A survey of knowledge, attitudes, and practices towards skin and soft tissue infections in rural Alaska.

BACKGROUND: Community-acquired methicillin-resistant Staphylococcus aureus and methicillin-sensitive S. aureus infections are common to south-western Alaska and have been associated with traditional steambaths. More than a decade ago, recommendations were made to affected communities that included preventive skin care, cleaning methods for steambath surfaces, and the use of protective barriers while in steambaths to reduce the risk of S. aureus infection. OBJECTIVE: A review of community medical data suggested that the number of skin infection clinical encounters has increased steadily over the last 3 years and we designed a public health investigation to seek root causes. STUDY DESIGN: Using a mixed methods approach with in-person surveys, a convenience sample (n=492) from 3 rural communities assessed the range of knowledge, attitudes and practices concerning skin infections, skin infection education messaging, prevention activities and home self-care of skin infections. RESULTS: We described barriers to implementing previous recommendations and evaluated the acceptability of potential interventions. Prior public health messages appear to have been effective in reaching community members and appear to have been understood and accepted. We found no major misconceptions regarding what a boil was or how someone got one. Overall, respondents seemed concerned about boils as a health problem and reported that they were motivated to prevent boils. We identified current practices used to avoid skin infections, such as the disinfection of steambaths. We also identified barriers to engaging in protective behaviours, such as lack of access to laundry facilities. CONCLUSIONS: These findings can be used to help guide public health strategic planning and identify appropriate evidence-based interventions tailored to the specific needs of the region.

Supportive Care of the First 2 Ebola Virus Disease Patients at the Monrovia Medical Unit.

We describe the first 2 patients admitted to the Monrovia Medical Unit, a facility established to treat Liberian and international response workers with suspected or known Ebola virus disease (EVD). Their recoveries illustrate the value of local point-of-care diagnostics, parenteral therapies, and electrolyte replacement in EVD supportive care.

A Case-Study of Implementation of Improved Strategies for Prevention of Laboratory-acquired Brucellosis.

BACKGROUND: In 2012, the Alaska Section of Epidemiology investigated personnel potentially exposed to a Brucella suis isolate as it transited through three laboratories. METHODS: We summarize the first implementation of the United States Centers for Disease Control and Prevention 2013 revised recommendations for monitoring such exposures: (1) risk classification; (2) antimicrobial postexposure prophylaxis; (3) serologic monitoring; and (4) symptom surveillance. RESULTS: Over 30 people were assessed for exposure and subsequently monitored for development of illness. No cases of laboratory-associated brucellosis occurred. Changes were made to gaps in laboratory biosafety practices that had been identified in the investigation. CONCLUSION: Achieving full compliance for the precise schedule of serologic monitoring was challenging and resource intensive for the laboratory performing testing. More refined exposure assessments could inform decision making for follow-up to maximize likelihood of detecting persons at risk while not overtaxing resources.

Case report: Co-infection of Rickettsia rickettsii and Streptococcus pyogenes: is fatal Rocky Mountain spotted fever underdiagnosed?

Rocky Mountain spotted fever, a tick-borne disease caused by Rickettsia rickettsii, is challenging to diagnose and rapidly fatal if not treated. We describe a decedent who was co-infected with group A ß-hemolytic streptococcus and R. rickettsii. Fatal cases of Rocky Mountain spotted fever may be underreported because they present as difficult to diagnose co-infections.

Hepatitis B virus antibody levels 7 to 9 years after booster vaccination in Alaska native persons.

Hepatitis B antibody persistence was assessed in individuals who had previously received a vaccine booster. We measured hepatitis B surface antigen antibody (anti-HBs) levels 7 to 9 years post-hepatitis B booster in individuals with primary vaccination at birth. While 95 (91.3%) of 104 participants had detectable anti-HBs (minimum, 0.1 mIU/ml; maximum, 1,029 mIU/ml), only 43 (41%) had protective levels of ≥10 mIU/ml. Pre- and week 4 postbooster anti-HBs levels were significant predictors of hepatitis B immunity at follow-up (P < 0.001). Almost all participants had detectable anti-HBs 7 to 9 years after the hepatitis B vaccine booster, but less than half had levels ≥10 mIU/ml.

Duration of protection against hepatitis A for the current two-dose vaccine compared to a three-dose vaccine schedule in children.

