Rheumatic Heart Disease Study in Lusaka
Condition: Rheumatic Heart Disease
MeSH terms: Rheumatic Heart Disease; Rheumatic Diseases; Heart Diseases
Study type: Observational

Summary: 
      This study will determine the prevalence of rheumatic heart disease (RHD) in Lusaka, Zambia
      through school-based screening methodology using ultraportable echocardiography and a
      recently validated, abridged screening protocol based on World Heart Federation criteria.
      Children that screen positive for RHD at schools will undergo confirmatory evaluation at
      University Teaching Hospital (UTH), Lusaka's main referral hospital.
    

Detailed description: 
      It has been estimated that RHD affects over 32 million people worldwide, with the vast
      majority of cases occurring in the developing world. RHD is the most common cardiovascular
      disease in children and young adults and is a major cause of death in children above the age
      of 5 in many parts of the developing world, particularly sub-Saharan Africa.

      RHD results from repeated attacks of acute rheumatic fever (ARF). ARF is a systemic
      inflammatory disease occurring mainly in children, characterized by fever, painful joints,
      and heart, skin, and neurological manifestations. ARF is linked with preceding Group A
      streptococcal (GAS) throat infections, which, if left untreated, carry an estimated 2-3% risk
      of developing ARF.

      The pathologic hallmark of RHD is classically a valvulitis that affects mostly the mitral
      and/or aortic valves. Inflammation of the myocardium and pericardium may exacerbate the
      effects of valvular insufficiency, resulting in congestive heart failure, stroke and other
      complications. Over time, severe disability or death can ensue, especially in developing
      countries where the management of RHD patients is challenging and surgical interventions are
      not readily available.

      ARF and RHD are diseases of poverty, especially in countries with limited healthcare systems.
      GAS thrives in situations of over-crowding where poor nutrition and sanitation are common and
      where medical treatment for sore throat is not readily available. For these reasons, RHD is
      endemic in many parts of the developing world, particularly sub-Saharan Africa, while it
      almost disappeared from most parts of the developed world (except for indigenous populations
      in some countries). It should be noted that the initial decline of ARF/RHD in the US and
      Europe most likely was due to improved living conditions and hygiene (primordial prevention),
      since it predated the introduction of penicillin.

      RHD is one of few truly preventable chronic diseases. Currently, many sub-Saharan African
      countries do not focus efforts on primary and secondary prevention due to lack of resources.
      The long-term goal of an ongoing effort in Zambia is to develop capability to provide
      effective primary and secondary prevention of RHD, with the ultimate goal of eliminating new
      cases.

      Although RHD is associated with major morbidity and mortality in children and young adults,
      until recently few reliable estimates of the burden from this disease existed in sub-Saharan
      Africa. Population-based screening for RHD had been limited to clinical examination, which
      does not detect early RHD in which a heart murmur or other clinical signs of disease are
      absent (subclinical disease). Estimates of RHD prevalence based on clinical surveillance
      methods compared with screening echocardiography have been shown to result in gross
      underestimates (up to 10 fold).

      With advances in portable ultrasonography and the development of international guidelines for
      echocardiographic diagnosis of RHD, population-based screening for subclinical RHD is now
      possible. Using this new approach, recent studies in countries with similar geographic and
      demographic profiles to Zambia showed that RHD prevalence in sub-Saharan Africa is much
      higher than previously thought; approximately 1-3% of schoolgoing children appear to have
      evidence of definite or borderline RHD.

      In this study, the investigators will apply echocardiographic screening methods to determine
      the prevalence of RHD in a large population of Zambian school children. Data on the disease
      burden of RHD in Zambia will be used to inform the design and conduct of health programs to
      combat RHD.

      The proposed study will involve a sample size of at least 1,024 students in grades 7-12 in
      fifteen randomly selected schools in Lusaka. Each student that meets inclusion criteria will
      undergo a focused history and physical examination and rapid echocardiographic screening. The
      fifteen schools involved in the study will be identified as a random sample from 119
      currently operating primary and secondary schools in Lusaka using standard sampling methods.
      Approximately 60-80 students from each school will be screened. The screening will be
      conducted using an ultraportable ultrasound device and an abridged screening protocol that
      has been validated in a separate study by investigators at the University of Cape Town in
      South Africa. Children with suspected ARF or RHD will be followed up at UTH for an in-depth
      clinical examination and quantitative electrocardiogram. Children with definite or borderline
      RHD according to World Heart Federation Criteria will be offered secondary penicillin
      prophylaxis according to national guidelines in Zambia. Children with sore throat will be
      referred for evaluation and treatment with penicillin according to national guidelines for
      primary prevention of RHD at UTH or a local health clinic.

      An additional feature of this study is the development of local technical expertise to
      conduct echocardiographic screening. This is necessary because few health workers in Lusaka
      are proficient in cardiac echocardiography. The feasibility of task-shifting
      echocardiographic screening to non-expert health workers has been demonstrated in similar
      settings. The investigators will therefore train radiography technicians who have little or
      no previous experience with echocardiography to conduct school-based screening.

      Given that radiographers will be newly trained to conduct screening echocardiography, two
      mechanisms will be implemented to help ensure successful school screening: (1) international
      echocardiography technician experts will periodically accompany study staff during school
      screenings to support the work of local radiographers; and (2) all screening echocardiograms
      will be de-identified and reviewed remotely by a professional third-party echocardiographer
      who will report back on any echocardiograms that are determined to be read as falsely
      negative by the field team.

      Most data that will be obtained for the study will be entered through mobile electronic
      devices (computer tablets) at the time of capture into a digital system ("eRegister") that
      will be developed specifically for the study. The system uses DiMagi's "CommCare" platform,
      which includes a customizable mobile health data collection application and an online portal,
      "CommCareHQ," for secure data viewing and reporting. All access to the CommCare platform
      including mobile submissions will be done over HTTPS (hypertext transfer protocol) and will
      be cryptographically secure. Mobile devices will be password-locked and accessible only by
      the study staff member to whom the device is allocated. Once data are submitted to the server
      they will be automatically erased from the mobile device. Echocardiograms will also be saved
      in the system; images and videos will be temporarily stored on the hard drive of the
      ultrasound device and then transferred to the eRegister.
    

Observational model: Ecologic or Community
Time perspective: Cross-Sectional
Sampling method: Non-Probability Sample
Study population: 
        A population of approximately 1,024 schoolchildren drawn from 15 primary and secondary
        schools in Lusaka, Zambia, to be screened for RHD in order to determine prevalence of the
        disease.
      
Keywords: Rheumatic heart disease