Annual report of the Australian National Poliovirus Reference Laboratory 2005.

In May 1988 the World Health Assembly adopted a resolution for the global eradication of poliomyelitis. Since then two target dates for eradication (2000 and 2003) have passed and the struggle to eradicate the poliovirus continues. Australia's commitment to the worldwide campaign began in December 1994 with the designation of the National Poliovirus Reference Laboratory at the Victorian Infectious Diseases Reference Laboratory and the initiation of acute flaccid paralysis (AFP) surveillance in March 1995. During 2005 the National Poliovirus Reference Laboratory did not isolate any wild or vaccine derived polioviruses from the 42 samples collected from eighteen cases of acute flaccid paralysis in Australian residents. Three Sabin-like polioviruses were isolated from three cases of acute flaccid paralysis but all were considered incidental isolations by the Polio Expert Committee and not implicated in the disease of the patients. After exceeding the World Health Organization target of one case of AFP per 100,000 children aged less than 15 years in 2004, Australia's non-polio AFP rate in 2005 fell to 0.75 cases per 100,000 children. The high number of wild poliovirus importations reported globally in 2005 into previously polio free countries, highlights the need for a sensitive AFP surveillance system within Australia and for specimens from AFP cases to be forwarded to the National Poliovirus Reference Laboratory.

Carbon nanotube filters.

Over the past decade of nanotube research, a variety of organized nanotube architectures have been fabricated using chemical vapour deposition. The idea of using nanotube structures in separation technology has been proposed, but building macroscopic structures that have controlled geometric shapes, density and dimensions for specific applications still remains a challenge. Here we report the fabrication of freestanding monolithic uniform macroscopic hollow cylinders having radially aligned carbon nanotube walls, with diameters and lengths up to several centimetres. These cylindrical membranes are used as filters to demonstrate their utility in two important settings: the elimination of multiple components of heavy hydrocarbons from petroleum-a crucial step in post-distillation of crude oil-with a single-step filtering process, and the filtration of bacterial contaminants such as Escherichia coli or the nanometre-sized poliovirus ( approximately 25 nm) from water. These macro filters can be cleaned for repeated filtration through ultrasonication and autoclaving. The exceptional thermal and mechanical stability of nanotubes, and the high surface area, ease and cost-effective fabrication of the nanotube membranes may allow them to compete with ceramic- and polymer-based separation membranes used commercially.

An increase in selenium intake improves immune function and poliovirus handling in adults with marginal selenium status.

BACKGROUND: Dietary selenium intakes in many countries, including the United Kingdom, are lower than international recommendations. No functional consequences of these lower intakes have been recognized, although experimental studies suggest that they might contribute to reduced immune function, increased cancer incidence, and increased susceptibility to viral disease. OBJECTIVE: The objective was to assess whether administration of small selenium supplements to otherwise healthy UK subjects leads to functional changes in immune status and the rates of clearance and mutation of a picornavirus: live attenuated polio vaccine. DESIGN: Twenty-two adult UK subjects with relatively low plasma selenium concentrations (<1.2 micromol/L, approximately 60% of those screened) received 50 or 100 microg Se (as sodium selenite) or placebo daily for 15 wk in a double-blind study. All subjects received an oral live attenuated poliomyelitis vaccine after 6 wk and enriched stable (74)Se intravenously 3 wk later. RESULTS: Selenium supplementation increased plasma selenium concentrations, the body exchangeable selenium pool (measured by using (74)Se), and lymphocyte phospholipid and cytosolic glutathione peroxidase activities. Selenium supplements augmented the cellular immune response through an increased production of interferon gamma and other cytokines, an earlier peak T cell proliferation, and an increase in T helper cells. Humoral immune responses were unaffected. Selenium-supplemented subjects also showed more rapid clearance of the poliovirus, and the poliovirus reverse transcriptase-polymerase chain reaction products recovered from the feces of the supplemented subjects contained a lower number of mutations. CONCLUSIONS: The data indicate that these subjects had a functional selenium deficit with suboptimal immune status and a deficit in viral handling. They also suggest that the additional 100 microg Se/d may be insufficient to support optimal function.

Annual report of the Australian National Poliovirus Reference Laboratory, 2002.

