Reduction of amputations of frostbitten limbs by treatment using microwave rewarming.

Drug treatment of limb frostbite injuries is complicated due to the poor delivery of medications to affected tissues. External rewarming of the frostbitten area is risky and does not always result in positive outcomes because the dilatation of superficial vessels with constricted deep vessels can lead to irreversible damage, necrosis, and amputation. One of the techniques to restore perfusion of deep vessels in an affected extremity is rewarming with low-power microwave radiation in a specially designed metal chamber. Below are findings following treatment of 14 volunteers with this technique in 2 Tomsk hospitals during winters of 2018-2021. It is demonstrated that timely, i.e. in the early reactive period, application of microwave radiation and appropriate supportive drug treatment results in positive amputation-free outcomes. The key requirement is prompt thermal insulation of the trauma and no prior exposure to external heat sources.

Microwave Treatment of Cold Injuries.

In spite of the fact that extremity frostbites are a widespread type of injuries in many countries, specialized equipment for frostbite treatment is lacking. Treatment is carried out by conservative methods. The best results are obtained by using thermal isolation of injured tissues and activation of internal warming. It is proposed to initiate deep warming of frostbitten extremities on exposure to low-power microwave radiation. A microwave chamber has been developed to implement this technique. The efficiency of the approach was earlier demonstrated on animals. An example is given of successful treatment of a cold injury of patient hands and feet that allowed amputation to be avoided.

Responding to a cVDPV1 outbreak in Ukraine: Implications, challenges and opportunities.

BACKGROUND: The European Region, certified polio-free in 2002, remains at risk of wild poliovirus reintroduction and emergence of circulating vaccine-derived polioviruses (cVDPV) until global polio eradication is achieved, as demonstrated by the cVDPV1 outbreak in Ukraine in 2015. METHODS: We reviewed epidemiologic, clinical and virology data on cVDPV cases, surveillance and immunization coverage data, and reports of outbreak-related surveys, country missions, and expert group meetings. RESULTS: In Ukraine, 3-dose polio vaccine coverage declined from 91% in 2008 to 15% by mid-2015. In summer, 2015, two unrelated children from Zakarpattya province were paralyzed by a highly divergent cVDPV1. The isolates were 20 and 26 nucleotide divergent from prototype Sabin strain (with 18 identical mutations) consistent with their common origin and ∼2-year evolution. Outbreak response recommendations developed with international partner support included conducting three nationwide supplementary immunization activities (SIAs) with tOPV, strengthening surveillance and implementing communication interventions. SIAs were conducted during October 2015-February 2016 (officially reported coverage, round 1-64.4%, round 2-71.7%, and round 3-80.7%). Substantial challenges to outbreak response included lack of high-level support, resistance to OPV use, low perceived risk of polio, widespread vaccine hesitancy, anti-vaccine media environment, economic crisis and military conflict. Communication activities improved caregiver awareness of polio and confidence in vaccination. Surveillance was enhanced but did not consistently meet applicable performance standards. Post-outbreak assessments concluded that cVDPV1 transmission in Ukraine has likely stopped following the response, but significant gaps in population immunity and surveillance remained. CONCLUSIONS: Chronic under-vaccination in Ukraine resulted in the accumulation of children susceptible to polioviruses and created favorable conditions for VDPV1 emergence and circulation, leading to the outbreak. Until programmatic gaps in immunization and surveillance are addressed, Ukraine will remain at high-risk for VDPV emergence and circulation, as well as at risk for other vaccine-preventable diseases.

Substantial decline in hepatitis B virus infections following vaccine introduction in Tajikistan.

BACKGROUND: Tajikistan, considered highly endemic area for hepatitis B virus (HBV) in a pre-vaccine era, introduced hepatitis B vaccine in 2002 and reported ≥80% coverage with three doses of hepatitis B vaccine (HepB3) since 2004. However, the impact of vaccine introduction has not been assessed. METHODS: We tested residual serum specimens from a 2010 national serosurvey for vaccine-preventable diseases in Tajikistan and assessed the prevalence of HBV infection across groups defined based on the birth cohorts' routine infant hepatitis B vaccination program implementation and HepB3 coverage achieved (≥80% versus <80%). Serosurvey participants were selected through stratified multi-stage cluster sampling among residents of all regions of Tajikistan aged 1-24 years. All specimens were tested for antibodies against HBV core antigen (anti-HBc) and those found positive were tested for HBV surface antigen (HBsAg). Seroprevalence and 95% confidence intervals were calculated and compared across subgroups using Satterthwaite-adjusted chi-square tests, accounting for the survey design and sampling weights. RESULTS: A total of 2188 samples were tested. Prevalence of HBV infection markers was lowest among cohorts with ≥80% HepB3 coverage (ages, 1-6 years): 2.1% (95% confidence interval, 1.1-4.3%) for anti-HBc, 0.4% (0.1-1.3%) for HBsAg, followed by 7.2% (4.1-12.4%) for anti-HBc and 2.1% (0.7-6.1%) for HBsAg among cohorts with <80% HepB3 coverage (ages, 7-8 years), by 12.0% (8.7-16.3%) for anti-HBc and 3.5% (2.2-5.6%) for HBsAg among children's cohorts not targeted for vaccination (ages, 9-14 years), and 28.9% (24.5-33.8%) for anti-HBc and 6.8% (4.5-10.1%) for HBsAg among unvaccinated adult cohorts (ages, 15-24 years). Differences across groups were significant (p<0.001, chi-square) for both markers. CONCLUSIONS: The present study demonstrates substantial impact of hepatitis B vaccine introduction on reducing HBV infections in Tajikistan. To achieve further progress in hepatitis B control, Tajikistan should maintain high routine coverage with hepatitis B vaccine, including birth dose.

