Culex torrentium mosquitoes from Germany are negative for Wolbachia.

Wolbachia (Rickettsiales: Anaplasmataceae) infects a wide range of arthropods, including several mosquito species. The bacterium is known to induce a plethora of phenotypes in its host, examples being the reproductive phenotype cytoplasmic incompatibility or resistance against infection with arboviruses. The latter is especially relevant when assessing the vector competence of mosquito species for emerging arboviruses. Thus, knowledge of Wolbachia infection status is important for the assessment of vector competence. To facilitate Wolbachia screening in mosquito populations, a quantitative polymerase chain reaction (qPCR) assay was developed to enable high-throughput analysis of mosquito samples. Using this assay, the Wolbachia infection status of the two most common Culex mosquito species in Germany, Culex pipiens biotype pipiens Linnaeus (Diptera: Culicidae) and Culex torrentium Martini (Diptera: Culicidae), was assessed. About 93% of all tested C. pipiens biotype pipiens individuals were positive for Wolbachia, whereas none of the C. torrentium samples was found to be infected. Furthermore, other applications of the qPCR assay were explored by assessing a potential link between the levels of Wolbachia and West Nile virus (WNV) infections in German C. pipiens biotype pipiens mosquitoes. No relationship was found between the two variables, indicating that a Wolbachia-induced antiviral phenotype in this mosquito population is not exclusively attributable to the general level of bacterial infection.

A simple laboratory algorithm for diagnosis of melioidosis in resource-constrained areas: a study from north-central Vietnam.

OBJECTIVES: Melioidosis may be endemic in many tropical developing countries, but diagnosis of the disease is currently unreliable in resource-limited areas. We aimed to validate a simple and cheap laboratory algorithm for the identification of Burkholderia pseudomallei from clinical specimens in parts of Vietnam where the disease has not previously been reported. METHODS: In June 2015, we conducted training courses at five general hospitals in north-central provinces in order to raise awareness of the disease and to introduce a simple and cheap laboratory identification algorithm for B. pseudomallei including the three-antibiotic disc test. RESULTS: Until the end of the year (7 months later), 94 suspected B. pseudomallei strains resistant to gentamicin and colistin but sensitive to amoxicillin/clavulanic acid were detected in clinical specimens from 70 patients. All strains were further confirmed as B. pseudomallei by using a specific TTSS1 real-time PCR assay and recA sequencing analysis. Among positive blood cultures, positive rates with B. pseudomallei ranged from 3.4% (5/147) to 10.2% (32/312) in the various clinics. A total of 82.8% (58/70) patients were bacteraemic, with a mortality of 50% (18/36) among patients with known outcome. No death occurred in nonbacteraemic patients. CONCLUSIONS: Our results demonstrate that the introduction of a simple and easy-to-perform laboratory algorithm for the identification of B. pseudomallei from clinical samples, together with clinical awareness raising, can lead to the diagnosis of a significant number of melioidosis cases in resource-limited clinical laboratories which previously did not identify the pathogen.

Mobile phone-based interactive voice response as a tool for improving access to healthcare in remote areas in Ghana - an evaluation of user experiences.

OBJECTIVES: To investigate and determine the factors that enhanced or constituted barriers to the acceptance of an mHealth system which was piloted in Asante-Akim North District of Ghana to support healthcare of children. METHODS: Four semi-structured focus group discussions were conducted with a total of 37 mothers. Participants were selected from a study population of mothers who subscribed to a pilot mHealth system which used an interactive voice response (IVR) for its operations. Data were evaluated using qualitative content analysis methods. In addition, a short quantitative questionnaire assessed system's usability (SUS). RESULTS: Results revealed 10 categories of factors that facilitated user acceptance of the IVR system including quality-of-care experience, health education and empowerment of women. The eight categories of factors identified as barriers to user acceptance included the lack of human interaction, lack of update and training on the electronic advices provided and lack of social integration of the system into the community. The usability (SUS median: 79.3; range: 65-97.5) of the system was rated acceptable. CONCLUSIONS: The principles of the tested mHealth system could be of interest during infectious disease outbreaks, such as Ebola or Lassa fever, when there might be a special need for disease-specific health information within populations.

Tropheryma whipplei in children with diarrhoea in rural Ghana.

