The emerging AIDS crisis in Russia: review of enabling factors and prevention needs.

Eastern Europe is experiencing increased rates of HIV/AIDS, and the Russian Federation is among the countries with the most alarming case rate increases. Behavioural and biological studies demonstrate that the transmission of HIV in Russia is occurring as a result of injection drug use, homosexual, and heterosexual risk behaviours. Factors that promote risk and therefore enable HIV transmission in Russia parallel those found in other countries, including epidemics of other sexually transmitted infections, economic instability, poverty, and social factors such as gender roles. Research is urgently needed to better understand and forecast the HIV epidemic in Russia, as well as to develop effective interventions to prevent a Russian AIDS crisis.

PIP: This article reviews the evidence of an emerging AIDS crisis in Russia and highlights the urgent need for comprehensive HIV prevention efforts in Eastern Europe. It is apparent that there are several HIV epidemics in Russia. Epidemiological data can attest to the multiple modes of HIV transmission in the country, and particularly among young people engaging in heterogeneous patterns of risk behaviors. In addition, HIV genotype research confirms that multiple HIV epidemics are simultaneously emerging in the country. Such research also shows that complicated social forces are advancing HIV sub-epidemics. Enabling factors propagating HIV epidemics include biological and social co-factors, particularly drug use, sexually transmitted diseases, sexual mixing patterns, economic instability, gender roles, and poverty. Wide scale public health education and AIDS awareness campaigns, specialized prevention outreach, social marketing, risk reduction counseling, and prevention policy initiatives directed toward communities and population segments at highest risk for infection are recommended to help curb the HIV epidemic.

Roll Back Malaria: spotlight on Africa.

PIP: Africa is the continent most severely affected by malaria. It is for this reason that the Roll Back Malaria (RBM) initiative has Africa as its main focus. This article examines the efforts, strategies and achievements of RBM in malaria prevention in Africa. It is shown that under the RBM banner two countries from Africa were able to report, by the end of 1999, adequate preparedness for anticipated malaria epidemics in the second quarter of 2000. Four other countries have pushed forward accelerated malaria control activities to cope with the complex emergency situations, and at least 10 others are in the process of doing so. In the field of research, RBM has collaborated with the UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases (TDR) to work on a number of areas such as product research and home management of malaria. On the other hand, it is noted that the Abuja Plan of Action promotes strengthening of research in particular, development of vaccines and exploration of traditional methods for malaria.^ieng

Modelling AIDS reduction strategies.

BACKGROUND: Mathematical models of the AIDS epidemic have not been able to give accurate predictions about the size of the epidemic because it is not possible to obtain sufficiently accurate measurements of the factors that enable HIV transmission. The uncertainties inherent in models of the AIDS epidemic appear to limit their relevance to epidemiologists. However, it is shown here that the uncertainties need not prevent models being used to make reliable decisions about which preventive strategy will be most effective. METHOD: A range of strategies are simulated in a model of the AIDS epidemic. The simulations are repeated as the value of what seems to be the most important uncertain factor, is varied. The effect of this variation on the effectiveness of each strategy is noted. In principle, the process could be repeated whilst all other uncertain factors are varied as well. RESULTS: Although varying one uncertain factor created enormous variation in the size of the epidemic, it is remarkable that for most preventive strategies the relative effectiveness of the strategies was barely altered. Hence for the most part the ranking of strategies in order of effectiveness is not affected by the area of uncertainty explored here. The results also highlight the potential effectiveness not only of general condom promotion, but also the use of circumcision and spermicides and general screening or targetted screening in sexually transmitted disease clinics. CONCLUSIONS: Epidemiological modelling may accurately rank the effectiveness of interventions although it may fail to predict the size of the epidemic.

Epidemics: models and data.

"The problems of understanding and controlling disease raise a range of challenging mathematical and statistical research topics, from broad theoretical issues to specific practical ones. In particular, recent interest in acquired immune deficiency syndrome has stimulated much progress in diverse areas of epidemic modelling, particularly with regard to the treatment of heterogeneity, both between individuals and in mixing of subgroups of the population. At the same time better data and data analysis techniques have become available, and there have been exciting developments in relevant theory.... This progress in specific areas is now being matched by interdisciplinary cooperation aimed at elucidating relationships between the widely varying types of model that have been found useful, to determine their strengths and limitations in relation to basic aims such as understanding, prediction, and evaluation and implementation of control strategies."

Long-run impacts of AIDS.

