Literature review
According to Haung (2016), HIV associated dementia is chronic, global, and usually irreversible deterioration of cognition that may occur in the late stages of HIV infection. Its chronic deterioration is due to the brain infection by HIV that causes anatomic changes and neuronal damage. Because of irreversible damage, there is therefore need for early diagnosis and management which is possible through periodic assessment to ascertain the level of dementia. Concerning the effects of HIV, Howlett (2012) also described that the HIV enters the Central Nervous System (CNS) within primary days of infection and cause neurological disorders related to direct HIV infection and this has been observed during all stages of disease including early infection. This finding informs that dementia can occur at any stage so long as the virus has entered and affected the brain. The damage result into HIV associated dementia which is a severe form of Neurocognitive disorder. The two researchers agrees on the effects of HIV virus in the brain in which its progression can be halted if diagnosed early through screening and initiation of ARVs.
There are other synonymous terms for HIV associated dementia (HAD). According to study done by Singh (2012) the synonymous terms include: AIDS dementia, AIDS dementia complex (ADC), and HIV encephalopathy. These has been used interchangeably in various studies including prevalence that the researcher seeks to compare the findings of the study.
In 2013, Arora and Sousa found that there has been an increase in prevalence of HAD worldwide due to antiretroviral therapy, the therapy has enhanced the survival of HIV patients with peripheral immunosuppression. The dominance of HIV persist due to poor blood barrier permeability of ARV drugs leading to a gross increase in HAD. However POZ (2016) presented a contrary findings, he found that with the availability of powerful Anti-HIV drug therapy, the prevalence is much lower today. WHO supports POZ s idea that, ARVs can work to halt progression and it goes ahead to recommend the use of ARVs in any patient found to be having dementia during assessment using International dementia scale should be commenced on ARVs. This has not been done because different countries rely more on other test to determine the severity of infection, this include CD4 count and viral load count .However the recommendation from WHO should be embraced because it is cost effective and does not require a lot of time.
A recent study by (Huang, 2016) found that global prevalence of HAD was 7 – 27 % in late stage of HIV, and this was associated with continuous deterioration due to brain infection. This also supports the recommendation by WHO that, any client discovered to be having dementia during assessment should be commenced on ARVs to prevent further deterioration because it is deemed to be in 4th stage of HIV infection, and with continues destruction of brain cells, patient will present with HAD.
Findings by (Keven et al, 2007) revealed that 10-15% of patients with advance disease in United States suffer from HAD and minor cognitive motor dysfunction, this shows that HAD cut across regardless of socioeconomic level though its high in developing countries. Before the advent of ARVs, dementia was a common source of morbidity and mortality in HIV-infected patients. It was usually observed in the late stages of acquired immunodeficiency syndrome (AIDS) when CD4 count dropped below 200 cells/ml, and was seen in up to 50% of patients prior to their deaths (Florian, 2016). There has been big decline in prevalence of HAD in those on ARVs, this is an indication that the ARVs works to prevent deterioration into HAD and improve the quality of life of any patient on medication. However good adherence is paramount in prevention of resistance and improvement of general health.
Heaton (2010) in Europe revealed that 13.7 % of HIV patients had neurological disorders but only 2% had HIV associated dementia, CD4 was found to be strong predictor of impairment. This prevalence of HAD was lower compared to other continents who are stable economically like United States, it was also observed that there are other two categories of asymptomatic and mild neurocognitive disorders which need to be addressed to prevent progression into HAD. Other than economic instability there could be other factors associated with HAD, this study will determine factors associated with dementia.
China has been known to be economically stable country because of its industrialization, this has not prevented development of neurocognitive disorder. (Dang, Wei, Long, Zhou, Han, & Zhao, 2015) study found that, China had prevalence of 8.26% HAD cases related to HIV. This prevalence was lower than United States and Europe though all are developed countries, Brazil record lower than the other countries. The researcher confirmed that International HIV dementia scale (IHDS) is a convenient and effective screening tool for HAD as it has the following characteristics: It avoids language and cultural issues, it consists of three main entries assessing four aspects, including memory registration, motor speed, psychomotor speed, and memory recall. The tool will be important in this study because patients across all the cultures will be assessed. From the above studies it can be conclude that the HAD in developed countries is lower than the prevalence in developing countries.
