Sandbox ID Gastrointestinal and Intraabdominal

Anthrax, gastrointestinal

• Gastrointestinal anthrax

• Preferred regimen: Ciprofloxacin 400 mg intravenously every 8 h OR Doxycycline 100 mg intravenously every 12 h combined with second agent: Clindamycin 600 mg intravenously every 8 h or Penicillin G 4 MU every 4-6 hours OR Meropenem 1 gm intravenously every 6-8 hours or Rifampin 300 mg every 12 h.
• Note:Treatment for 60 days is recommended to avoid relapse or breakthrough of incubating disease. If initial therapy is intravenous, then convert to oral administration (Ciprofloxacin or Doxycycline) when clinically indicated. Steroids may be considered as an adjunct therapy for patients with severe edema and for meningitis. For pregnant women, avoid Doxycycline. Use Ciprofloxacin and switch to oral penicillin once susceptibilities are known.

Cholecystitis

• Community-acquired acute cholecystitis of mild-to-moderate severity

• Community-acquired acute cholecystitis of severe physiologic disturbance, advanced age, or immunocompromised state
• Acute cholangitis following bilio-enteric anastamosis of any severity
• Health care-associated biliary infection of any severity

Hepatitis A

• The treatment should be conservative and supportive. There is no specific medication for HAV infection. Hygiene is very important, hands should always be washed after bathroom use. The management should focus on treating the symptoms and identifying the small proportion of patients with a particular risk of developing fulminant hepatic failure. Patients over the age of 40 and those with underlying chronic liver disease are most at risk.
• Contacts should be vaccinated.
• Oral contraceptive treatment and hormone replacement therapy should be stopped to avoid cholestasis.
• Alcohol consumption is not advised.

Hepatitis B

• Acute Hepatitis B

• Management

• Spontaneous recovery occurs after acute infection with HBV occurs in 95-99% of previously healthy adults. Antiviral therapy is not therefore likely to improve the rate of recovery and is not required unless the disease is accompanied by a nonhepatic complication such as periarteritis nodosa. In such cases, and in immunocompromised individuals (e.g., those with chronic renal failure), antiviral therapy with lamivudine may be recommended.

• In fulminant hepatitis, meticulous intensive care may improve the survival, but orthotopic liver transplantation is the only therapy that has been shown to improve patient outcomes.

• Full recovery with development of anti-HBs provides long-term protection.

• Prevention

• Vaccination (available since the early 1980s) continues to be the best way for dealing with the condition. Hepatitis B is preventable, and universal vaccination is probably best soloution in countries with a high prevalence.

• Preexposure vaccination:

• This is especially relevant in high-risk groups. There are a number of recombinant vaccines with similar efficacy, although the dosage may differ — for example:

• Recombivax HB (10 µg of HBsAg)

• Child < 11 y with an HbsAg-negative mother: 2.5 µg (babies at birth)
• Child < 11 y with an HBsAg-positive mother: 5 µg
• Child 11–19: 5 µg
• Immunocompetent adult: 10 µg
• Immunosuppressed person: 40 µg
• Renal dialysis patient: 40 µg

• Engerix-B (20 µg of HBsAg)

• Child < 10 y: 10 µg (babies at birth)
• Child > 10 y: 20 µg
• Adult: 20 µg
• Immunosuppressed person: 40 µg
• Dialysis patient: 40 µg 4.6.2

• Postexposure vaccination

• A combination of hepatitis B immunoglobulin (HBIg), when available, and HBV vaccine is recommended. If HBIg is available (in most countries it is not), it should be given to all children of HBs-positive mothers at the time of delivery. This is particularly important in neonates, in whom an immediate start of postexposure immunization will prevent infection in infants of HBV-infected mothers. It is important to vaccinate within 24 hours. There is no evidence of a protective effect if the vaccine is given more than 7 days after delivery.

• Direct exposure (percutaneous inoculation or transmucosal exposure) to HBsAg positive body fluid (e.g., needlestick injury):

• HBIg single intramuscular dose of 0.06 mL/kg (as soon as possible)
• Followed by a complete course of HBV vaccination (initiated within 7 days)

• Direct exposure following sexual contact with an individual with HBV:

• HBIg single intramuscular dose of 0.06 mL/kg (within 14 days; very expensive and not affordable in most places)
• Accompanied by a complete course of HBV vaccination (do not wait!).

