Download Associated Risk Factors and Immune Status

Jpn. J. Infect. Dis., 60, 76-81, 2007
Original Article
Enteric Opportunistic Parasites among HIV Infected Individuals:
Associated Risk Factors and Immune Status
Kaushal Kumar Dwivedi1*, Ganga Prasad2, Sanjeev Saini3,
Surbhi Mahajan1, Shiv Lal1 and Usha Krishan Baveja1,4
1
Centre for AIDS and Related Diseases, National Institute of Communicable Diseases, Delhi;
Department of Microbiology, Gurukul Kangari University, Haridwar; 3Department of Microbiology,
Maulana Azad Medical College; and 4William J. Clinton Foundation, New Delhi, India
2
(Received September 11, 2006. Accepted December 20, 2006)
SUMMARY: Data on various etiologic agents causing diarrhea in human immunodeficiency virus type-1 (HIV1) infected individuals are sparse in Delhi, India. The present study was undertaken to identify various causative
agents, the role of associated risk factors and immune status. A case-control study was conducted among 75 HIV1 infected individuals, 50 with and 25 without diarrheal infection. Fecal samples were screened for coccidian
parasites, enteric protozoa, and helminthes by using various staining techniques. The CD4+ T-lymphocyte count
was estimated. Enteric parasites were identified among 62.7% individuals, of which Cryptosporidium emerged
as the single largest pathogen predominant among 33% of the individuals (P < 0.025). Other parasites diagnosed
that were significantly associated with diarrhea were Giardia lamblia (13.3%), microsporidia (6.7%), and
Isospora belli (2.7%). Chronic infected diarrheal cases were found to have polyparasitic infections. The mean
CD4+ cell count was found to be lower among the diarrheal cases when compared with the non-diarrheal cases
(mean, 141 cells/mm3 versus 390 cells/mm3). Similarly, among diarrheal individuals, the chronic diarrheal cases
had a comparatively lower CD4+ cell count than the acute cases (mean, 123 cells/mm3 versus 265 cells/mm3). Risk
factors found significant during multivariate analysis were: residence in a slum, exposure to pets and animals,
use of public toilets, and practice of unsafe homosexual activity. Enteric coccidian parasites were identified as
significant agents associated with diarrhea, especially among those with improper hygiene, multiple infections
and a lower CD4+ cell count. Thus, this study emphasizes the need for routine screening of enteric parasites as
well as education about practicing personal hygiene and taking timely and appropriate prophylactic measures.
sites in HIV infected individuals with and without diarrhea,
and to measure associated risk factors and their correlation
with the CD4+ T-lymphocyte count.
INTRODUCTION
Human immunodeficiency virus (HIV)/AIDS ranks among
the most dreaded diseases afflicting mankind, causing dysfunction of both limbs of the immune system, resulting in overwhelming and fatal opportunistic infections. Gastrointestinal
involvement, primarily in the form of diarrhea, is a universal
problem affecting almost 90% of HIV infected patients in
developing countries (1).
Because of the increase of HIV in India (an estimated 5.2
million HIV infected persons with 111,000 AIDS cases among
them) (2) and the high incidence of diarrhea among persons
with HIV/AIDS, there is a strong need for regional and
parameter-specific studies of these infections. In particular,
Cryptosporidium parvum, Isospora belli, microsporidia,
Cyclospora cayetanensis, Giardia lamblia, and bacterial and
viral pathogens have been reported to be associated, as validated by various studies in this region (3,4). These pathogens
are recognized as an important cause of gastroenteritis in the
community as well as in immunocompromised individuals.
Various risk factors like using contaminated drinking water,
animal exposure, etc. have been studied in other countries,
but data related to such studies is sparse in India, particularly
in Delhi. Therefore, the present study was undertaken with
the objective of accounting for the prevalence of enteric para-
MATERIALS AND METHODS
This case-control study was conducted between January
2004 to February 2005 in the Centre for AIDS and Related
Diseases, National Institute of Communicable Diseases,
Delhi, after the approval of the institutional ethical committee. This center is one of the premier centers for HIV/AIDS
in India and provides services to all walk-in patients. Therefore, the enrolled patients included those referred by various
clinicians for CD4+ T-cell estimation and parasitic identification in fecal samples. Patients with confirmed HIV
seroreactivity who had not received any antiprotozoal or
antiretroviral treatment in the past 3 weeks were enrolled.
