|Year : 2020 | Volume
| Issue : 1 | Page : 27-36
Rheumatic heart disease in Nigeria: A review
Okechukwu S Ogah1, Fidelia Bode-Thomas2, Christopher Yilgwan2, Olukemi Ige2, Fisayo Ogah3, Oluwatoyin O Ogunkunle4, Chimezie Okwuonu5, Mahmoud Sani6
1 Division of Cardiology, Department of Medicine, University of Ibadan, Oyo State, Nigeria
2 Department of Paediatrics, University of Jos, Plateau State, Nigeria
3 Department of Chemical Pathology, University College Hospital, Ibadan, Nigeria
4 Department of Paediatrics, College of Medicine, University of Ibadan, Ibadan, Oyo State, Nigeria
5 Department of Internal Medicine, Federal Medical Centre, Umuahia, Abia State, Nigeria
6 Department of Medicine, Bayero University, Kano, Kano State, Nigeria
|Date of Submission||17-Nov-2019|
|Date of Acceptance||21-Nov-2019|
|Date of Web Publication||30-Jun-2020|
Dr. Okechukwu S Ogah
Department of Medicine, Division of Cardiology, University of Ibadan/ University College Hospital, P.O Box 14343 ,UI Post Office Ibadan, Oyo State
Source of Support: None, Conflict of Interest: None
Rheumatic heart disease (RHD) is a major public health problem in resource-poor countries, especially in sub-Saharan Africa where about 1 million affected children between 5 and 14 years of age live with the disease. The aim of this paper is to review current knowledge on the clinical epidemiology of RHD in Nigeria, identify gaps, and suggest possible future directions. A systematic literature search was conducted using African Journal online (AJOL), Cinahl, Google Scholar, PubMed, and Web of Science. In PubMed, the following medical subject headings and free text terms were used: “Rheumatic heart disease” OR “Rheumatic “Valvular heart disease” OR “Rheumatic fever” AND “Nigeria”. The same text word search was used in Google scholar, AJOL, CINAHL, and Web of Science. A search date was limited to articles published from January 1950 to December, 2018. A total of 44 original studies were reviewed. Nineteen (45.2%) of the studies used clinical criteria for diagnosis of RHD, 19 (40.5%) used echocardiographic diagnosis, and 6 (14.3%) used autopsy or post mortem examination of the patients for the diagnosis of RHD. Five (11.9%) of the studies were conducted in children only, 9 (16.7%) were in both children and adults, and the remaining 31 (73.8%) were done in adults only. Only 6 (14.3%) of the studies reported complications seen in patients with RHD. Of the 6 studies that reported on complications, only 1 reported on recurrent of acute rheumatic fever. Mitral valvular disease was the most common lesion reported in all the studies. RHD still remains a major cardiovascular health problem in Nigeria. There is therefore a need for more recent clinical studies on the contemporary pattern of RHD in Nigeria. In addition, community based screening for RHD is needed to determine the true burden of the disease in Nigeria. Finally, primary and secondary preventive measures are needed to help reduce the burden of RHD in Nigeria.
Keywords: Heart disease, Nigeria, rheumatic fever, rheumatic heart disease
|How to cite this article:|
Ogah OS, Bode-Thomas F, Yilgwan C, Ige O, Ogah F, Ogunkunle OO, Okwuonu C, Sani M. Rheumatic heart disease in Nigeria: A review. Nig J Cardiol 2020;17:27-36
|How to cite this URL:|
Ogah OS, Bode-Thomas F, Yilgwan C, Ige O, Ogah F, Ogunkunle OO, Okwuonu C, Sani M. Rheumatic heart disease in Nigeria: A review. Nig J Cardiol [serial online] 2020 [cited 2020 Aug 5];17:27-36. Available from: http://www.nigjcardiol.org/text.asp?2020/17/1/27/288651
| Introduction|| |
Rheumatic heart disease (RHD), a disease of social disadvantage, is a clinical condition caused by rheumatic fever (RF); an autoimmune reaction to infection with Group A beta-hemolytic streptococcus. Although infectious in origin, RHD is now recognized as a chronic noncommunicable disease. This is because RHD, a disease characterized by severe valve damage, usually leads to chronic heart failure (HF), chronic atrial fibrillation (AF), and thromboembolic complications such as stroke.
