Table 1: Studies on prevalence of Enterocytozoon bieneusi infection in humans.

ContinentCountry Patient sourceMajor clinical presentationSpecimens analyzedDiagnostic method Prevalence (%) of
infection
Reference

USAHIV+Chronic diarrheaIntestinal biopsiesLM, TEM30% (20/67)[16]
USA
HIV+Chronic diarrhea and other gastrointestinal complaintsDuodenal biopsiesTEM33% (18/55) with chronic diarrhea;  
25% (13/51) without chronic diarrhea
[83]
USAHIV+Chronic diarrheaFecal samples, intestinal biopsiesLM, confirmed by EM78% (14/18)[36]
USAHIV+Diarrhea, other complaintsDuodenal biopsiesPCR, confirmed by TEM44% (30/68) with diarrhea; 2.3% (1/43) without diarrhea [17]
USAHIV+DiarrheaFecal samplesLM8.8% (137/1,557) in 1993; 9.7% (193/1,991) in 1994; 6.6% (155/2,346) in 1995; 2.9% (73/2,545) in 1996[70]
AmericaPeruHIV+DiarrheaFecal samplesLM, confirmed by PCR3.9% (105/2,672)[56]
PeruHIV+Diarrhea and other gastrointestinal complaintsFecal samplesLM, confirmed by PCR2.2% (56/2506)[48]
PeruChildren apparently immunocompetentDiarrhea, weight loss Fecal samplesLM, confirmed by PCR, sequence analysis8% (31/388)[75]
ColombiaHIV+DiarrheaFecal samplesLM, PCR2.9% (3/103)[88]
BrasilHIV+Chronic diarrheaFecal samples,  
intestinal biopsies
LM, TEM or PCR27.5% (11/40)[89]
CubaHIV+ adults; HIV– adultsDiarrhea, other complaintsFecal samplesLM(0/67) in HIV+;  
(0/136) in HIV–
[90]

PortugalHIV+DiarrheaFecal samplesLM, PCR29% (20/69)[38]
PortugalHIV+, HIV−; Adults and childrenGastrointestinal complaintsFecal samplesPCR6.3% (54/856)[45]
SpainHIV+ children58% with diarrheaFecal samplesLM, confirmed by PCR1.2% (1/83); 2% (1/48) with diarrhea[76]
SpainReturning travelers from tropical countriesTravelers’ diarrheaFecal samplesLM, confirmed by PCR10% (4/40)[6]
SpainHIV– elderly DiarrheaFecal samplesLM, confirmed by PCR17.0% (8/47)[7]
SpainImmunocompetent Diarrhea, pneumoniaFecal, urine and sputum samplesLM, PCR, hybridization11.54% (18/156) in feces; 16.22% (6/37) in sputa; 2.5% (1/40) in urine[46]
FranceHIV+Chronic diarrheaFecal samples and intestinal biopsiesLM, partially confirmed by EM50% (9/18)[41]
FranceHIV+Diarrhea Duodenal biopsiesLM1.6% (1/61)[37]
FranceHIV+Chronic diarrheaFecal samplesLM24% (11/46)[91]
FranceHIV+; HIV–DiarrheaFecal samplesLM, partially confirmed by EM, PCR-RFLP88 HIV+ infected; 12 HIV– (10 immunocompromised and 2 immunocompetent) infected. [92]
GermanyHIV+DiarrheaIntestinal biopsiesPCR21.7% (10/46)[93]
GermanyHIV+Chronic diarrheaFecal samplesLM, PCR, sequence analysis12 fecal samples from 8 patients[94]
GermanyHIV+Diarrhea, other complaintsFecal samplesLM36% (18/50) with diarrhea; 4.3% (2/47) without diarrhea[43]
EuropeGermanyHuman patientsDiarrheaFecal samplesPCR, sequence analysis7.7% (2/26)[95]
GermanyReturning travelers from tropical countriesTravelers’ diarrheaFecal samplesLM, PCR0.7% (1/148); 4.7% (7/148)[8]
SwitzerlandHIV+Diarrhea, other gastrointestinal complaintsFecal samplesLM, partially confirmed by EM and PCR12.7% (20/164) in 1992–94; 5.8% (9/156) in 1994–96; 0.4% (4/949) without diarrhea[71]
HollandHIV+DiarrheaFecal samplesLM, confirmed by EM7.7% (11/143)[96]
UKHIV+DiarrheaFecal samples, intestinal biopsiesLM, EM, confirmed by TEM14.3% (9/63) in fecal samples; 7.9% (3/38) in biopsies[40]
UKHIV+Gastrointestinal complaintsFecal samplesLM, PCR, qPCR, TEM8.3% (14/168)[97]
ItalyHIV+Chronic diarrheaIntestinal biopsiesLM, TEM4.2% (3/72)[44]
Czech RepublicAsymptomatic healthy people NAFecal samplesPCR 6.0% (23/382);
[20]
RussiaHIV+, adultsDiarrheaFecal samplesPCR1.3% (2/159)[87]
RussiaHIV/AIDS patientsNASerumIFAT13.0% (6/46)[98]

