| 1. |
- Brynildsrud, Ola B., et al.
(författare)
-
Global expansion of Mycobacterium tuberculosis lineage 4 shaped by colonial migration and local adaptation
- 2018
-
Ingår i: Science Advances. - : AMER ASSOC ADVANCEMENT SCIENCE. - 2375-2548. ; 4:10
-
Tidskriftsartikel (refereegranskat)abstract
- On the basis of population genomic and phylogeographic analyses of 1669 Mycobacterium tuberculosis lineage 4 (L4) genomes, we find that dispersal of L4 has been completely dominated by historical migrations out of Europe. We demonstrate an intimate temporal relationship between European colonial expansion into Africa and the Americas and the spread of L4 tuberculosis (TB). Markedly, in the age of antibiotics, mutations conferring antimicrobial resistance overwhelmingly emerged locally (at the level of nations), with minimal cross-border transmission of resistance. The latter finding was found to reflect the relatively recent emergence of these mutations, as a similar degree of local restriction was observed for susceptible variants emerging on comparable time scales. The restricted international transmission of drug-resistant TB suggests that containment efforts at the level of individual countries could be successful.
|
|
| 2. |
- Kepp, Kasper P., et al.
(författare)
-
Panel stacking is a threat to consensus statement validity
- 2024
-
Ingår i: Journal of Clinical Epidemiology. - : Elsevier. - 0895-4356 .- 1878-5921. ; 173
-
Tidskriftsartikel (refereegranskat)abstract
- Consensus statements can be very influential in medicine and public health. Some of these statements use systematic evidence synthesis but others fail on this front. Many consensus statements use panels of experts to deduce perceived consensus through Delphi processes. We argue that stacking of panel members toward one particular position or narrative is a major threat, especially in absence of systematic evidence review. Stacking may involve financial conflicts of interest, but nonfinancial conflicts of strong advocacy can also cause major bias. Given their emerging importance, we describe here how such consensus statements may be misleading, by analyzing in depth a recent high-impact Delphi consensus statement on COVID-19 recommendations as a case example. We demonstrate that many of the selected panel members and at least 35% of the core panel members had advocated toward COVID-19 elimination (Zero-COVID) during the pandemic and were leading members of aggressive advocacy groups. These advocacy conflicts were not declared in the Delphi consensus publication, with rare exceptions. Therefore, we propose that consensus statements should always require rigorous evidence synthesis and maximal transparency on potential biases toward advocacy or lobbyist groups to be valid. While advocacy can have many important functions, its biased impact on consensus panels should be carefully avoided.
|
|
| 3. |
- Linz, Bodo, et al.
(författare)
-
An African origin for the intimate association between humans and Helicobacter pylori
- 2007
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 445:7130, s. 915-918
-
Tidskriftsartikel (refereegranskat)abstract
- Infection of the stomach by Helicobacter pylori is ubiquitous among humans. However, although H. pylori strains from different geographic areas are associated with clear phylogeographic differentiation(1-4), the age of an association between these bacteria with humans remains highly controversial(5,6). Here we show, using sequences from a large data set of bacterial strains that, as in humans, genetic diversity in H. pylori decreases with geographic distance from east Africa, the cradle of modern humans. We also observe similar clines of genetic isolation by distance (IBD) for both H. pylori and its human host at a worldwide scale. Like humans, simulations indicate that H. pylori seems to have spread from east Africa around 58,000 yr ago. Even at more restricted geographic scales, where IBD tends to become blurred, principal component clines in H. pylori from Europe strongly resemble the classical clines for Europeans described by Cavalli-Sforza and colleagues(7). Taken together, our results establish that anatomically modern humans were already infected by H. pylori before their migrations from Africa and demonstrate that H. pylori has remained intimately associated with their human host populations ever since.
|
|