• Contraindications and side effects

• There are very few contraindications:

• Severe allergic reaction to previous doses
• If the patient has a severe allergic reaction to baker’s yeast, plasma-derived HBV vaccine can be used instead
• Fever > 38.5 °C

• The following are not contraindications to administering HBV vaccine:

• Any minor illness, such as respiratory tract infection or diarrhea with a temperature below 38.5 °C
• Allergy or asthma
• Treatment with antibiotics
• Human immunodeficiency virus (HIV) infection; however more information is needed on the efficacy of HBV vaccination in neonates or infants who are infected with HIV.
• Breastfeeding
• History of seizures
• Chronic illnesses
• Stable neurological conditions
• Prematurity or low birth weight
• History of jaundice at birth
• Pregnancy (although not generally recommended)

Hepatitis C

Acute Hepatitis C

• Most cases of acute hepatitis C are asymptomatic and seldom diagnosed. Nonetheless, acute hepatitis C represents an opportunity to offer effective therapy. Acute hepatitis C is usually diagnosed under three circumstances: documented seroconversion, known exposure (eg, needle-stick exposure) and acute, clinical hepatitis.
• There has been a high rate of spontaneous clearance of virus following acute hepatitis C, which was more than 50% in some studies. The younger the age of the infection, the more likely is spontaneous clearance of the virus. Icteric hepatitis predicts spontaneous clearance with a high accuracy. Clearance usually occurs within 14 weeks of exposure. Most patients clear virus within 12 weeks. However, a single negative HCV RNA is insufficient to confirm clearance, and the test should be repeated at least once.
• Because seroconversion is unpredictable, treatment should be considered in all patients. Treatment is most effective when started before 12 weeks. Sustained virological response (SVR) rates of greater than 90% have been described using pegylated interferon (PEG IFN) monotherapy.

• Recommendations:

• Patients with acute, icteric hepatitis C can be observed for up to 12 weeks to determine whether spontaneous clearance occurs. If clearance has not occurred, treatment should be initiated by 12 weeks.
• In patients with acute, nonicteric hepatitis C, the likelihood of spontaneous clearance is lower, so treatment should start soon after diagnosis.
• Treatment is with PEG IFN-alpha monotherapy. Genotypes 2 and 3 should be treated for 12 weeks, and genotype 1 should be treated for 24 weeks.

Infectious diarrhea

Immunocompetent

• Bacterial

• Shigella species

• Preferred regimen:

• Adult dose: TMP-SMZ, 160 and 800 mg, respectively bid for 3 days (if susceptible ) OR Fluoroquinolone (e.g., 300 mg Ofloxacin, 400 mg Norfloxacin, OR 500 mg Ciprofloxacin bid for 3 days)
• Pediatric dose:TMP-SMZ, 5 and 25 mg/kg, respectively bid for 3 days

• Preferred regimen:

• Adult dose: Nalidixic acid 1 g/d for 5 days OR Ceftriaxone; Azithromycin
• Pediatric dose: Nalidixic acid, 55 mg/kg/d for 5 days

• Non-typhi species of Salmonella

• Preferred regimen: Not recommended routinely, but if severe or patient is <6 monthes or >50 year old or has prostheses, valvular heart disease, severe atherosclerosis, malignancy, or uremia, TMP-SMZ (if susceptible) OR Fluoroquinolone, bid for 5 to 7 days; Ceftriaxone, 100 mg/kg/d in 1 or 2 divided doses

• Campylobacter species

• Preferred regimen:Erythromycin, 500 mg bid for 5 days

• Escherichia coli species

• Enterotoxigenic

• Preferred regimen: TMP-SMZ, 160 and 800 mg, respectively, bid, for 3 days (if susceptible), OR Fluoroquinolone (e.g., 300 mg Ofloxacin, 400 mg Norfloxacin, or 500 mg Ciprofloxacin bid for 3 days)

• Enteropathogenic

• Preferred regimen: TMP-SMZ, 160 and 800 mg, respectively, bid, for 3 days (if susceptible), OR Fluoroquinolone (e.g., 300 mg Ofloxacin, 400 mg Norfloxacin, or 500 mg Ciprofloxacin bid for 3 days)

• Enteroinvasive

• Preferred regimen: TMP-SMZ, 160 and 800 mg, respectively, bid, for 3 days (if susceptible), OR Fluoroquinolone (e.g., 300 mg Ofloxacin, 400 mg Norfloxacin, or 500 mg Ciprofloxacin bid for 3 days)

• Enterohemorrhagic

• Preferred regimen: Avoid antimotility drugs; role of antibiotics unclear, and administration should be avoided.

