Climate warming could increase malaria risk in cooler regions
Malaria parasites develop faster in mosquitoes at lower temperatures than previously thought, according to researchers at Penn State and the University of Exeter. The findings suggest that even slight climate warming could increase malaria risk to hundreds of thousands, if not millions, of people—including travelers—in areas that are currently too cold for malaria parasites to complete their development. The researchers used two of the most important malaria-hosting mosquito species in the world—Anopheles stephensi and Anopheles gambiae—to conduct their experiments. They maintained these malaria-infected mosquitoes in the laboratory under a variety of temperatures ranging from 16 to 20 degrees Celsius, or 60 to 68 degrees Fahrenheit. They maintained a separate control set of mosquitoes at 27 degrees Celsius, or about 80 degrees Fahrenheit, which is the temperature at which malaria transmission is typically highest. The traditional model estimates that parasites in the mosquito take 56 days to develop at temperatures just above the minimum threshold for development—a cool 18 degrees Celsius, or 64 degrees Fahrenheit. However, the current study shows that as few as 31 days are required for such development for Anopheles stephensi. The researchers also found that variation in temperature at this cooler end of the range promotes faster parasite development. Parasites developed in as few as 27 days at 18 degrees Celsius.
Cambodia sees rise in dengue fever cases
Cambodia reported 13,000 cases of dengue fever from January to June 24, about five-fold rise over the same period last year, Huy Rekol, director of the National Center for Parasitology, Entomology and Malaria Control, said on Thursday. In a bid to control the outbreak of the virus, about 300 tons of Abate (a chemical substance used to put in water pots to kill larvae) has been handed out to households, he said, adding that health officials have also been spraying insecticide to target Aedes mosquitoes which are the carrier of the dengue virus. According to a health ministry report, there were 24,684 cases of dengue fever with 23 deaths last year compared with 6,372 cases with three deaths in 2017.
The Big Read: As temperatures and urbanisation increase, fight against dengue will only get tougher
“Dengue always felt like a ‘it will happen to someone else but not me’ kind of thing, so it was a huge shock to find out that I had this virus,” said Ms Poh, a communications executive.' The experiences of Ms Poh and Mr Toh reflect just how enigmatic dengue fever can be — almost impossible to trace and at times, tricky to diagnose, and hard to guard against. The dengue virus also has four known strains or stereotypes. While infection with one strain appears to provide immunity against that one stereotype, evidence points towards increased risk of severe symptoms upon subsequent infections by the other three strains. The existence of these strains is one reason why dengue continues to be a perennial problem, especially in places like Singapore, whose tropical climate — abundant rainfall, high humidity and temperatures — creates an ideal breeding ground for mosquitoes. Despite stepped-up inspections and having a predictive model to help forecast dengue incidence, our national pre-emptive response to impending dengue outbreaks appears to have limited effectiveness.
Bovine Tuberculosis—International Perspectives on Epidemiology and Management
Andrew W. Byrne, Adrian R. Allen, Daniel J. O'Brien and Michele A. Miller
Bovine tuberculosis (bTB) remains a prominent zoonotic pathogen on the world stage, with significant impacts on animal and human health, and economic well-being.Modeling approaches were used to gain insights and make inferences on a number of different problems in bTB management.The use of genetic selection to improve animal health has emerged from recent advances in genomics and their application to epidemiological data. Resistance to bTB is a heritable trait in cattle, and provides an additional tool by which the disease can be controlled. Genomic methods are revolutionizing traditional molecular epidemiological approaches to disease source attribution, principally due to their much superior resolution. Application to bTB infectious systems promises to improve our knowledge of transmission dynamics. In multi-host epidemics, control or eradication of bTB in domestic hosts is often unachievable if disease control in wildlife reservoir populations is not simultaneously implemented. Vaccination with BCG has been shown to reduce disease in humans caused by M. tuberculosis, and Palmer and Thacker have also recently shown its potential for wildlife as well as the diagnostic regent variation, host physiological and immunological status can affect the performance of diagnostic tests. The “human component” of bTB epidemiology and control was highlighted in a number of papers relating to societal values and ethics of bTB control, as well as human zoonotic risk.Although bTB is a global disease, it can be neglected in smaller nations. Borja et al. describe findings of bTB in Fiji in “A Retrospective Study on Bovine Tuberculosis in Cattle on Fiji: Study Findings and Stakeholder Responses.”