It is estimated that 33 million people have RHD worldwide., Furthermore, approximately 319,400 individuals died from RHD in 2015, while about 471,000 new cases were diagnosed annually. RHD is also the most common cause of cardiovascular disease (CVD) in young people aged 25 years or below, majority of whom live in Africa, the South Pacific, Middle East, Central, and South Asia. It afflicts them in their most productive years with associated high mortality and high disability-adjusted life years. It is also a major contributor to maternal and perinatal mortality in the aforementioned regions. RHD was once common in high income countries, however by the 1980s, the condition had been almost eliminated in these countries.
The lesson from high-income countries and some developing countries is that the disease can be controlled through comprehensive, register-based RHD control programs. The World Health Organization has launched a 25 × 25 <25 campaign which calls for multisectoral action to reduce premature CVD mortality by 25% by the year 2025. The global body is optimistic that within this adopted framework, the mortality associated with RHD can be reduced by 25% by 2025 for individuals under the age of 25 years (25 × 25 <25).
In Nigeria, the true burden of the disease is not known, and there is limited population based data for informed decision-making. According to WHO, the country belongs to the group of countries where it is estimated that between 1000 and 4999 people died from the disease in 2002.
The aim of this paper is to review current knowledge on the clinical epidemiology of RHD in Nigeria, identify gaps and suggest possible future directions.
| Methods|| |
A PubMed search was conducted from January 1, 1950, to December 31, 2018. The search criteria adopted were “Rheumatic Heart Disease,” “Valvular Heart Disease,” “Cardiac Failure,” “heart failure” AND “Nigeria,” Additional publications were sought from references of retrieved articles and other databases such as the African Journals Online and the African Index Medicus, African Index Medicus, CINHL, Google scholar and Web of Science).
The identified papers were classified into: hospital-based clinical studies on diseases leading to HF in Nigeria [Table 1],,,,,,,,, report on echocardiographic registries [Table 2],,,,,,, mortality and autopsy studies [Table 3],,,,,, specific studies on RHD [Table 4],,,,,,,,,,,,,,, and population based studies [Table 5].,,, In many of the publications, cases in children and adults were reported together.
|Table 1: Prevalence of rheumatic heart disease in clinical studies of heart disease/heart failure in Nigeria|
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|Table 2: Prevalence of rheumatic heart disease in echocardiography registries in different parts of Nigeria|
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|Table 3: Prevalence of rheumatic heart disease in autopsy or mortality studies|
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Like high blood pressure, RHD was earlier thought to be uncommon in tropical and subtropical climate., “This assumption was to the extent of patients were being transferred to tropical countries in an attempt to improve or alter the progress of RF or its usual complications.”, Workers in India were the first to report that RHD constituted 20.5% of cardiac related conditions in a tropical/subtropical milieu.,, Thereafter, many investigators in other countries outside India (including Africa) also recognized RHD as an important cause of cardiac morbidity and mortality.,, RHD was recognized as responsible for 12.9%–40% of cardiac admissions in Africa.
The earliest publications on RHD in Nigeria were probably the reports in 1955 by Nwokolo in Eastern Nigeria and 1956 by Beet in Northern Nigeria. Beets examined all cardiac cases admitted to three main hospitals in Northern Nigeria (Kano, Kaduna, and Jos) and reported that RHD was responsible for 23% of cardiac conditions. Probably due to few data from Southern Nigeria at that time, he assumed that the high burden was only peculiar to Northern Nigeria and might not be applicable to coastal areas of West Africa However, subsequent work in Ibadan by Lauckner et al. using an analysis of medical admissions to the University College Hospital Ibadan in 1958, showed that acute carditis was responsible for about 18.7% of all cardiac admissions. Lauckner et al., therefore, concluded that with further experience as well as improved diagnostic facilities at the hospital, RHD was by no means uncommon in Nigeria. This was further reinforced by other workers from other parts of Nigeria.,,,,, The seminal work of Cole and Cole and Adeleye,, Antia and Jaiyesimi,,, at Ibadan, Ogunbi et al. and Fadahunsi et al.,, in Lagos and Okoroma in Enugu shaped our understanding of the clinical characteristics, profile, and natural history of this condition in Nigeria. Recent advances in the diagnosis of RHD, especially with the advent of echocardiography and its widespread availability in Nigeria, has improved our understanding of the epidemiology and spectrum of presentation of RHD.