Tropheryma whipplei has been hypothesized to be able to cause diarrhoea, but data from young children are scarce. In this hospital-based case-control study 534 stool samples of children aged between 2 months and 15 years from rural Ghana were analysed for the presence of T. whipplei. Overall stool prevalence of T. whipplei was high (27.5%). Although there was no difference in T. whipplei carriage overall between cases and controls, cases aged between 0 and 12 months carried T. whipplei in their stool twice as often as controls without diarrhoea. The results from this study may support the hypothesis that T. whipplei can cause diarrhoea in first-time infection.

Similar virus spectra and seasonality in paediatric patients with acute respiratory disease, Ghana and Germany.

Epidemiological differences between tropical and temperate regions regarding viruses causing acute respiratory infection are poorly understood. This is in part because methodological differences limit the comparability of data from these two regions. Using identical molecular detection methods, we tested 1174 Ghanaian and 539 German children with acute respiratory infections sampled over 12 months for the 15 most common respiratory viruses by PCR. A total 43.2% of the Ghanaian and 56.6% of the German children tested positive for at least one respiratory virus. The pneumoviruses respiratory syncytial virus and human metapneumovirus were most frequently detected, in 13.1% and 25.1% within the Ghanaian and German children, respectively. At both study sites, pneumoviruses were more often observed at younger ages (p <0.001). In the Ghanaian rainy season, enveloped viruses were detected twice as often as non-enveloped viruses (prevalence rate ratio (PR) 2.0, 95% CI 1.7-2.4). In contrast, non-enveloped viruses were more frequent during the Ghanaian dry season (PR 0.6, 95% CI 0.4-0.8). In Germany, enveloped viruses were also more frequently detected during the relatively colder winter season (PR 1.6, 95% CI 1.2-2.1) and non-enveloped viruses during summer (PR 0.7, 95% CI 0.5-0.9). Despite a distance of about 5000 km and a difference of 44° latitude separating Germany and Ghana, virus spectra, age associations and seasonal fluctuation showed similarities between sites. Neither respiratory viruses overall, nor environmentally stable (non-enveloped) viruses in particular were more frequent in tropical Ghana. The standardization of our sampling and laboratory testing revealed similarities in acute respiratory infection virus patterns in tropical and temperate climates.

Extrapolating respiratory tract infection incidences to a rural area of Ghana using a probability model for hospital attendance.

OBJECTIVE: The aim of the current study was to extrapolate incidences for respiratory tract infections (RTI) using referral data from a local hospital in Ghana weighted by the individual likelihood of a hospital visit. METHODS: Diagnoses from children visiting a rural hospital in Ghana during August 2007 to September 2008 were recorded. A logistic regression model, based on a population study conducted within the hospital catchment area, was used to calculate the individual probability of clinic attendance and to extrapolate the number of recorded cases. Cumulative incidences for children living in the hospital catchment area were estimated. RESULTS: Upper RTI was the most common respiratory diagnosis, with an extrapolated incidence of 17481 cases per 100000 per year, followed by pneumonia with an incidence of 2496 per 100 000 per year. All diseases analyzed were most common in the first year of life. CONCLUSIONS: In general the study results are in line with comparable studies. Several methodological issues biasing the results in different directions were identified. For example, opportunistic infections that are more often observed in hospital attendees are likely to be overestimated. However, the applied approach presents a tool for areas where disease monitoring systems are not established.

Health service resource needs for pandemic influenza in developing countries: a linked transmission dynamics, interventions and resource demand model.

We used a mathematical model to describe a regional outbreak and extrapolate the underlying health-service resource needs. This model was designed to (i) estimate resource gaps and quantities of resources needed, (ii) show the effect of resource gaps, and (iii) highlight which particular resources should be improved. We ran the model, parameterized with data from the 2009 H1N1v pandemic, for two provinces in Thailand. The predicted number of preventable deaths due to resource shortcomings and the actual resource needs are presented for two provinces and for Thailand as a whole. The model highlights the potentially huge impact of health-system resource availability and of resource gaps on health outcomes during a pandemic and provides a means to indicate where efforts should be concentrated to effectively improve pandemic response programmes.

Developing policy options for SARS and SARS-like diseases - a Delphi study.

