Discussion:
Rheumatic heart disease still constitutes a health problem in low- and middle-income countries in Africa, Middle East, India and Southeast Asia with health, social and economic consequences as it affects children, adolescents and young generation mainly (1). That is why much emphasis should be given by the health system in these developing countries to combat this problem which includes screening not only for the cases but also for subclinical RHD for early detection and identifying patients affected will have an impact on secondary prophylaxis and general health of the country.
In Egypt there is a great concern among medical profession and health care authorities of the still existence of RHD in the country with its unwanted sequalae of morbidity in important section of age of the population. Egypt has 100 million inhabitants and has traditionally good infrastructure primary health care system spread all over the country which encouraged us to plan for nationwide screening for RHD aiming to identify the size of the problem and start a process of secondary prophylaxis in response to WHO statement that a proper health care and secondary prevention are both cost effective and inexpensive and hence reduce the burden of the disease which has been estimated that about 20 million people worldwide diagnosed as RHD and 47000 new cases 233000 deaths annually.
Screening of subclinical RHD using portable echocardiography in developing nations was tested and proved beneficial by many authors as it improves case detection which result in better chances of appropriate prevention of advanced RHD (11).

In agreement with other previous survey studies, the mean age in our study was 12 years of age in the spectrum of age group we studied. The prevalence of RHD was more in male gender than in females in our study in contrast to the study by El-Aroussy et al who reported more definite RHD diagnosis in females than males. This may be contributed to the geographic difference of the two studies and the number recruited in both. The community factors that may contribute to the development of rheumatic fever and hence RHD was claimed to be poverty, high crowding index and parental education among to the region of living either urban or rural. In our study these factors although were studied but were not found to be statistically significant between children who developed RHD and healthy ones (12). In the study by Yacoup et al, they also reported some community factors but were all found non-significant as well (13).
It has been established now from different studies that clinical examination and auscultation is not accurate in detection of RHD and echocardiography study is 10 times more sensitive in case detection than clinical examination particularly in subclinical RHD. This category of patients is recommended to be labeled probable RHD and consideration of secondary prophylaxis. In 2001 WHO had set up criteria to define subclinical RHD using echocardiography and consequently in 2007 auscultation guidelines now consider subclinical valve regurgitation is a major criteria for ARF in endemic area (2). We used the world heart federation criteria for echocardiographic diagnosis of subclinical RHD and by application of morphological valve changes criteria; many children with subclinical RHD but without significant valve regurgitation had been detected which make them eligible for secondary RHD prophylaxis under current international guidelines(11).
We found that definite RHD cases represents 2.3% (4% after adding equivocal cases) of the total number of the echocardiographically screen school children. Though the data about the prevalence of RHD in Egypt is scant; our data was comparable to the most recent data from Northwestern Egypt stating that definite rheumatic valvular disease was documented in 2.2% (6.6% after adding equivocal cases) of the school children by using portable echocardiography screening (12).

Rural vs urban prevalence:
Our findings show that echocardiographic screening of schoolchildren, and particularly urban children, greatly underestimates the true prevalence (rural and urban) of this disease in countries such as Ethiopia. The likely reason for this is that the poverty-related major risk factors for the disease are more prevalent and thus more important in rural areas and are linked with poor school attendance(13).
 We found mitral valve involvement in most of the cases and MR is the commonest lesion (75%) in RHD cases and this goes with data from many authors (14). We didn’t find any MS , this could be explained as we screened children younger than 15 years and the development of MS takes a longer time to develop, but in general this is lower MS incidence compared the previous study in India for school children (up to 16 years of age) where they found MS in 50% of the cases but this may be due to higher incidence of juvenile MS in India as noted in earlier studies (14).

Combined mitral and aortic valve disease, is the second most common lesion representing 25% of diagnosed cases. All TR cases we found were functional unlike the other lesions, which were pathological which is the same found by previous authors. The incidence of aortic valve disease was found to be low (25%) in our study. Routray et al has reported combined mitral and aortic valve involvement as 27%, which is close to our findings. AS also was not found in our study which is the same found by many previous authors (14).
The most recent world heart federation criteria have solved many debates concerning signs early rheumatic heart disease. Application of this criteria may result in higher numbers diagnosed with RHD and less equivocal and borderline cases. Gemechu et al had applied the same criteria during their screening of RHD in rural Ethiopia and accordingly the had less borderline cases compared to previous studies(13). It was also found that diagnosing subclinical rheumatic heart disease is more specific when both Doppler criteria and morphologic valve changes are present (12).
It worth mentioning that echocardiographic screening may face some obstacles such as significant costs, and practitioners would require education and training about echocardiography. But we found that after appropriate training, the use of echocardiography for RHD screening is relatively straightforward not only for cardiologists but also for many non-cardiologist physicians which goes with some previous authors’ recommendations (11).