Initially, 100 patients were enrolled, but 25 of them were later
excluded from the study: 12 patients who did not submit
fecal samples, six who had taken medications in the past 3
weeks, five who did not provide consent, one patient who
was HIV seronegative and one patient in whom the CD4+
cell count could not be performed. The final study was conducted among 75 HIV seropositive patients, 50 who presented
with diarrhea and were thus considered case-subjects, and
25 without diarrhea who were considered case-controls. In
addition, the controls had to be non-diarrheals for at least 14
days prior to enrollment in the study. Background information, including the sociodemography, type of illness, clinical
symptoms and risk factors (for the last 3 months) were
*Corresponding author: Mailing address: Centre for AIDS and
Related Diseases, National Institute of Communicable Diseases,
22- Shamnath Marg, Delhi-110054, India. Tel & Fax: +91-1123934517, E-mail: [email protected]
76
collected from each patient.
In the study, diarrhea was defined as having three or more
loose bowel movements within a 24-h period. These cases
were further subdivided into acute and chronic groups. Acute
cases were defined as those in whom diarrhea had lasted for
14 days, while those having diarrhea for more than 2 weeks
were identified as chronic.
The HIV-1 serostatus of each participant was confirmed
by adopting standard guidelines formulated by the National
AIDS Control Organization (NACO), Government of India
(5). A single fecal sample was collected in a leak proof,
labeled and sterile plastic container with 10% buffered
formalin as a preservative. The samples were concentrated
by the formalin-ether sedimentation technique and were
examined as a wet saline mount and iodine preparation for
the detection of ova, larvae and cysts (both direct and concentrated specimens). The samples were subjected to the
modified Ziehl-Neelsen technique for intestinal coccidian
infection (6). Positive or doubtful cryptosporidial samples
were further confirmed by direct immunofluorescence assay
(IFA) (Cellabs, Brookvale, Australia). A modified trichome
stain was used for confirmation of microsporidia (7). No
attempt was made to isolate bacteria and viruses.
Three mililiters of whole blood was collected in a vacutainer
containing K3 EDTA (Becton Dickinson, Paramus, N.J.,
USA) for enumeration of the CD4+ T-lymphocytes by flow
cytometer on an FACSCount system (Becton Dickinson).
Statistical analysis was performed to test the significance
of association between enteric parasites and risk factors by
using the chi-square (χ2) test, bivariate tabulation and calculations of odd ratios (OR) with a 95% confidence interval
(CI) limit. Factors found significant in univariate analysis were
entered in a multivariate model. A P value of <0.05 was
considered statistically significant.
by homosexuals (18, 24%) and transfusion recipients (12,
16%). Most of the participants resided in slums (27,
36%), followed by rural (25, 33.3%) and urban (23, 30.7%)
localities.
Many of the enrolled participants (10.7%) had taken
prophylactic antibiotics in the past few months (although
not within the 3 weeks prior to enrollment), especially for
Pneumocystis carinii pneumonia (PCP), and 18 (24%) had
experienced antiretroviral treatment but had discontinued it
because of side effects or because of financial hardship.
Twenty-seven (36%) and 16 (21.3%) individuals took up treatment for tuberculosis and oral ulcers, respectively.
The overall prevalence of enteric parasites was 62.7% (47
participants). Among diarrheal cases, 72% (36 participants)
were found positive for intestinal parasites, of whom
Cryptosporidium alone was predominant in 23 (63.9%) along
with other mixed infections. Furthermore, this infection was
significantly higher in diarrheal cases when compared with
non-diarrheal cases (P < 0.01).
A significantly higher proportion of diarrheal cases were
found to harbor enteric parasites when compared with nondiarrheal cases (72 versus 44%; P < 0.05). Among the infected diarrheal cases, enteric parasites were more frequent in
chronically infected individuals as compared to those having
acute infection (66.7 versus 33.3%). Overall, Cryptosporidium
and Ascaris were the parasites identified more frequently. In
addition, after comparing the parasites found in diarrheal cases
with non-diarrheal cases on the basis of the CD4+ count, the
former were found to be infected more with Cryptosporidium,
Giardia, Ascaris, and Ancyclostoma and to have a statistically significant lower mean CD4+ count (P < 0.001, < 0.01,
< 0.001 and < 0.05, respectively) as compared to the latter.