Acute flaccid paralysis is the main clinical manifestation of poliomyelitis. Faecal specimens from cases of acute flaccid paralysis in Australia are referred to the National Poliovirus Reference Laboratory for virus culture to determine if poliovirus is the causative agent. Isolations of poliovirus are tested to determine whether they have characteristics of the Sabin oral polio vaccine virus strains or wild type polioviruses. In 2002, a poliovirus type 3, which tested as Sabin vaccine-like, was isolated from an Australian patient with acute flaccid paralysis. A non-polio enterovirus, Echovirus type 18, was isolated from the faecal specimens of another case of acute flaccid paralysis. In the same period, the laboratory identified 35 Sabin-like polioviruses from 52 referred specimens and isolates from cases without acute flaccid paralysis. Australia is a member nation of the World Health Organization's Western Pacific region that was declared free of endemic wild poliovirus in October 2000. Poliomyelitis remains endemic in three of the WHO regions of the world and wild poliovirus may be re-introduced to Australia. While the number of polio-endemic countries has been reduced to seven, the total number of wild polioviruses identified increased in 2002 compared to 2001 due to a sharp rise in isolations of wild virus from Northern India. Until global eradication of poliomyelitis is achieved, it is essential that a high level of poliovirus vaccination coverage, and surveillance for cases of acute flaccid paralysis, be maintained in Australia.

Brote de poliomielitis en Haiti y la Republica Dominicana debido a un virus derivado de la vacuna antipoliomielitica oral / Poliomyelitis outbreak caused by vaccine-derived virus in Haiti and the Dominican Republic

In October 2000, the Ministries of Helth of the Dominican Republic and Haiti notified two cases of acute flaccid paralyis (AFP) in rural areas, one of them in a 9-month-old female, and the other in a 2-year-old female, respectively. Stool samples that were obtained from these cases, which occured in July and August 2000, after a 9-year interruption of wild poliovirus circulation in the Western Hemisphere, revealed the presence of type 1 poliovirus. Genetic sequencing, which was later performed at the CEnters for Disease Control and Prevention, in Atlanta, Georgia, United States of America, revealed an atypical descendant of the virus used in the manufacture of the oral polio vaccine (OPV), but with 3 percent genetic divergence with respect to the parent strain. Normally, viral isolates that derive from vaccine components show 99.5 percent genetic agreement with the parent strain; in wild polioviruses, on the other hand, this agreement is usually less than 82.0 percent. Thus, the 3 percent genetic divergence detected in this study suggests that, in areas with low vaccine coverage, the virus used in the vaccine remained in circulation for at least two years, during which it recovered the neurovirulence and communicability of wild poliovirus type 1. This report describes the characteristics and results of the active search for cases of AFP that was sparked by the detection of the two index cases. It also looks at the public health implications of this outbreak for the entire Region of the Americas (AU)

Use of ionic detergents for enterovirus recovery from waste water.

Virus recovery from poliovirus-seeded waste water was attempted after treatment of the samples with ionic detergents in the presence of acoustic energy. Viral titers strongly fluctuated depending upon concentration and chemical structure of the detergent as well as upon the dissolved organic content of the aqueous samples. Supplementation of the cellular monolayers with an additional amount of cell culture medium or with a nonionic detergent in a subcytotoxic concentration 48 h after inoculation partly induced cytopathic effects in silent dilution steps. Since, in the presence of the same detergent, viral recovery rates varied with the type of waste water, titer-conditioning activity of detergents was suggested to depend upon their effective critical micellization concentration. Especially for virus recovery from concentrated waste water, treatment with strongly disruptive detergents such as sodium dodecylsulfate revealed to be much more efficient than with the less hydrophilic sodium N-laurylsarcosine, sodium glycodeoxycholate or lauryldimethylamine-oxide, whereas the opposite seemed to be the case if virus recovery from filtrate samples were to be optimized. The mechanisms by which viral particles become infectious for the cell appear to be triggered by general principles of equilibrium thermodynamics, which means that interactions between viral surface proteins and cellular receptor molecules seem to reflect the tendency of these reagents to assume the energetically most favored orientation.

Epidemic poliomyelitis in The Gambia following the control of poliomyelitis as an endemic disease. I. Descriptive findings.

