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).