Similarly, when all protozoa and helminths were compared
between the two groups, a significantly lower mean CD4+
count was observed in the diarrheals than the non-diarrheals
(P < 0.001 and < 0.005) (Table 1).
We compared certain characteristics of the participants of
both groups, out of which gender and age were found to be
non-significant factors responsible for enteric parasitic infestations. A significant trend of infection was detected among
diarrheal individuals residing in slums (86.4%), followed by
RESULTS
Of the 75 enrolled cases, 57 (76%) were males and 18 (24%)
females. The males were older than the females (median age,
34 versus 31.5 years; range, 20 - 55 years). The majority of
the study participants were heterosexual (45, 60%) followed
Table 1. Prevalence of different enteric parasites among HIV/AIDS patients with comparison to
CD4+ T-lymphocyte count
Diarrheal (n = 50)
Mean CD4 count
(cells/mm3)
Non-diarrheal (n = 25)
%
Mean CD4 count
(cells/mm3)
Parasite1)
%
Cryptosporidium parvum 2)
Giardia lamblia
Microsporidium
Isospora belli
Entamoeba coli
Cyclospora cayetanensis
Ascaris lumbricoide
Ancyclostoma duodenale
Strongyloides stercoralis
All protozoa
All helminths
46
16
10
4
8
0
18
6
0
70
24
125
166
56
96
185
–
132
50
–
126
91
8
8
0
0
12
0
12
8
0
28
20
301
479
–
–
243
–
507
354
–
341
431
<0.001
<0.01
–
–
NS
–
<0.001
<0.05
–
<0.001
<0.005
Total infected
72
132
44
355
<0.05
1)
P value 3)
: The number of parasites may exceed the number of patients, as more than one parasite was
found in some patients.
2)
: P-value < 0.005 (chi-square test).
3)
: Student t test to compare CD4 count between diarrheal and non-diarrheal cases.
77
Table 2. Prevalence of enteric parasites in HIV/AIDS patients with and without diarrhea on the basis of different characteristics
Characteristic
Male
Female
Age (yrs)
15 - 24
25 - 44
≥45
Residence
Slum
Rural
Urban
Diarrheal status
Acute
Chronic
No
Pets and animal contact
Yes
No
Toilet facility
In-house
Open field
Public
Source of drinking water
Hand pump
Water tanker
Tap water
Risk group
Heterosexual
Homosexual
Transfusion recipient
Diarrheal
n = 50
n (%)
Odd ratio
(95% CI)
P value
(χ2 test)
Non-diarrheal
n = 25
n (%)
Odd ratio
(95% CI)
8/17 (47.0)
3/8 (37.5)
1.5 (0.4 - 6.4)
1
1/3 (33.3)
10/20 (50.0)
0/2 (0)
1
2 (0.3 - 12.5)
–
4/5 (80.0)
3/6 (50.0)
4/14 (35.7)
1.4 (0.3 - 5.7)
0.9 (0.2 - 4.9)
1
0 (0)
0 (0)
11/25 (44.0)
–
–
*
<0.9
P value
(χ2 test)
29/40 (72.5)
7/10 (70.0)
1.1 (0.3 - 3.9)
1
3/6 (50.0)
26/35 (74.2)
7/9 (77.8)
1
2.8 (0.6 - 12.3)
3.5 (0.5 - 22.7)
19/22 (86.4)
13/19 (68.4)
4/9 (44.4)
7.9 (1.8 - 35.4)
2.7 (2 - 10.6)
1
<0.025
for trend
12/23 (52.2)
24/27 (88.9)
0 (0.0)
1
1.7 (0.8 - 3.5)
<0.25
27/31 (87.1)
9/19 (47.4)
7.5 (2.4 - 24.0)
1
<0.01
8/11 (72.7)
3/14 (21.4)
9.8 (2.2 - 44.0)
1
<0.05
2/9 (22.2)
11/15 (73.3)
23/26 (88.5)
1
9.6 (1.9 - 49.0)
26.8 (5.1 - 141)
<0.001
for trend
1/8 (12.5)
4/8 (50.0)
6/9 (66.7)
1
7 (0.9 - 57.2)
3.5 (0.4 - 28.5)
<0.05
for trend
11/15 (73.3)
17/22 (77.3)
8/13 (61.5)
1.7 (0.4 - 6.4)
2.1 (0.6 - 7.3)
1
3/9 (33.3)
5/9 (55.6)
3/7 (42.9)
2.5 (0.5 - 12.3)
1.4 (0.3 - 7.7)
1
23/31 (74.2)
11/13 (84.6)
2/6 (33.3)
5.8 (1.8 - 28.7)
11.0 (1.8 - 67.2)
1
6/14 (42.9)
3/5 (60.0)
2/6 (33.3)
1.5 (0.3 - 8.0)
3.0 (0.4 - 23.5)
1
<0.1
<0.25
for trend
<0.025
<0.95
<0.25
<0.75
for trend
–
<0.75
for trend
<0.75
*Odd ratio cannot be estimated.
