[Pathologic-anatomic and morphometric examinations on the heart in feral cockatoos]. / Pathologisch-anatomische und morphometrische Untersuchungen am Herzen von wildlebenden Kakadus.

OBJECTIVE: To evaluate the heart of free-living psittacine birds macroscopically and morphologically, and to compare the results to findings published for psittacine birds living in captivity to obtain information on the influence of bird keeping in a human environment on the psittacine heart. MATERIAL AND METHODS: In total, 84 wild-living cockatoos were examined, including 50 sulphur-crested cockatoos (Cacatua galerita), 31 galahs (Eolophus roseicapilla) and three long-billed corellas (Cacatua tenuirostris). The birds were euthanized because of a local cockatoo control program in Australia, and were examined pathologically within 8 hours of euthanasia. A macroscopic necropsy was performed, and the heart was assessed morphologically. Furthermore, a histological organ screening was conducted. RESULTS: The birds demonstrated good body condition and excellent muscle condition. Except for some paleness of the heart muscle, none of the animals showed any pathological alteration of the heart or large vessels. The mean heart mass was 8.7 g for the sulphur-crested cockatoos, 5.3 g for the galahs and 8.6 g for the long-billed corellas. Independent of the species examined, a highly significant correlation was found between the heart and body masses (r = 0.91; p < 0.001), which was also confirmed as significant within the sulphur-crested cockatoo (r = 0.59; p < 0.001) and galah groups (r = 0.52; p = 0.003). This correlation can be used to calculate the expected heart mass based on the body mass, using the formula: heart mass (g) = 2.9 + 0.01 x body mass (g). In comparison to reports on Australian parakeets, the relative thickness of the heart muscle wall of the left ventricle found in this study was greater. CONCLUSION: In comparison to psittacine birds kept in captivity, wild-living cockatoos have good body condition and rarely suffer from macroscopically detectable diseases of the heart or large vessels. The cardiac fitness level is superior in comparison to that found in healthy appearing psittacine birds kept in captivity. CLINICAL RELEVANCE: The results can serve as a basis for the assessment of the heart in psittacine birds, because in contrast to earlier reports, the heart of healthy psittacine birds not previously exposed to any human influence could be assessed.

Strengthening national health laboratories in sub-Saharan Africa: a decade of remarkable progress.

OBJECTIVES: Efforts to combat the HIV/AIDS pandemic have underscored the fragile and neglected nature of some national health laboratories in Africa. In response, national and international partners and various governments have worked collaboratively over the last several years to build sustainable laboratory capacities within the continent. Key accomplishments reflecting this successful partnership include the establishment of the African-based World Health Organization Regional Office for Africa (WHO-AFRO) Stepwise Laboratory Quality Improvement Process Towards Accreditation (SLIPTA); development of the Strengthening Laboratory Management Toward Accreditation (SLMTA) training programme; and launching of a Pan African-based institution, the African Society for Laboratory Medicine (ASLM). These platforms continue to serve as the foundations for national health laboratory infrastructure enhancement, capacity development and overall quality system improvement. Further targeted interventions should encourage countries to aim at integrated tiered referral networks, promote quality system improvement and accreditation, develop laboratory policies and strategic plans, enhance training and laboratory workforce development and a retention strategy, create career paths for laboratory professionals and establish public-private partnerships. Maintaining the gains and ensuring sustainability will require concerted action by all stakeholders with strong leadership and funding from African governments and from the African Union.

Performance of six commercial enzyme immunoassays and two alternative HIV-testing algorithms for the diagnosis of HIV-1 infection in Kisumu, Western Kenya.

