This document discusses enteric bacterial pathogens in HIV infected patients. It covers the epidemiology, pathogenesis, clinical presentation, diagnosis, and treatment of common enteric bacteria like E. coli, Salmonella, Shigella, and Campylobacter in HIV patients. Enteric bacteria normally found in the gut can cause severe illness in HIV patients due to their weakened immunity. The rates of infection are 10 times higher in AIDS patients. Clinical symptoms range from self-limiting diarrhea to bloody diarrhea. Diagnosis involves stool culture and blood culture if sepsis is suspected. Treatment depends on the bacteria and severity of infection, and involves antibiotics like ciprofloxacin. Preventing exposure to contaminated food and water and practicing good hand hygiene

1. TOPIC: EPIDEMIOLOGY, DIAGNOSIS AND TREATMENT OF
ENTERIC BACTERIA PATHOGENS IN HIV INFECTED
PATIENTS
By
Akinyemi Testimony
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2. TABLE OF CONTENTS
 INTRODUCTION
 AETIOLOGY
 EPIDEMIOLOGY
 PATHOLOGY
 PATHOGENICITY
 CLINICAL MANIFESTATION
 DIAGNOSIS
 PREVENTION
 TREATMENT
 REFERENCES
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3. INTRODUCTION
 Human immunodeficiency virus (HIV) associated
immunosuppression increases the vulnerability of patients
to various infections.
 The symptoms, duration and potential for severe
manifestations of enteric bacterial infections for instance
have been shown to be influenced by several factors such
as immunity status of the patient.
(Pavlinac et al., 2014; Kebede et al., 2017)
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4. AETIOLOGY
 Enteric bacteria are generally refered to as normal gut
flora, but they can be pathogenic /opportunistic pathogens
 Enteric bacterial pathogens has been identified as etiologic
agents with the potential to cause severe illness in HIV-
infected patients.
 Examples of these enteric bacteria pathogens are
Escherichia coli, Salmonella, Shigella, Yersinia,
Campylobacter jejuni and Clostridium difficile e.t.c.
(Mercado et al., 2018; Ngalani et al., 2019)
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5. Figure 1: Etiologic features of diarrheagnic enteric bacterial
Source: (Okada et al., 2020) 1-21 3

