To our knowledge, this is the first report on the seroprevalence of antibodies to CMV among blood donors in the country. The results of this study showed an overall prevalence rate of 93.2% of CMV IgG among blood donors at the MHBTU, suggestive of ubiquitous past exposure to infection. On the other hand, none of the donors tested positive for CMV IgM, indicating the absence of primary infection. The high seroprevalence rate in adult blood donors reported in this study is comparable to the rates (97% and 96%) reported in Tunisia and India, respectively16–18
. The high prevalence rate in the country indicates the endemicity of infection, and this perhaps could be related to socio-economic, environmental, and climatic factors19
. In the study reported herein, the seroprevalence of CMV IgG among the blood donors varied with age ranging from 91.9% in 20 to 29 year, 95.7% in the 30 to 39 year, to 100% in the 60 to 69 year age groups (). The decrease in the percentage seropositivity in the 40 to 49 year and 50 to 59 year age groups is likely due to smaller number of blood donors. Despite this limitation, the results are similar to studies reported elsewhere which showed a significantly increased seropositivity with increasing age of blood donors20,21
. However, there was no statistically significant difference (P>0.05) in the CMV IgG serostatus with age, when the other age groups were compared to the 50 to 59 year group with lowest seroprevalence.
The American Association of Blood Banks has recommended transfusion from blood donors who are seronegative for CMV or the use of deglycerolized frozen RBCs whenever transfusion is contemplated in high-risk individuals22
. These guidelines have helped in drastically minimizing transfusion-transmitted (TT) CMV infection in immunosuppressed recipients in the US. Since about 93% of blood donors at the MHBTU are seropositive for CMV, it would therefore be very useful to screen blood donors in Ghana for CMV to identify the very few CMV-seronegative blood donors, and maintain an inventory of them for use as donors for immunosuppressed individuals. Furthermore, we propose that the future strategies for the prevention and/or reduction of TT-CMV in Ghana should include the routine screening of donor blood for CMV antibodies as a first step, the subsequent identification of the very few CMV-seronegatives, the education and counselling of these CMV-seronegatives on the importance of their status for themselves and the increasing immunosuppressed population and how to maintain their staus, the motivation of these CMV seronegatives for them to become periodic repeat donors, and the maintenance of a database of the epidemiological and contact information of these CMV seronegatives to enable their rapid recall in times of need. This proposed CMV screening of blood donors and the subsequent determination of the actual titres of neutralization antibodies in the numerous CMV-seropositives will ensure the identification of those CMV-seropositives with very high neutralizing antibody titres from whom immunoglobulins can be obtained to treat CMV infections in immunosuppressed individuals, and who will be followed-up and recalled when necessary in the same manner described above for the few CMS-seronegatives.
The above recommendation, though implies a drastic change in blood banking practice in Ghana with financial implications, is timely because transfusion-transmitted CMV (TT-CMV) is a significant cause of morbidity and mortality in immuncsuppressed patients, including premature low-birth weigh infants (<150g) born to CMV-seronegative mothers and HIV-AIDS patients23
, whose population increasing in Ghana. Additionally, recent studies have associated chronic CMV infection with prevalent frailty, a state with increased morbidity and mortality in older adults24,25
. Ghana must introduce the provision of CMV seronegative blood product support to the above stated vulnerable individuals as soon as possible, since this has been the standard of care since the late 1980s in most developed countries after studies showed this strategy significantly reduced the rate of TT-CMV26–28
. However, the maintenance of CMV-seropositive and CMV-seronegative “dual inventories” is expensive, and some countries with high CMV seroprevalence have found it difficult to maintain adequate supplies of CMV-seronegative products29
, as would be the case for Ghana with a 93% CMV seroprevalence among healthy blood donors herein reported. Thus, alternate methods for the provision of “CMV safe” blood products have been pursued, including the use of leucoreduced blood products which was reported to be comparable to the use of CMV-seronegative blood products for the prevention of TT-CMV infection after marrow transplant30
. However, a more recent study has demonstrated that TT-CMV does occur even after leucoreduction, that CMV-seronegative blood products may thus be superior to leucoreduced blood products, and cautioned against the premature abandonment of the use of CMV-negative inventories particularly for the populations at high risk of and vulnerable to CMV disease for an era of “universal” leucoreduction29
. It must be noted though that both approaches, of using CMV-seronegative and leucoreduced blood products, may fail and carry a low but definite risk of transmitting CMV infection with “breakthrough” infections occurring at rates as high as 1 to 2%26–30
, compared to up to 12% TT-CMV infection rate when blood products unscreened for CMV antibodies are used11
. A recent study demonstrated that plasma viremia in seroconverting donors may partially explain the low residual risk of CMV transmission by both CMV-seronegative and leucoreduced CMV- seropositive blood products31
Limitations of the study included the small sample size (which is due to financial constraints in acquiring enough test kits) and the small number of female volunteers presenting at the Blood Bank. Despite this limitation, the general observation is that donated blood at the MHBTU, Accra, Ghana have a high prevalence of antibodies to CMV.