Habitat loss linked to global emergence of infectious diseases
Auburn University researchers have published a new hypothesis that could provide the foundation for new scientific studies looking into the association of habitat loss and the global emergence of infectious diseases. Globally, scientists believe habitat loss is associated with emerging infectious diseases, or EIDs, spreading from wildlife to humans, such as Ebola, West Nile virus, SARS, Marburg virus and others. The Auburn team developed a new hypothesis, the coevolution effect, which is rooted in ecology and evolutionary biology, to explain the underlying mechanisms that drive this association. "We provide a testable hypothesis that we hope other researchers will try to test with their data, as we will be doing," Schwartz said. "Through our hypothesis, we propose that as humans alter the landscape through habitat loss, forest fragments act as islands, and the wildlife hosts and disease-causing microbes that live within them undergo rapid diversification," Zohdy said.
ICMR scientists identify new biomarker for malaria
Dr. Aditi Jain
Detection of malaria infection could become more accurate soon. A team of researchers from Indian Council of Medical Research’s Jabalpur-based National Institute of Research in Tribal Health (NIRTH) has identified a genetic sequence in the body of malaria parasite that promises to help develop a more sensitive diagnostic test for the disease. An enzyme called glutamate dehydrogenase could offer a solution. “Our study provides scientific evidence for the conserved nature of glutamate dehydrogenase sequences in Indian isolates which can be used as a potential biomarker for diagnosis of malaria,” said Dr. Praveen Kumar Bharti, leader of the research team.
Biosecurity and germ warfare
Dr Norman Swan
Dr Michael Osterholm was among the first to describe toxic shock syndrome — and also analysed one of the earliest descriptions of infection during warfare. He's currently serving as US Science Envoy on Global Health Security, working to ensure cooperation across countries when it comes to combating infectious disease. He reflects on the current biosecurity landscape, the possibilities for low-tech labs to engineer germs for warfare, and the history of bacterial infection.
The inappropriate use of antibiotics in hospitalized dengue virus-infected children with presumed concurrent bacterial infection in teaching and private hospitals in Bandung, Indonesia
Via CIDRAP - Riyadi Adrizain et al.,
Dengue virus infection (DVI) among children is a leading cause of hospitalization in endemic areas. Hospitalized patients are at risk of receiving unnecessary antibiotics. A retrospective medical review analysis study was conducted to evaluate the prevalence, indication, and choice of antibiotics given to hospitalized patients less than 15 years of age with DVI in two different hospital settings (teaching and private hospitals) in the Municipality of Bandung. Epidemiological, clinical, and laboratory data were obtained using a pre-tested standardized questionnaire from patients’ medical records admitted from January 1 to December 31, 2015. The use of antibiotics in private hospitals was inappropriate in most cases while the use of antibiotics in the teaching hospital was more accountable. This study indicated that interventions, such as the implementation of the antibiotics stewardship program, are needed especially in private hospitals to reduce inappropriate use of antibiotics.
Health Dept takes aim at dengue sources
Owners of properties who fail to get rid of mosquito larvae might face jail terms of up to three years and/or have to pay a fine of up to 25,000 baht, according to Dr Sukhum Kanchanapimai, permanent secretary of the Ministry of Public Health. In a bid to control the disease, the Ministry of Public Health and another eight agencies yesterday signed an environmental management pact for mosquito control, which will become effective in 2019-2023.
Oceania representatives build public health emergency response capability
Humanitarian public health and disaster response professionals located throughout the Oceania region gathered at James Cook University in Cairns, Australia, for the Health and Humanitarian Action in Emergencies (HHAE) course, June 3-14. HHAE is a two-week course developed by the Center for Excellence in Disaster Management and Humanitarian Assistance from Joint Base Pearl Harbor-Hickam, Hawaii, and James Cook University’s College of Health of Public Health, Medical and Veterinary Sciences to improve the management of public health emergencies during a humanitarian crises.