Sunday, March 25, 2012

Cholera in Bangaldesh introduction, Ana Weil, Internal Medicine MGH 2

           The International Centre for Diarrheal Disease Research, Bangladesh (icddr, b) where I am working in cholera is a research center and hospital in Dhaka, unique because of the commitment of those who work there to savings lives through both clinical care and research. Known in Dhaka as the “cholera hospital” or “diarrhea hospital”, admission to the hospital requires diarrhea (except in HIV patients). During cholera season two times a year, up to a thousand patients per day can present at the hospital for treatment; during these times, tents for makeshift cholera wards are assembled in the parking lots. Cholera cots, or wooden cots lined with plastic sheeting with holes in the middle for stool collection and measurement of fluid losses, appear in every corner of the hospital.
            The staff at the icddr, b knows that if a patient arrives to the hospital breathing, death can be avoided. Even if a pulse is absent, an IV is placed and rehydration is initiated. The speed at which this treatment begins is incredible; I have seen large-bore IVs placed in an unconscious patient still in the doorway in the arms of a family member. The nurses and IV teams at the hospital know how important speed is; they are empowered to save lives and go to great extents to do so. They are the world’s experts in treating cholera. Medical staff from the icddr, b has traveled to every major cholera outbreak in the world in the last decade to train local staff. Because the amount of rehydration required in cholera is much more than used in other diarrheal diseases, inexperienced staff can inadvertently under resuscitate patients and death can result. Research studies have documented the decrease in case-fatality rate that occurs after an icddr, b team arrives at the site of a cholera outbreak.

            Oral rehydration solution was first used in Bangladesh during a cholera outbreak in the 1970s. This simple mixture of clean water, sugar and salt is one of the most important medical discoveries of the 21st century, and has saved millions of lives. For several decades, the icddr, b and other sites in Bangladesh have been leaders in research and clinical care of patients with diarrheal disease.

            More recently, the icddr, b has changed HIV care in Bangladesh. HIV is thought to be rare in Bangladesh, and the prevalence of disease is not known. The icddr, b is the only hospital in the country with an HIV ward with care specifically for HIV patients and their families. During my month in Dhaka I was able to join in on rounds during my time out of the lab, and also took part in teaching medical residents working in the HIV ward.
            For more than a decade the icddr, b and MGH have collaborated to study the immune responses to cholera with an aim to improve cholera vaccines. After cholera, patients are protected from severe disease for at least several years through immune mechanisms that are not well understood. We believe that anamnestic memory responses in the gut confer protection, and T cells may have a role in the creation or maintenance of this response. When a person is diagnosed with cholera at the icddr,b, a large field team in Dhaka enrolls patients and their household contacts in the immunology studies at the time of hospitalization for cholera. In the lab, we receive blood from the patient on day 2 of their hospitalization (usually also the day of discharge) after their stool culture grew Vibrio cholerae overnight. With fresh blood, PBMCs are extracted for B cell studies and whole blood is prepared for flow cytometry examination. During the next year, this same patient and their household contacts with have blood drawn several times, and field workers will visit their homes to ask them about any symptoms they have and send them back to the icddr, b for severe illness. My immunology work is focused on T cell responses to acute cholera infection, and utilizes unique techniques in preparation of whole blood for flow cytometry.
            During medical school I worked at the icddr,b for one year, and made lifelong friendships with my colleages in the lab at the iccdr,b. Together we stayed late in the lab, came in on weekends, and spent hours troubleshooting the flow cytometer. It was wonderful to return to the lab and continue this work, see old friends, and spend time in this colorful city. The relationship between the icddr, b and the community allow work in cholera immunology to enter a second decade, and I hope to continue to be part of this work because of both the importance of the science and the wonderful people I have had the privilege of working with.  

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