Migrants and emerging public health issues in a globalized world: threats, risks and challenges, an evidence-based framework.

International population mobility is an underlying factor in the emergence of public health threats and risks that must be managed globally. These risks are often related, but not limited, to transmissible pathogens. Mobile populations can link zones of disease emergence to lowprevalence or nonendemic areas through rapid or high-volume international movements, or both. Against this background of human movement, other global processes such as economics, trade, transportation, environment and climate change, as well as civil security influence the health impacts of disease emergence. Concurrently, global information systems, together with regulatory frameworks for disease surveillance and reporting, affect organizational and public awareness of events of potential public health significance. International regulations directed at disease mitigation and control have not kept pace with the growing challenges associated with the volume, speed, diversity, and disparity of modern patterns of human movement. The thesis that human population mobility is itself a major determinant of global public health is supported in this article by review of the published literature from the perspective of determinants of health (such as genetics/biology, behavior, environment, and socioeconomics), population-based disease prevalence differences, existing national and international health policies and regulations, as well as inter-regional shifts in population demographics and health outcomes. This paper highlights some of the emerging threats and risks to public health, identifies gaps in existing frameworks to manage health issues associated with migration, and suggests changes in approach to population mobility, globalization, and public health. The proposed integrated approach includes a broad spectrum of stakeholders ranging from individual health-care providers to policy makers and international organizations that are primarily involved in global health management, or are influenced by global health events.

Is compulsory overseas medical screening of migrants justifiable?

For more than four decades the international Organization for Migration (IOM) has been providing medical screening of prospective migrants according to the admission requirements of resettlement countries. The main reason resettlement countries impose mandatory medical screening is to prevent the entrance of migrants with certain health problems in the belief that they pose a potential public health risk or financial burden to the nation. High rates of communicable diseases among foreign-born residents of industrial countries have raised concern about the impact of international migration on transmission of such diseases and the role and efficacy of medical screening. IOM's experience provides insight into the complex and sensitive problems related to mandatory screening of migrant populations, including: conflicting objectives, epidemiological concerns, uncertain economic benefit, and ethical dilemmas. Medically sound screening mechanisms must be formulated that meet the needs of receiving countries while responding to the epidemiology of disease, the rights of individuals, and the public health concerns of the community.

[Microbiological and serological verification of cornea donors]. / Vérification microbiologiques et sérologiques des donneurs de cornées.

A study was made during 1994 about microbiological contamination on the donor eyes before enucleation of whole globe. We studied the efficiency of the decontamination method by checking sterility of corneal storage medium after two days. We give results of serological tests on 252 donors.

[Medium term preservation of corneas. Comparative study of 4 preservation media]. / Conservation des cornées à moyen terme. Etude comparative de quatre milieux de conservation.

A comparative study of four preservation medium was made (Corneal Storage Solution, K-Sol, RPMI Hepes buffer, RPMI bicarbonate buffer). After a five days preservation delay there is no statistical difference between the percentage of the endothelial cellular mortality amongst the three first medium. In the fourth medium the cellular mortality is statistically higher. For longer preservation delay between 5 and 15 days, only the corneas preserved in K-Sol medium have a cellular mortality under 20% and could be used for keratoplasty.

Corneal endothelial cell density in acute angle-closure glaucoma.

The endothelial cell density of 44 eyes after an acute attack of angle-closure glaucoma is statistically lower than the cellular density of 174 control eyes. The decrease in endothelial cell density increases the risk of edematous corneal dystrophy, more specially after surgery (e.g. cataract extraction). The modifications in corneal endothelial cell density are compared with the alterations of the iris after a crisis of angle-closure glaucoma.

[Long-term study of endothelial cell density after penetrating keratoplasty. Comparative study of fresh and median-term preserved cornea]. / Etude à long terme de la densité cellulaire endothéliale après kératoplastie perforante. Etude comparative des cornées fraîches et conservées à moyen terme.

A retrospective specular microscopic study of 118 clear corneal grafts shows that the endothelium of these grafts is progressively destroyed during the two first years. The reduction of cellular density is rapid at the beginning of postoperative period, stabilizing after two years. The comparison of endothelial cellular density in fresh non selected grafts versus grafts preserved in culture seems to indicate a longer survival of preserved grafts. This study shows the utility of wide-field specular microscopy in the follow-up of clear corneal grafts. This technique furnishes useful information for postoperative management and long-term prognosis.

[Selection criteria and results of medium-term storage of corneas for keratoplasty (author's transl)]. / Critères de sélection et résultats de la conservation à moyen terme des cornées destinées à la kératoplastie.

A double-staining technique allowing calculation of the percentage of dead endothelial cells in corneas during medium-term storage is described. A positive correlation was found between the thickness of the cornea and the time since death, and between the percentage of dead endothelial cells and the thickness of the cornea. A negative correlation existed between age and cellular density of the endothelium. Conclusions of these data provides practical applications for the selection of corneas for keratoplasty.

[Keratoplasty. Urgent treatment of the corneal perforation (author's transl)]. / La kératoplastie. Traitement urgent de la perforation de la cornée.

Sixteen keratoplasties (15 perforating, 1 lamellar) were performed on 12 perforated corneas and on 2 eyes threatened by imminent corneal perforation. The causal disease was metaherpetic kératitis (6 cases), chronic and recurrent ulcers (4 cases), acute keratoconus (1 case) and corneal traumas (3 cases). Enucleation has been avoided and the anterior chamber was restored in all the cases, with or without anterior synechiae. One case only developed ocular hypertension which was cured by fistulisation. Architectonic results are satisfying in all the cases. Recuperation of visual functions is possible only in the most favourable cases. It is indicated to perform keratoplasty before the perforation when this one seems unavoidable and to consider this surgical procedrue as an emergency when the cornea is perforated.

[The effects of intraocular irrigating solutions on the human corneal endothelium (author's transl)]. / Effets de différentes solutions d'irrigation intraoculaires sur l'endothélium de la cornée humaine.

Human corneas from enucleated eyes get thicker during perfusion with B.S.S. On the contrary, their thickness decreases when perfused with T.C. Earle solution. Addition of reduced glutathion and adenosine does not change the results obtained with T.C. Earle. Histological study of the endothelium after a 24 hours perfusion demonstrates a better conservation of the cells with T.C. Earle and T.C. Earle glutathion--adenosine than with B.S.S.