disease is strongly associated with owning a kitten, and fleas may be involved in its transmission. The serologic test for rochalimaea may be useful diagnostically, and our results suggest an etiologic role for this genus.

Adolescent↗
PubMed1993

Cat scratch disease in the United States: an analysis of three national databases.

OBJECTIVES: Current knowledge of the epidemiology of cat scratch disease is based primarily on information from case series. We used three national databases to obtain more representative data to determine the incidence and demographics of cat scratch disease. METHODS: Records coded with the diagnosis of cat scratch disease from two hospital discharge databases and an ambulatory care database were analyzed. Costs of diagnostic tests and hospitalization were obtained from a sample of providers and published data. RESULTS: The incidence of patients discharged from hospitals with a diagnosis of cat scratch disease was between 0.77 and 0.86 per 100,000 population per year. Fifty-five percent of the case patients were 18 years of age or younger. Males accounted for 60% of cases. Incidence varied by season; approximately 60% of case patients were discharged in the months September through January. The estimated incidence of disease in ambulatory patients was 9.3 per 100,000 population per year. On the basis of these rates, we estimated the annual health care cost of the disease to be more than $12 million. CONCLUSIONS: The rates and seasonality of cat scratch disease found in this study were consistent with previous reports. Adults represented a higher percentage of the total than reported in previous case series, suggesting that the disease may affect more adults than previously recognized.

Abstracting and Indexing↗
PubMed1992

Protective efficacy of a serogroup B meningococcal vaccine in Sao Paulo, Brazil.

Serogroup B Neisseria meningitidis is the most common cause of epidemic meningococcal disease in developed countries. Until recently no vaccine has been available for prevention of infection with this organism. In an attempt to control epidemic serogroup B meningococcal disease in greater Sao Paulo, Brazil, during 1989 and 1990, a Cuban-produced outer-membrane-protein-based serogroup B meningococcal vaccine was given to about 2.4 million children aged from 3 months to 6 years. We have done a case-control study to estimate the efficacy of the vaccine in greater Sao Paulo. Microbiologically confirmed cases of serogroup B meningococcal disease were identified through hospital-based surveillance. Controls were matched by neighbourhood and age. Vaccination status was confirmed by inspection of vaccination cards. Between June, 1990, and June, 1991, 112 patients and 409 matched controls with confirmed vaccine status were enrolled. Estimated vaccine efficacy varied by age: 48 months or older = 74% (95% Cl 16 to 92%), 24 to 47 months = 47% (-72 to 84%), and less than 24 months = -37% (< -100 to 73%). Our results suggest that the Cuban-produced vaccine may be effective for prevention of serogroup B meningococcal disease in older children and adults.

Adult↗
PubMed1992

Serological response to "Rochalimaea henselae" antigen in suspected cat-scratch disease.

There are no generally accepted diagnostic tests for cat-scratch disease (CSD), the cause of which is unknown. During the development of an indirect fluorescence antibody (IFA) test for detection of antibodies to "Rochalimaea henselae", sera from patients with CSD were found to have high titres to R henselae antigens. Further tests with this assay showed that 36 (88%) of 41 patients with suspected CSD had serum titres of 64 or more to R henselae antigen, that there was a low prevalence (3%) of substantial titres to R henselae in healthy controls (n = 107), and that the immune responses to R henselae antigens were specific. These data suggest that the R henselae IFA test, or other serological assays based on R henselae, may be useful for diagnosis of CSD.

Antigens, Bacterial↗
PubMed1992

Epidemic meningococcal disease in Nairobi, Kenya, 1989. The Kenya/Centers for Disease Control (CDC) Meningitis Study Group.

An epidemic of meningococcal disease occurred in Nairobi, Kenya, during 1989, outside the "meningitis belt" of sub-Saharan Africa. About 3800 cases occurred between April and November (250/100,000 population). The case-fatality rate was 9.4% among hospitalized patients. Areas that included Nairobi's largest slums had particularly high attack rates. The epidemic displayed an unusual age distribution, with high attack rates among those 20-29 years old. A vaccination campaign was conducted. By early January, the weekly case count had fallen to 25 from a high of 272 (in September). A case-control study estimated the vaccine efficacy to be 87% (95% confidence interval, 67%-95%). A model estimated that the vaccination campaign reduced the number of cases by at least 20%. Multilocus enzyme electrophoretic typing demonstrated that the strain responsible for this large epidemic is closely related to strains that caused other recent epidemics, documenting further spread of what may be a particularly virulent clonal complex of group A Neisseria meningitidis.