TunisiaHIV+HIV−Diarrhea, other gastrointestinal complaintsFecal samplesPCR20% (7/35) in HIV+
5.35% (3/56) in HIV−
[62]
MaliHIV+, 
and HIV–
80% with chronic diarrheaFecal samplesLM, partially confirmed by TEM32% (28/88) in HIV+;
27% (3/11) in HIV–
[51]
MaliHIV+ adults;HIV– childrenDiarrheaFecal samplesLM, IFAT, PCR13.1% (8/61) in HIV+;
(0/71) in HIV–
[47]
NigerHIV+ (227 adults, 1 child) NAFecal samplesLM, RT-PCR, sequence analysis10.5% (24/228), all but one were adults[76]
NigerHIV+ adults;
HIV– children
Diarrhea, other gastrointestinal complaints Fecal samplesLM, partially confirmed by EMIn adults 7% (4/60) with diarrhea; in children 1% (6/593) with diarrhea, 0.5% (2/397) without diarrhea [49]
NigeriaHIV− childrenDiarrheic and nondiarrheic childrenFecal samplesPCR, sequence analysis9.3% (4/43)[67]
NigeriaHIV+ childrenDiarrheic and nondiarrheic childrenFecal samplesLM, IFAT, PCR, sequence analysis2.6% (193)[68]
CameroonHIV+Diarrhea, other complaintsFecal samplesLM, PCR-RFLP6.5% (3/46) with diarrhea; 4.6% (5/108) without diarrhea[55]
CameroonVillagers <1 to 80 years;
NAFecal samplesIFAT-MAb, confirmed by PCR, sequence analysis2.9% (22/758) in HIV–  
0.5% (4/758) HIV+
[99]
CameroonHIV+ with TB; HIV– with TB; apparently immunocompetent personsDiarrheic and asymptomatic personsFecal samplesLM, IFAT-MAb35.7% (10/28) in HIV+ with TB; 24,0% (6/25) in HIV– with TB; 67.5% (85/126) in immunocompetent persons[53]
AfricaGabonHIV+ > 16 yearsDiarrhea, other gastrointestinal complaintsFecal samplesIFAT-MAb, confirmed by PCR, sequence analysis3.0% (25/822)[99]
Democratic Republic of the CongoAIDS patients,
>15 years
Diarrhea, other gastrointestinal complaintsFecal samplesPCR5.1% (9/175) in hospital patients[60]
UgandaChildren (immune status not determined) Diarrhea, other complaintsFecal samplesLM, confirmed by PCR, sequence analysis17.4% (310/1,779) with diarrhea; 16.8% (112/667) without diarrhea[18]
UgandaHIV+ children;HIV– childrenPersistent diarrhea, dehydrationFecal samplesPCROvelall 32.9% (80/243);
76.9% (70/91) in HIV+;
6.6% (10/152) in HIV–
[64]
EthiopiaHIV+ and HIV– > 14 yearsDiarrheaFecal samplesLM, PCR12.3% (30/243) in HIV+;
(0/29) in HIV–
[82]
TanzaniaIn patients HIV+ adults;
HIV+ and HIV– children
Chronic diarrhea, other complaintsFecal samplesLM, TEM3.5% (3/86) adults;
3.4% (2/59) children with diarrhea; 20% (4/20) control children
[77]
ZambiaHIV+Chronic diarrheaFecal samplesLM23% (16/69)[100]
ZimbabweHIV+Persistent diarrheaFecal samplesLM10% (13/129)[57]
ZimbabweHIV+DiarrheaFormalin-fixed fecal samplesPCR46% (34/74)[101]
ZimbabweHIV+DiarrheaFecal samplesLM, PCR18% (10/55) by LM;
51% (28/55) by PCR
[50]
ZimbabweHIV−Diarrhea, other gastrointestinal complaintsFecal samplesLM, confirmed by PCR33% (2/6)[61]
South AfricaHospital patients, HIV+ and HIV–;  school childrenDiarrhea Fecal samplesLM, PCR-RFLP, confirmed by RT-PCR12.9% (33/255) in hospital patients; 4.5% (3/67) of school children; 21.6% in HIV+ and 9% in HIV– with diarrhea[54]

ChinaChildrenDiarrheaFecal samplesPCR22.5% (9/40)[30]
IndiaHIV+DiarrheaFecal samplesLM2.5% (3/120)[55]
ThailandHIV+Chronic diarrheaFecal samplesLM, TEM27.2% (18/66)[58]
ThailandHIV+DiarrheaFecal samplesLM, confirmed by TEM11% (32/288)[59]
ThailandHIV+ children; HIV– childrenDiarrheaFecal samplesLM confirmed by TEM25.3% (24/95) in HIV+;
14.9% (13/87) in HIV–
[65]
AsiaThailandHIV+ and HIV– children from an orphanageAsymptomaticFecal samplesLM, confirmed by TEMOverall 4.1% (12/290);   2.6% (1/39) in HIV+; 4.4% (11/251) in HIV–[5]
ThailandHIV+ adultsNAFecal samplesLM, PCR5.6% (5/90)[102]
Thailand73 HIV+, 463 HIV−; children (<11 years) and child care workers533 asymptomatic and 7 patients with diarrhea.Fecal samplesLM, PCR1.3%−6.5%  overall 13.9% (75/540)[19]
VietnamHIV+NAFecal samplesLM, RT-PCR, sequence analysis7.1% (3/42)[76]
AustraliaHIV+Diarrhea and other gastrointestinal complaintsDuodenal biopsiesLM, confirmed by EM30% (33/109) with diarrhea; 1.4% (1/71) without diarrhea[39]

OceaniaAustraliaHIV+DiarrheaFecal samplesLM3.6% (5/139)[103]

LM: light microscopy, EM: electron microscopy, TEM: transmission electron microscopy, IFAT-MAb: indirect immunofluorescent assay with monoclonal antibodies, NA: not available, TB: tuberculosis, Pts: patients.