arthropod-borne encephalitis viruses, The neglected serious diseases

Arthropod-borne encephalitis viruses are highly adapted to a particular reservoir host. Viruses spread from animal to animal by an infected specific mosquito or tick species. Mosquito or tick becomes infected when feeding on the viremic animal blood. Virus then replicates in the vector, ultimately infecting the salivary glands, which transmits the virus to a new host with infective saliva while taking a blood meal. Infected patients may become ill; they usually do not develop sufficient viremia to infect feeding vectors, and thus do not contribute to the transmission cycle. Among mosquito-borne encephalitis, the greatest public health threat in North America and is posed by the West Nile, St. Louis encephalitis, and La Crosse encephalitis viruses. Venezuelan equine encephalitis virus is of concern in Central and South America, while Japanese encephalitis virus affects residents or visitors to parts of Asia. Among the tick-borne encephalitis, tick-borne Encephalitis virus causes the greatest public health threat among residents or visitors to Eastern Europe and Asia. Eastern equine encephalitis [EEE] virus is widely distributed throughout North, Central, and South America and the Caribbean. EEE virus is the most severe one, with mortality up to 30% .Western equine encephalitis [WEE] virus is a found in North and South America and is a potential agent of bioterrorism through the aerosol route. Case fatality rate is 3 to 7%, .La Crosse virus [LAC] is the most pathogenic member of California encephalitis serogroup in central and eastern United States, mostly in school-aged children. Most infections are asymptomatic with low mortality rates. Treatment is supportive, with emphasis on control of cerebral edema and seizures. Murray Valley encephalitis [MVE] virus occurs in Australia, New Guinea, and probably islands in the eastern part of the Indonesian archipelago. MVE virus is maintained in a natural cycle involving water birds and Culex annulirostris. Only 1 in 1000 to 2000 infections had clinical illness; but, about one-third of patients die and about half the survivors suffered from neurologic deficits. Venezuelan equine encephalitis [VEE] widely spread from Florida to South America, occur periodically, but occasionally, large epidemics occur among equine and humans. VEE is infectious via aerosols, making it an occupational risk to certain laboratory workers and a potential agent of bioterrorism. Effective prevention by immunizing equines, which serve as the primary amplification hosts for the epizootic VEE viruses. Tick-borne encephalitis [TBE] exists over a wide geographical area, including Russia and Europe. Human exposure occurs through work or recreational activities when the ticks are most active. TBE virus is transmitted from the saliva of an infected tick while taking blood meal. Case fatality rates range from 2 to 8%, Treatment is mainly supportive

General principles of infection control and safety initiatives

Standard precautions are guidelines established to break the infection chain and reduce risk of pathogen transmission in hospitals. Standard precautions apply to blood, body fluids, secretions and excretions [except sweat], non-intact skin, and mucous membranes

Fungemia in immunocompromised patients [hematological malignant and hematopoietic stem cell transplant patients during febrile neutropenia]

Background: Fungal infections are a major cause of morbidity and mortality among febrile neutropenic patients. The choice of empiric antifungal regimen is based on susceptibility pattern of locally prevalent pathogens

Objectives: to determine fungemia, identify fungal spectrum and their antifungal susceptibility pattern

Methods: From 150 hematological malignant and hematopoietic stem cell transplant patients during febrile neutropenia, blood cultures [B.C] were processed

Results: Eight fungal isolates [5.3%] were recovered which found to be represented by candida spp. Five of them were non albicans Candida [62.5%] and three of them were Candida albicans [37.5%]. C. parapsilosis resulted in the most frequent Candida non albicans [CnA] species [37.5%]. All C. parapsilosis strains were isolated from patients with vascular catheters. C. krusei fungemia generally occur in patients with previous exposure to fluconazoles. All species of Candida were sensitive to amphoterecin B, echinocandins and voriconazole. Persistent fever for prolonged duration and prolonged broad spectrum antibiotic use were statistically significant risk factors for developing fungemia. Also extent of neutropenia, duration of chemotherapy, immunosuppressive therapy, altered mucosal barriers and presence of central venous lines were considered major risk factors for development of fungemia

Conclusion: The current study was limited by method of diagnosis and low sample size in a single center experience. Furthermore review of the epidemiology of fungemia which was represented by candidemia at our institution revealed the percentage of candidemia was 5.3% and non albicans Candida species were the predominant isolates

Recommendations: The choice of therapy in neutropenic patients should be formulated based on local antimicrobial susceptibility of these organisms. Close monitoring of fungal infection in patients receiving broad-spectrum antibiotics is mandatory