Genetic analysis and characterization of wild poliovirus type 1 during sustained transmission in a population with >95% vaccine coverage, Israel 2013.

BACKGROUND: Israel has >95% polio vaccine coverage with the last 9 birth cohorts immunized exclusively with inactivated polio vaccine (IPV). Using acute flaccid paralysis and routine, monthly countrywide environmental surveillance, no wild poliovirus circulation was detected between 1989 and February 2013, after which wild type 1 polioviruses South Asia genotype (WPV1-SOAS) have persistently circulated in southern Israel and intermittently in other areas without any paralytic cases as determined by intensified surveillance of environmental and human samples. We aimed to characterize antigenic and neurovirulence properties of WPV1-SOAS silently circulating in a highly vaccinated population. METHODS: WPV1-SOAS capsid genes from environmental and stool surveillance isolates were sequenced, their neurovirulence was determined using transgenic mouse expressing the human poliovirus receptor (Tg21-PVR) mice, and their antigenicity was characterized by in vitro neutralization using human sera, epitope-specific monoclonal murine anti-oral poliovirus vaccine (OPV) antibodies, and sera from IPV-immunized rats and mice. RESULTS: WPV1 amino acid sequences in neutralizing epitopes varied from Sabin 1 and Mahoney, with little variation among WPV1 isolates. Neutralization by monoclonal antibodies against 3 of 4 OPV epitopes was lost. Three-fold lower geometric mean titers (Z = -4.018; P < .001, Wilcoxon signed-rank test) against WPV1 than against Mahoney in human serum correlated with 4- to 6-fold lower neutralization titers in serum from IPV-immunized rats and mice. WPV1-SOAS isolates were neurovirulent (50% intramuscular paralytic dose in Tg21-PVR mice: log10(7.0)). IPV-immunized mice were protected against WPV1-induced paralysis. CONCLUSIONS: Phenotypic and antigenic profile changes of WPV1-SOAS may have contributed to the intense silent transmission, whereas the reduced neurovirulence may have contributed to the absence of paralytic cases in the background of high population immunity.

Challenges of maintaining polio-free status of the European Region.

BACKGROUND: The European region, certified as polio free in 2002, had recent wild poliovirus (WPV) introductions, resulting in a major outbreak in Central Asian countries and Russia in 2010 and in current widespread WPV type 1 circulation in Israel, which endangered the polio-free status of the region. METHODS: We assessed the data on the major determinants of poliovirus transmission risk (population immunity, surveillance, and outbreak preparedness) and reviewed current threats and measures implemented in response to recent WPV introductions. RESULTS: Despite high regional vaccination coverage and functioning surveillance, several countries in the region are at high or intermediate risk of poliovirus transmission. Coverage remains suboptimal in some countries, subnational geographic areas, and population groups, and surveillance (acute flaccid paralysis, enterovirus, and environmental) needs further strengthening. Supplementary immunization activities, which were instrumental in the rapid interruption of WPV1 circulation in 2010, should be implemented in high-risk countries to close population immunity gaps. National polio outbreak preparedness plans need strengthening. Immunization efforts to interrupt WPV transmission in Israel should continue. CONCLUSIONS: The European region has successfully maintained its polio-free status since 2002, but numerous challenges remain. Staying polio free will require continued coordinated efforts, political commitment and financial support from all countries.

Characteristics of an environmentally monitored prolonged type 2 vaccine derived poliovirus shedding episode that stopped without intervention.