Performances of serological parallel and serial testing algorithms were analyzed using a combination of three ELISA and three rapid tests for the confirmation of HIV infection. Each was assessed individually for their sensitivity and specificity on a blinded panel of 769 retrospective sera of known HIV status. Western blot was used as a confirmatory assay for discordant results. Subsequently, one parallel and one serial testing algorithm were assessed on a new panel of 912 HIV-positive and negative samples. Individual evaluation of the ELISAs and rapid tests indicated a sensitivity of 100% for all assays except Uni-Gold with 99.7%. The specificities ranged from 99.1% to 99.4% for rapid assays and from 97.5% to 99.1% for ELISAs. A parallel and serial testing algorithms using Enzygnost and Vironostika, and Determine followed by Uni-Gold respectively, showed 100% sensitivity and specificity. The cost for testing 912 samples was US$4.74 and US$ 1.9 per sample in parallel and serial testing respectively. Parallel or serial testing algorithm yielded a sensitivity and specificity of 100%. This alternative algorithm is reliable and reduces the occurrence of both false negatives and positives. The serial testing algorithm was more cost effective for diagnosing HIV infections in this population.

Reduced risk of transfusion-transmitted HIV in Kenya through centrally co-ordinated blood centres, stringent donor selection and effective p24 antigen-HIV antibody screening.

BACKGROUND: Following a 1994 study showing a high rate of transfusion-associated HIV, Kenya implemented WHO blood safety recommendations including: organizing the Kenya National Blood Transfusion Service (NBTS), stringent blood donor selection, and universal screening with fourth-generation p24 antigen and HIV antibody assays. Here, we estimate the risk of transfusion-associated HIV transmission in Kenya resulting from NBTS laboratory error and consider the potential safety benefit of instituting pooled nucleic acid testing (NAT) to reduce window period transmission. METHODS: From November to December 2008 in one NBTS regional centre, and from March to June 2009 in all six NBTS regional centres, every third unit of blood screened negative for HIV by the national algorithm was selected. Dried blood spots were prepared and sent to a reference laboratory for further testing, including NAT. Test results from the reference laboratory and NBTS were compared. Risk of transfusion-associated HIV transmission owing to laboratory error and the estimated yield of implementing NAT were calculated. FINDINGS: No cases of laboratory error were detected in 12,435 units tested. We estimate that during the study period, the percentage of units reactive for HIV by NAT but non-reactive by the national algorithm was 0·0% (95% exact binomial confidence interval, 0·00-0·024%). INTERPRETATION: By adopting WHO blood safety strategies for resource-limited settings, Kenya has substantially reduced the risk of transfusion-associated HIV infection. As the national testing and donor selection algorithm is effective, implementing NAT is unlikely to add a significant safety benefit. These findings should encourage other countries in the region to fully adopt the WHO strategies.

New multiple antigenic peptide-based enzyme immunoassay for detection of simian immunodeficiency virus infection in nonhuman primates and humans.

Infections with human immunodeficiency virus types 1 and 2 (HIV-1 and HIV-2, respectively) are zoonotic infections. In Africa, the potential exists for additional cross-species transmissions from at least 33 different species of simian immunodeficiency virus (SIV)-infected nonhuman primates (NHPs) through hunting and butchering of these animals for food. Here we describe a highly sensitive and specific enzyme immunoassay (EIA) with chemically modified, multiple antigenic peptides (MAPs) developed for the detection and discrimination of antibodies to SIV genetic lineages. The SIV EIA was developed by using a comprehensive array of MAPs covering two envelope gene regions from all of the SIV lineages for which env sequences were available. Assay sensitivity was evaluated by using 63 plasma or serum samples obtained from primates naturally or experimentally infected with SIVs from 10 genetic lineages. Assay specificity was determined by using 97 known SIV-negative plasma specimens from these same species. Also used in the evaluations were 369 human samples: 198 HIV seronegative, 170 HIV-1 and/or HIV-2 seropositive, and 1 from a human SIVsm infection. Overall assay sensitivity and specificity were 100% with both immunodominant region (IDR) and V3 region MAPs. Although SIV env sequences from talapoin monkeys were not available for specific MAP inclusion, 5 (100%) of 5 SIVtal-infected samples were detected through cross-reactivity with other SIV IDR MAPs used in the assay. The one human SIVsm infection was identified. In conclusion, our SIV MAP EIA proved to be highly sensitive and specific for detecting SIV infections in NHPs and humans. As shown with SIV-infected talapoin monkeys, this assay has the potential to detect previously unidentified SIV strains and should be suitable for sentinel surveillance for potential new cross-species transmissions of SIVs to humans.

