Diffuse small bowel thickening in aids patient - a case report
BMC Infectious Diseases
Diffuse small bowel thickening in Aids patient - a case report
Rohit Singla 0
Samriti Hari 1
Surendra K Sharma 0
0 Department of Medicine, All India Institute of Medical Sciences , New Delhi , India
1 Department of Radio Diagnosis, All India Institute of Medical Sciences , New Delhi , India , Study conducted at All India Institute of Medical Sciences , New Delhi-110029 , India
Background: Diarrhea is common in HIV/AIDS patients, caused by both classic enteric pathogens and different opportunistic agents. Infection with these different pathogens may lead to similar radiological findings, thus causing diagnostic confusion. Case presentation: A 30-yr-old female with AIDS presented with chronic diarrhea of 4 months duration. She had diffuse small bowel thickening present on CT scan of her abdomen, with stool examination showing no parasites. She was erroneously diagnosed as abdominal tuberculosis and given antituberculosis drugs with which she showed no improvement. Repeat stool examination later at a specialized laboratory revealed Cryptosporidium parvum infection. The patient was given an extended course of nitazoxanide treatment, as her stool examination was positive for Cryptosporidium parvum even after 2 weeks of drug consumption. Parasite clearance was documented after 10 weeks of treatment. Interestingly, the bowel thickening reversed with parasitological clearance. Conclusions: Cryptosporidium parvum may lead to small bowel thickening in AIDS patients. This small bowel thickening may reverse following parasitological clearance.
Diarrhea is a common manifestation of AIDS [1,2]
(acquired immunodeficiency syndrome), causing
significant morbidity and mortality. Diarrhea in AIDS patients
is caused by both classic enteric pathogens and different
opportunistic agents. Infection with these different
pathogens may lead to similar radiological findings, thus
causing diagnostic confusion.
Cryptosporidium parvum is a common cause of
diarrhea in AIDS patients . The fact that it may cause
diffuse small bowel thickening has been reported by
Redvanly et al , but is not widely recognized. Limited
treatment options are available against this parasite.
Nitazoxanide is the only drug approved for treatment of
this disease. However, there is not much data supporting
its efficacy in immunocompromised individuals. Also,
there are no clear guidelines stating the exact duration
of treatment with this drug.
A 30-yr-old female, diagnosed case of AIDS, was
admitted for evaluation of weight loss and intractable
diarrhea of 4 months duration. The patient complained
of chronic, painless, nonbloody, profuse watery diarrhea
with a weight loss of 10 kg (decrease to 30 kg from 40 kg
prior to illness). She had no complaints of fever, cough
Previously, during evaluation of her complaints in the
outpatient department, she was discovered to be HIV
(human immunodeficiency virus) infected with a CD4
count of 38 cells/l. She also had anemia with
hemoglobin value of 8 g/dl, normal kidney function, normal
AST/ALT (aspartate aminotransferase/alanine
aminotransferase) and elevated serum alkaline phosphatase.
Stool examination showed no red blood cells or
leukocytes, and no ova or cysts were observed. A contrast
enhanced CT scan of the abdomen (figure 1) showed
diffuse small bowel wall thickening, a fatty liver and no
significant lymphadenopathy or ascites. Her chest
radiograph was normal. Based on these details, a diagnosis of
abdominal tuberculosis was made 2 months back, and
she was started on standard 4-drug regimen for
treatment of tuberculosis. Besides this, she was also
given co-trimoxazole and once a week azithromycin
prophylaxis for Pneumocystis jiroveci and mycobacterium
avium-intracellulare infection respectively. Two weeks
later she was started on non-zidovudine based HAART
(highly active antiretroviral therapy), after she had
tolerated antituberculosis drugs. However diarrhea failed to
improve, and she continued to lose weight.
During this admission her stool sample was sent to a
specialized microbiology laboratory, where acid fast
oocysts of Cryptosporidium parvum were observed. Her
antituberculosis drugs were stopped and she was started
on treatment with tablet Nitazoxanide 500 mg twice a
day. Her peripheral smear showed a megaloblatic
anemia (mean corpuscular volume - 120 fl), for which folate
and vitamin B12 were supplemented. Her kidney
functions, AST/ALT were again normal, but she had raised
serum alkaline phosphatase and a low serum albumin of
2.8 g/dl. In hospital she was also given supportive care
with oral rehydration solution, antidiarrhoeals, and a
nutritious diet low in lactose. After 2 weeks of
nitazoxanide treatment the patients stool remained positive for
cryptosporidium. Her hemoglobin level had improved
with folate and vitamin B12 supplementation. At this
moment it was decided to discharge her on extended
nitazoxanide treatment while continuing HAART,
antibiotic prophylaxis and folate and vitamin B12, with
monthly follow up.
Patient was again observed 2 months after discharge.
Her diarrhea had settled for last 1 week. Her stool this
time was negative for Cryptosporidium parvum, which
was confirmed twice. Repeat CT scan of the abdomen
(figure 2) showed resolution of the small bowel
thickening, persistent fatty liver, no lymphadenopathy or ascites.