Peculiarities of rheumatic heart disease in Nigeria
RHD is mainly a disease that begins in childhood. It has its peak incidence in children aged 5–15 years and young adults below the age of 30 years. Affected children in the absence of any intervention, progress to severe disease and eventually die before they reach adulthood. However, where the disease is milder or adequate care is available, affected children live with the disease carrying it into adulthood.
The general pattern of RHD in Nigeria is similar to the established pattern in many tropical and subtropical climates:,,,,,,,,,,, It is highly prevalent in the low socioeconomic class of the population with an infrequent and atypical nature of preceding history of RF in patients with established RHD. It is also associated with an early onset of established rheumatic valve disease and pulmonary hypertension, rapid progression of the disease, and frequent presentation as HF, especially in young adults. Furthermore, the comparatively low frequency of pure mitral stenosis (MS), the predominance of pure mitral regurgitation (MR) and mixed mitral valve lesions and a relatively low frequency of atrial fibrillation (AF) despite the severity of the mitral valve lesion was highlighted by earlier authors [Figure 1].,,,,,
|Figure 1: (a) Pattern of valve lesion in male children and, (b) in female children in Ibadan. Adapted from Jaiyesimi and Antia|
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There are similarities in the presentation of the disease between children and adults in Nigeria though some differences in spectrum exist. In children, the disease mainly presents with chronic HF although anemia, respiratory tract infections and congenital heart disease are more frequent causes of HF in Nigerian children. In adults, our understanding of the disease stems from the retrospective and prospective studies of RHD undertaken by Cole and Ogunlesi in Ibadan in the 1970s and 1980s coupled with studies of heart disease in other centers in the country. RHD was demonstrated to be a common cause of HF in adults presenting to the cardiology clinic and emergency room,,,,, as seen in [Table 1]. This is however no longer the case.,, RHD was also shown to be responsible for 2.4% to 25.6% of diseases leading to adult HF in the country in that era.
In both children and adults, the disease is more common in females with a male to female ratio ranging from 1:1.2 to 1:2.0,,,, The only exception is the small sample reported by Akpa et al. from Port-Harcourt. Women contributed between 50.3% and 70.9% of the burden of the disease in most of the series reported. The reason for higher prevalence in females is not fully known.
In one report, majority (71%) of the patients were in the 6–10 year age group, 10% were aged 3–5 years while those aged 11–15 years constituted 19%. In general, Nigerian children are susceptible to RHD between the ages of 3 and 15 years [Figure 2].,,, In many mixed studies,,, the mean age at presentation ranges from 26.6 to 27.6. years (range 12–70 years) [Table 4]. In a recent review of adult RHD cases in the Abeokuta Heart Disease Registry, a higher mean age of 43 years was reported. [Figure 3] shows age distribution of cases in the Abeokuta Heart Disease Registry.
|Figure 2: The mean age of presentation of childhood RHD and other conditions in Jos Nigeria (Adapted from Bode-Thomas et al.)|
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|Figure 3: Findings in adult patients with Rheumatic fever in Ibadan in 1976 (a), and 1980 (b),|
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Poverty and social disadvantage are important drivers and predisposing factors to the RHD scourge globally. Poverty and social disadvantage drive overcrowding, poor ventilation, malnutrition, poor sanitation and hygiene, and the poor access to healthcare associated with the development of RHD in Nigeria and elsewhere. This was classically demonstrated by Cole et al. in Ibadan where majority of their patients though living in urban and peri-urban areas of Ibadan, were from low socioeconomic quintiles. Similarly, the report by Jaiyesimi and Antia in 1981 on children from Ibadan showed that most of the children (90%) with RHD came from poor homes which were most often over-crowded. The number of siblings per patient ranged from 2 to 14, with a mean of 5. Recent reports still show the predominance of poverty and poverty related factors in families of patients with RHD in Nigeria.
RHD occurs after an episode or recurrent episodes of untreated or poorly treated acute RF. A past history of RF though relevant may not be readily volunteered or even remembered by many patients, especially adults with RHD. In addition, many people, especially children and adolescents affected with RHD present with severe HF as a result of severe valvular insufficiency resulting from chronic inflammation with deformed and fibrosed valvular apparatus, while the adults present with AF and embolic phenomenon in addition to the HF.
