Cardiovascular Journal of Africa: Vol 29 No 5 (September/October 2018)

CARDIOVASCULAR JOURNAL OF AFRICA • Volume 29, No 5, September/October 2018

AFRICA

275

Out of 59 children with positive HHE results, 34 were

available for a SE study while 15 were unable to attend due to

social reasons and 10 were travelling. Of the 34 children who

underwent SE, 29 were found to have RHD (85.2%); 22 had

definite and seven borderline disease. The ratio of definite-to-

borderline RHD by SE was 3.1:1, with females representing 72%

of the definite cases. The echo prevalence was 19/1 000 children.

The bias-adjusted kappa test showed good agreement between

the two echo readers of 92.9% (= 2, Agreement 1 = 2 × 0.9643

– 1).

All the cases with definite and borderline RHD were asked

to come for a follow-up study by SE after six months. Definite

RHD cases were started on benzathine penicillin prophylaxis.

Table 2 and Figs 1 and 2 summarise these findings.

Table 3 details the echo findings of 29 cases found positive

using SE. MR was present in all the cases detected by SE and

in 58/59 of those by HHE (Fig. 3). AR was present in seven

cases using HHE (11.8%) and in four with SE. Of those with

AR detected by HHE, only four came for SE. Two children had

aortic valve morphological abnormalities detected by HHE but

did not come for SE. These included irregular thickening in one,

and in another case it was associated with leaflet prolapse and

asymmetry (Fig. 4). No cases of mitral or aortic stenosis were

identified.

The agreement between HHE and SE on the assessment

of mitral valve morphological criteria as well as the diagnosis

of RHD were calculated. Bias-adjusted kappa showed a fair

agreement of anterior mitral valve leaflet thickness > 3 mm,

chordal thickening and excessive leaflet tip motion in systole (28,

28 and 32%, respectively) and good agreement (66%) with the

diagnosis of definite versus borderline RHD.

Discussion

This is the first study that has measured the echo-diagnosed

prevalence of RHD in Sudan. This was coupled with the

initiation of a control programme based on training of health

personnel, and raising public awareness in South Darfur.

Compared with the 1992 clinical prevalence of 11 per 1 000,

RHD prevalence in Khartoum has dropped significantly, which

could be attributed to the relative improvement of health services

and living conditions in urban areas. On the other hand, this

study unmasked a huge burden of asymptomatic patients living

in a poor rural community. In sharp contrast to Khartoum, the

prevalence in South Darfur camps was over 60 times higher. This

prevalence may have been underestimated due to the smaller

sample size and the high number of children who could not

attend the SE study in Niyala.

The Khartoum study was conducted by paediatric cardiology

fellows who were experienced in echo and were using three echo

views as per the modified WHF protocol, therefore the accuracy

of the echo studies was expected to be high. Moreover, the inter-

observer agreement was 92%, indicating the reliability of echo

interpretation. This disparity in prevalence could be attributed

to many factors, including the availability of more health centres

within Khartoum compared to the Darfur area, and a relatively

better socio-economic status and more secure living conditions

in the Mayo area, which is only 9 km from the Khartoum centre.

The ratio of definite-to-borderline RHD cases of 3:1 further

supports the notion that the disease is well established in Darfur

Total number

screened = 1515

Total number

analysed = 1498

Positive by HHE = 59

Definite = 44

Borderline = 15

Those who had

SE = 34

Positive cases by SE = 29

Definite = 22

Borderline = 7

Fig. 2.

Total subjects screened in Darfur and their results.

Khartoum

Niyala-Darfur

HHE

Fig. 1.

Prevalence of RHD in Khartoum and Niyala, Darfur

(per 1 000 population) by hand-held echo (HHE) and

standard echo (SE).

Table 2. Summary of the clinical and echo findings

of children in Khartoum and Niyala, Darfur

Characteristics

Khartoum Niyala, Darfur

Number of school children

3 000

1 515

Number of echo studies analysed

3 000

1 498

Mean age in years (± SD)

10.5 (0.4)

10.8 (0.2)

Female gender (%)

Echo findings

Positive by HHE

Positive by SE

29/34

Definite-to-borderline ratio using HHE

0.16/1

2.9/1

RHD prevalence using echo

0.3/1 000

19/1 000

Table 3. Features of patients who were found

to have RHD by standard echo (total = 29)

Patient characteristics

No (%)

Type of RHD

Definite

22 (76)

Borderline

7 (24)

Female:male ratio

3:1

Echo features

Definite Borderline

Pathological MR

22 (100)

7 (100)

AML thickening

18 (81)

4 (57)

Chordal thickening

22 (100)

4 (57)

Restricted leaflet motion

1 (0.04)

Excessive anterior leaflet tip motion

13 (59)

Pathological AR

4 (18)

Morphological aortic valve criteria

Borderline disease in both mitral and aortic valves

3 (14)

MR: mitral regurgitation, AML: anterior mitral valve leaflet, AR: aortic regur-

gitation.