Investigating outbreaks of initially unknown aetiology in complex settings: findings and recommendations from 10 case studies.

BACKGROUND: Outbreaks of unknown aetiology in complex settings pose challenges and there is little information about investigation methods. We reviewed investigations into such outbreaks to identify methods favouring or impeding identification of the cause. METHODS: We used two approaches: reviewing scientific literature and soliciting key informants. Case studies were developed through interviews with people involved and triangulated with documents available from the time of the investigation. RESULTS: Ten outbreaks in African or Asian countries within the period 2007-2017 were selected. The cause was identified in seven, of which two had an unclear mode of transmission, and in three, neither origin nor transmission mode was identified. Four events were caused by infectious agents and three by chemical poisoning. Despite differences in the outbreaks, similar obstacles were noted: incomplete or delayed description of patients, comorbidities confounding clinical pictures and case definitions wrongly attributed. Repeated rounds of data collection and laboratory investigations were common and there was limited capacity to ship samples. DISCUSSION: It was not possible to define activities that led to prompt identification of the cause in the case studies selected. Based on the observations, we conclude that basing case definitions on precise medical observations, implementing initial comprehensive data collection, including environmental, social and behavioural information; and involving local informants could save precious time and hasten implementation of control measures.

A State-of-the-Science Review of Mercury Biomarkers in Human Populations Worldwide between 2000 and 2018.

BACKGROUND: The Minamata Convention on Mercury provided a mandate for action against global mercury pollution. However, our knowledge of mercury exposures is limited because there are many regions and subpopulations with little or no data. OBJECTIVE: We aimed to increase worldwide understanding of human exposures to mercury by collecting, collating, and analyzing mercury concentrations in biomarker samples reported in the published scientific literature. METHOD: A systematic search of the peer-reviewed scientific literature was performed using three databases. A priori search strategy, eligibility criteria, and data extraction steps were used to identify relevant studies. RESULTS: We collected 424,858 mercury biomarker measurements from 335,991 individuals represented in 312 articles from 75 countries. General background populations with insignificant exposures have blood, hair, and urine mercury levels that generally fall under [Formula: see text], [Formula: see text], and [Formula: see text], respectively. We identified four populations of concern: a) Arctic populations who consume fish and marine mammals; b) tropical riverine communities (especially Amazonian) who consume fish and in some cases may be exposed to mining; c) coastal and/or small-island communities who substantially depend on seafood; and d) individuals who either work or reside among artisanal and small-scale gold mining sites. CONCLUSIONS: This review suggests that all populations worldwide are exposed to some amount of mercury and that there is great variability in exposures within and across countries and regions. There remain many geographic regions and subpopulations with limited data, thus hindering evidence-based decision making. This type of information is critical in helping understand exposures, particularly in light of certain stipulations in the Minamata Convention on Mercury. https://doi.org/10.1289/EHP3904.

A promising poison information centre model for Africa.

INTRODUCTION: The burden of poisoning exposures in Africa is a significant public health concern, yet only ten African countries have poisons information centres. The establishment of poisons centres was subsequently identified as a priority. This article focuses on workshop discussions with international multi-sector stakeholders in Eastern Africa regarding the possibility of a sub-regional poisons centre serving multiple countries. METHODS: The project was led by an independent consultant under the guidance of an international steering group. Steering group members provided input at international multi-stakeholder meetings and during monthly teleconferences. RESULTS: Participants of the stakeholder meetings agreed that the establishment of a sub-regional poisons centre in Eastern Africa was necessary and feasible. Virtual collaboration is possible due to recent technological developments, and the overall suggestion was for countries to establish their own poisons centres and to network and coordinate these centres through a network hub. CONCLUSION: A number of benefits might result from such a poisons centre network hub, including: (1) Improved cooperation between countries on poisoning problems; (2) Harmonisation and strengthening of research and surveillance; (3) Common standards and best practices e.g. regulating chemicals, data management, and staff training; and (4) Greater bargaining power to secure resources. Further investigation is needed to identify the most suitable location for the network hub, the activities it should fulfil, and the availability of specialists in poisons information who could become members of the hub.

