I Omalu, D Duhlinska, G Anyanwu, V Pam, P Inyama
cd4 lymphocytes counts, microsporidia, serological evaluation
I Omalu, D Duhlinska, G Anyanwu, V Pam, P Inyama. Seroprevalence of Microsporidiosis in Immunocompromised Patients in Kano-Nigeria. The Internet Journal of Parasitic Diseases. 2006 Volume 1 Number 2.
Microsporidial infections have been recognized as an increasingly important infection in immuncompromised patients, particularly those infected with HIV/AIDS.
Stool samples were examined for microsporidial spores by modified Giemsa staining technique and IgG antibodies to Microsporidia in Sera samples were detected by ELISA. Feacal examination showed that 14/192 (7.29%) of HIV/AIDS patients had microsporidia, comprising -
Serological evaluation showed that 22/168(13.10%) of HIV/AIDS and 2/60 (3.33%) of HIV-negative patients were seropositive. There was a significant difference (X2, p<0.05) in their infection rates. 0/30 of TB patients were seropostive.
There was a significant association (p<0.05) between patients with Microsporidia and CD4 lymphocytes counts of ≤ 50 cells/µl and also with diarrhoea.
Detection of Microsporidia in Immunocompromised patients has not been described previously in this area.
Since the advent of HIV infection with its profound and progressive effect on the cellular immune system, a group of human opportunistic pathogens has come into prominence, namely the microsporidia. Microsporidia are widespread, small obligate intracellular protozoan parasites which are transmitted via resistant spores.1 Many genera of the family microspora were known to be pathogens of invertebrates and vertebrates hosts. 2 Their role in human disease was not appreciated until the AIDS pandemic.
Study populations were in and out patients of Infectious Disease Hospital (IDH) Kano state. Each patient had a standardized clinical evaluation and provided a fresh stool specimen upon admission.
For microsporidial investigation, feacal (0.5g) specimen was homogenized in distilled water in ratio 1:8. After filtration in a 300µm pore mesh sieve and centrifuged at 1500rpm, smears were prepared from sediments, fixed in methanol and stained with 10% Giemsa solution 10and examined at x1000 magnification (oil emersion). Giemsa stained spores were broadly oval, with the cytoplasm staining light grey-blue with a dark stained nucleus Spores were classified as either small about 1.0 – 1.6 x 0.7 – 1.0µm (
For serological evaluation an Indirect Enzyme Linked Immunosorbent assay ELISA technique was carried out with washed whole spores of microsporidia. Micro-ELISA plates were coated with 105 microsporidial spores as antigens; test and control sera were diluted in 1:2000. 11T-lymphocytes were counted with a CD4 cell kit, and clinical evaluations were done physically and by oral examination.
Prevalence of microsporidia in stool samples of immuncompromised patients is shown in Table 1. In HIV/AIDS Patients 14(7.29%) of the 192 patients examine had microsporidia, comprising-
Six (100%) HIV/AIDS patients had CD4 lymphocytes counts of < 50 cells/µl while 5(25.00%) had CD4 lymphocytes counts of > 50 cells /µl. their difference was very signifcant (X2, p<0.05). Only 1(100 %) TB/HIV/AIDS patient with microsporidia had a CD4 lymphocyte count of < 50 cell/µl(Table 3).
In HIV/AIDS patients 34(43.59%) had diarrhoea, 21(26.29%) had abdominal pain, 19(24.36%) had both diarrhoea and abdominal pain, while 4(5.03%) showed no clinical symptoms.
In TB/HIV/AIDS patients 2(28.57%) had diarrhoea, 1(14.29%) had abdominal pain, 1(14.29%) had both abdominal pain and diarrhoea, while 3(42.86%) had none. 3(23.08%) of the TB/HIV- negative patients had diarrhoea, 2(15.38%) had abdominal pain, 2(15.38%) had both and 6(46.15%) had none (Figure 1). There was a significant association between microsporidia and diarrhoea.
This report described an emerging gastrointestinal protozoon in Kano, where there has been little or no study. Microsporidia generally
All the patients with CD4 lymphocytes counts of < 50 cells/µl had microsporidia which confirmed the fact that microsporidia is usually observed in patients with low CD4 cells. 1, 5 Possible explanation of fewer patients with low CD4 cells of < 50 cells/µl is probably due to the fact that patients in developing countries like Nigeria die from other tropical disease before the CD4 cells drop to the critical level of about 50 cells or less, below which the intestinal microsporidia becomes clinically significant. Most of the HIV/AIDS patients had chronic diarrhoea leading to severe weight loss, this report conforms to earlier findings, 5, 14, 15 and this was followed by abdominal pain and both. In TB patients few had diarrhoea, which might be due to the fact that patients were already on medication as of the time of this study.
A final deduction from this study is the appreciation of the increasing prevalence of microsporidia and that most patients have antigens and antibody levels, indicative of subclinical infections, suggesting that this parasite could be a serious hazard to AIDS and other immunodeficient patients due to causes other than AIDS, or probably due to most tropical diseases like malaria, schistosomiasis etc., and that infection are not at present being diagnosed. Since presently there is no satisfactory treatment for microsporidial infections, there is need for making chemotherapy for microsporidial disease a priority area of research.