Patient description: A 34 year old man comes to the clinic complaining of dizziness and severe diarrhea since yesterday. He has returned from an international trip few days ago and was living in a camp in Sudan for a month. He developed abdominal pain followed by bloating and nausea as well as loose bowel movements. Soon he was having profuse watery diarrhea without odor. The stool is watery and white but the patient has no fever. Blood pressure is 95/62 lying down and drops to 75/40 standing. The skin turgor has reduced. HR is 110 and he looks ill with dry mucosa. V. cholerae was seen in dark-field microscopy of a fresh stool specimen. The lab study is as bellow: Sodium 137 meq/L Potassium 2 meq/L Chloride 94meq/L CO2 15 meq/L Fecal leukocytes None seen Fecal occult blood Negative

Clinical trial eligibility criteria: eligible ages (years): 18.0-45.0,  Cholera Vibrio Infections Diarrhea HIV-seropositive, non-pregnant adults, aged 18 years old who have been on standard highly active antiretroviral therapy (HAART) for at least 6 months prior to enrollment or who have never started HAART regimen will be recruited in the study. All subjects must satisfy the following at study entry: 1. Male and female HIV seropositive adults aged 18 to 45 years old who have given the written informed consent. 2. Will comply with the requirements of the protocol (i.e. available for follow-up visits and specimen collection). 3. CD4 T-lymphocyte count >500/mm3 for at least 6 months prior to Subjects that have never started HAART regimen must satisfy the following additional at study entry. 1. Asymptomatic HIV infection as determined by: Medical history, Physical examination, Laboratory tests, Clinical judgment of the investigator Subjects that have been on standard highly active antiretroviral therapy (HAART) for at least 6 months prior to enrollment must satisfy the following additional at study entry. 1. History of CD4 nadir >150/mm3 2. Viral load (HIV-1 RNA levels) <200 copies/mL for at least 6 months prior to  The following should be checked at the time of study entry, if any of the following is present then the subject will be excluded from the study: 1. Overt signs of immunodeficiency e.g. oral thrush, rapid weight loss, recurrent pneumonia (i.e. Stage 3 or 4 of the WHO clinical staging system for HIV infection and disease in adults and adolescents 2. Ongoing serious chronic illness (e.g. with signs of cardiac or renal failure) 3. Abdominal pain or cramps, loss of appetite, nausea, general ill-feeling or vomiting in the past 24 hours 4. Presence of V. cholerae 01 or 0139, Shigella, or Cryptosporidium in stool at baseline 5. Intake of any anti-diarrhoeal medicine in the past week 6. Acute disease one week prior to enrollment, with or without fever. Temperature ≥38ºC (oral or otic) warrants deferral of the vaccination pending recovery of the subject 7. Receipt of antibiotics in the past 2 weeks 8. Receipt of live or killed enteric vaccine in the last 4 weeks 9. Receipt of killed oral cholera vaccine in the past 10. Diarrhea (3 or more loose stools within a 24-hour period) 6 weeks prior to enrollment 11. One or more episodes of diarrhea lasting for more than 2 weeks in the past 6 months 12. One or more episodes of abdominal pain lasting for more than 2 weeks in the past 6 months 13. Receipt of blood, blood products or a parenteral immunoglobulin preparation in the previous 6 months 14. Receipt of any immunosuppressive therapy during the past 6 months 15. A woman pregnant or planning to become pregnant during the period of subject's participation 16. Any condition which in the opinion of the investigator, might interfere with the evaluation of the study objectives