Search PubMedSearch

Biomedical subjects

W DeWitt

Publications and source records attributed to W DeWitt.

12 recordsLinked to original sources

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

Respiratory viruses and mycoplasma as cofactors for epidemic group A meningococcal meningitis.

To investigate the role of coincident respiratory viral and mycoplasmal agents in the pathogenesis of meningococcal meningitis, we performed a matched case-control study of 62 patients with group A meningococcal meningitis during an epidemic in Chad. Case patients were more likely than controls to have nasal colonization or infection with respiratory viruses and Mycoplasma species (matched odds ratio, 23; 95% confidence interval, 3.1 to 170). Respiratory pathogens were found more commonly in older patients with meningitis (odds ratios were 2.9 for children under age 5 years and 46.5 in those over age 15 years), consistent with the increasing risk of meningitis with age during epidemics. In controls, the presence of respiratory pathogens increased the risk of upper-respiratory-tract symptoms but did not significantly increase meningococcal carriage.

Adolescent

Haemophilus ducreyi infection in south Florida: a rare disease on the rise?

Increased numbers of patients with genital ulcers sought medical attention in the Palm Beach County, Florida, Sexually Transmitted Disease clinics from Aug 1, 1982 to Aug 31, 1983. We established that a small proportion of subsequent cases of genital ulcers were caused by Haemophilus ducreyi, the etiologic agent associated with chancroid. We also set up a surveillance system to monitor this sexually transmitted infection, and have illuminated several recent cases of chancroid occurring in that area. This outbreak of chancroid suggest that clinicians practicing in south Florida consider chancroid (generally a rare disease in the United States) in their differential diagnoses of genital ulcers.

Adult

Correlation of auxotype and protein I type with expression of disease due to Neisseria gonorrhoeae.

To explore the correlation of outer membrane protein I (PI) type and auxotype to clinical expression of infection with Neisseria gonorrhoeae, we characterized nutritional requirements by auxotyping and PI serovars by coagglutination assay with monoclonal antibodies of 325 consecutive clinical isolates of N. gonorrhoeae. The clinical status of each infected individual was determined by chart review. The predominant auxotype required proline, citrulline, and uracil with or without hypoxanthine (Pro-Cit-Ura-[Hyx-]) and accounted for 22% of all gonococcal strains. Pro-Cit-Ura-(Hyx-) strains were recovered from seven of 15 men with asymptomatic urethral infections (P less than .01). Of the 325 strains, 33% were PIA and 67% were PIB serovars. All five isolates in disseminated gonococcal infection were PIA serovars (P less than .01). Three percent of 168 urethral infections in men were complicated by epididymitis, and 17% of 135 cervical infections in women were complicated by pelvic inflammatory disease (P less than .0005). Neither of these complications was associated with a particular auxotype or PI serovar.

Bacterial Outer Membrane Proteins

Plasmid profile, serogrouping, and auxotyping of Neisseria gonorrhoeae isolates from Africa.

The plasmid patterns of 90 isolates of Neisseria gonorrhoeae (including 39 penicillinase-producing strains) originating from various countries in Africa were determined. Serogrouping by coagglutination and auxotyping were used to characterise the isolates. The 4.4-megadalton plasmid was present in seven isolates out of 39 penicillinase-producing strains, two of which occurred with a conjugative 24.5-megadalton plasmid. The African strains were predominantly serogroup WI and wild type. Arginine-dependent isolates were as common as proline-dependent types.

Africa

Epidemiological characterisation of Neisseria gonorrhoeae isolates from the Far East.

One hundred strains of Neisseria gonorrhoeae (including 30 penicillinase producing (PPNG) strains) originating from Korea were characterised by plasmid analysis, auxotyping, and serogrouping. Eighty per cent of the isolates possessed the conjugative 24.5 megadalton (Mdal) plasmid. A novel 7.8 Mdal plasmid was present in four isolates (one PPNG and three non-PPNG strains). Seventy five per cent of all the strains tested were wild type and belonged to serogroup WII, while 20% were proline requiring and belonged to serogroup WII. Two of the remaining strains were tyrosine auxotrophs, while another strain was arginine requiring; these three strains carried the conjugative plasmid and belonged to serogroup WII.

Gonorrhea