Early studies from Ibadan demonstrated previous history of RF in about 26% of the children studied, while 16% had fever, carditis, and raised anti-streptolysin–O (ASO) titer. Only about 8% had migratory polyarthritis while chorea and subcutaneous nodules were seen in only one patient of the 80 consecutive cases studied in the Ibadan series by Jaiyesimi and Antia. Three quarters of the children presented in NYHA classes III and IV. Only 6% and 19% presented in NYHA classes I and II, respectively.
Three quarters of the children presented in NYHA classes III and IV. Only 6% and 19% presented in NYHA classes I and II, respectively [Figure 4]. According to Antia, the possible explanations for the apparent rarity of RF included late presentation when the signs would have disappeared, custom, ignorance, traditional beliefs and socio-economic status of the people. Due to ignorance, parents may not relate the symptoms of HF in their children with any past history of RF. Some would deliberately withhold information of past history for fear of being scolded for not seeking medical care early.
|Figure 4: The age distribution of RHD patients in the Abeokuta Heart Disease registry|
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Traditional beliefs often underlie the lack of faith in orthodox medical treatment. Parents of these children sought the advice of traditional healers first, and only resorted to orthodox care after exhausting other options. According to Antia, the Nigerian environment might also have played a role, as fever is often first treated as malaria, and joint swellings as cases of trauma.
Previous history of RF was obtained in 67 (41%) of 163 adult patients prospectively studied in Ibadan. Recurrence of rheumatic activity occurred in 60 (36.8%) cases. Those with evidence of active rheumatic activity were also found to be younger (mean age 18.4 years, range 12–35 years). Poly- or monoarthralgia were more common (rather than objective polyarthritis) with clinical evidence of active carditis.
According to recent data from Abeokuta, southwest Nigeria, most patients presented in advanced HF (NYHA functional class III and IV); 73.9% of patients were in NYHA classes III and IV. Only about 5% could recall having symptoms suggesting RF in the past and 8% had previous history of HF.
The common symptoms at presentation include cough (87.9%), easy fatigability (50.5), dyspnea on exertion (100%), orthopnea (100%), and paroxysmal nocturnal dyspnea (74.8%). Other symptoms include leg swelling (74.8%), palpitation (33.6%), chest pain (50.5%), hemoptysis (16.8%), and fever (7.5%). In terms of clinical signs, elevated jugular venous pressure (JVP), basal crepitations, displaced apex beat, and third heart sounds were common, occurring in 66.4%, 77.6%, 39.3%, 174.3%, and 5.8%, respectively. Other signs include diastolic murmur (8.4%), hepatomegaly (74.8), splenomegaly (8.4%), and ascites (33.6%).
Hospitalization in adult RHD in Nigeria is often precipitated by uncontrolled AF (25.8%), active rheumatic activity, superadded chest infection, infective endocarditis, pregnancy and cerebrovascular events. In the series by Onwuchekwa in Maiduguri (North Eastern Nigeria), about 28% presented during pregnancy while four percent presented with stroke.,
Pattern of valve disease
Pure MR is by far the most common valvular lesion in most adult series in Nigeria. It is responsible for 35% of cases. This is followed by mixed mitral value disease and pure MS in the order of frequency,,,, [Table 5] and [Figure 1].
The earlier clinical studies reported in Nigeria have consistently showed a predominance of mitral valve involvement similar to what has been reported globally. This trend has not changed over the years even with the advent of echocardiographic diagnosis, a tool which has improved the case detection of RHD thus improving our understanding of the spectrum and pattern of the disease. Jaiyesimi and Antia in their study of 86 children aged 3–15 years in the Ibadan, reported that single valve lesions (pure MR or MS) constituted about 59 (67%) of the cases while double valve lesions (MS/MR, MR/tricuspid regurgitation [TR], MR/aortic regurgitation [AR] and AR/aortic stenosis [AS]) were seen in a quarter. Triple disease (MR/MS/TR) and quadruplet lesions (MR/MS/AR/AS) were each recorded in 21 (24.4%) of cases. The remaining 6 patients had more than 2 valves involved.