The objective of the SARSControl Delphi study was to develop options for national and international emerging infectious diseases policies. The aim of this paper is to present the results of the study, which gathered expert opinions on gaps and inconsistencies concerning preparedness and response planning for Severe Acute Respiratory Syndrome (SARS) and SARS-like diseases. The Delphi technique was employed, which comprised a pilot round, two written rounds and a face-to-face meeting. The Delphi panel consisted of 38 experts from 22 countries, who highlighted the necessity to test plans and stressed the importance of surveillance measures for the swift containment of communicable disease outbreaks and the inclusion of detailed triage plans in national pandemic plans. The experts also suggested a need to define criteria for testing pandemic preparedness plans at different regional levels. New policy alternatives were identified, such as the need for generic plans on pandemics and universal access to healthcare during an outbreak. The usefulness of some non-medical interventions, such as bans on travel, could not be established and need further research. Dissemination of the findings will help to bridge gaps and rectify inconsistencies in current pandemic planning and response strategies for SARS and SARS-like diseases, as well as add valuable knowledge towards the development of national and international emerging infectious disease policies.

[Prevention and control of infectious diseases with pandemic potential: the EU-project SARSControl]. / Prävention und Kontrolle von pandemischen Infektionskrankheiten: Das EU-Projekt SARSControl.

INTRODUCTION: The influenza pandemics of the 20th century, the SARS epidemic in 2002/03 and the growing number of human cases infected with the H5N1 avian influenza virus clearly demonstrate that the threat of new pandemics is very real. These events have intensified pandemic prevention and control activities worldwide. "SARSControl" is a three-year project funded by the European Commission with the objective to aid European member states in the public health management of new emerging infections. This article summarises the main research results and recommendations arising from this project. METHOD: The reports and papers published in the SARSControl project form the basis of this article. In addition, a literature search for SARS and pandemic influenza was conducted and information on pandemic planning and management guidelines obtained from the WHO and EU websites. The project results are discussed in this context. RESULTS: A lack of knowledge and delayed international communication resulted in the rapid spread of SARS, highlighting the importance of a global system for rapid and transparent information transfer. Epidemiological and economic modelling studies have shown that, in comparison to travel restrictions, applying intervention measures to interrupt local transmission within a country and investing into vaccine research and anti-viral stockpiling, is a more cost-effective and efficient use of resources for the containment of pandemics. A study investigating the perceived threat associated with pandemics showed that the subjective risk perception of people varies among countries. This influences human behaviour and should hence be considered during risk communication and implementation of pandemic control measures. DISCUSSION: The basic prerequisites of an efficient pandemic management are operationalisable pandemic plans, subjected to regular exercises, backed by adequate resources and a sound health-care infrastructure. At international level cross-border co-operation and information exchange on infection control is the key to pandemic mitigation and containment. Strengthening surveillance systems at the international level, to allow the timely monitoring of infectious agents and outbreaks is essential. Transferring such outbreak information in real time into mathematical models and the resulting essential epidemiological information to policy makers would facilitate a more efficient use of scarce resources. Involvement of the public in decisions regarding the implementation of restrictive control measures which often curtail individual liberty is necessary for the acceptance and ultimate success of pandemic control.

[Methods of infectious disease epidemiology for public health services: case control studies as bridge between practical work, surveillance and epidemiology]. / Infektionsepidemiologische Methoden für den OGD: Fall-Kontrollfall-Vergleiche als Brücke zwischen Praxis, Surveillance und Epidemiologie.

Routine surveillance of infectious diseases is one important task of national public health services. Due to globalization the impact of international disease monitoring rises. The volume of traffic and trade is constantly increasing, which makes a spread of infectious diseases to distant places more likely then ever. This are challenges international infectious disease networks have to deal with. Thus, the role of investigation of disease outbreaks is not only relevant for local level; it furthermore prevents broader spread. To eliminate outbreak sources good epidemiological analyses have to be conducted. However, this often leads to extra time and personal resources. In addition classical studies, like case-control studies, underlay methodical limitations. Case-control studies, especially if conducted on the basis of notified cases from surveillance data, are susceptible to bias (like selection- and recall bias). Another study design, the case-case study (case-case comparison), provides an alternative, which is less affected by such limitations. In this approach a number of cases related within an outbreak, is compared with a group of infected individuals of the same disease, not belonging to the outbreak. Results from recently published studies lead to the assumption that this study design is adequate for the investigation of infectious disease outbreaks, captured by surveillance systems. The practical application of this study design makes it especially useful for local public health services and thus provides a bridge between surveillance, epidemiology and practical work in Public Health.