# High Prevalence of Sickle Cell Disease in Low-Endemic Areas: A Pilot Study in Chunya Tanzania

## TL;DR

This study found a high prevalence of sickle cell disease in a low-endemic area of Tanzania, highlighting the need for early screening and awareness programs.

## Contribution

The study identifies a high SCD prevalence in Chunya district and links migration patterns to shifts in disease distribution.

## Key findings

- The prevalence of SCD in Chunya was 1.91%, with most cases in children five years and below.
- Sickle cell trait prevalence was 8.41%, with paternal origin from the Northern Zone as a risk factor.
- Maternal origin from the Southern Zone was a protective factor against SCT.

## Abstract

Tanzania has the fifth highest prevalence of Sickle Cell Disease (SCD) worldwide. Annually, 11,000 children are born with SCD, but only 10% survive to their fifth birthday. Limited screening has led to underestimation of the burden in regions such as the southern highlands. The epidemiology of SCD, just like other diseases, is affected by climate change through increasing migration in search of arable land hence the shifts in the geographical prevalence of SCD from high prevalent areas to low prevalence areas. Early identification of SCD across all regions is therefore essential to improve survival, quality of life, mental health, reduce stigma, and alleviate the financial burden.

The objective of the study was to assess the prevalence of SCD and SCT in Chunya district, Mbeya Region, Tanzania and to identify demographical factors associated with the risk of SCT among community members.

A cross-sectional study on SCD was conducted in Chunya district, Mbeya Region, between 21st and 22nd February 2020. A total of 523 villagers were selected and screened for SCD and sickle cell trait (SCT) using rapid test (SICKLE SCAN(®).

The study revealed a notably high prevalence of SCD in southern highlands of Tanzania which highlighted the need for early screening and community-based awareness programs. The prevalence of SCD in the tested population was 1.91% and the prevalence of SCT was 8.41% of which the majority of the SCD patient were five years and below P=.02. Having a mother from Southern Zone was a protective factor (OR 0.2) against acquiring SCT while having a father from Northern Zone was a risk factor (OR 10), P value <.005.

To reduce the burden of SCD, new strategies of screening should be developed to enable timely diagnosis and management of the disease.