Molecular surveillance of HIV-1 field strains in Nigeria in preparation for vaccine trials.

We conducted a national molecular epidemiologic survey of HIV-1 strains in Nigeria to determine the most prevalent subtype(s) for use in developing candidate vaccines. A total of 230 HIV-1-positive blood samples collected from 34 of the 36 Nigerian states were analyzed by our modified env gp41-based heteroduplex mobility assay (HMA) and/or gp41 sequencing and analysis. Overall, 103 (44.8%) were subtype A, 125 (54.3%) were subtype G, one (0.4%) was subtype C, and one (0.4%) was subtype J, and one (0.4%) was unclassifiable. To further characterize Nigerian viruses to aid in strain selection for candidate vaccines, one gp41 subtype G and five gp41 subtype A strains were selected for full envelope sequencing. The one subtype G sequence had consistent phylogenies throughout gp160, using programs to detect recombination. However, all five sequences that were primarily subtype A in gp41 were found to be recombinant viruses. Two of the five (40%) were A/G/J mosaics with common breakpoints. The remaining three gp160 recombinants all had their own unique break points: two A/? and one A/?/G, however, all five had the majority of their mosaic breakpoints occurring in gp41. None of the five were consistent with the circulating recombinant form (CRF)02_AG strain previously reported to be prevalent in West Africa. In conclusion, we showed a clear dominance and widespread distribution of gp41 subtypes A and G in fairly equal proportions, suggesting that vaccines designed for use in this geographic locale should incorporate the gene(s) of both subtypes. However, appreciating the magnitude of diversity of HIV-1 strains in Nigeria may require sequencing and analysis of longer gene regions for the identification of prevalent or emerging CRFs.

Assessment of the performance of a rapid, lateral flow assay for the detection of antibodies to HIV.

Rapid HIV assays have recently been shown to have important applications for various testing situations, including early identification of infected individuals, to allow intervention strategies in a clinically relevant time frame. A rapid, lateral flow, HIV-1/2/O assay was evaluated using 2,000 serum or plasma samples from various risk groups and geographic locations, including HIV-1 and HIV-2 positive sera from five countries. Two U.S. Food and Drug Administration (FDA)-licensed screening assays and a FDA-licensed confirmatory assay were used as reference tests. The rapid assay exhibited a near-perfect sensitivity (99.2%) and an excellent specificity (99.9%). Moreover, its analytical sensitivity was found to be better than most FDA-licensed enzyme-linked immunosorbent assays (ELISAs), detecting infection at the same time as the most sensitive ELISA in two of five seroconversion panels, and at the same time or earlier than four of five ELISAs in all five panels. We conclude that this rapid assay is a suitable test for the detection of HIV infection that could be particularly useful in developing countries where facilities may not support the use of instrumentation.

Development of an env gp41-based heteroduplex mobility assay for rapid human immunodeficiency virus type 1 subtyping.

The gp120 region of the human immunodeficiency virus type 1 (HIV-1) envelope (env) gene exhibits a high level of genetic heterogeneity across the group M subtypes. The heteroduplex mobility assay (HMA) has successfully been used to assign subtype classifications, but C2V5 primers often fail to amplify African strains. We developed an env gp41-based HMA for which the target sequence is amplified with highly conserved gp41 primers, known to efficiently amplify nucleic acids from HIV-1 group M, N, and O viruses. By using gp41 from a new panel of reference strains, the subtype assignments made by our modified HMA were concordant with those obtained by sequencing and phylogenetic analysis of 34 field strains from 10 countries representing subtypes A to G. Testing of field strains from Nigeria further demonstrated the utility of this modified assay. Of 28 samples, all could be amplified with gp41 primers but only 17 (60.7%) could be amplified with the standard C2V5 primers. Therefore, gp41-based HMA can be a useful tool for the rapid monitoring of prevalent subtypes in countries with divergent strains of circulating HIV-1.