The African continent has not been spared either, Howlette (2012) found that, overall prevalence of HAD was between 10-20%. This is a generalized prevalence because the study has not been done in many other countries. Africa is a continent that is stricken by poverty with health challenges, this may raise the prevalence of HAD especially in individual countries with higher HIV burden.
There were no previous data for comparison, this calls for more studies in order to determine HAD prevalence in all African countries than using generalized studies in specific countries for example Nigeria to represent West Africa and Uganda to represent Sab-Saharan Africa.
South Africa is economically better compared to Countries in Sub Saharan Africa but it also bears the scourge of HIV complication. Robbins et al (2011) found that, among adults under the age of 40 years initiating ART, 25.4% met the criteria of HAD. There was no data for comparison within the same country. This country has been in different level in terms of development and establishment of health facilities, it is not disadvantaged like East African countries that fall under Sub-Saharan Africa.
West African countries have also been affected, Asekomeh et al, in 2013, found that prevalence of HAD in West Africa among HIV positive population was 66.2%. The research was done in Nigeria to represent West African countries, those assessed scored low in cognitive domains. This score is much higher compared to South Africa, poverty level is lower than South Africa.
East African countries have been hit hard more than other countries that do not fall Under Sub-Saharan Africa. In Tanzania, Nyundo et al. (2015) on a study at Muhimbili National Hospital Dar salaam-Tanzania, found that the prevalence of Neurocognitive disorder was 68.4 % with a cut of < 10 on IHDS. Another study by Asekomeh et al. (2013) done earlier in the same country but in different location found that the prevalence of dementia in Tanzania was 56%. The difference was brought about by the study site, Muhimbili is a national hospital and could have received more patient as referrals with already existing challenges.
In 2013, Nakku, Kinyanda, & Hoskins did a study at Entebbe District Hospital-Uganda, the researchers found that probable HIV dementia in ambulatory HIV adult population was 64.4%. Increasing stress and psychological impairment contributed to the high prevalence. Johns Hopkins University chose Uganda to represent Sub-Saharan Africa in 2007 and 2010, the findings were 31% and 64.1% respectively. These three studies shows that there has been progressive increase in prevalence within a span of 10 years. This calls for extensive and periodic study in various countries in order to determine the prevalence of HAD to aid in planning and intervention in specific countries. The study has also given clear picture that the prevalence changes over time, the above two studies in Tanzania has also shown that changes occur over a period of time. High prevalence could be due to high disease burden and low socio-economic level.
A pilot study done in 2012 by Kwasa et al in western Kenya to test diagnostic tools for HIV associated dementia found that, prevalence of HAD was 20%.The researcher emphasized on the need to train community Health workers on the use of the brief tools in order to reach many. However the sample size was 30 patients which was small to be used as a representative sample of HAD in Kenya the objective was to test the tool.
The available data has shown that, African countries are faced with huge burden of HAD, Nigeria 66.2%,Uganda has a prevalence of 31-64.4%, Tanzania 56-68.4% , South Africa 25.4% (those initiating ARVs), Ethiopia 24.8%,Cameroon 21.1%, western Kenya 20%, Malawi 14.0%. Democratic republic of Congo 8.7% .Carey et al (2012) has also established that, information on dementia in Africa is very limited, further research will not only provide more reliable estimate of disease burden, but will also raise awareness of the problem. Other Countries have not carried out studies to determine prevalence of HAD, therefore the magnitude is unknown. The information on dementia will help in planning for intervention in order to halt progression into HAD. The finding in this study will give the prevalence of HAD which is important in planning for intervention and also it can be used as a baseline in subsequent studies.