• Aeromonas/Plesiomonas

• Preferred regimen: TMP-SMZ, 160 and 800 mg, respectively, bid for 3 days (if susceptible), Fluoroquinolone (e.g., 300 mg Ofloxacin, 400 mg Norfloxacin, or 500 mg Ciprofloxacin bid for 3 days)

• Yersinia species

• Preferred regimen: Antibiotics are not usually required; Deferoxamine therapy should be withheld; for severe infections or associated bacteremia treat as for immunocompromised hosts, using combination therapy with Doxycycline, Aminoglycoside, TMP-SMZ, OR Fluoroquinolone

• Vibrio cholerae O1 or O139

• Preferred regimen: Doxycycline, 300-mg single dose; or Tetracycline, 500 mg qid for 3 days; or TMP-SMZ, 160 and 800 mg, respectively, bid for 3 days; or single-dose Fluoroquinolone

• Toxigenic Clostridium difficile

• Preferred regimen: Offending antibiotic should be withdrawn if possible; Metronidazole, 250 mg qid to 500 mg tid for 3 to 10 days

• Parasites

• Giardia

• Preferred regimen:Metronidazole, 250-750 mg tid for 7-10 days

• Cryptosporidium species

• Preferred regimen: If severe, consider Paromomycin, 500 mg tid for 7 days

• Isospora species

• Preferred regimen: TMP-SMZ, 160 and 800 mg, respectively, bid for 7 to 10 days

• Cyclospora species

• Preferred regimen: TMP/SMZ, 160 and 800 mg, respectively, bid for 7 days

• Microsporidium species

• Preferred regimen: Not determined

• Entamoeba histolytica

• Preferred regimen: Metronidazole, 750 mg tid for 5 to 10 days, plus either Diiodohydroxyquin, 650 mg tid for 20 days, or Paromomycin, 500 mg tid for 7 days

Immunocompromised

• Bacterial

• Shigella species:

• Preferred regimen:

• Adult dose: TMP-SMZ, 160 and 800 mg, respectively bid for 7 to 10 days (if susceptible ) OR fluoroquinolone (e.g., 300 mg Ofloxacin, 400 mg Norfloxacin, OR 500 mg Ciprofloxacin bid for 7 to 10 days)
• Pediatric dose:TMP-SMZ, 5 and 25 mg/kg, respectively bid for 7 to 10 days

• Preferred regimen:

• Adult dose: Nalidixic acid 1 g/d for 7 to 10 days OR Ceftriaxone; Azithromycin
• Pediatric dose: Nalidixic acid, 55 mg/kg/d for 7 to 10 days

• Non-typhi species of Salmonella

• Preferred regimen: Not recommended routinely, but if severe or patient is <6 monthes or >50 year old or has prostheses, valvular heart disease, severe atherosclerosis, malignancy, or uremia, TMP-SMZ (if susceptible) OR Fluoroquinolone, bid for 14 days (or longer if relapsing); ceftriaxone, 100 mg/kg/d in 1 or 2 divided doses

• Campylobacter species

• Preferred regimen:Erythromycin, 500 mg bid for 5 days (may require prolonged treatment)

• Escherichia coli species

• Enterotoxigenic

• Preferred regimen: TMP-SMZ, 160 and 800 mg, respectively, bid for 3 days (if susceptible), OR Fluoroquinolone (e.g., 300 mg Ofloxacin, 400 mg Norfloxacin, or 500 mg Ciprofloxacin bid for 3 days) (Consider fluoroquinolone as for enterotoxigenic E. coli)

• Enteropathogenic

• Preferred regimen: TMP-SMZ, 160 and 800 mg, respectively, bid,for 3 days (if susceptible), OR Fluoroquinolone (e.g., 300 mg Ofloxacin, 400 mg Norfloxacin, or 500 mg Ciprofloxacin bid for 3 days)

• Enteroinvasive

• Preferred regimen: TMP-SMZ, 160 and 800 mg, respectively, bid,for 3 days (if susceptible), OR Fluoroquinolone (e.g., 300 mg Ofloxacin, 400 mg Norfloxacin, or 500 mg Ciprofloxacin bid for 3 days)

• Enterohemorrhagic

• Preferred regimen: Avoid antimotility drugs; role of antibiotics unclear, and administration should be avoided.

