Geospatial analysis of time to HIV diagnosis and adult HIV testing coverage highlights areas for intervention in the U.S. Southeast

Background

In the U.S., 44% of people with HIV (PWH) live in the Southeastern census region; many PWH remain undiagnosed. Novel strategies to inform testing outreach in rural states with dispersed HIV-epidemics are needed.

Methods

Alabama state public health HIV testing surveillance data from 2013-2017 were used to estimate time from infection to HIV diagnosis using CD4 T-cell depletion modeling, mapped to county. Diagnostic HIV tests performed 2013-2021 by commercial testing entities were used to estimate HIV tests per 100,000 adults (15-65-year-old), mapped to client ZIP code tabulation area (ZCTA). We then defined testing “cold spots”: those with <10% adults tested plus either (a) within or bordering one of the 13 counties with HIV prevalence greater than 400 cases per 100,000 population or (b) within a county with average time to diagnosis greater than the state average to inform testing outreach.

Results

Time to HIV diagnosis is a median of 3.7 (IQR 0-9.2) years across Alabama, with a range from 0.06-12.25 years. Approximately 63% of counties (N=42) have a longer time-to-diagnosis compared to national U.S. estimates. 643 ZCTAs tested 17.3% (IQR: 10.3%,25.0%) of the adult population from 2013-2017. To prioritize areas for testing outreach, we generated maps to describe 47 areas of HIV-testing cold spots at the ZCTA level.

Conclusions

Combining public health surveillance with commercial testing data provides a more nuanced understanding of HIV testing gaps in a state with a rural HIV epidemic and identifies areas to prioritize for testing outreach.

A Comparison of Cold Storage Solutions for Pancreas Preservation Prior to Islet Isolation

BACKGROUND

Several solutions are used to preserve the pancreas prior to islet isolation. This study sought to assess whether the type of solution had an impact on the isolation outcome.

METHODS

We reviewed data from 125 islet isolation procedures performed from January 2002 to January 2005. Pancreata were preserved in University of Wisconsin (UW) (n = 101), Celsior (CS) (n = 19), or IGL-1 (n = 5) solutions. Islet isolation results and transplantation rates were compared between groups.

RESULTS

UW, CS, and IGL-1 groups were similar according to donor's age, weight, and body mass index. Weight of undigested pancreas was 20 +/- 13.1, 21.4 +/- 15.7, and 17.4 +/- 8.7 g for UW, CS, and IGL-1, respectively (P > .2). Final total number of IEQ was 267,000 +/- 132,000, 277,000 +/- 155,000, and 311,000 +/- 163,000, respectively (P > .4). Success rate (defined as >250,000 IEQ) was 55.5%, 52.9%, and 60% for UW, Celsior, and IGL-1 (P > .9); the transplantation rate was 42.2% for UW, 36.8% for Celsior, and 80% for IGL-1 preservation (P > .2).

CONCLUSIONS

In this preliminary study, UW, Celsior, and IGL-1 solutions demonstrated similar islet isolation results. The new IGL-1 solution appears promising.

Comparative potency of gemifloxacin, new quinolones, macrolides, tetracycline and clindamycin against Mycoplasma spp

This study determined the comparative in vitro potency of the new investigative quinolone gemifloxacin (SB-265805) using low-passaged clinical isolates and type strains of mycoplasma commonly found in the human respiratory and urogenital tracts. Organisms studied were Mycoplasma pneumoniae, Mycoplasma hominis, Mycoplasma fermentans, Mycoplasma genitalium, Mycoplasma penetrans and Ureaplasma urealyticum, obtained from different geographical regions. Comparator drugs were levofloxacin, trovafloxacin, grepafloxacin, azithromycin, clarithromycin, tetracycline and clindamycin. MICs were determined using a microbroth dilution method. The overall range of MICs of gemifloxacin was < or =0.008-0.125 mg/L for different Mycoplasma spp. and < or =0.008-0.5 mg/L for Ureaplasma spp. Depending on the species tested, gemifloxacin showed variable results when compared with the macrolides. However, gemifloxacin was as potent as, or more potent than, tetracycline, clindamycin and the other quinolones investigated.

Different manifestations of Toxoplasma gondii infection in F344 and LEW rats

There is evidence that not only the immune status, but also the genetic predisposition of certain hosts influence the clinical outcome of Toxoplasma gondii infection. By far the majority of our knowledge on genetic and immunological mechanisms involved in control of T. gondii infection has been obtained by studying mouse models, which in terms of clinical outcome of infection differ considerably from humans. Rats which show a rather similar course of infection in comparison to humans have not so far been investigated for effects of genetic differences on course of the infection. In this study we show that, like mice, different strains of rats exhibit a remarkable variation in the number of brain cysts arising from chronic infection. LEW rats seem to be highly resistant to cyst formation, in contrast to F344 rats that are susceptible. In addition, F344 rats express high numbers of gammadelta T cells during the acute phase of infection, whereas LEW rats express elevated but comparably low numbers of gammadelta T cells. The RT1 (rat MHC) haplotypes of both strains are identical in the RT1A and RT1B/D regions, which encode the restriction elements for conventional peptide antigens. Consequently, rat strain-specific differences may be useful to define MHC-independent mechanisms of resistance against T. gondii, which may also act in humans.

Reactivation of chronic toxoplasmosis: is there a link to strain-specific differences in the parasite?

The protozoan parasite Toxoplasma gondii comprises three clonal lineages that are associated with the clinical outcome in infected individuals. Whereas group C strains are mainly found in animals, group A and B strains are associated with human disease (Howe and Sibley, 1995). An increased level of transcripts of the tachyzoite-specifically expressed gene SAG1 could be identified in group A T. gondii strains compared to group B strains. Since SAG1-mediated host-cell invasion seems to be important for parasite replication, the observed higher replication rate in group A T. gondii strains might explain the association with clinically overt symptoms at the acute stage in patients who are infected with this group of parasite strains. The presence of external stress factors, such as interferon-gamma (IFN-gamma)-mediated nitric oxide (NO) formation has been identified to stabilize the cyst stage, most likely by activation of promoter(s) which drive the expression of genes encoding bradyzoite-specific antigens. Reactivation of chronic toxoplasmosis thus might occur in the absence of external stress factors, as has been observed in AIDS patients with decreases levels of IFN-gamma. Since group B T. gondii strains might form more cysts in infected individuals due to an increased potential to convert into bradyzoites, reactivation with resulting toxoplasmic encephalitis could be a more common event in those AIDS patients who were infected with persistent cysts of this group of parasite strains.