In this GBD study, we describe the burden of disease in Sierra Leone from 1990 to 2017. Overall, the burden of disease improved significantly resulting in decreased mortality rates. According to the trend analysis Sierra Leone is faced with a dual burden of disease, with CMNNs contributing about 65% while NCDs account for about 29% and 6% represent injuries.,the CNMMs and NCDs [11, 12]. In Sierra Leone, CMNNs continue to be a problem due to the prevalence of endemic diseases . The most important CMNNs are respiratory infections, neglected tropical diseases and malaria, and maternal and neonatal disease, they contribute significantly to (YLLs), mortality and disablity . The burden of NCDs was low compared to CMNNs, a trend which is likely to change as the health system recovers and populations age. The end of the Sierra Leone civil war brought the government, international partners, stakeholders, and civil society together to start reconstructing the health system. The recovering health system and implementation of health policy interventions has resulted in the decline of YLLs due to CMNNs and NCDs. Our study shows that Sierra Leone has made progress in population health outcomes despite multiple challenges.
The Sierra Leone civil war took place from 1991 to 2002, lasted 11 years and left more than fifty thousand people dead. The civil war would have contributed to burden of disease in many ways, including an increase in injuries. Mortality rates due to NCDs peaked between 1990 and 1994, reflecting the potential impact of the civil war. Mortality rates have declined consistently after the end of the civil war, suggesting efforts to rebuild the health system. Contrary to this the two- year Ebola outbreak contributed to a slight increase in mortality in 2014 .
Sierra Leone is dominated by communicable,maternal neonatal diseases since 1990 to date . The burden of CMNNs is high when compared to other countries . The burden of CMNNs peaked in 1990 and 1992 and can be attributed to persistent endemic malaria . Malaria is the leading cause of death and poses a serious threat to the whole population [14, 15]. Sierra Leone health services treat approximately 2,240,000 outpatients annually for malaria and almost half of these are children under the age of five years [14, 16]. Malaria mortality was estimated at approximately 4.4% of pregnant women and 17% of children. Malaria contributes to 40% of hospitalised morbidity in all ages and 37% of children under five [14, 15]. Malaria has been a priority and remains on Sierra Leones health agenda since 1990 but the civil war in 1991 the civil war resulted in the displacement and uncoordinated efforts of malaria control . In 2004, Sierra Leone launched their first National Malaria Strategic Plan (2004–2008), which was funded by the Global fund, nevertheless they continue to fight malaria . The National Malaria Control programme within the Ministry of Health continues to distribute insecticide-treated nets and provide access to malaria preventive therapy. Key challenges include a lack of human resources to coordinate and implement the programme in the rural districts and a limited supply chain at all levels [14, 15].
Sierra Leone was reported to have the highest Maternal mortality ratios in the world at 1360 deaths per 100,000 live births in 2015, which far exceeds the MDG targets of 450 deaths per 100,000 births [12, 17]. In Sierra Leone, children under five years suffer high mortality rates with 120 deaths per 1000 children . To achieve Millennium Developmental Goal 5a, the government made commendable efforts to reduce maternal mortality by 75 percent, but these efforts were hampered by the effects of the civil war and the Ebola outbreak, which crippled the infrastructure and economy . In 2010, the Sierra Leone government launched the Free Health Care Initiative to reduce mortality and morbidity due maternal and neonatal disorders [8, 12]. The Free Health Care Initiative has contributed to a significant improvement in the health system access and coverage as shown by the statistics in the study . Similarly successful health care Initiatives and policies were implemented in Burundi and Ghana .
In Sierra Leone, respiratory diseases and tuberculosis, HIV/AIDS, and enteric infections are the major drivers of YLLs . In the 2016 WHO Global TB Report, Sierra Leone was ranked ninth in the world in terms of incidence per capita . In 1990, the German Leprosy Relief Association assisted the Ministry of Health and Sanitation to establish the National Leprosy and Tuberculosis Control Programme to monitor the surveillance of tuberculosis control activities [13, 18]. Sierra Leone continues to have one of the highest tuberculosis burdens in the world despite the fact that treatment is free and readily available [15, 19]. Sierra Leone opened its first drug-resistant tuberculosis treatment centre at Lakka Government Hospital in 2017 . Shortage of human resources and long distances from health facilities are the main challenge in this program . Nonetheless, new recommendations, constant monitoring and surveillance of the National Tuberculosis Program remain necessary .
Enteric diseases are most prevalent in children under the age of five and account for around 12% of all child deaths in Sierra Leone . Sierra Leone added the rotavirus vaccine to its immunization schedule to combat diarrhoeal infections on March 28, 2014, in an effort to address this issue . The government continues to prioritise prevention and treatment of childhood illnesses.