"Over the next century, the impact of the AIDS epidemic on the supply of and returns to factors of production may be significant. Public policies might offset some of the long run impacts, especially if initiated early in the epidemic. History suggests the types of economic effects that can occur in the long run and the limits of public policies' effectiveness in controlling diseases of this type. The models developed here to show possible long run time paths for the epidemic also imply a long-run equilibrium, a concept not appreciated in most disciplines. Because data deficiencies make long run numerical forecasting highly controversial, this paper uses history and modeling to emphasize qualitative understanding of the epidemic."

The road to health.

This article is published as a tribute to Professor Thomas McKeown, the eminent epidemiologist, who died in 1988 aged 75. In it the author urges that the spread of services comprising primary health care be arranged in strict order of priority. Since improvements in nutrition have a particularly profound effect on health they should be the primary aim of developing countries.

PIP: Research programs in developing countries show no priorities. The World Health Organization (WHO) has promoted primary health care (PHC) and the experience of the developed countries and the developing countries is the same namely that the health improvement was due to a reduction of deaths from infectious diseases. The direct reasons for this are: 1) increased resistance; and 2) reduced exposure. Indirect influences include fertility control and advances in primary and secondary education. Economic prosperity is not always essential. Equity of access to the health determinants was important, as was the social and political will to bring about health improvements. Food is a major influence on health. People must have enough to eat. Many countries do not have enough food. Supplies are insufficient to provide everyone with an adequate diet. Several countries which do produce enough food for their populations cannot meet unstable world prices. The food available is often unevenly distributed, between countries and within them. In 1987, 50% of the children of the world were protected against tetanus, poliomyelitis, whopping cough, diphtheria, tuberculosis, and measles; 10 years earlier, it had been 5%. By the year 2000, poliomyelitis should be eradicated; deaths from neonatal tetanus should disappear, and measles mortality should be reduced by 95%. Diarrhea is serious in children. Attempts are being made to treat it with oral rehydration therapy (ORT). It is also necessary to prevent transmission of germs that cause diarrhea. In Africa, before 1950, the population growth rate was over 1% per year. Today is it 3%, on average. Many epidemic plagues have lost their demographic import. UN estimates show that world population, now 5 billion, will be 6 billion by 2000, 8 billion by 2025, and 10 billion when it stabilized in 2100. A consequence of demographic trends is the movement of people, not only from 1 country to another, but from rural to urban areas within a country. The setting of population goals is a sensitive issue.

AIDS in Asia and the Pacific.

PIP: Acquired immune deficiency syndrome (AIDS) has been an African and Western concern due to its epidemic nature. Although nearly 99% of all reported cases occurred in these regions, Asia has reported cases, and the potential for devastation of Asia's already strained health care reserves are undeniable. This review compiled by analysis of 1986-88 articles on AIDS research, demographics, official statements from government and health organizations, news reports, and public statements describe how AIDS has spread in well documented regions like America, Europe, and Africa, and how the Asian regions have attempted to handle the AIDS epidemic before it becomes as serious as in the West. The topics covered include a clinical overview of how human immunodeficiency virus (HIV) causes AIDS, how it is transmitted, and what are the primary forms of transmission in well documented regions. The report briefly documents what policies China, Hong Kong, Japan, Republic of Korea, Taiwan, Philippines, Thailand, Singapore, Malaysia, Indonesia, India, Sri Lanka, Bangladesh, Nepal, Pakistan, Australia, and New Zealand have individually instituted to stem the flow of AIDS into their country, and/or stop the spread of AIDS already found there. The efforts to combat AIDS globally by the World Health Organization/United Nations Development Program alliance (WHO-UNDP) along with the US Agency for International Development (USAID), and UNICEF are highlighted. The available research and aid programs are contrasted with how the Asian nations are preparing to deal with the AIDS epidemic. 1) AIDS has an incubation time wherein an infected individual is not AIDS symptomatic, but is capable of infecting others, and this hidden infected population makes it essential that containment policies are also enforced in countries with few reported cases. 2) A committee should be established in all Asian countries to coordinate education on safe sexual behaviors with specific programs for prostitutes, intravenous drug users, and prison inmates. 3) HIV testing of foreigners and students returning from abroad was discouraged due to its logistic impracticality and consumption of health resources. 4) AIDS education in the schools and sterile needle distribution to drug addicts was encouraged.^ieng

Seroepidemiology of human immunodeficiency viruses in Africa.