A repeat CD4 count was done which was 36 cells/l
Following parasitological clearance, the patient showed
improvement in appetite and gained 5 kg weight over
next one month. HAART and vitamin supplementation
was continued. In view of lack of definite guidelines on
secondary prophylaxis, the authors decided to continue
nitazoxanide until the patient would achieve a CD4
count of 100 cells/l.
The number of HIV infected individuals is continuing to
increase worldwide. World Health Organization
estimated that 33 million individuals worldwide were HIV
infected at the end of year 2007 . Diarrhea is a
common manifestation of this disease, causing significant
morbidity and mortality [2,3]. Superimposed infection
by both classic pathogens and different opportunistic
agents results due to defective immunity, leading to
Cryptosporidium is a protozoan parasite which causes
a self-limited diarrhoeal illness in immunocompetent
individuals and chronic, intractable diarrhea in AIDS
patients; especially those with a CD4 count < 100/ul.
Typically, diarrhea is profuse, watery, nonbloody, leading
to fluid and electrolyte depletion. Stool examination
shows no red blood cells or leukocytes. In a recently
done study at Pune in India , 16 (12%) of 137
consecutive HIV infected patients with diarrhea had
Cryptosporidium parvum infection.
Cryptosporidial infection has a predilection for the
proximal small bowel, resulting in nonspecific thickening
of the duodenum, jejenum and proximal ileum .
Multiple loops of fluid-filled and thickened small bowel loop
can be identified on CT. Lymphadenopathy is not a
feature of the disease . Infection with Isospora belli can
result in a gastrointestinal disease that is clinically and
radiologically indistinguishable from cryptosporidiosis
. Small bowel thickening in AIDS patients may also be
seen due to small bowel lymphoma  or infection with
mycobacterium avium-intracellulare [9,10], both of
which are associated with lymphadenopathy.
Mycobacterium tuberculosis infection results in necrotic lymph
nodes on CT in 90% of patients, with focal hepatic and
splenic lesions, ascites and distal ileal thickening .
Hence, the finding of diffuse small bowel wall thickening
with no lymphadenopathy and no focal lesions in liver/
spleen in our case argued against a diagnosis of
Our case also shows that the small bowel thickening
seen on CT abdomen resolved with parasitological
clearance. Such a result is expected, but not previously
reported in English literature.
Limited treatment options are available which have
shown success in eradicating this parasite in
immunocompromised patients. In a double-blind randomised
controlled trial in Mexico , nitazoxanide 1-2 g daily
for 2 weeks resulted in parasitologic cure in 65% of
treated patients. Another trial done at United States 
supported the use of nitazoxanide in AIDS patients with
diarrhoea. However, a recently conducted Cochrane
review  which included 7 trials involving 169
patients showed no reduction in the duration or
frequency of diarrhoea by nitazoxanide compared with
placebo. Also, there was a lot of heterogeneity in drug
dosage and duration of treatment. The CDC guidelines
presently recommend nitazoxanide along with
antiretroviral treatment for AIDS patients with
cryptosporidiosis. These antiparasitic drugs, however, should never be
used as a substitute for HAART in the treatment of
Our case shows that extended treatment with
nitazoxanide may lead to parasitological clearance, even in face
of low CD4 count. In our case, the lack of rise in CD4
count, despite consuming 4 months of HAART can be
explained by various factors. It could be ascribed to
malabsorption of drugs due to chronic diarrhea.
Additionally, non-adherence may also explain poor response
to HAART in addition to malabsorption. Lack of rise in
CD4 count supports the notion that parasitological
clearance was likely because of nitazoxanide, and not
secondary to immune reconstitution. However, change in CD4
count is an indirect measure of efficacy of HAART. This
observation in the absence of demonstration of
concomitant rise in viral load does not definitively prove that
HAART was not efficacious.
Paromomycin and azithromycin have also been tried,
with little data supporting their efficacy. Best treatment
option remains immune reconstitution with HAART. This
results in excellent clinical responses as assessed by stool
frequency, weight gain, and clearance of oocysts from the
stool. However, rapid relapse after discontinuation of
antiretroviral therapy suggests that cryptosporidial
infection is suppressed rather than cured [15,16]. Supportive
care with antidiarrhoeals, correction of fluid and
electrolyte disturbance, and a nutritious diet low in lactose
should also be provided to these patients.
Cryptosporidium parvum is a frequent cause of
diarrhea in AIDS patients, especially those with a CD4
count < 100/ul. It may lead to small bowel thickening,
which should not be ascribed to other etiologies in an
appropriate clinical setting. This small bowel
thickening may reverse following parasitological clearance.
Limited treatment options are available against this
pathogen. Extended treatment with nitazoxanide along
with HAART may help in achieving parasitological
AIDS: acquired immunodeficiency syndrome; ALT: alanine aminotransferase;
AST: aspartate aminotransferase; HIV: human immunodeficiency virus;
RS was involved in patient care, and was a major contributor in writing the
manuscript. SH was the radiologist who interpreted the CT films. SKS was
involved in writing the manuscript and patient care. All authors have read
and approved the final manuscript
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