6. Figure 2: Globally Statistics of People living with HIV
Source: (Gassama et al., 2018)
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7. EPIDEMIOLOGY (CONT’D)
 Gastrointestinal tract (GIT) illnesses such as diarrhoea affect up to
95% of persons with AIDS, frequently causing malabsorption,
significant weight loss, higher rates of extra-intestinal infections, and
increased mortality in developing countries.
 Salmonella bacteria causes about 1.35 million infections, 26,500
hospitalizations, and 420 deaths in the United States every year.
 Rates of Gram-negative bacterial enteric infections are at least 10-
fold higher among HIV-infected adults and the risk is greatest in
individuals with clinical AIDS.
(Mercado et al., 2018; Haung et al., 2019)
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8. PATHOLOGY
 Enteric bacteria: Watery diarrhoea e.g
 ETECs (Enterotoxigenic E. coli)
 EPECs (Enteropathogenic E. coli)
 Invasive Tissue Damaging Enteric pathogens: Bloody
diarrhoea and dysentery e.g
 EIECs (Enteroinvasive E. coli)
 Shigella spp
 Salmonella spp
 EHECs (Enterohemmorhagic E. coli)
(Davies et al., 2008)
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9. PATHOGENICITY AND VIRULENCY
Enteric bacteria pathogens produce a variety of virulence factors:
 Toxins
 Fimbria
 Flagella
 Adhesins
 Invasins
(Davies et al., 2008)
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10. Figure 3: Antigens and Virulence Factors of a typical enteric
bacterium
Source: (Gassama et al., 2018)
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11. CLINICAL MANIFESTATION
 Three major clinical syndromes:
 Self-limited gastroenteritis
 Diarrhoeal disease, bloody diarrhoea,
 Weight loss, possible bacteremia
 Bacteremia associated with extraintestinal involvement, with or
without GI illness.
 Other signs and symptons include:
 Ache
 Fever
 Vomiting
 Diarrhoea
 Abdominal pain
(Gassama et al., 2018; Haung et al., 2019).
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12. CLINICAL DIAGNOSIS
 Assessment of patients with diarrhoea should include
 Complete exposure to medical history e.g. medication
review
 A quantification of the diarrhoeal illness by stool
frequency, volume, presence of blood, and
 Associated signs/symptoms (e.g. presence and duration
fever)
(Call et al., 2016)
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13. LABORATORY DIAGNOSIS
 The diagnosis of Gram-negative enteric infection is established
majorly through stool culture.
 Because the incidence of bacteraemia associated with salmonella
gastro-enteritis is high in HIV infected individuals, blood cultures
should be obtained from any patient with diarrhoea and fever.
 Toxin tests can also be carried out through ELISA (Enzyme-linked
immunosorbent assay) techniques E.g. Identification of C. difficile
toxin.
 PCR (Polymerase Chain Reaction) assays are also significant
(Call et al., 2016)
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14. PREVENTION
• Multiple exposures can place patients at risk of enteric illnesses.
the most common are ingestion of contaminated food and water
or fecal-oral exposures.
• Preventive methods should include:
 Regular hand washing with soap and water to reduce risk of
enteric infections
 Avoid unprotected sexual practices such as anal sex and oral-
anal contact.
(Huang et al., 2019)
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15. TREATMENT
Treatments usually the same as in immunocompetent individuals
 Empiric Therapy
CD4 count and clinical status guide initiation and duration of empiric
antibiotics, e.g
 CD4 count >500 cells/µL with mild symptoms: only rehydration
may be needed.
 CD4 count = 200-500 cells/µL and symptoms that compromise
quality of life: consider short course of antibiotics.
 CD4 count <200 cells/µL with severe diarrhea, bloody stool, or
fevers/chills: diagnostic evaluation and antibiotics.
(Call et al., 2016)
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16. TREATMENT (CONT’D)
Empiric Therapy (cont.)
 Preferred: ciprofloxacin 500-750 mg PO (or 400 mg IV) Q12H.
 Alternative: ceftriaxone 1 g IV Q24H or cefotaxime 1 g IV Q8H.
 Adjust therapy based on study results
 Traveler’s diarrhoea: consider possibility of antibiotic resistance.
(Call et al., 2016)
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17. PATHOGEN SPECIFIC THERAPY
BACTERIAL
ENTERIC
INFECTION
DISEASES DURATION OF THERAPY THERAPY
Salmonella
spp(Salmon
ellosis)
Gastro-enteritis
without
bacteraemia
Gastro-enteritis
with bacteraemia
7-14 days.
2-6 weeks.
14 days
2-6 weeks
Preferred: Ciprofloxacin
500-750 mg PO (or 400 mg
IV) Q12H
Shigella
spp(Shigell
osis)
Gastroenteritis
Bacteremia
Recurrent
infection
7-10 days (5 days for
azithromycin)
≥14 days
up to 6 weeks
Preferred: Ciprofloxacin
500-750 mg PO or 400 mg
IV Q12H
Campyloba
cter
spp(Campyl
obacteriosi
s)
Gastroenteritis
Bacteremia
Recurrent
bacteremic
disease
7-10 days (5 days for
azithromycin)
>14 days
2-6 weeks
Preferred: Ciprofloxacin
500-750 mg PO or 400 mg
IV Q12H
Azithromycin 500 mg PO
QD for 5 days (avoid if
bacteremia)
Source: (Huang et al., 2019)
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Table 1: Therapy treatments for some enteric bacteria
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18. CONCLUSION
 Enteric infection is one of the major health problems among patients
infected with HIV.
 Enteric bacteria are also opportunistic pathogens, for which there is
no effective treatment for, and the enlarging pattern of drug resistance
continues to be a challenging task.
 Hence, there is need for thorough investigations on more patients to
study these pathogens for proper management, control and treatment.
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19. REFERENCES
Call, S.A.; Heudebert, G.; Saag, M. And Wilcox, C.M. (2016): The changing etiology of chronic diarrhea in
HIV-infected patients with CD4 cell counts less than 200 cells/mm3. The American Journal of
Gastroenterology, 95(11): 3142-3146
Davies, N.E.C.G. and Karstaedt, A.S. (2008): Shigella bacteraemia over a decade in Soweto, South
Africa. Transactions of the Royal Society of Tropical Medicine and Hygiene, 102(12): 1269-1273
Gassama, A.; Sow, P.S.; Fall, F.; Camara, P.; Philippe, H.; Guèye-N’diaye, A. and Aïdara-Kane, A. (2018):
Ordinary and opportunistic enteropathogens associated with diarrhea in Senegalese adults in relation
to human immunodeficiency virus serostatus. International Journal of Infectious Diseases, 5(4): 192-
198.
Huang, D.B. and Zhou, J. (2019): Effect of intensive handwashing in the prevention of diarrhoeal illness
among patients with AIDS: a randomized controlled study. Journal of Medical Microbiology, 56(5),
659-663.
Kebede, A.; Aragie, S. and Shimelis, T. (2017): The common enteric bacterial pathogens and their
antimicrobial susceptibility pattern among HIV-infected individuals attending the antiretroviral
therapy clinic of Hawassa university hospital, southern Ethiopia. Antimicrobial Resistance & Infection
Control, 6(1): 1-7. 1-21

20. REFERENCES
Kownhar, H.; Muthu Shankar, E.; Rajan, R.; Vengatesan, A. and Rao, U.A. (2007): Prevalence of Campylobacter
jejuni and enteric bacterial pathogens among hospitalized HIV infected versus non-HIV infected patients with
diarrhoea in southern India. Scandinavian Journal of Infectious Diseases, 39(10): 862-866.
Mercado, E.H.; Ochoa, T.J.; Ecker, L.; Cabello, M.; Durand, D.; Barletta, F. and Cleary, T.G. (2011): Fecal leukocytes
in children infected with diarrheagenic Escherichia coli. Journal of clinical Microbiology, 49(4), 1376-1381.
Ngalani, O.J.; Mbaveng, A.T.; Marbou, W.J.; Ngai, R.Y. and Kuete, V. (2019):. Antibiotic resistance of enteric
bacteria in HIV-Infected patients at the Banka Ad-Lucem Hospital, West region of Cameroon. Canadian
Journal of Infectious Diseases and Medical Microbiology,
Okada, K.; Wongboot, W.; Kamjumphol, W.; Suebwongsa, N.; Wangroongsarb, P.; Kluabwang, P. and Hamada, S.
(2020): Etiologic features of diarrheagenic microbes in stool specimens from patients with acute diarrhea in
Thailand. Scientific Reports, 10(1), 1-10.
Pavlinac, P.B.; John-Stewart, G.C.; Naulikha, J.M.; Onchiri, F.M.; Denno, D.M.; Odundo, E.A. and Walson, J.L.
(2014): High-risk enteric pathogens associated with HIV-infection and HIV-exposure in Kenyan children with
acute diarrhoea. AIDS (London, England), 28(15): 2287.
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21. THANK YOU!