The burden of HIV/AIDS and sexually transmitted infections (STIs) increased over the 27 years . The prevalence of HIV/AIDS is approximately 1.7%.The prevalence of HIV/AIDS prevalence in Freetown, the capital city . It affects age group ranging from 15–49 years all sexes . In 2013 and 2014, commercial sex workers were responsible for 40% of newly infected HIV patients . The Sierra Leone government is stepping up efforts to test, prevent, treat and increase awareness with the support of the WHO, Global Fund and many other partners. The Sierra Leone government has implemented a national HIV AIDS strategic plan 2016–2020, including programmes such as Prevention of Mother to Child Transmission .
As a developing country with a young population, the risk factors associated with YLLs due to CMNNs are linked to the health and wellbeing of younger age groups. The most important risk factors for CMMN YLLs were environmental risk factors including child and maternal nutrition, unsafe water and sanitation and exposure to air pollution. Less important risk factors included lifestyle risk factors such as alcohol and tobacco use, drug use and intimate partner violence. In Sierra Leone, environmental risk factors are being addressed on various fronts. These lifestyle risk variables were associated with a relatively small number of deaths; for example, cigarette smoking was associated with 5% of YLLs . Although the number of YLLs connected with these risk factors is still small, it is increasing and requires monitoring by local organizations.
The global prevalence of NCDs is expected to grow by 25% globally by 2030 . In 2008, the WHO estimated that NCDs accounted for 18% of fatalities in Sierra Leone, followed by cardiovascular disease at 7%, cancer at 3%, diabetes at 1%, and chronic respiratory illness at 2% . Sierra Leone was also predicted to experience an increase in Non-Communicable diseases [23–25]. In 2012, mortality from NCDs increased to 26%. Sierra Leone's government developed its first strategic plan and policy for NCDs in 2013, in response to the World Health Organization's global status report on NCDs. The 2013–2017 strategic plan, of Sierra Leone aimed to mitigate the burden of NCDs such as cardiovascular disease, chronic lung disease, diabetes mellitus, obesity, cancer, sickle cell disease, mental disorders, and epilepsy [24, 26]. By 2014, the incidence of NCDs had reduced across all age groups and sexes which shows the strategy had positive results .
The burden of NCDs remained constant between 2005 and 2017. In our study, most YLLs due to NCDs can be attributed to cardiovascular related diseases and neoplasms contributing to approximately 9% of NCD deaths . There is evidence that NCDs are increasing. In 1993, 68% of hospitalisations at Freetown hospital were admitted due stroke . In 1994, 25% of the population above 50 years of age were estimated to be hypertensive . A review of death certificates issued between 1983 and 1992, showed an increase in deaths related to hypertension in Sierra Leone . There is little information on the prevalence of cancer in Sierra Leone, even though our study reported that neoplasms were among the top ten causes of mortality . In Sierra Leone, recording and reporting of data on NCDs remains inconsistent even though there is a ministerial department responsible for NCDs .
Sierra Leone suffered an Ebola outbreak in 2014 and 2015, led to inadequate quality surveillance data on the incidences, cases and deaths of NCDs . The Ebola outbreak occurred when the government was transitioning from hospital care for NCDs to management, treatment and care in primary health care facilities . Following the Ebola outbreak, significant reporting systems focusing on morbidity and risk factors for NCDs were put in place. Although policies are being developed by the government, there seems to be little funding for treating and controlling NCDs .
Dietary risks are also associated with YLLs due to NCDs in Sierra Leone. A nutritional survey done in 2014 revealed that more than 25% of children younger than five years old had stunted growth [24, 27]. Glucose has recently become an important risk factor NCD associated YLLs and is growing in importance. High fasting plasma glucose is an indicator of diabetes mellitus. The prevalence of diabetes in Sierra Leone has also increased from 2.4% in 1997 to 7% in 2014 .
Tobacco use is an important risk factor of NCDs, including cardiovascular disease, respiratory diseases and lung cancers . In Sierra Leone, 14.3% of men and 1.4% of women, comprising 34% of people, smoke more than 10 cigarettes a day . Sierra Leone signed the WHO Framework Convention on Tobacco Control in May 2009, with the objective of reducing tobacco consumption, and the Ministry of Health and Sanitation adopted a National Tobacco Control Strategic Plan in 2012.In addition to problems of hypertension, glucose and substance abuse is the fact that Sierra Leoneans engage in low to moderate physical activity. The importance of high body mass index as a risk factor jumped from 9th in 1990 to 5th place in 2017 . The burden of NCDs remains low compared to CMNNs, which may contribute to few resources being allocated to preventing NCDs at this point.
There is a general dearth of information due to the multiple systems utilised by the Ministry of Health and the private sector, Sierra Leone's health information systems are still fragmented and multi-operating, causing it to lag behind . The district’s health information system and integrated disease surveillance and response systems are not well-coordinated, so the data's veracity is generally sceptical. The information on non-communicable disease is limited . To strengthen research, it is necessary to strengthen information monitoring and evaluation tools.
Access to high-quality, efficient service delivery remains a challenge due to lack of financial resources, essential medicines, and equipment. Sierra Leone continues to struggle with human resource shortages and misdistribution in rural and urban areas . The country is also experiencing massive migration of highly specialised health workers. An estimated 300 health workers died during the Ebola outbreak .