The first generation of serological tests for anti-HIV-1 gave so many false positives with African sera that it was wrongly postulated that the virus was endemic in Africa. As there is no simian or other virus sufficiently closely related to HIV-1 as to suggest a recent common ancestor, the evolution of HIV-1 is obscure and there is no current evidence to support the hypothesis of an African origin. However, the similarity of HIV-2 to SIV and its geographical distribution do suggest an evolution of this virus in west Africa. The earliest anti-HIV-1 positive serum was from a subject in Kinshasa in 1959. Seroprevalence rose in pregnant women in Kinshasa from 0.25% in 1970, to 3.0% in 1980 and 5.7% in 1986. When two sexually promiscuous groups are compared, seropositivity rose sharply in female prostitutes in Nairobi from 4% in 1981, to 59% in 1984 and 64% in 1986, a curve which is approximately parallel to, but three years later than that of homosexual males in San Francisco. In central and east Africa, HIV-1 is now epidemic from Congo to Kenya and from Uganda to Zimbabwe. In west Africa, both HIV-2 and HIV-1 are epidemic: seroprevalence of HIV-2 is highest in southern Senegal, Guinea-Bissau and Côte d'Ivoire: HIV-1 has the highest frequency in Côte d'Ivoire and Ghana. HIV-2 has not been reported, and HIV-1 is pre-epidemic in Africa north of the Sahara, Nigeria, Angola, Mozambique and southern Africa, being found at significant frequency only in female prostitutes, patients with STD, or, in Morocco and South Africa only, in male homosexuals. Seroprevalence is greatest in female prostitutes and patients with STD: infection is more frequent in urban than in rural populations, except in Uganda. The peak frequency is at 30-34 yr in males and 20-24 yr in females. Other groups at risk are infants born to infected mothers, and those requiring blood transfusions, especially pre-school children, patients with sickle-cell disease and pregnant women. The doubling time for seropositivity is about one year in the sexually active age range in some populations. Even at existing seroprevalence, decimation or worse of the most productive age groups is inevitable during the next few years in certain countries.(ABSTRACT TRUNCATED AT 400 WORDS)

PIP: The 1st generation of serological tests for anti-HIV-1 gave so many false positives with African sera that it was wrongly postulated that the virus was endemic in Africa. As there is no simian or other virus sufficiently closely related to HIV-1 as to suggest a recent common ancestor, the evolution of HIV-1 is obscure and there is no evidence to support the hypothesis of an African origin. However, the similarity of HIV-2 to SIV and its geographical distribution do suggest an evolution of this virus in west Africa. The earliest anti-HIV-1 positive serum was from a subject in Kinshasa in 1959. Seroprevalence rose in pregnant women in Kinshasa from 0.25% in 1970 to 3.0% in 1980 and 5.7% in 1986. When 2 sexually promiscuous groups are compared, seropositivity rose sharply in female prostitutes in Nairobi from 4% in 1981 to 59% in 1984 and 64% in 1986, a curve which is approximately parallel to, but 3 years later than that of homosexual males in San Francisco. In central and east Africa, HIV-1 is now epidemic from Congo to Kenya and from Uganda to Zimbabwe. In west Africa, both HIV-2 and HIV-1 are epidemic; seroprevalence of HIV-2 is highest in southern Senegal, Guinea-Bissau, and Cote d'Ivoire: HIV-1 had the highest frequency in Cote d'Ivoire and Ghana. HIV-2 has not been reported, and HIV-1 is pre-epidemic in Africa north of the Sahara, Nigeria, Angola, MOzambique, and southern Africa, being found at significant frequency only in female prostitutes, patients with STD, or, in Morocco and South Africa only, in male homosexuals. Seroprevalence is greatest in female prostitutes and patients with STD; infection is more frequent in urban than in rural populations, except in Uganda. The peak frequency is at 30-34 years in males and 20-24 years in females. Other groups at risk are infants born to infected mothers, and those requiring blood transfusions, especially preschool children, patients with sickle cell disease, and pregnant women. The doubling time for seropositivity is about 1 year in the sexually active age range in some populations. Even at existing seroprevalence, decimation or worse of the most productive age groups is inevitable during the next few years in certain countries. Accelerated progression of the disease during pregnancy will lead to higher morbidity and mortality among fertile women than among men. The recent reductions in infant and childhood mortalities will be reversed, and populations may decline. Devastating social, economic, and demographic consequences are forecast. (author's)

The epidemiology of diarrhoeal diseases.

PIP: This article offers quidelines to health officials on determining whether diarrhea is a major problem in a given area, evaluating the effectiveness of a program for combating diarrheal diseases, and identifying the onset of a diarrhea epidemic. Data recorded at sick-children consultations can be used to determine trends and seasonal variations in diarrhea; however, such statistics omit untreated cases. To combat this problem, a home survey covering a representative sample of all children under 5 years of age should be established. A count is made of the number of children under age 5 years, the number of cases of diarrhea during a 2-week period, the number of treated cases, the number of cases treated by oral rehydration salts, and the number of hospitalized cases. Also calculated is the overall mortality rate for children in the sample and the rate of mortality from diarrhea. The effectiveness of a diarrhea control program can be evaluated by analyzing trends in the curve of incidence of diarrhea over time and in the proportion of children seen in a state of obvious dehydration or requiring hospitalization. Comparison of weekly observations of diarrhea incidence with average weekly figures over the past 2 years can indicate whether an epidemic is beginning. If a dramatic rise in the number of cases is observed, it must be determined whether the cases all come from the same area or if all cases participated in a common activity such as a festival.^ieng

Whooping cough and whooping cough vaccine: the risks and benefits debate.

