Archive for April, 2009

Emergence of Communicable Diseases due to Travel

In recent years international travel has become a threat in spreading many diseases as well as reemergence of many diseases like of cholera and others as a global health threat. As one Nobel laureate once told “The microbe that felled one child in a distant continent yesterday can reach yours today and seed a global pandemic tomorrow”. This is very true in the era of “global village” idea.

Due to international travel for commerce and recreation HIV have spread throughout the world in only a few decades and created considerable fear about the possible spread of severe acute respiratory syndrome (SARS) and avian influenza also known as “bird flu” (H5N1). HIV is a classic example of fast spread of a communicable and infectious disease due to international travel.

There are many instances where a non existent disease suddenly appear in a particular geographical area with no history of the disease before in that area, e.g. appearance of schistosomiasis in previously unaffected lakes in Africa; appearance and outbreak of dengue fever in Latin America and appearance of antibiotic resistant strains of sexually transmitted diseases (STDs) and intestinal pathogens at an alarming rate in the developing countries.

There is also serious concern about possible bioterrorism by terrorists which is a of grave concerns because of use of not only standard strains of unusual agents but mutant strains as well. Only time can tell if all international travelers’ (as well as for everybody at who remain at home and do not travel) will need to get vaccinated for diseases like anthrax and smallpox.

International and national vigil is required for prevention of spread of infectious and communicable diseases and every individual and every Govt. need to play its role in preventing spread of communicable disease from one place to the other.

Treatment of Travelers’ Diarrhea

Travelers’ who suffer from travelers’ diarrhea, approximately 20% of them become bedridden and need proper treatment (should not do self treatment if diarrhea becomes severe).

In many cases a specific diagnosis is available to guide treatment and is also not necessary. The treatment should be started based on history, stool examination and severity of dehydration. The empirical treatment regimens for travelers’ diarrhea are based on certain clinical syndromes:

(1) Clinical syndrome, watery diarrhea without fever or blood in stool and 1 or 2 unformed stools per day without distressing enteric symptoms:- the treatment is with oral fluid (preferably with ORS or oral re-hydration salt or flavored mineral water).

(2) Clinical syndrome, watery diarrhea without fever or blood in stool and 1 or 2 unformed stools per day with distressing enteric symptoms:- treatment for adults bismuth subsalicylate 30 ml or 2 tablets (262 mg/tablet) every 30 min for a maximum of 8 doses or loperamide 4 mg initially followed by 2 mg after passage of each unformed stool, not to exceed 16 mg per day or 8 tablets and loperamide can be taken for 2 days.

(3) Clinical syndrome, watery diarrhea without fever or blood in stool, but more than 2 unformed stools per day without distressing enteric symptoms:- treatment is antibiotics plus loperamide 4 mg initially followed by 2 mg after passage of each unformed stool, not to exceed 16 mg per day. Antibiotics that are used in travelers’ diarrhea are fluoroquinolones like ciprofloxacin 750 mg single dose or 500 mg twice a day for 3 days (levofloxacin, 500 mg as a single dose or norfloxacin, 800 mg as a single dose or 400 mg two times a day for 3 days are also used effectively), azithromycin, 1000 mg as a single dose or 500 mg twice a day for 3 days, Rifaximin, 200 mg 3 times a day or 400 mg 2 times a day for 3 days (this is not recommended if case of dysentery). All the above regimens are for adults. For children azithromycin, 10 mg/kg on day 1, 5 mg/kg on days 2 and 3 if diarrhea persists (furazolidone, 7.5 mg/kg per day in four divided doses for 5 days is an effective alternative to azithromycin).

In Thailand organisms (mainly Campylobacter) causing travelers’ diarrhea are resistant to fluoroquinolones and the antibiotic of choice in Thailand is azithromycin at the same dose as given above.

(4) Clinical syndrome, passing of blood in stool (dysentery) or fever of more than 37.8° C:- Antibiotic therapy as given above.

(5) Clinical syndrome, vomiting with minimal diarrhea:- treatment for adults bismuth subsalicylate 30 ml or 2 tablets (262 mg/tablet) every 30 min for a maximum of 8 doses.

(6) Clinical syndrome, in infants less than 2 years old:- fluid and electrolyte replacement with ORS (intravenous fluid may also be required), continue feeding (continue breast feeding if infant is breast fed). If diarrhea is with dysentery or fever, antibiotics like azithromycin will be required and dose is as given above.

(7) Clinical syndrome, diarrhea in pregnant women:- Fluids and electrolytes should be given. Consider giving attapulgite, 3 gm initially, repeat after passage of each unformed stool or every 2 hour, whichever is earlier, for a total dosage of 9 gm per day.

(8) Clinical syndrome, diarrhea despite prophylaxis with trimethoprim-sulfamethoxazole:- Fluoroquinolone (ciprofloxacin) with loperamide if no fever and no blood in stool, ciprofloxacin alone if fever or dysentery is present.

(9) Clinical syndrome, diarrhea despite prophylaxis with fluoroquinolone (ciprofloxacin):- For adults bismuth subsalicylate 30 ml or 2 tablets (262 mg/tablet) every 30 min for a maximum of 8 doses for mild to moderate diarrhea. If severe diarrhea persists consult doctor for proper antibiotic therapy like azithromycin.

