Molecular Studies On Microsporidia Species And Their Prevalence In Lagos, Nigeria

ABSTRACT

Microsporidia cases due to Enterocytozoon bieneusi and Encephalitozoon intestinalis are emerging

opportunistic infections associated with a wide range of clinical syndromes in humans. A cross-sectional

study was conducted to determine the prevalence of microsporidia spores, Cryptosporidium oocyst and

other enteric intestinal parasites from faeces of HIV-positive individuals (with and without diarrhoea)

attending the HIV/AIDS Clinics and from HIV-negative individuals and animal samples from different

sites in Lagos. Fresh faecal samples were collected from 770 HIV-positive patients {225(29.2%) (CI =26.1

to 32.6%) with diarrhoea and 545 (70.8%) (CI = 67.4 to 73.9%)} without diarrhoea of age range from 2-70

years (mean age 34.6 years); from 250 HIV- negative patients (age range 2-50 years; mean age = 25.0

years) and 250 animal samples. Microscopy was used for initial screening of all faecal samples using wet

mount microscopy with 5% Lugol’s iodine, modified Weber green chromotrope stain (Trichrome stain)

and Kinyoun carbol fuschin stain for the detection of enteric intestinal parasites, microsporidia spores and

Cryptosporidium oocysts respectively. The prevalence rate of microsporidia infection was 51(6.6%). Of the

225 diarrhoeic faeces, 36 (16.0%) were positive for microsporidia spores, 41(80.4%) for Enterocytozoon

bieneusi and 10 (19.6%) for Encephalitozoon species and 49 (6.4%) for Cryptosporidium oocysts. Of the

545, 15 (2.8%) and 13 (2.3%) patients were also positive for both organisms in non-diarrhoeic faeces

respectively. Mixed infection was recorded in 14 (28.1%) between microsporidia spores and

Cryptosporidium oocysts. Of the males, 21(6.3%) had microsporidia spores compared with

Cryptosporidium oocysts 22 (6.6%) while the 30 (6.8%) of the females and 27(6.2%) males were positive

for microsporidia spores and Cryptosporidium oocysts respectively (P value = 0.0154; P value = 0.0146).

Similarly, among the diarrhoeal patients with CD4+ T-lymphocyte cell count < 200, 4.9% and 10.1% were

positive for both microsporidia spores and Cryptosporidium oocysts.