BACKGROUND: Hepatitis A is mostly a self-limiting disease but causes substantial economic burden. Consequently, United States Advisory Committee for Immunization Practices recommends inactivated hepatitis A vaccination for all children beginning at age 1 year and for high risk adults. The hepatitis A vaccine is highly effective but the duration of protection is unknown. METHODS: We examined the proportion of children with protective hepatitis A antibody levels (anti-HAV ≥20 mIU/mL) as well as the geometric mean concentration (GMC) of anti-HAV in a cross sectional convenience sample of individuals aged 12-24 years, who had been vaccinated with a two-dose schedule in childhood, with the initial dose at least 5 years ago. We compared a subset of data from persons vaccinated with two-doses (720 EL.U.) at age 3-6 years with a demographically similar prospective cohort that received a three-dose (360 EL.U.) schedule and have been followed for 17 years. RESULTS: No significant differences were observed when comparing GMC between the two cohorts at 10 (P=0.467), 12 (P=0.496), and 14 (P=0.175) years post-immunization. For the three-dose cohort, protective antibody levels remain for 17 years and have leveled-off over the past 7 years. CONCLUSION: The two- and three-dose schedules provide similar protection >14 years after vaccination, indicating a booster dose is not needed at this time. Plateauing anti-HAV GMC levels suggest protective antibody levels may persist long-term.

Long-term immunogenicity of hepatitis A virus vaccine in Alaska 17 years after initial childhood series.

The Centers for Disease Control and Prevention recommends hepatitis A virus (HAV) vaccination for all children at age 1 year and for high-risk adults. The vaccine is highly effective; however, protection duration is unknown. We report HAV antibody concentrations 17 years after childhood immunization, demonstrating that protective antibody levels remain and have stabilized over the past 7 years.

Evidence for a new species of Leishmania associated with a focal disease outbreak in Ghana.

A previously unknown Leishmania spp., inferred by DNA sequence analysis of the small subunit ribosomal RNA gene and the internal transcribed spacer region (ITS1), was detected in tissue biopsies from patients living in the Eastern Ghanaian community of Taviefe. Restriction fragment length polymorphism analysis of the ITS1 amplicon supports the possibility of an uncharacterized Leishmania spp.

Protein synthesis in Escherichia coli with mischarged tRNA.

Two types of aspartyl-tRNA synthetase exist: the discriminating enzyme (D-AspRS) forms only Asp-tRNA(Asp), while the nondiscriminating one (ND-AspRS) also synthesizes Asp-tRNA(Asn), a required intermediate in protein synthesis in many organisms (but not in Escherichia coli). On the basis of the E. coli trpA34 missense mutant transformed with heterologous ND-aspS genes, we developed a system with which to measure the in vivo formation of Asp-tRNA(Asn) and its acceptance by elongation factor EF-Tu. While large amounts of Asp-tRNA(Asn) are detrimental to E. coli, smaller amounts support protein synthesis and allow the formation of up to 38% of the wild-type level of missense-suppressed tryptophan synthetase.

Bacterial genomics: potential for antimicrobial drug discovery.

The sequencing of entire bacterial genomes is becoming increasingly routine, promising to revolutionise approaches to identifying putative antimicrobial drug targets. In silico methods can be used to identify putative gene products by comparing sequences of biochemically characterised enzymes and proteins with data produced by sequencing projects. Comparative genomics between a pathogenic bacterium versus nonpathogen as well as pathogen versus host can identify molecular targets that would be ideal for future investigation. The aim of these comparisons would be to identify genes that code for pathogenicity factors in the bacterium or genes essential for bacterial survival. The latter set of genes includes those that are nonfunctional or redundant in the host as well as genes absent from the host but essential in the pathogen. The products of these genes would be ideal targets for antimicrobial compounds. If compounds could be generated that disrupt the pathogen's ability to thrive but not affect the host, since there is a lack of the targeted protein, they could prove to be powerful therapeutics. An elegant example illustrating the power of comparative genomics involves comparison of the pathways of bacterial and eukaryotic aminoacyl-tRNA synthesis. Comparison of pathogenic bacterial genomes shows that many bacteria lack the genes encoding either one or two specific aminoacyl-tRNA synthetases, enzymes involved in ensuring correct aminoacylation of tRNA for subsequent translation of the genetic code. Bacteria have an alternative pathway by which amide aminoacyl-tRNAs are formed. Comparative genomics has demonstrated that this pathway is uniquely prokaryotic/archaeal and also relatively widely found in pathogenic bacteria, indicating the potential of the catalytic enzymes of the pathway as targets for novel antimicrobial drugs.