Persistent polyclonal lymphocytosis of B lymphocytes.
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Biomedical subjects
Publications and source records attributed to D N Lawrence.
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Ciguatoxic fish constitute a continuing foodborne disease problem in Miami. Information from 129 cases of ciguatera fish poisoning reported to the Dade County (Miami) department of Public Health during 1974 to 1976 was used for epidemiologic study of the syndrome. The case definition required that both gastrointestinal and paresthetic neurological symptoms be experienced within 36 hours after eating fish. Grouper and snapper were the fish most frequently implicated. Neither methods of storage nor means of preparation seemed to affect fish toxicity. A predominantly late spring and summer seasonality was noted. The true annual incidence of this syndrome in Miami may be ten times the number reported to the health department, suggesting an average annual incidence of at least five cases per 10,000 resident population. Recent advances in ciguatoxin research may lead to much needed assays for toxin detection.
HLA typing was performed in 1978, using antisera recognizing specificities defined by the Seventh Workshop, on lymphocytes separated and frozen in the field during a 1976 expedition among Amazonian Ticuna Indians. Family segregation of HLA antigens was used to ascertain haplotypes of a sample of essentially unrelated reproductive-age adults. "Expaternal" haplotypes were also included in the total of 81 haplotypes used for calculating the A and B locus gene frequencies. Common A and B locus antigens among the Ticuna were Aw24, Aw31, A2, Bw39, B40, Bw35, and B15.1. Bw53 were also present. No A or B locus "blanks" were found. A slight degree of European admixture was apparent. Bw16-reactive cells from certain persons consistently failed to react with Oxford antisera capable of recognizing the Bw38 or Bw39 subspecificities. Cw1 and Cw3 were found in association with typical South American Indian haplotypes. The results of HLA typing of a large extended family with multiple cases of leprosy are depicted and compared to recently reported family studied of leprosy.
Microfilariae of Mansonella ozzardi, concentrated from human blood, frozen with a cryoprotectant chemical, and stored at liquid or vapor-phase liquid nitrogen temperatures were motile when thawed after 2.5 years of preservation.
The prevalences of intestinal parasites among the residents of three South American Indian villages in the process of acculturation were compared with those found in earlier unpublished surveys in two newly contracted village.s Although one individual in an acculturating village harbored 11 different intestinal parasites, in general the average number of different parasitic species carried per person was somewhat higher in the newly contacted villages. Helminth egg counts, performed on direct smears of each specimen from one newly contacted village, were low. There were no sex-associated differences in prevalences. The overall prevalences, unadjusted for age, were among the highest recorded for Amerindians. No Taenia species were present. Balantidium coli was present in two acculturating villages, concomitant with the beginning of agricultural practices which include raising swine. No cases of moderate or severe protein-calorie malnutrition was observed in any of the villages during the surveys. These limited data provide a baseline for future comparisons and, perhaps, a glimpse into the past.
Outbreaks of Vibrio parahaemolyticus gastrointestinal illness occurred on two Caribbean cruise ships in late 1974 and early 1975. In all, 697 passengers and 27 crew were affected. Epidemiologic evidence incriminated seafoods served on the ships as the vehicles of transmission. The seafoods were probably contaminated by V. parahaemolyticus after cooking in seawater from the ships' internal seawater distribution systems. Use of seawater in foodhandling areas was discontinued, and no further outbreaks occurred.
The prevalence of microfilaremia among Indians in 13 Amazon Indian villages was determined by examining Giemsa-stained peripheral blood smears and preparations from peripheral blood lymphocyte cultures. Mansonella ozzardi was the only species found in the 601 persons tested. Prevalence was highly village-specific, ranging from 0% in four villages to as high as 93% among persons aged 10 years and older in others. Comparisons of the two methods showed that the concentration effect of the peripheral blood lymphocyte culture preparations allowed the detection of a greater number of microfilaria-positive persons, especially women and children with lower levels of parasitemia.