CI, confidence interval.
significant (P < 0.025 and P < 0.05, respectively) as compared to acutely infected ones. Furthermore, 14 (51.8%)
out of 27 chronically infected individuals and 6 (26.1%) out
of 23 acutely infected individuals presented with clinical
symptoms suggestive of AIDS (data not shown).
Of the total infected (n = 47), multiple parasitic infestations were identified in 17 (36.2%) individuals, among whom
16 (94.1%) were from the diarrheal group and only one (5.9%)
from the non-diarrheal group (P < 0.001). In addition, of
multiple infected diarrheal individuals, 14 (87.5%) and 2
(12.5%) were diagnosed with double and triple parasitic
infections, respectively, though in the non-diarrheal cases,
only one case of double parasitic infection was detected.
The immune status of the enrolled participants was assessed
by measuring the CD4+ T-cell count. The mean CD4+ count
of the study population was 224 ± 160 cells/mm3. Among
diarrheal cases it was 142 ± 97 cells/mm3 (range, 2 - 399),
whereas in non-diarrheal cases it was 390 ± 129 cells/mm3
those living in rural (68.4%) and urban areas (44.4%), (Pvalue for trend <0.025). Similarly, in the non-diarrheal cases,
inhabitants of slums were also found to be harboring more
parasitic infestation (80%) as compared to those from rural
and urban settings. In the diarrheal cases, chronic diarrhea
was observed in 27 (54%) and acute diarrhea in 23 (46%)
cases, of whom chronic cases had more enteric parasites
than acute ones (88.9 versus 52.2%). Contact with pets and
animals emerged as a significant factor with higher odds,
in both the diarrheal (P < 0.01) as well as the non-diarrheal
(P < 0.05) groups harboring enteric parasites. As far as toilet
facilities were concerned, public toilet users in diarrheal cases
were at a higher risk of harboring enteric parasites compared
to open field and in-house toilet users (P-value for trend
<0.001). A similar trend was also noticed in non-diarrheal
cases (P < 0.05). Regarding the source of drinking water, no
significant difference was noticed in both groups, perhaps
because water tanker users were found to be slightly more
infected than hand pump or tap water consumers. When
comparing the impact of risk groups among infected individuals, homosexual males were found to be at a significantly
higher risk (P < 0.025) in diarrheal cases (Table 2). In addition, diarrheal cases also reported various symptoms like
vomiting (6%), nausea (13%), flatulence (17%), fever (20%),
anorexia (30%), weight loss (32%), and abdominal pain
(33%). However, again in chronically infected cases, weight
loss (67%) and anorexia (65%) were found to be statistically
Table 3. Single and multiple parasitic infections in HIV/AIDS patients
Infection
Single
Dual
Triple
78
%
Diarrheal (n = 36)
Mean CD4 count
(cells/mm3)
55.6
38.9
5.6
161
105
33
Non-diarrheal (n = 11)
%
Mean CD4 count
(cells/mm3)
90.9
9.1
0
412
354
–
Table 4. Pattern of enteric parasitic infection in different immune categories on the basis of status of diarrhea
CD4 count
(cells/mm3)
0 (n = 14)
Acute Chronic
≤ 50
50 - 99
100 - 199
200 - 499
0
1
8
2
1
0
1
1
1 (n = 20)
Acute Chronic
0
1
2
7
2 (n = 14)
Acute Chronic
3
2
5
0
1
0
0
1
Residence in slum
Pets and animal contact
Public toilets
Homosexual risk activity
Odd ratio
95% CI
P-value (χ2 test)
10.8
8.8
22.6
7.0
3.5 - 33.8
3.8 - 21.7
6.2 - 82.9
1.7 - 28.4
<0.001
<0.001
<0.005
<0.001
0
0
0
0
2
0
0
0
Total (n = 50)
Acute Chronic
1
2
10
10
12
5
8
2
in diarrheal cases compared to that found in our study.
