Concluding Remarks

From the preceding chapters, it is evident that Africa is in the middle of a severe HIV epidemic and its opportunistic infections such as TB and PCP. In Zambia, the epidemic has affected all aspects of the society and has resulted in increases in non-traditional causes of maternal mortality (Ahmed et al.

1999), increases in orphans, increased mortality from opportunistic infections and reduced life expectancy in the general population (UNAIDS Country Report 1999). The impact on the social economic sector due to recurrent illnesses has been devastating and it is feared that many economies in this part of the world will continue showing negative growth as has been the case since the beginning of the epidemic (MON Strategic Document 1999). ... .

Despite having major devastating consequences on the health of the majority of its population, scientific and clinical studies on HIV, TB and other infectious diseases in the field in Africa are limited by lack of laboratory tests, poor accessibility to affected populations, lack of financial and human resources. Large scale epidemiological studies are not only hampered by the aforementioned factors but also by perennial factors such as ignorance, traditions and fear of modern technology.

The technique of collecting specimens on absorbent filter paper (Guthrie 1963) provides a practical and economical solution to many of these problems. As in new-born metabolic screening, whole blood, plasma or other body fluid is simply spotted onto the filter, dried and then shipped without cryo-preservation at minimal cost and low biohazard risk. In this study, I have used samples spotted onto filter papers for the quantification of HIV-1 RNA and the results obtained compare favourably with those obtained by others (Cassol et al 1997; Comeau et al. 1996). The wealth of filter paper applications now available, combined with the ease and economy of filter sampling (<50 cents per collection), suggests that these methods will be useful in large cross sectional and longitudinal studies of HIV-1 disease. The number of possible applications using filter papers can be used to develop an integrated, cost effective world-wide surveillance system to monitor HIV-1 activities and evaluate the effectiveness of intervention efforts. The wealth of filter paper studies have been extended to the study of Malaria (Singh et al

1996) and tuberculosis.

Most developing countries have also been crippled by debt repayments to International lending institutions which have led to further deterioration of the health services. The duet of TB and HIV have further stressed the diagnostic services of most countries that depend on only microscopy for the diagnosis of TB but now have to monitor HIV as well. The impact of HIV has led to the collapse of many a TB program and there is urgent need to redress the situation through improved diagnostics and monitoring of patients. In

resource poor settings, there is an urgent need to explore field friendly technology if newer challenges are to be tackled adequately.

In many parts of Africa, the majority of health centres and hospital laboratories fail to meet the requirements of even the most critical elements of the package of care. The reasons for this failure are vast and include factors such as lack of equipment, supplies and human resource. It is equally true that most parts of Africa do not have facilities for storage of samples such as dry ice, freezers, centrifuges and transport to take the samples to more specialised laboratories. Thus most of the crucial tests in HIV and TB tests can not be processed at field sites due to the constraints mentioned above. It is also true that most assays currently in use have not been evaluated in Africa and it is generally assumed that they will perform just as well in the field. A point in question may be the HIV assays used in the quantification of HIV-1 RNA which had the original primers that were made for the clade B of the virus and ended up performing poorly on the African strains. The dangers of using such an assay in blood screening cannot be overemphasised.

A lot of clinical trials are taking place in Africa but there is very little quality assurance programmes for the laboratories involved for more or less the same reason of sample processing and transportation to centralised laboratories in Europe or North America. As an illustration, I conducted a PUBMED search on the inter-net to find out studies that have evaluated or designed any diagnostic tests in Zambia. Of the 309 records retrieved

running from 1974 to date, only 10 studies had looked at the evaluation or designing a new diagnostic technology and the majority were clinical trials of new therapies. This observation is true for most African countries. As research and clinical trials on HIV and TB intensify, there is a strong need more than ever before to have laboratories that would spin remote and inaccessible areas and the more specialised central laboratories. More importantly will be to equip these laboratories with manpower and equipment that can process large samples from the field. These laboratories should be able to send samples for quality assurance within the region or to more specialised laboratories in Europe and North America.

The situation in Africa regarding tuberculosis and HIV is that:

1. Tuberculosis and HIV/AIDS are two major health problems and are leading causes of morbidity and mortality.

2. Treatment and laboratory investigations available in the west will not in the foreseeable future be available to most African states and therefore there is need for the development of field friendly technology. Accurate laboratory diagnosis of TB, PCP and HIV is currently not possible for the majority of cases across most countries and thus accurate data on the incidence, prevalence, drug resistance patterns are not available.

3. Most countries do not use anti-retroviral treatment for the majority of patients infected with HIV and it is highly unlikely that the situation will change in the near future. When they do become available, monitoring of the treatment will be hampered by the expense of HIV viral load measurement and CD4 measurements.