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Rheumatic Fever/Rheumatic Heart Disease.
Magnitude and results from some prevention programmes
Dr. Porfirio Nordet, MD, DSc.
Cardiovascular Disease Programme, World Health Organization
Rheumatic fever/rheumatic heart disease (RF/RHD) is the most common cardiovascular disease in children and young adults and remains a major public health problem in developing countries. It results in high costs because of repeated hospitalizations (often resulting in premature death or disability), the necessity for increased resources to support the medical and surgical treatment of large numbers of patients, and suffering caused to patients and their relatives.1-6
Rheumatic Fever/Rheumatic Heart Disease (RF/RHD) was a devastating childhood disease in economically developed countries in the 19th century. RF incidence began to decline in these areas slowly but steadily after 1900 and became much more pronounced after the 1940s. In contrast, RF/RHD was believed to be a rare disease in tropical and sub-tropical countries during the 19th century. However, since the 1940s it has become a significant health problem in these regions, and often with very severe effects similar to those observed in Europe a century ago.1
Pharyngitis/sore-throat is common throughout the world, especially during childhood. It has been estimated that every child has at least one episode per year and that during endemic conditions GABHS can usually be isolated from 20-35% of clinically acute sore-throat, in both developed and developing countries. However, relatively few individuals (0.3 to 3 %) contract rheumatic fever after acute streptococcal pharyngitis.1,2,7,8
Appropriate case management of symptomatic streptococcal sore-throat is easy and cost-effective. It is thus important,1,2,4-15 because it can:
- reduce the incidence of suppurative and non-suppurative complications;
- reduce the inappropriate use of antibiotics for upper respiratory infections (when medical information and health education on RF prevention are effective);
- reduce the incidence of symptomatic strep-throat and the average level of streptococcal antibody in the community;
- reduce the infection contagion rate;
- alter the chain of transmission of GABHS and thus diminish the chance of increasing its virulence.
RF/RHD is both a biological and a social problem. Its public health importance is not only a direct result of its high occurrence rates (mortality, prevalence and incidence), but is also due to target population (children and young adults), effects in the community and high costs of medical and surgical treatment, as well as its feasible and cost-effective prevention. It can result in premature death or disability.1,2
In some ways, rheumatic fever can be regarded as a "social" disease: liked to poverty, overcrowding, poor housing conditions and inadequate health service. It declines sharply when the standard of living is improved.1-6
II. Magnitude and Characteristics
The mortality, incidence, prevalence and severity of RF/RHD show a wide variation, not only amongst different countries, but amongst different areas of some countries.1-4
Today in developed countries, the occurrence of RF/RHD is nil or very low, with an incidence below 5.0 per 100 000 per year, a prevalence below 0.5 per 1000 schoolchildren and a low mortality rate,1-7 although recent data from former Yugoslavian and Soviet republics show a high mortality.16,17 In contrast, since the 1940s RF/RHD has become a significant health problem in tropical and subtropical countries.1-7
* There are one to two cases of inactive RF for each RHD case.
° In most countries more than 50% of the cases are unaware of their
disease and do not receive secondary prophylaxis.
In developing countries with available data, the RHD mortality rate varies from 0.9 to 8.0 per 100000 population, with higher rates in Easter Mediterranean countries. Children and young adults still die from acute RF. Prevalence in schoolchildren ranges from 1.0 to 15 per 1000, higher in EMRO, AFRO and WPRO countries, and incidence ranges from 10 to 100 per 100 000, higher in EMRO and AFRO, with a high rate of recurrence attack and severity. RHD ranges from 12 to 65 per 100 of all cardiac patients admitted to hospital. In most developing countries, more than 50% of RF/RHD patients are unaware of their disease and do not receive secondary prophylaxis. (Figure I to IV).1-7
To date, we can assume a conservative estimate of 12 million people affected by RF/RHD, with more than 2 million requiring repeated hospitalization and 1 million requiring heart surgery in the next 5 to 20 years. There are 500 000 deaths annually, and hundreds of thousands of people disabled, mainly children and young adults, who have no access to the expensive medical and surgical care that RHD demands. (Figure V).16-17
However, the small outbreaks of RF which occurred in the mid-1980s in some cities of the USA and other countries, and the recent and well documented worldwide resurgence of severe infections with virulent streptococci has clearly demonstrated that streptococcal infections and their sequelae can not be considered as a disease which will disappear only with improved living standards and better access to health facilities; RF/RHD needs adequate medical and public health approaches.1,4-7
RHEUMATIC FEVER / RHEUMATIC HEART DISEASE
An estimated of 12 million people are affected
More than 2 million require repeated hospitalization
One million will require heart surgery within the next 20 years
500 000 deaths occur annually
Thousands of people are disabled
Most patients are children and young adults
Results from selected programmes on the prevention and control
Since the late 1940s several programmes have been implemented in different countries including RF/RHD registers, follow-up and secondary prophylaxis, as well as some comprehensive programmes on the prevention of RF/RHD integrated into the health care system and facilities of the country (Figure VI X). Such programmes have resulted in decreases in mortality, prevalence, incidence, hospital admissions and severity of RF/RHD. It should be emphasized that secondary prophylaxis is useful even if not given according to a completely regular schedule, though its efficacy declines as fewer injections are given. Patients out of secondary prophylaxis have a high recurrence rate (5.5 to 25.0% of patient-years) and severe RHD.1-7,11-14,18-28
There is, as yet no available any safe and effective anti-rheumatic streptococcal vaccine nor a genetic marker to identify people at high risk of developing RF. In the meantime, Ministries of health in all countries where RF/RHD is a problem, as well as nongovernmental organizations and donor agencies are urged to intensify their prevention efforts applying a cost-effective (1,3,22,23) secondary prevention programme, and a primary prevention approach whenever feasible (1-3,20,24,25,26).