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N A Ward

Publications and source records attributed to N A Ward.

13 recordsLinked to original sources
PubMed1995

Polio eradication.

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Developing Countries↗
PubMed1994

Paralytic poliomyelitis: seasoned strategies, disappearing disease.

With more than 2 years having elapsed since the last case of paralytic poliomyelitis occurred in the Western Hemisphere, significant progress has been made towards the global eradication of wild polioviruses. Poliomyelitis is disappearing from Europe, North Africa, Southern Africa, the Middle East, China, and the Pacific. Reported poliomyelitis cases declined to 15,587 cases in 1992. Current eradication strategies recommended by the World Health Organization include national mass campaigns administering oral poliovaccine to all children under 5 years of age, enhanced surveillance to detect cases of acute flaccid paralysis, creating a network of laboratories for viral diagnosis, and targeted immunisation to areas and populations where poliovirus transmission is likely to persist. The major obstacles to eradication include inadequate political support for eradication and insufficient funding, especially for the purchase of vaccine. With additional support for the international eradication effort, epidemics of poliomyelitis will cease in developing countries, and industrialised countries will be able to save the large sums spent each year on poliovaccine and rehabilitation.

Global Health↗
PubMed1993

The WHO-EPI initiative for the global eradication of poliomyelitis.

Since the development of attenuated oral polio vaccine, Dr Albert Sabin consistently maintained that the global eradication of wild poliovirus was possible, but that to achieve polio eradication in developing countries would require the mass administration of the oral vaccine. Experience in Cuba and Czechoslovakia proved the effectiveness of this technique, but it was only with its deployment in Brazil in 1980 that its role in eradicating the virus from a broad geographical area started to be realized. With the declaration in 1985 of a target of regional polio eradication, extension of this policy, allied with the development of effective surveillance of acute flaccid paralysis in children, with laboratory confirmation of diagnosis rapidly led to apparent interruption of wild poliovirus transmission throughout the Americas. The World Health Assembly in 1988 committed WHO to the global eradication of poliomyelitis. Based on experience in the Americas and building on the solid foundation established by the Expanded Programme on Immunization, WHO has defined the strategies through which the global target could be achieved. Progress is encouraging and where the advocated strategies have been fully implemented, the incidence of poliomyelitis has declined dramatically. Significant geographical areas in Western Europe, the Maghreb, the Arabian peninsula, the Pacific basin and Southern Africa, each incorporating several countries, are now thought to be free of the disease caused by wild poliovirus. The target of a world free of polio by the year 2000 can be achieved.

Developing Countries↗
PubMed1992

Progress towards the global eradication of poliomyelitis.

Poliomyelitis has been virtually eliminated from the industrialized countries by mass campaigns conducted with oral polio vaccine (OPV). In 1988, the World Health Assembly set the goal of global eradication of poliomyelitis by the year 2000. The current WHO strategy for eradication uses three primary activities beyond routine immunization with OPV. They are: (i) improved disease surveillance, (ii) building a global network of laboratories, and (iii) supplemental immunization strategies which include mass immunization campaigns with OPV at the national level, and targeted campaigns at the local level. Eradication of polio from the Region of the Americas is close and may have already been achieved. In other regions, the number of reported polio cases has declined, largely as a result of high immunization coverage. As more countries implement polio eradication strategies, the number of polio cases will continue to fall until eradication is achieved.

Humans↗
PubMed1980

Smallpox surveillance in Bangladesh: I - Development of surveillance containment strategy.

A major epidemic of Variola major with an estimated 90 000 cases and 18 000 deaths occurred in Bangladesh in 1972. During a 3-year period methods of active surveillance (market search, outbreak investigation, and house-to-house search) were developed to supplement the passive reporting system. The percentage of smallpox cases detected increased from 11.8% in 1972 to 83% in 1975. Together with the implementation of improved methods of outbreak control, smallpox transmission was interrupted in October 1975.

Bangladesh↗
PubMed1975

Treatment of variola major with adenine arabinoside.

A double-blind study of the efficacy of adenine arabinoside in the treatment of patients with variola major was conducted. Adenine arabinoside (20 mg/kg of body weight) was given to patients intravenously every 24 hr for seven days in a 8-hr infusion. Five of the nine patients receiving adinine arabinoside died, and four of 11 patients receiving placebo died. Mortality was related to the severity of illness for both groups of patients. No difference was found between the drug and control groups in number of febrile days after initiation of therapy or in the period during which it was possible to isolate virus from skin lisions, throat swabs, and sources of clotted blood. Formation of scabs on skin lesions was complete 8.3 days after the initiation of therapy for the drug group and after 11.3 days for the control group. The findings suggest that adenine arabinoside is not effective in the chemotherapy of smallpox.

Adenine↗
PubMedDate not supplied

Fundamental studies in reversed-phase liquid-solid extraction of basic drugs; I: Ionic interactions.

Seven basic solutes with known and controlled pKa (7.93-9.5) and log P (0.23-6.63) values have been used as test probes to study the mechanism involved in liquid-solid extraction with C2 and C18 bonded silica phases. A limited comparison has also been made with underivatized silica and CN phases. In addition to the reversed-phase mechanism, cation-exchange was shown to play a very significant role in the retention process. Various cations both organic and inorganic were assessed for their elution strength, and the ordering was similar to that for classical ion-exchange chromatography. Control of selectivity in the elution process can be achieved by varying the concentration of cation or methanol in the eluent. The C2 cartridge in combination with an aqueous ammonium acetate-methanol eluent proved to be the most versatile in that all compounds, irrespective of pKa or log P could be recovered in high yield. The optimal eluent in terms of selectivity with respect to related compounds could be predicted from the solute log P. Blocking of silanols by pre-conditioning the cartridges with cations prior to sample applications was also studied. The order of cation strengths although somewhat variable was similar to that established at the elution stage. To achieve quantitative elution with methanol or aqueous methanol solutions however, high concentrations of inorganic cations, equivalent to 1 ml of a 1 M solution were required to pre-condition a 100 mg cartridge.

Ion Exchange↗
PubMedDate not supplied

Practicalities of a global poliomyelitis control program.

Much progress has been achieved in making the world free of poliomyelitis. The countries that have achieved control should be giving practical help to those where the disease is still endemic, while developing their own competence in surveillance, laboratory support, and effective immunization policies. The polio vaccines have been proved effective. The need is now to implement programs by solving their practical difficulties in order to make use of the presently available vaccines.

Humans↗