However, in non-diarrheal cases, workers have reported the
prevalence of intestinal parasites ranging from 12.9 - 40.0%
compared to 23.7% found in our study (1,9,10).
A high prevalence of Cryptosporidium was noticed in this
study (33.3%), as compared to other studies that reported a
prevalence ranging between 3.7 - 11.8% in India (1,3,4,11)
and 1.5 - 13.3% from other countries (9,10,12). However,
our results are in accordance with the study carried out in
Tanzania, where an up to 36% prevalence was reported (9).
To the best of our knowledge, such a high prevalence of
Cryptosporidium has been reported for the first time in Delhi,
India. This high prevalence may be due to overcrowding and
a low level of sanitation, as the majority of infected individuals were residing in slums and practicing personal unhygiene.
In addition to this, use of a direct IFA may have also led to an
improved diagnosis, otherwise, samples with low number
of oocysts may get overlooked by conventional acid fast
staining (13). In addition, in this study we also noticed a low
prevalence of I. belli (2.6%) with no cases of Cyclospora,
though prevalence has been mentioned in some reports from
different regions of this country (1,3,4). These observations
may be justified by the explanation that most of these patients
had taken trimethoprim-sulphamethoxazole as prophylactic
measures for PCP, which is quite effective against I. belli
and Cyclospora. This inexpensive drug may therefore have
additional beneficial effects as far as parasitic infections
are concerned. In addition, our findings for microsporidia
compared well with the studies carried out elsewhere (12).
We have found that the extent of deterioration of immunity, as measured by the CD4+ count, could predict the status
of diarrhea, i.e., acute or chronic and the presence of coccidian
parasites with or without multiple infections. It has been observed that patients with Cryptosporidium, microsporidia
or multiple infections who presented with chronic diarrhea
had a lower CD4+ count. These findings are consistent with
other studies (12). It is relevant to mention here that CD4+ Tlymphocytes are necessary for the resolution of both acute
and chronic cryptosporidiosis. The results of experimental
infection studies with Cryptosporidium in mice and calves
have shown that immunity is dependent on the number of
CD4+ T cells. CD4+ cells help in increasing the intraepithelial
lymphocyte population and generating gamma interferon.
Interleukin-12 may play a role, possibly through its ability
to induce gamma interferon production. Antigen-driven
interleukin-12 production in macrophages requires interaction between CD40 on antigen presenting cells and CD40
ligands on CD4+ T-lymphocytes (14). Furthermore, the presence of Cryptosporidium in two individuals from the nondiarrheal group (though they may be acting as carriers
shedding oocysts in feces without any clinical manifestation)
may be explained by the fact that they were not co-infected
with any other parasites and had a higher CD4+ count.
In the present study, three helminths (Ascaris, Ancyclostoma,
and Strongyloides) were taken into consideration. A very high
Table 5. Multivariate logistic regression analysis showing association of
different risk factors with and without diarrhea
Risk factors
6
3
2
1
3 (n = 2)
Acute Chronic
CI, confidence interval.
(range, 156 - 660). The mean CD4+ count was found to be
significantly lower in the diarrheal cases with triple parasitic
infection (33 cells/mm3) as compared to those with double
(105 cells/mm3) and single infections (161 cells/mm3). Both
individuals with a triple infection were found to have CD4+
counts ≤ 50 cells/mm3. Only one individual was found to be
infected with a double parasitic infection in the non-diarrheal
group with a CD4+ count of 354 cells/mm3 as compared to 10
individuals infected with a single parasite (mean, 412 cells/
mm3). However, diarrheal individuals with either single or
multiple infections had a lower mean CD4+ count than the
non-diarrheal cases (Table 3).
