The control of viral diseases in the developing countries with the use of existing vaccines]

In developing countries, every year about 70 million measles cases occur with 1.5 million deaths, over 200,000 children contract paralytic poliomyelitis, 50 million people get infected with viral B hepatitis causing over 1 million deaths, and several thousand people perish because of yellow fever according to WHO data. At the present time, there are 12 vaccines against viruses: vaccines against German measles and mumps in addition to the above. The universal immunization program (UIP) of WHO targets measles and polio. In 1989, a WHO resolution envisioned a 90% immunization coverage by the year 2000. Measles vaccination is recommended for children aged 9-23 months, since most children have maternal antibodies during the first 3-13 months of age. The Edmonston-Zagreb vaccine provided seroconversion of 92, 96, and 98% for 18 months vs. the 66, 76, and 91% rate of the Schwarz vaccine. In the US, measles incidence increased from 1497 cases in 1983 to 6382 cases in 1988 to over 14,000 cases in 1989, prompting second vaccination in children of school age. The highest incidence of polio was registered in Southeast Asia, although it declined from 1 case/100,000 population in 1975 to .5/100,000 in 1988. Oral poliomyelitis vaccine (OPV) provides protection: there is only 1 case/2.5 million vaccinations. Hepatitis B has infected over 2 billion people. About 300 million are carriers, with a prevalence of 20% in African, Asian, and Pacific region populations. Plasmatic and bioengineered recombinant vaccine type have been used in 30 million people. The first dose is given postnatally, the second at 1-2 months of age, and the 3rd at 1 year of age. Yellow fever vaccine was 50 years old in 1988, yet during 1986-1988 there were 5395 cases with 3172 deaths in Africa and South America. Vaccination provides 90-95% seroconversion, and periodic follow-up vaccinations under UIP could eradicate these infections and their etiologic agents.     

Animal diseases affecting human welfare in developing countries: impacts and control

Animal diseases adversely affect human populations by reducing the amount and quality of food and fiber, and draft power. Epizootics of diseases such as rinderpest have caused massive mortality among domestic and wild animals. Extensive outbreaks of Venezuelan equine encephalltis have caused massive mortality in equines, and significant morbidity among people. Foot-and-mouth disease can cause high morbidity and great direct economic loss, and loss of markets as a trade barrier. Old diseases such as yellow fever and Rift Valley fever are still with us, and diseases such as the viral haemorrhagic fevers have suddenly appeared for the first time. The transmission of some of these diseases has been facilitated inadvertently by ecological change resulting from development projects. Animal disease control must be based on dealing with disease agents, and their hosts and vectors, as part of ecosystems and farming systems. Better disease surveiliance, diagnosis and reporting is needed. The economics of disease loss and the benefits of interventions must become part of the decision-making process.This paper was presented at the IUMS Symposium on New Developments in Diagnosis and Control of Infectious Diseases held in conjunction with the Eighth International Congress of Virology, Berlin, Germany, 24–31 August 1990.     

Hemovigilance in developing countries

Hemovigilance like quality systems and audits has become an integral part of the Blood Transfusion Service (BTS) in the developed world and has contributed greatly to the development of the blood service. However developing countries are still grappling with donor recruitment and efforts towards sufficiency and safety of the blood supply. In these countries the BTS is generally fragmented and a national hemovigilance program would be difficult to implement. However a few developing countries have an effective and sustainable blood program that can deliver equitable, safe and sufficient blood supply to the nation. Different models of hemovigilance program have been introduced with variable success. There are deficiencies but the data collected provided important information that can be presented to the health authorities for effective interventions.Hemovigilance program modeled from developed countries require expertise and resources that are not available in many developing countries. Whatever resources that are available should be utilized to correct deficiencies that are already apparent and obvious. Besides there are other tools that can be used to monitor the blood program in the developing countries depending on the need and the resources available. More importantly the data collected should be accurate and are used and taken into consideration in formulating guidelines, standards and policies and to affect appropriate interventions. Any surveillance program should be introduced in a stepwise manner as the blood transfusion service develops.     

Nutrition and infectious diseases in developing countries and problems of acquired immunodeficiency syndrome

Infectious diseases are the major causes of death and morbidity in underdeveloped countries, particularly in children. Increasing evidence suggests that malnutrition-both Protein-Energy type Malnutrition (PEM) and essential micronutrient (vitamins, trace minerals, essential amino acids, polyunsaturated fatty acids) type-is the underlying reason for increased susceptibility to infections. On the other hand, certain infectious diseases also cause malnutrition, which results in a vicious cycle. Before its viral origin was known, acquired immunodeficiency syndrome (AIDS) had been termed the thin disease because cachexia was AIDS' main clinical manifestation. The relationship between infection and malnutrition is well documented in the literature. Our experience supports this. Preventive and therapeutic measures are suggested.     

Reproductive technologies in developing countries

Are there any ethical concerns about reproductive technologies that are specific or unique to developing countries? Three ethical concerns often mentioned specifically in regard to developing countries are (1), the "overpopulation argument"; (2) the limited resources argument; and (3) the ethical problem of poorly trained practitioners offering their services to unsuspecting and uninformed infertile individuals or couples. Each argument is explored in some detail, with the conclusion that ethical problems do, in fact, exist but are not unique to developing countries. Nevertheless, the difficulties relating to reproductive technologies are likely to be greater in developing countries than in developed ones because of limited resources and a larger number of poor people residing there.