Pyoderma was studied among a representative sample of the residents of four remote Amerindian villages, Amazonas State, Brazil, during July-August 1976. The overall prevalence among the 775 inhabitants examined was 11%, with little intervillage variation. When the attack rates for the entire sample population were calculated by 5-year age intervals, the 0- to 4-year-olds had the highest rate, 31%. The highest prevalence, 38%, was found among 3-year-olds. Attack rates were not apparently related to sex. Cultures which were taken from representative pyoderma lesions from people in the four survey villages and from three additional villages were studied by a modified delayed culture technique for recovery of gram-positive pathogens from silica-gel desiccated swabs. Group A and group G B-hemolytic streptococci, coagulase positive Staphylococcus aureus, and Corynebacterium diphtheriae were isolated. Group A S. pyogenes was most commonly found, occasionally as the sole pathogenic species. No nephritogenic M-types were found, although most isolates were not M-typable. The T-types found corresponded to those previously reported as being pyoderma-associated. Most pyoderma-associated C. diphtheriae isolates were non-toxigenic. Biotypes gravis and mitis were equally represented.
Corynebacterium diphtheriae was isolated from pyoderma and ulcerative skin lesions with a modified delayed culture procedure as late as 9 weeks after field collection of silica gel-desiccated swabs. Biotypes gravis and mitis were identified. Most isolates were nontoxigenic. Todd-Hewitt broth enrichment enhanced recovery of C. diphtheriae by 70%.
Between August 16 and 21, 1974, an outbreak of beta-hemolytic group A M-9 T-9 streptococcal pharyngitis affected 49% of a randomly selected group of inmates at a jail in southern Florida. Food-specific attack rates incriminated improperly stored egg salad served at lunch on August 16 as the vehicle of transmission. By August 20, 290 symptomatic inmates had been placed on penicillin or erythromycin; on that day fewer than 5% of throat cultures from 400 allegedly non-penicillin-allergic largely asymptomatic inmates, cultured just before penicillin prophylaxis, were positive for the epidemic strain. At the time prophylaxis was given, secondary transmission had accounted for only 3% of cases. No non-suppurative sequelae were observed but 5% of inmates who received penicillin prophylaxis experienced an adverse reaction to the drug. Although widespread penicillin prophylaxis during outbreaks of group A beta-hemolytic streptococcal pharyngitis will likely prevent transmission of these organisms, prompt treatment of all symptomatic cases may be equally as effective in controlling adult institutional foodborne outbreaks of streptococcal pharyngitis and will likely minimize the number of adverse reactions to penicillin which may be seen.
Between January 1 and March 15, 1974, approximately 1200 cases of acute gastrointestinal illness occurred in Richmond Heights, Florida, a residential community of 6500 in south Dade County. Over one-third of all families in the area had at least one member affected. The findings of 10 culture-proven cases of shigellosis among those who became ill and clinical signs and symptoms in the others suggest that most of the other cases that were not cultured may have been shigellosis also. Epidemiologic investigation showed that consumption of tap water was associated with illness in the initial cases of affected families. Evaluation of the Richmond Heights public water supply disclosed numerous inadequacies in both design and operation. One of the wells providing water to the community was continuously contaminated with excessive levels of fecal coliforms from a nearby septic tank, and a breakdown in chlorination on January 14-15 caused approximately 1 million gallons of inadequately chlorinated water from the contaminated well to be distributed to the community 48 hours before the epidemic began. Correction of deficiencies in the water plant was undertaken by the utility company; the residents of Richmond Heights were instructed to boil their drinking water or to use commercially bottled water pending completion of corrective measures. A FUll scale study is planned for all similar public water supplies in Dade County.
Efficacy trials of prophylactic HIV vaccines will be among the most difficult clinical trials ever attempted. Not only will there be challenges with the recruitment and retention of high-risk uninfected individuals, there will be many statistical challenges to the design, conduct, analysis, and interpretation of these trials. General features of an efficacy trial are described, including choice for the primary endpoint and testing for and estimating vaccine efficacy. Secondary objectives of trials are also discussed. These include determining the correlates of protective immunity, assessing the impact of HIV genetic variation on vaccine efficacy, and using biological markers such as viral load and CD4+ lymphocyte cell count to gain insight on a vaccine's ability to prevent or delay disease. The use of biological markers as surrogates for disease outcome is discussed. Last, trial designs for studying several candidate vaccines or other HIV prevention strategies in a single trial are examined.
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The risk of transfusion-associated acquired immunodeficiency syndrome (AIDS) has been difficult to estimate because of the long and variable incubation period. Mathematical modeling suggests there may eventually be 2100 cases among persons aged 13 to 65 who received transfusions between 1978 and 1984. An estimated 12,000 living transfusion recipients of all ages from these years are infected with the human immunodeficiency virus, the virus that causes AIDS. Secondary transmission might be prevented by testing and counseling recipients, but the likelihood of infection in any single recipient is small.