PIP: There has been extensive debate in Great Britain regarding the risks and benefits of routine infant immunization against whooping cough. As a result of highly publicized cases of brain damage alleged to have been caused by the vaccine, immunization acceptance rates have dropped dramatically and epidemics of the disease have recurred. On the basis of a review of the current state of knowledge on whooping cough, the vaccine, and vaccine safety, the authors conclude that the dangers of the disease outweigh any known hazards of the vaccine. Although whooping cough is less important a cause of death and disability at present, it remains a potentially lethal disease that should be controlled. The safety of the vaccine is an especially critical question, however, since it is being advocated for use on a mass scale in previously healthy children. The results of studies such as the National Childhood Encephalopathy Study suggest DPT vaccination is associated with a greater frequency of acute neurological illnesses than would be expected by chance. On the other hand, most cases of such complications were not time-associated with DPT vaccination and may have resulted from the less purified vaccines used in the past. The most critical element in decision making is the readiness of parents and doctors to accept the fact that active preventive measures such as pertussis immunization sometimes carry unavoidable risks that have to be weighed against the risk of nonintervention.^ieng

The epidemiology of poliomyelitis: enigmas surrounding its appearance, epidemicity, and disappearance.

PIP: The emergence of a debate in the US regarding poliomyelitis immunization practices makes it important to examine unresolved issues about the epidemiology of this disease. The literature suggests that poliomyelitis initially appears as a disease of preschool children, but then there is a trend toward increasing age of cases. Age differences in the case: infection ratio do not appear to have a consistent, predictable impact on overall incidence. The appearance of epidemic poliomyelitis is assumed to have resulted from a reduction in levels of maternal antibodies as booster reinfections became less common, a reduction in the frequency of antibody levels sufficient to produce cross-protection between virus types, and an increase in the average age of primary infections. The relative importance of virus virulence and of elevated infection rate in the production of epidemics remains unknown. The use of poliovirus vaccine in the US has reduced paralytic disease from an annual incidence of about 10,000 cases to 10 cases. The eradication of poliomyelitis in spite of the fact that no more than 90% of US children have been reached indicates that either vaccine virus has spread to the unimmunized or a herd immunity effect is operating and the resultant disappearance of wild poliovirus prevents exposure of the unimmunized. The unexpected eradication of natural poliomyelitis in the US has raised the problem of vaccine-associated disease when oral vaccine is used. Since oral poliovirus vaccine appears to have provided protection through herd immunity, any change in immunization practices that might increase the exposure of susceptibles should be undertaken with great caution. Evidence of repeated importations of wild poliovirus emphasizes this concern. If inactivated vaccine is seriously considered for primary immunization, it should be followed by reimmunization with oral vaccine.^ieng

Smallpox eradication in West and Central Africa.

PIP: The history of smallpox eradication in the 20 countries of West and Central Africa from Mauritania to Zaire is recounted, including background, evolution of strategy, assessment, maintenance, costs, and significance of the campaign. Smallpox was endemic in these countries, peaking each year at the end of the spring dry season, usually occurring in isolated villages only periodically. The average case fatality was 14.5%, but twice as high in infants and older adults. Clinical exams showed that those with actual vaccination scars rarely got smallpox. The campaign was made feasible because of lyophilized heat-stable vaccine and bifurcated needles or jet injectors. The initial strategy called for mass vaccination and assessment of achieved vaccination. Between 1967 and 1969 100 million persons were vaccinated at collecting points; by 1972, 28 million more children had been protected. In 1966 an outbreak of 34 cases in Nigeria was blocked within 3 weeks of initiation of surveillance and containment. This effort also demonstrated that actual smallpox transmission was slow and relatively ineffective, and further that vaccination of contacts even after exposure was effective. The strategy was replaced by surveillance-containment begun in the seasonal low. The results were that smallpox disappeared within 5 months in an area of 12 million, and within 1 year in 19 of the 20 countries. Maintenance vaccination to prevent importation of the virus is continuing. The cost of the program was $15 million to the U.S. sponsors, or 1/10 the yearly price of smallpox control in the U.S.^ieng