INTRODUCTION: La charge que représentent les expositions à l'empoisonnement en Afrique est une préoccupation de santé publique importante, et pourtant, seuls une dizaine de pays africains sont dotés de centres d'information antipoison. La création de centres antipoison a donc été identifiée comme une priorité. Cet article se concentre sur les discussions de l'atelier organisé avec les parties prenantes multisectorielles internationales en Afrique de l'Est concernant la possibilité de la création d'un centre antipoison sous-régional desservant plusieurs pays. MÉTHODES: Le projet a été mené par un consultant indépendant, sous la direction d'un groupe de pilotage international. Les membres du groupe de pilotage ont apporté leur contribution lors de réunions internationales multipartites et de téléconférences mensuelles. RÉSULTATS: Les participants des réunions des parties prenantes ont convenu que la mise en place d'un centre antipoison sous-régional en Afrique de l'Est était nécessaire et faisable. La collaboration virtuelle est possible grâce aux récents développements technologiques, et la suggestion générale était que les pays établissent leurs propres centres antipoison et mettent en réseau et coordonnent ces centres par le biais d'une tête de réseau. CONCLUSION: Une telle tête de réseau de centres antipoison pourrait présenter un certain nombre d'avantages, notamment: (1) Une amélioration de la coopération entre les pays sur les problèmes d'empoisonnement; (2) Une harmonisation et un renforcement de la recherche et de la surveillance; (3) Des normes communes et des meilleures pratiques, par exemple la réglementation des produits chimiques, la gestion des données et la formation du personnel; (4) Une meilleure position de négociation pour obtenir des ressources. Une enquête plus approfondie est nécessaire pour identifier l'emplacement le plus approprié pour la tête de réseau, les activités qu'elle devra remplir et la disponibilité de spécialistes en information antipoison qui pourraient participer à cette tête de réseau.

Mass lead intoxication from informal used lead-acid battery recycling in dakar, senegal.

BACKGROUND AND OBJECTIVES: Between November 2007 and March 2008, 18 children died from a rapidly progressive central nervous system disease of unexplained origin in a community involved in the recycling of used lead-acid batteries (ULAB) in the suburbs of Dakar, Senegal. We investigated the cause of these deaths. METHODS: Because autopsies were not possible, the investigation centered on clinical and laboratory assessments performed on 32 siblings of deceased children and 23 mothers and on 18 children and 8 adults living in the same area, complemented by environmental health investigations. RESULTS: All 81 individuals investigated were poisoned with lead, some of them severely. The blood lead level of the 50 children tested ranged from 39.8 to 613.9 microg/dL with a mean of 129.5 microg/dL. Seventeen children showed severe neurologic features of toxicity. Homes and soil in surrounding areas were heavily contaminated with lead (indoors, up to 14,000 mg/kg; outdoors, up to 302,000 mg/kg) as a result of informal ULAB recycling. CONCLUSIONS: Our investigations revealed a mass lead intoxication that occurred through inhalation and ingestion of soil and dust heavily contaminated with lead as a result of informal and unsafe ULAB recycling. Circumstantial evidence suggested that most or all of the 18 deaths were due to encephalopathy resulting from severe lead intoxication. Findings also suggest that most habitants of the contaminated area, estimated at 950, are also likely to be poisoned. This highlights the severe health risks posed by informal ULAB recycling, in particular in developing countries, and emphasizes the need to strengthen national and international efforts to address this global public health problem.

Developing and maintaining quality in poisons information centers.

The development of poisons information centers has in general complied with the actual needs and conditions in the society, and a pragmatic approach and limited funds have been characteristic for these units. To operate in a satisfying way a poisons information center is dependent on two cornerstones-a well educated and specifically trained staff on the one hand, and reliable, up-dated and easily manageable information sources on the other. Once a poisons information service has started to operate, it must more or less instantly launch a process to develop and continuously check the standards and the quality of the service. The European Association of Poisons Centres and Clinical Toxicologists (EAPCCT) has for this purpose developed a self-assessment checklist, addressing and defining minimum and optimum standards to be considered when running a poisons information service [J. Toxicol. Clin. Toxicol. 39 (2001) 2226]. Items covered are poisons center operations, direction and management, education and training of staff, location of poisons centers, information sources, documentation of enquiries/cases, funding, publications and quality control.