An epidemic of type 1 poliomyelitis involving 305 cases occurred in The Gambia (estimated 1986 population, 768,995) from May through November 1986, following a 6-year period when only five cases were reported. Cases were identified by physician reporting during the epidemic and by a national village-to-village search conducted after the epidemic. The national attack rate was 40 cases per 100,000 people. Cases lived in all parts of the country except the capital, Banjul. The peak month of the epidemic was August (139 cases). The highest attack rate by year of age was in 1-year-old children (394 cases per 100,000 persons), and 75% of cases were 3 years of age or less. A vaccination coverage survey showed that 64% (95% confidence interval 60-68) of 1- to 2-year-old children were vaccinated with at least three doses of trivalent oral polio vaccine at the beginning of the epidemic. Fifty-seven cases became paralyzed more than 2 weeks after a national mass campaign in which 95% of children 1-7 years old were reported to have received a dose of trivalent oral polio vaccine. Experience in The Gambia shows that a several-year period of excellent control of endemic poliomyelitis by a vaccination program can be followed by a major epidemic and that a mass vaccination campaign may be only partially successful in ending the epidemic.

Recovery of viruses from water by a modified flocculation procedure for second-step concentration.

A reduction in virus recovery efficiencies stemming from a change in the commercial processing of powdered beef extract was reversed by the addition of Celite analytical filter aid. Supplementing beef extract with this silicate is recommended as a modification to the organic flocculation procedure for second-step concentration in monitoring for waterborne viruses. Considerable differences in virus recovery were found among lots of beef extract and Celite preparations; this indicates that the performance of each lot of these substances should be checked before use.

Elution of enteric viruses from Mississippi estuarine sediments with lecithin-supplemented eluents.

Isoelectric casein supplemented with lecithin was tested for its ability to recover enteric viruses from estuarine sediments of varied sand, silt, and clay composition. Recoveries were higher when lecithin was incorporated into an eluent as compared with trials with only the casein solution. Semipurified soybean lecithin (3%) allowed the highest overall recovery of virus from all sediments tested; crude soybean lecithin produced the lowest recovery. A difference in the percentage of virus able to be recovered from a sediment was related to the percentage of clay in the sample. Correlational statistics indicated a trend toward lower virus recovery as the clay composition of a sediment increased. Virus adsorption to the four sediments tested revealed differences between poliovirus, coxsackievirus, and echovirus adsorption that could not be explained on the basis of the clay content of a sediment.

Chronic progressive poliomyelitis secondary to vaccination of an immunodeficient child.

We investigated an immunodeficient child in whom chronic progressive poliomyelitis developed after she had received live oral poliovirus vaccine. Poliovirus, Type II, was isolated from throat and stool during life and from several sites within the brain at autopsy. The brain isolate was classified as vaccine-like on the basis of temperature sensitivity and antigenic markers. However, in the monkey neurovirulence test, the brain isolate produced moderately severe lesions throughout the spinal cord and brainstem and appeared nonvaccine-like. Thus, the brain isolate demonstrated a dissociation between the antigenic and neurovirulence markers. Our observations suggest that, under unusual circumstances, such as immunodeficiency, attenuated poliovirus can produce a chronic progressive neurologic disease. This case also emphasizes the need to diagnose immunodeficiency as early as possible, so that live-virus vaccines will not be administered.

Concentration of enteric viruses from water with lettuce extract.

A method for recovering enteroviruses, adenovirus, and reovirus from water with lettuce extract is described. Lettuce extract at pH 8.5 was added to the sample and the pH was reduced stepwise with hydrochloric acid to 4.0 to 4.5. The flocculent lettuce-extract particles, and adsorbed virus, were readily removed from solution by low-speed centrifugation. Electron microscopy suggests that, under conditions suitable for adsorption, virus particles are coated with the lettuce-extract colloid.

Purification of the Sabin strain of poliovirus type I through treatment with sarkozyl.

Sodium dodecyl sulfate was found to aggregate virions from the Sabin Lsc2ab strain of poliovirus type 1. Aggregation was prevented by high ionic strength buffers. A procedure is described for the rapid purification of the virus through the use of sarkozyl.