The pattern of enteric parasitic infections at various
immunity levels on the basis of diarrheal status showed
that the chronically infected diarrheal individuals had a
significantly lower mean CD4+ count than the acute infected
individuals (123 cells/mm3 versus 265 cells/mm3). Furthermore, enteric parasites were more prevalent in the chronic
group, of whom the maximum number of individuals (11,
30.6%) belonged to the immune category with a CD4+ count
of ≤ 50 cells/mm3, followed by those in an immune category
with a CD4+ count of 100 - 199 cells/mm3 (7, 19.4%) (Table
4). Similarly, in cases of acute infection, 8 (66.7%) individuals were in the range of 200 - 499 cells/mm3 followed by 2
(16.7%) in 100 - 199 cells/mm3.
Risk factors found significant in univariate analysis, namely
residence, exposure to pets and animals, and using public toilet
were entered into the multivariate model, where residence in
a slum (P < 0.001), exposure to pets and animals (P < 0.001),
using public toilet (P < 0.005) and practicing homosexual
risk activity (P < 0.001) emerged as significant factors related
to enteric parasitic infection (Table 5).
DISCUSSION
Due to deterioration of the immune system because of HIV
infection, numerous opportunistic infections occur, of which
gastrointestinal parasitic infection is a universally recognized
problem. This largely presents with diarrheal symptoms leading to life threatening complications (8).
In the present study, the overall prevalence of intestinal
parasites was found to be considerably high (62.7%); of which
diarrheal and non-diarrheal cases accounted for 76.6 and
23.4%, respectively. Studies carried out by other workers
have documented a relatively lower prevalence (53.6-57.4%)
79
of transmission cannot be identified, some possible modes
may be through touching door handles or taps, or using the
cups which are kept in public toilets for cleaning, as water
is often used for cleaning in India rather than toilet paper.
Being a homosexual was also found to be a significant factor
for harboring enteric parasites (OR, 7.0; 95% CI, 1.7 - 28.4).
Eisenberg et al. have found that the odds of cryptosporidiosis
were increased among those who had insertive anal sex (21).
Hallard et al. have also supported the same finding. Moreover, they also found that men who had had more than one
sexual partner in the past month were nearly 7 times more
likely to have had Cryptosporidium diarrhea (OR, 6.67; 95%
CI, 1.15 - 38.60; P = 0.034) (22).
There were some limitations to this study. First, the study
was performed using a small sample size. Second, due to
resource constraints we were not be able to isolate bacteria
or viruses, or to perform sensitive tests like PCR for confirmation of parasites such as microsporidia. In addition, the participants were unwilling to participate in a follow up, and thus
no attempt was made to obtain follow up information regarding diarrheal episodes, effectiveness of prophylactic regimens,
etc.
In conclusion, the present study highlights the magnitude
of enteric parasites in HIV infected individuals with and without diarrhea. Cryptosporidium was found to be an important
parasite in HIV positive patients with diarrhea (P < 0.01).
Polyparasitic infection was further observed in diarrheal
patients (chronic), particularly in those with a lower CD4+
count. Therefore, when assessing a patient’s immune status
and enteric pathogenic profile, it is recommended that a
routine screening for fecal specimens is performed and that
the CD4+ count is obtained.
Pathogenic burden accelerates HIV disease progression and
contributes towards early morbidity. Coccidian and other
intestinal parasites were largely diagnosed in those practicing
poor sanitation and improper personal hygiene practices. This
emphasizes the need to educate HIV infected individuals about
practicing safer sexual practices, better sanitation and personal hygiene, and in using boiled or properly filtered water
and avoiding exposure to domestic pets. Furthermore, routine anti-enteric parasitic prophylactic measures should be
provided in clinical settings on a regular basis to persons with
a significantly lower CD4+ count. Finally, the findings in this
study are limited due to the small sample size. A large, prospective cohort study is needed to obtain conclusive results
so as to formulate further appropriate intervention strategies.
prevalence of Ascaris (16%) and Ancyclostoma (6.7%) was
observed with no case of Strongyloides seen as compared
to other studies reported from this country. Surprisingly,
Strongyloides is very low in the general population (0.4%)
as well as in HIV infected individuals (0.9 - 6.3%) in India
except in Manipur, one of the northeastern states in which a
high prevalence of this helminth (27.3%) has been reported
(1,4,11,15-17). It is clear that there is no specific prevalence
pattern of occurrence of parasites among HIV/AIDS patients.