Early onset of MS and rapid progression to HF was common. Earlier authors had attributed this to the predisposition of Africans to forming keloids. On the contrary, it has been shown that histological features of keloids and stenosed mitral valves are different.,,
The best explanation is that intense host reactions and recurrent RF were the major determinants of accelerated MS. In the series by Jaiyesimi and Antia, there was a relative excess of MS in children with recurrent RF. Higher ASO titres were also documented even in those patients with MS who did not have a recurrence.
Rheumatic heart disease and pregnancy in Nigeria
In the series by Onwuchekwa and Ugwu in Maiduguri, 28.3% of the patients presented in pregnancy. In an early study of HF and pregnancy at the Ahmadu Bello University Teaching Hospital, Kaduna, North Western Nigeria and Abengowe reported that RHD was responsible for 30.6% of cases, 53.3% presented in the postpartum period while the rest antepartum. MR accounted for 66.7% of the valve lesions. In an early study of HF and pregnancy at the Ahmadu Bello University Teaching Hospital, Kaduna, North Western Nigeria, Abengowe reported that RHD was responsible for 30.6% of cases, 53.3% presented in the postpartum period while the rest presented antepartum. Others included pure MS (6.7%), double valve lesions (MS/MR or MS/ AR) (20%), and triple lesions (MS/MR/AR) (6.7%). Majority presented in NYHA functional classes III/IV.
Cole and Adeleye at Ibadan studied 44 pregnancies in 32 Nigerian women between the ages of 16 and 38 years (mean 27 years) with RHD. Majority of the women were gravida three, but were closely followed by the primigravidae. Pure MR was the most common valve lesion encountered. Acute pulmonary edema was common, occurring in 11 patients and which was responsible for 2 of the 3 maternal deaths. Congestive cardiac failure was the second commonest presentation (in 7) and infective endocarditis occurred in 4 patients. The third maternal death was in a woman with mitral valve prosthesis who was also on warfarin. The major precipitating factors for HF include infective endocarditis, AF with uncontrolled ventricular rate, anemia, and chest infection. In the series reported by Abengowe, congestive HF was more common than acute pulmonary edema. The perinatal mortality was 11/1000 and average birth weight was 2.7 kg, but there were five cases of low birth weight babies. At 6 months' postpartum, there was evidence of progression in eight cases. [Figure 4] shows the cardiac complications in the Ibadan series.
Diagnosis of rheumatic heart disease
The diagnosis of RHD in Nigeria has evolved over the past several decades since the early cases were reported. While clinical and autopsy diagnostic tools predominated in the early reports, current reports use mainly echocardiography in making diagnosis thereby improving our knowledge and understanding of the disease.
In [Table 3], the prevalence of RHD in autopsy/morbidity studies is presented, with the prevalence of RHD ranging from 7.5% to 17.1%.
As shown in [Table 2] which represents the burden of RHD in various echocardiography registries in the country, the prevalence of RHD ranges from 2.5 to 38.5. It has to been noted, however, that in many of the studies, there is a mixture of adults and children.,,,
Congestive HF is by far the most common complication in Nigerian children (88%). Others include pulmonary hypertension (45%), bacterial endocarditis (14%), and AF (11%) [Table 6]. Intramural thrombosis and superior vena cava occlusion were reported in 2.5% and 1.3%, respectively, in the Ibadan series.
|Table 6: Spectrum of complications/mode of presentation reported from different centres in Nigeria|
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The spectrum of complications in various adult studies in the country is also shown in [Table 6]. Congestive cardiac failure is by far the most common complication. This is the mode of presentation in over 80% of cases in Abeokuta. Pulmonary hypertension is common occurring in 54.2%–72.1% of adult RHD in the country. Others include AF (10.1%–25.8%), infective endocarditis (4.7%–14%), stroke (1.1%–4.2%), intramural thrombosis (2.3%–2.8%), and valvular cardiomyopathy (31.8%, reported in only one study).
About 20% of children with RHD die within 6 years of onset of the illness. About half of the deaths occurred within the 1st year. Most deaths occurred as a result of HF or bacterial endocarditis.,,,
In a reassessment of 25 children with RHD who were followed up for up to 4 years, Jaiyesimi and Antia noted that compared to their initial status, 20% of them had improved, 32% remained about the same while 48% had deteriorated.