Vaccine derived poliovirus (VDPV) type 2 strains strongly divergent from the corresponding vaccine strain, Sabin 2, were repeatedly isolated from sewage in Slovakia over a period of 22 months in 2003-2005. Cell cultures of stool specimens from known immune deficient patients and from an identified putative source population of 500 people failed to identify the potential excretor(s) of the virus. The occurrence of VDPV in sewage stopped without any intervention. No paralytic cases were reported in Slovakia during the episode. According to a GenBank search and similarity plotting-analysis, the closest known relative of the first isolate PV2/03/SVK/E783 through all main sections of the genome was the type 2 poliovirus Sabin strain, with nucleotide identities in 5'UTR, P1, P2, P3, and 3'UTR parts of the genome of 88.6, 85.9, 87.3, 88.5, and 94.0 percent, respectively. Phenotypic properties of selected Slovakian aVDPV strains resembled those of VDPV strains isolated from immune deficient individuals with prolonged PV infection (iVDPV), including antigenic changes and moderate neurovirulence in the transgenic mouse model. One hundred and two unique VP1 coding sequences were determined from VDPV strains isolated from 34 sewage specimens. Nucleotide differences from Sabin 2 in the VP1 coding region ranged from 12.5 to 15.6 percent, and reached a maximum of 9.6 percent between the VDPV strains under study. Most of the nucleotide substitutions were synonymous but as many as 93 amino acid positions out of 301 in VP1 showed substitutions. We conclude that (1) individuals with prolonged poliovirus infection are not as rare as suggested by the studies on immune deficient patients known to the health care systems and (2) genetic divergence of VDPV strains may remain extensive during years long replication in humans.

Molecular genotyping and epidemiology of measles virus transmission in the World Health Organization European Region, 2007-2009.

BACKGROUND: In 2002, the World Health Organization (WHO) adopted a goal to eliminate measles in the European Region by 2010. Measles elimination is defined as the interruption of indigenous measles virus (MV) transmission. The molecular epidemiology of MV transmission in the WHO European Region was studied through the investigation of reported cases and outbreaks to monitor the region's progress toward its measles elimination goal. METHODS: National and regional laboratories performed molecular characterization of MV detected between 2007 and 2009 in the WHO European Region. To document indigenous transmission and importations into the region, we analyzed genotyping results and epidemiological data on measles outbreaks reported by the member states. RESULTS: Since 2007, MV genotype D6 has not been reported in the WHO European Region, suggesting that its chains of transmission have been interrupted, whereas several other MV genotypes are still circulating. Although several European countries have already interrupted indigenous MV transmission, genotyping showed that 3 endemic MV transmission chains have been reestablished in other countries. CONCLUSIONS: The WHO European Region 2010 goal will not be met, as indigenous transmission of MV has not been interrupted. As the region begins to document its process of elimination verification to monitor progress toward the goal, countries will need to ensure that genotyping is performed in all measles outbreaks.

Expansion of the global measles and rubella laboratory network 2005-09.

Enhancing measles surveillance with integration of epidemiologic and laboratory information is one of the key strategies for accelerated measles control and elimination. The World Health Organization (WHO) Global Measles and Rubella Laboratory Network (LabNet) has been developed since 2000 to currently include 690 laboratories serving 183 countries. The LabNet testing strategy follows well-validated, standardized procedures for confirming suspected cases and for monitoring measles and rubella virus transmission patterns. The strength of the LabNet is a strong quality assurance program that monitors the performance of all laboratories through annual proficiency testing and continuous assessment. In the 5-year period 2005-2009, the results of >1 million measles immunoglobulin M (IgM) tests have been reported by the LabNet and, in addition, sequence information on >7000 measles and 600 rubella viruses has been shared. Progress with the development of the LabNet during 2005-2009 is discussed.

Importation and circulation of poliovirus in Bulgaria in 2001.

OBJECTIVE: To characterize the circumstances in which poliomyelitis occurred among three children in Bulgaria during 2001 and to describe the public health response. METHODS: Bulgarian authorities investigated the three cases of polio and their contacts, conducted faecal and serological screening of children from high-risk groups, implemented enhanced surveillance for acute flaccid paralysis, and conducted supplemental immunization activities. FINDINGS: The three cases of polio studied had not been vaccinated and lived in socioeconomically deprived areas of two cities. Four Roma children from the Bourgas district had antibody titres to serotype 1 poliovirus only, and wild type 1 virus was isolated from the faeces of two asymptomatic Roma children in the Bourgas and Sofia districts. Poliovirus isolates were related genetically and represented a single evolutionary lineage; genomic sequences were less than 90% identical to poliovirus strains isolated previously in Europe, but 98.3% similar to a strain isolated in India in 2000. No cases or wild virus isolates were found after supplemental immunization activities were launched in May 2001. CONCLUSIONS: In Bulgaria, an imported poliovirus was able to circulate for two to five months among minority populations. Surveillance data strongly suggest that wild poliovirus circulation ceased shortly after supplemental immunization activities with oral poliovirus vaccine were conducted.