Distribution of parasites may depend on geographical/ecological variation and behavioral activities (18). Thus, this
difference can be seen between country-to-country and even
within different regions of the same country.
A low CD4+ count was observed in diarrheal cases with
helminth infestation as compared to non-diarrheal cases. This
may be due to the fact that diarrheal cases with helminths
presented with other enteric parasitic infections, which may
lead to severe suppression of the immune system. Therefore,
screening of helminths must be included in routine parasitic
examination, as studies showed that helminthic infection in
HIV infected individuals may accelerate HIV disease progression. It has also been shown that the treatment and successful
elimination of intestinal worms was associated with decreased
HIV plasma viral load (15,18,19). Interestingly, multiple
infections were reported in 32% of diarrheal individuals as
compared to other studies carried out in different region of
India, which showed a comparatively lower prevalence (4,11).
However, we are not able to explain this finding.
As far as risk factors are concerned, we have taken eight
variables into consideration, out of which four variables,
residence, exposure to pets and animals, type of toilet used,
and the practice of risky behaviors were found significant for
acquiring parasitic infections. Poor sanitation emerged as a
crucial factor in our study, as highlighted from the variables
found significant in the multivariate model. The odds of
acquiring various diarrheal parasites were found to be higher
for slum residents compared to urban and rural inhabitants
(OR, 10.8; 95% CI, 3.5 - 33.8). However, in a study carried
out in Africa, it was found that persons who had spent time in
rural areas were at risk of having parasites in their stool (18).
A higher prevalence of intestinal parasitic infection was not
found in Delhi villages, which contradicts the finding reported
in the African study. This may be due to the highly developed
civil structure in Delhi villages.
Exposure to pets and animals also accounted for a significant parasitic burden, as was obeserved in our study (OR,
8.8; 95% CI, 3.8 - 21.7). After asking participants about
their contact with animals, the majority of them (56%)
reported a positive history of contact with pets and animals,
mainly dogs, cows, buffalloes, pigs, sheep, goats, and other
domestic animals within at last 3 - 4 months. They had generally kept these animals as sources of milk and meat within
their house premises, and also had frequent contact with them
for cleaning, milking, etc. Glaser et al. (20) in their study
have shown that HIV positive patients who own dogs were at
increased risk of Cryptosporidium infection (OR, 2.19; 95%
CI, 0.9 - 5.3; P = 0.05). Moreover, according to one other
study, contact with farm animals, including cleaning up after
them, milking them, etc., has also been shown to be associated with a risk of diarrhea (OR, 2.4; 95% CI, 0.6 - 10.0)
(21). After getting information regarding the type of toilet
facility used, the majority of the participants using public
toilets were found to be infected with various diarrheagenic
parasites (OR, 22.6; 95% CI, 6.2 - 82.9). Although, the mode
ACKNOWLEDGMENTS
We would like to thank Mr. Pritam Singh (Opportunistic Infection Unit,
Centre for AIDS & Related Diseases, NICD) for his continuous support for
various tests.
REFERENCES
1. Mukhopadhya, A., Ramakrishna, B.S., Kang, G., et al. (1999): Enteric
pathogens in southern Indian HIV-infected patients with and without
diarrhoea. Indian J. Med. Res., 109, 85-89.
2. National AIDS Control Organization: Facts and Figures. Online at <http://
www.nacoonline.org>. Accessed 16 May 2006.
3. Mohandas, K., Sehgal, R., Sud, A., et al. (2002): Prevalence of intestinal
parasitic pathogens in HIV-seropositive individuals in Northern India.
Jpn. J. Infect. Dis., 55, 83-84.
4. Kumar, S.S., Ananthan, S. and Saravanan, P. (2002): Role of coccidian
parasites in causation of diarrhoea in HIV infected patients in Chennal.
Indian J. Med. Res., 116, 85-89.
5. Government of India (2001): Manual on Quality Assurance Practices in
HIV Testing Laboratories. p. 8-12. In U.K. Baveja and D. Chattopadhya
80
(ed.), National AIDS Control Organization, New Delhi.