The authors went further to prospectively study 48 Nigerian children (22 males and 26 females, aged 3–15 years; mean 8 years) with established RHD to determine the factors that influenced prognosis in a 3-year follow-up period. They reported that at the end of the 3-years, 12 (25%) had improved, 14 (29%) remained the same while 22 (46%) had deteriorated or died.
A poor socioeconomic status, delays in seeking medical care, and recurrence of the RF were associated with poor prognosis, as were the presence of MS, multiple valve lesions, presence of elevated pulmonary pressure, bacterial endocarditis, and pulmonary embolism. Outcome was not affected by age, gender and PR-interval.
The authors concluded that in “developing countries where primary prevention of RF might be vitiated by poverty, ignorance and scarcity of health facilities, the prognosis in childhood RHD can be improved by simple and relatively inexpensive measures like health education, effective SBE prophylaxis and prevention of recurrent ARF. Mitral valvotom, where feasible can improve not only the chances of survival of but also the quality of life in children with disabling mitral stenosis.”
Economic cost of rheumatic heart disease in Nigeria
Chronic RHD is associated with huge financial burden on the families of affected children. It renders a large proportion of children physically and educationally handicapped and therefore deprives the country of potential skilled workforce.
Jaiyesimi assessed the cost of medical care of 20 patients with RHD seen at the UCH, Ibadan over a 1-year period. He observed that despite the fact that majority of the children were from poor homes, the caregiver contributed about 4.4% of their annual income in the care of these patients. In addition, the country spends a substantial amount in their care and that the total costs of treating one patient medically for 12 months could have prevented 4–5 cases of RHD.
Changing face of rheumatic heart disease in Nigeria
In a more recent report of adult patients seen in a tertiary care center over a 9 years period in Oshogbo south west Nigeria, RHD was seen among 11 of the 9,423 patients seen in the medical outpatient clinic giving a hospital-based prevalence of 1.2 per thousand. Similar reports from the southeastern part of the country also showed a low prevalence of RHD pointing to a probability of a declining burden of RHD in Nigeria. But as it is with previous reports, the most common valve affected was mitral (90.9%), followed by the aortic (36.4%), and the tricuspid (18.2%). Mitral and aortic lesions coexisted in 18.2% of the patients. Late presentation was a common phenomenon among the patients seen.
Community screening for rheumatic heart disease in Nigeria
The earliest community based study for RHD in Nigeria was the one reported by Ogunbi et al. in Lagos in 1978 where 12, 755 school children were screened for evidence of RHD. They reported RHD in 11 (7 old and 4 new cases), given a community prevalence of 0.08%. recently, Yilgwan et al. in Jos and Sadoh et al. in Benin used the same clinical screening methods among school children as Ogunbi. Yilgwan et al. found no child with RHD after screening 418 children using cardiac auscultation while Sadoh et al. reported a case of RHD among 1,766 using similar methods. These findings though gladdening may reflect the low sensitivity of the methods used. Echocardiographic screening has been shown to be a more sensitive method for detecting RHD among asymptomatic patients in the community. A community based echo screening for RHD will thus need to be planned as a way to evaluate the true community based prevalence of RHD.
Recently Ekure et al. screened 4107 children (mean age of 11.3 years), 53.7% females in urban and periurban areas of Lagos. They detected 38 children with abnormal echocardiograms, of which 11 (0.27%) showed RHD including two cases of definite RHD giving a prevalence of 2.7/1000 (2.9/1000 in the periurban, 2.4/1000 in the urban area). Echocardiography was reported to detected RHD 10 times better than auscultation (echocardiography 11 (0.27%) vs. auscultation 1 (0.02%); P = 0.003]. The remaining 27 children with abnormal echocardiograms had congenital heart defects (CHD) giving a prevalence of 6.6/1000 for CHD, a yield higher than for RHD.
| Conclusions|| |
RHD still remains a major cardiovascular health problem in Nigeria. There is therefore a need for more recent clinical studies on the contemporary pattern of RHD in Nigeria. In addition, more community-based screening for RHD is needed to determine the true burden of the disease in Nigeria. Finally, primary and secondary preventive measures are needed to help reduce the burden of RHD in Nigeria.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6]