Adolescent↗
PubMed1992

Comparative efficacy of oral rifampin and topical chloramphenicol in eradicating conjunctival carriage of Haemophilus influenzae biogroup aegyptius. Brazilian Purpuric Fever Study Group.

Persistent conjunctival carriage of the Haemophilus influenzae biogroup aegyptius (Hae) strain (BPF clone) responsible for Brazilian purpuric fever (BPF) has been documented. Topical chloramphenicol is routinely used to treat conjunctivitis in areas affected by BPF in Brazil. Although the BPF clone is susceptible to chloramphenicol, we observed a number of children treated with topical chloramphenicol for conjunctivitis who still developed BPF. During an investigation of an outbreak of BPF in Mato Grosso State, Brazil, we compared oral rifampin (20 mg/kg/day for 4 days) with topical chloramphenicol for eradication of conjunctival carriage of H. influenzae biogroup aegyptius among children with presumed BPF clone conjunctivitis. Conjunctival samples were taken for culture on the day treatment was initiated and a mean of 8 and 21 days later. At 8 days the eradication rates for oral rifampin and topical chloramphenicol were 100 and 44%, respectively (P = 0.003); at 21 days they were 100 and 50% (P = 0.01). Oral rifampin was more effective than topical chloramphenicol for eradication of the BPF clone and may be useful in prevention of BPF.

Administration, Oral↗
PubMed1992

In vitro activities of streptomycin and 11 oral antimicrobial agents against clinical isolates of Klebsiella rhinoscleromatis.

We tested in vitro the activities of streptomycin and tetracycline--antibiotics that have long been used to treat rhinoscleroma--as well as several newer oral agents by using 23 isolates of the causative organism Klebsiella rhinoscleromatis. All isolates were inhibited by clinically achievable concentrations of trimethoprim-sulfamethoxazole, amoxicillin-clavulanate, chloramphenicol, ciprofloxacin, cephalexin, cefuroxime, and cefpodoxime.

Anti-Bacterial Agents↗
PubMed1983

Effect of mannitol infusions into the internal carotid artery on entry of two antibiotics into the cerebrospinal fluid and brains of normal rabbits.

The rapid infusion of hyperosmolar solutions into the internal carotid artery transiently disrupts the integrity of the blood-brain barrier, permitting entry of substances normally excluded from the nervous system. This study examined the effect of such an infusion on the penetration of vancomycin and tobramycin into the cerebrospinal fluid and brains of normal rabbits. Groups of five to seven animals were assigned either to control groups, receiving vancomycin or tobramycin alone, or to experimental groups, receiving these antibiotics with 40-s intracarotid infusions of 8.0 ml of 25% mannitol. Serum, cerebrospinal fluid, and brain specimens were obtained for assay 135 min after dosage. Concentrations of these antibiotics in serum were comparable in control and experimental groups; concentrations of the antibiotics in cerebrospinal fluid were significantly higher in the experimental groups. Mean (+/- standard deviation) concentrations of the antibiotics in cerebrospinal fluid were, respectively, less than 0.5 and 4.1 +/- 4.6 micrograms of vancomycin per ml and 0.6 +/- 0.5 and 3.4 +/- 2.4 micrograms of tobramycin per ml in the control and experimental groups. The concentrations of these antibiotics in brains were also higher in the experimental groups. This trend achieved statistical significance in the tobramycin studies, where control animals uniformly had tobramycin concentrations in brains of less than 0.1 microgram/g and experimental group animals had a mean concentration of 0.4 microgram/g. Additional studies with tobramycin indicated that intracarotid antibiotic administration immediately after the mannitol infusion further augmented antibiotic concentrations in brains.

Animals↗