6. Garcia, L.S. and Bruckner, D.A. (1997): Macroscopic and microscopic
examination of fecal specimens. p. 608-651. In L.S. Garcia and D.A.
Bruckner (ed.), Diagnostic Medical Parasitology. 3rd ed. American
Society for Microbiology Press, Washington, D.C.
7. Weber, R., Bryan, R.T., Owen, R.L., et al. (1992): Improved lightmicroscopical detection of microsporidia spores in stool and duodenal
aspirate. N. Engl. J. Med., 326, 161-166.
8. Hailemariam, G., Kassu, A., Abebe, G., et al. (2004): Intestinal parasitic infections in HIV/AIDS and HIV seronegative individuals in a
teaching hospital, Ethiopia. Jpn. J. Infect. Dis., 57, 41-43.
9. Zali, M.R., Mehr, A.J., Rezaian, M., et al. (2004): Prevalence of Intestinal parasitic pathogens among HIV- positive individuals in Iran. Jpn.
J. Infect. Dis., 57, 268-270.
10. Carcamo, C., Hooton, T., Wener, M.H., et al. (2005): Etiologies and
manifestations of persistent diarrhea in adults with HIV-1 infection: a
case-control study in Lima, Peru. J. Infect. Dis., 191, 11-19.
11. Prasad, K.N., Nag, V.L., Dhole, T.N., et al. (2000): Identification of
enteric pathogens in HIV- positive patients with diarrhea in Northern
India. J. Health Popul. Nutr., 18, 23-26.
12. Navin, T.R., Weber, R., Vugia, D.J., et al. (1999): Declining CD4+
T-lymphocyte counts are associated with increased risk of enteric parasitosis and chronic diarrhea: results of a 3- year longitudinal study. J.
Acquir. Immune. Defic. Syndr., 20, 154-159.
13. Baron, E.J., Peterson, L.R. and Finegold, S.M. (1994): Laboratory
methods for diagnosis of parasitic infections. p. 791. In E.J. Baron,
L.R. Peterson and S.M. Finegold (ed.), Bailey and Scott’s Diagnostic
Microbiology. 10th ed. The CV Mosby Co., St. Louis.
14. Hunter, P.R. and Nichols, G. (2002): Epidemiology and clinical features of Cryptosporidium infection in immunocompromised patients.
Clin. Microbiol. Rev., 15, 145-154.
15. Singh, L.A., Chinglensana, L., Singh, Ng.B., et al. (2004): Helminthiasis
in HIV infection: a brief report from Manipur, (India). J. Commun. Dis.,
36, 293-296.
16. Ananthasubramanian, M., Ananthan, S., Vennila, R., et al. (1997):
Cryptosporidium in AIDS patients in South India: a laboratory investigation. J. Commun. Dis., 29, 29-33.
17. Nagamani, K., Rajkumari, A. and Gyaneshwari. (2001): Cryptosporidiosis
in a tertiary care hospital in Andhra Pradesh. Indian J. Med. Microbiol.,
19, 215-216.
18. Modjarrad, K., Zulu, I., Redden, D.T., et al. (2005): Prevalence and
predictors of intestinal helminth infections among human immunodeficiency virus type 1-infected adults in an urban African setting. Am.
J. Trop. Med. Hyg., 73, 777-782.
19. Bentwich, Z., Kalinkovich, A. and Weisman, Z. (1995): Immune activation is a dominant factor in the pathogenesis of African AIDS.
Immunol. Today, 16, 187-191.
20. Glaser, C.A., Safrin, S., Reingold, A., et al. (1998): Association between
Cryptosporidium infection and animal exposure in HIV-infected individuals. J. Acquir. Immune. Defic. Syndr., 17, 79-82.
21. Eisenberg, J.N.S., Wade, T.J., Charles, S., et al. (2002): Risk factors in
HIV-associated diarrhoeal disease: the role of drinking water, medication and immune status. Epidemiol. Infect., 128, 73-81.
22. Hellard, M., Hocking, J., Willis, J., et al. (2003): Risk factors leading to
Cryptosporidium infection in men who have sex with men. Sex. Trans.
Infect., 79, 412-414.
81