Reflections on amyloidosis in Papua New Guinea

The amyloidoses comprise a heterogeneous group of diseases in which 1 out of more than 25 human proteins aggregates into characteristic beta-sheet fibrils with some unique properties. Aggregation is nucleation dependent. Among the known amyloid-forming constituents is the prion protein, well known for its ability to transmit misfolding and disease from one individual to another. There is increasing evidence that other amyloid forms also may be transmissible but only if certain prerequisites are fulfilled. One of these forms is systemic AA-amyloidosis in which an acute-phase reactant, serum AA, is over-expressed and, possibly after cleavage, aggregates into amyloid fibrils, causing disease. In a mouse model, this disorder can easily be transmitted from one animal to another both by intravenous and oral routes. Also, synthetic amyloid-like fibrils made from defined small peptides have this property, indicating a prion-like transmission mechanism. Even some fibrils occurring in the environment can transmit AA-amyloidosis in the murine model. AA-amyloidosis is particularly common in certain areas of Papua New Guinea, probably due to the endemicity of malaria and perhaps genetic predisposition. Now, when kuru is disappearing, more interest should be focused on the potentially lethal systemic AA-amyloidosis

Voluntary lay supervisors of directly observed therapy for tuberculosis in Africa

3 page(s

Discussion following lecture by T.H.M. Ottenhoff

Item does not contain fulltex

Role of flies and provision of latrines in trachoma control: cluster-randomised controlled trial

Eye-seeking flies have received much attention as possible trachoma vectors, but this remains unproved. We aimed to assess the role of eye-seeking flies as vectors of trachoma and to test provision of simple pit latrines, without additional health education, as a sustainable method of fly control. METHODS: In a community-based, cluster-randomised controlled trial, we recruited seven sets of three village clusters and randomly assigned them to either an intervention group that received regular insecticide spraying or provision of pit latrines (without additional health education) to each household, or to a control group with no intervention. Our primary outcomes were fly-eye contact and prevalence of active trachoma. Frequency of child fly-eye contact was monitored fortnightly. Whole communities were screened for clinical signs of trachoma at baseline and after 6 months. Analysis was per protocol. FINDINGS: Of 7080 people recruited, 6087 (86%) were screened at follow-up. Baseline community prevalence of active trachoma was 6%. The number of Musca sorbens flies caught from children's eyes was reduced by 88% (95% CI 64-100; p<0.0001) by insecticide spraying and by 30% (7-52; p=0.04) by latrine provision by comparison with controls. Analysis of age-standardised trachoma prevalence rates at the cluster level (n=14) showed that spraying was associated with a mean reduction in trachoma prevalence of 56% (19-93; p=0.01) and 30% with latrines (-81 to 22; p=0.210) by comparison with the mean rate change in the controls. INTERPRETATION: Fly control with insecticide is effective at reducing the number of flies caught from children's eyes and is associated with substantially lower trachoma prevalence compared with controls. Such a finding is consistent with flies being important vectors of trachoma. Since latrine provision without health education was associated with a significant reduction in fly-eye contact by M sorbens, studies of their effect when combined with other trachoma control measures are warranted