Self-Treatment of Traveler’s Diarrhea

The traveler’s diarrhea is diarrhea which is seen among traveler’s (mainly from developed country to a developing country, but can occur during travel from anywhere to other country and in on study the rate of traveler’s diarrhea was, as low as 8% per 2-week stay in industrialized countries and as high as 55% in parts of Africa, Central and South America, and Southeast Asia), that is generally short lived and self limited. Though short lived about 40% of affected individuals need to alter their scheduled activities and another 20% become bedridden for few days. The causative organisms of traveler’s diarrhea are entero-toxigenic Escherichia coli and entero-aggregative E. coli. Sometimes it may be due to Campylobacter infections, Salmonella, Shigella or rotavirus.

Traveler’s diarrhea can occur despite rigorous precautions regarding food and water during travel to a developing country, all the traveler’s should carry some medication for self-treatment with them (preferably traveler’s medical kit). Antibiotic therapy will generally reduce the duration and severity (reduce frequency of stools) of traveler’s diarrhea in moderate to severe cases. The standard antibiotic regimen for traveler’s diarrhea is 3-day course of quinolone like ciprofloxacin (single double dose of quinolone is equally effective regimen). But if you are traveling to Thailand quinolone like ciprofloxacin will not work due to resistance (in Thailand more then 90% of traveler’s diarrhea is due to Campylobacter infections which are resistant to quinolone like ciprofloxacin) and azithromycin is a better alternative in such cases. Rifaximin (a poorly absorbed rifampin derivative) is also highly effective (especially against noninvasive bacterial pathogens such as entero-toxigenic and entero-aggregative E. coli) alternative to quinolone.

The present recommendation of self-treatment of travelers’ diarrhea is for the traveler to carry three once-daily doses of an antibiotic (azithromycin or ciprofloxacin) and to use as many doses as necessary to correct the diarrhea. If there is no fever or blood in stool, loperamide can be taken in combination with the antibiotic (but never take loperamide if you have fever or blood in stool as it may prolong diarrhea).

Prevention of Traveler’s Diarrhea

Traveler’s diarrhea can be prevented if precautions are observed properly during international travel. The main preventive measures of traveler’s diarrhea are related to food and water precautions. But studies indicate that indiscretion in eating and drinking water is done by approximately 98% of traveler’s upon arrival of their destination within 72 hours. That means only a handful of cautious travelers follow the precautions for prevention of traveler’s diarrhea. No wonder that such a large percentage of travelers suffer from traveler’s diarrhea. There is a popular slogan for travelers “Boil it, cook it, peel it, or forget it!” and it is easier to remember than following it as the studies indicate.

In general a traveler should follow some precautions for prevention of traveler’s diarrhea. The food precautions are eating food when it is still hot, avoid foods that are raw, poorly cooked, or sold by street vendors etc. Water precautions include drinking only boiled or commercially bottled beverages (preferably those that are carbonated). Heating can kill organisms that cause traveler’s diarrhea (entero-toxigenic Escherichia coli, entero-aggregative E. coli, Campylobacter, Salmonella, Shigella, rotavirus, norovirus etc.), but freezing can not kill them and due to this reason ice cubes made from unpurified water should be avoided.

Prophylaxis of traveler’s diarrhea:

The most commonly used prophylaxis for traveler’s diarrhea is bismuth subsalicylate, but it is only 60% effective. In special cases (athletes, persons with a repeated history of travelers’ diarrhea, and persons with chronic diseases) a single daily dose of a quinolone or azithromycin or a once-daily rifaximin regimen during travel of more than 1 month’s duration is effective in preventing travelers’ diarrhea in 75% to 90% of cases.

Self treatment of traveler’s diarrhea:

Ideally all travelers should carry some medication for traveler’s diarrhea for self-treatment, as it can occur despite rigorous food and water precautions. An antibiotic can reduce the frequency of stools and duration of illness in moderate to severe diarrhea. The standard regimen for traveler’s diarrhea is a single daily dose of quinolone (ofloxacin, ciprofloxacin etc.) for 3 successive days. Rifaximin, a poorly absorbed rifampin derivative and is highly effective against noninvasive bacterial pathogens like entero-toxigenic E. coli and entero-aggregative E. coli. But if you acquire traveler’s diarrhea, in Thailand, where more than 90% of Campylobacter infections are quinolone resistant, azithromycin can be a good choice.

Mesothelioma and Asbestos

Mesotheloima is a rare neoplasm (cancerous neoplasm) that arises from mesothelial cells lining the parietal and visceral pleura of the lungs. Mesothelium is the protective lining that covers most of the internal organs (including lungs) of the body.

The commonest site of mesothelioma is the pleura, which is the outermost lining of the lungs and the chest wall. But mesothelioma can occur at any site where mesothelial cells lining is present like peritoneum, heart etc.

The most important cause (and most likely the only cause) of mesothelioma is exposure to asbestos. Most of the patients of mesothelioma have worked on jobs where they inhaled asbestos particles, or they have been exposed to asbestos dust and fiber in one way or other. The washer men who wash cloths of persons who work with asbestos can also cause mesothelioma.

The symptoms of mesothelioma may not appear for more than 20 years of last exposure to asbestos. They may appear as late as 50 years after last exposure to asbestos, which is also a unique for a disease. The symptoms of mesothelioma include shortness of breath (due to pleural effusion), chest pain, weight loss (like any cancer), generalized weakness etc.

As mesothelioma is caused by asbestos the asbestos compensation via asbestos fund or by law-suit is an important issue in this disease. Due to the uniqueness of the disease mesothelioma (as it is caused only due to exposure to asbestos) the mesothelioma claim and compensation is very common.

Smoking does not increase (no relation with smoking and mesothelioma) the incidence of mesothelioma, unlike lung cancer.