Factors contributing to the emergence of Escherichia coli O157 in Africa

In 1992, a large outbreak of bloody diarrhea caused by Escherichia coli O157 infections occurred in southern Africa. In Swaziland, 40,912 physician visits for diarrhea in persons ages >5 years were reported during October through November 1992. This was a sevenfold increase over the same period during 1990-91. The attack rate was 42% among 778 residents we surveyed. Female gender and consuming beef and untreated water were significant risks for illness. E. coli O157:NM was recovered from seven affected foci in Swaziland and South Africa; 27 of 31 patient and environmental isolates had indistinguishable pulsed-field gel electrophoresis patterns. Compared with previous years, a fivefold increase in cattle deaths occurred in October 1992. The first heavy rains fell that same month (36 mm), following 3 months of drought. Drought, carriage of E. coli O157 by cattle, and heavy rains with contamination of surface water appear to be important factors contributing to this outbreak.

Testing umbilical cords for funisitis due to Treponema pallidum infection, Bolivia

To establish the frequency of necrotizing funisitis in congenital syphilis, we conducted a prospective descriptive study of maternal syphilis in Bolivia by testing 1,559 women at delivery with rapid plasma reagin (RPR). We examined umbilical cords of 66 infants whose mothers had positive RPR and fluorescent treponemal antibody absorption tests. Histologic abnormalities were detected in 28 (42%) umbilical cords (seven [11%] had necrotizing funisitis with spirochetes; three [4%] had marked funisitis without necrosis; and 18 [27%] had mild funisitis), and 38 [58%] were normal. Of 22 umbilical cords of infants from mothers without syphilis (controls), only two (9%) showed mild funisitis; the others were normal. Testing umbilical cords by using immunohistochemistry is a research tool that can establish the frequency of funisitis due to Treponema pallidum infection.

An HIV type 2 DNA vaccine induces cross-reactive immune responses against HIV type 2 and SIV

We have previously reported on the generation of specific functional immune responses after inoculation of animals with expression vectors encoding HIV-1 genes. This article provides the details of the first application of this new technology to induce immune responses against HIV-2. This virus is molecularly and serologically distinct from HIV-1 and is in fact more closely related to the simian immunodeficiency virus (SIV). Anti-HIV-2 and SIV antibodies were induced in mice of three different haplotypes following a single intramuscular inoculation with an HIV-2/ROD envelope glycoprotein expression vector (pcEnv-2). Boosting of animals with pcEnv-2 induced both anti-HIV-2 neutralizing antibodies and T cell-proliferative responses against HIV-2 and SIVmac proteins. We compared the humoral and cellular immune responses of mice injected with pcEnv-2 and then boosted with either the homologous DNA construct or a recombinant Env protein. Animals boosted with pcEnv-2 generated B and T cell immune responses as strong as those of mice boosted with recombinant gp140 protein in adjuvant. Finally, cellular immune responses were significantly increased with the coadministration of pcEnv-2 and a plasmid expressing interleukin 12. We therefore conclude that DNA plasmid inoculation induces cross-reactive anti-HIV-2 and anti-SIVmac immune responses in mice. This technology should be further investigated as a potential vaccine component for this human pathogen.

Post-load plasma glucose and cancer mortality in middle-aged men and women. 12-year follow-up findings of the Chicago Heart Association Detection Project in Industry

The relation of post-load plasma glucose to 12-year cancer mortality was studied in 11,521 white men and 8,591 white women aged 35-64 years at entry in the Chicago Heart Association Detection Project in Industry. There were 298 deaths in which cancer was the underlying cause in men and 186 such deaths in women. Plasma glucose levels at baseline measured one hour after a 50 g oral glucose load were positively related to cancer mortality in men but not in women. This increased mortality in men persisted after controlling for age, body mass index, smoking, serum cholesterol, systolic blood pressure, education, and anti-hypertensive treatment. A site-specific analysis of the male cancer deaths demonstrated higher mean plasma glucose levels for decedents for nearly all sites except oral cancers, liver cancer, and other respiratory cancers. For women, elevations existed for those who died of colon, lung, and hematologic/lymphatic tumors, but not for most other sites. The associations between baseline post-load plasma glucose levels and cancer mortality were similar for earlier and later cancer deaths, which indicates that incipient or occult neoplasm at baseline was not responsible for elevated glucose levels in men who subsequently died of cancer. Cancer mortality rates were also higher for those with a clinical diagnosis of diabetes than for those without, but the numbers of persons with diabetes were small as were the numbers of cancer deaths (19 in the men and 10 in the women).

Serum uric acid and 11.5-year mortality of middle-aged women: findings of the Chicago Heart Association Detection Project in Industry

The relationships of serum uric acid to mortality from all causes, the cardiovascular diseases, and cancer were evaluated in 6797 white women age 35-64 years followed for an average of 11.5 years in the Chicago Heart Association Detection Project in Industry (CHA). Serum uric acid levels at baseline were strongly and significantly associated with all causes mortality in this cohort, with control for multiple risk factors and with exclusion of hypertensives on treatment. When the analysis was performed on age-specific groups 35-44, 45-54, and 55-64 years of age, the association was observed primarily in women in the oldest age group. All cardiovascular deaths, deaths due to coronary heart disease, and all cancer deaths were also associated with serum uric acid levels in the 55-64 year old group. The relationships persisted with control for multiple risk factors and with exclusion of treated hypertensives. A site-specific analysis of cancer deaths demonstrated elevations in mean serum uric acid levels for nearly all sites. Differences in mean serum uric acid levels between decedents and survivors tended to be largest in the first 5 years of follow-up for the cardiovascular deaths, but for cancer decedents they tended to be larger for subsequent years of follow-up. As an initial report on the association of serum uric acid and cancer in women in this age group, the results of this study require confirmation. Although hormonal influences may play a role, pathophysiologic mechanisms relating serum uric acid to mortality in white women aged 55-64 are currently unknown.