• Aeromonas/Plesiomonas

• Preferred regimen: TMP-SMZ, 160 and 800 mg, respectively, bid for 3 days (if susceptible), Fluoroquinolone (e.g., 300 mg ofloxacin, 400 mg norfloxacin, or 500 mg Ciprofloxacin bid for 3 days)

• Yersinia species

• Preferred regimen: Doxycycline, Aminoglycoside (in combination) or TMP-SMZ or Fluoroquinolone

• Vibrio cholerae O1 or O139

• Preferred regimen: Doxycycline, 300-mg single dose; or Tetracycline, 500 mg qid for 3 days; or TMP-SMZ, 160 and 800 mg, respectively, bid for 3 days; or single-dose Fluoroquinolone

• Toxigenic Clostridium difficile

• Preferred regimen: Offending antibiotic should be withdrawn if possible; Metronidazole, 250 mg qid to 500 mg tid for 3 to 10 days

• Parasites

• Giardia

• Preferred regimen:Metronidazole, 250-750 mg tid for 7-10 days

• Cryptosporidium species

• Preferred regimen: Paromomycin, 500 mg tid for 14 to 28 days, then bid if needed; highly active antiretroviral therapy including a protease inhibitor is warranted for patients with AIDS

• Isospora species

• Preferred regimen: TMP-SMZ, 160 and 800 mg, respectively, qid for 10 days, followed by TMP-SMZ thrice weekly, or weekly Sulfadoxine (500 mg) and Pyrimethamine (25 mg) indefinitely for patients with AIDS

• Cyclospora species

• Preferred regimen: TMP-SMZ, 160 and 800 mg, respectively, qid for 10 days, followed by TMP-SMZ thrice weekly indefinitely

• Microsporidium species

• Preferred regimen: Albendazole, 400 mg bid for 3 weeks; highly active antiretroviral therapy including a protease inhibitor is warranted for patients with AIDS

• Entamoeba histolytica

• Preferred regimen: Metronidazole, 750 mg tid for 5 to 10 days, plus either Diiodohydroxyquin, 650 mg tid for 20 days, or Paromomycin, 500 mg tid for 7 days

Leptospirosis

• Management

• Early treatment with antibiotics.
• Severe cases usually treated with high doses of IV Benzylpenicillin (30 mg/kg up to 1.2 g IV 6-hourly for 5-7 days).
• Less severe cases treated orally with antibiotics such as Doxycycline (2 mg/kg up to 100 mg 12-hourly for 5-7 days), Tetracycline, Ampicillin or Amoxicillin.
• Third-generation cephalosporins, such as Ceftriaxone and Cefotaxime, and Quinolone antibiotics may also be effective.
• Jarisch-Herxheimer reactions may occur after the start of antimicrobial therapy.
• Monitoring and supportive care as appropriate, e.g. dialysis, mechanical ventilation.

• Prevention

• Preventing infection or disease in human hosts:

• Antibiotic prophylaxis of exposed persons in areas of high exposures may be effective, e.g. soldiers (Doxycycline 200mg in one weekly dose)
• Raising awareness of the disease and its of modes of transmission.

Peptic ulcer disease

• Preferred regimen: The current treatment of choice for H. pylori infected patients is a combination of PPI (standard dose twice daily) with Amoxicillin (1 g twice daily) and Clarithromycin (500 mg twice daily) administered for 7-10 days (7-day therapy is approved with Rabeprazole; 10-day therapy is approved with Lansoprazole, Omeprazole, Pantoprazole, and Esomeprazole). Metronidazole (400 mg twice daily) may be substituted for Amoxicillin in this regimen if the patient is allergic to Penicillin.

• Alternative regimen: An alternative strategy is the combination of Bismuth, Metronidazole, and Tetracycline (Bismuth subsalicylate 525 mg QID + Metronidazole 250 mg QID + Tetracycline 500 mg QID) combined with a PPI for 14 days.

Algorithm for the management of uninvestigated dyspepsia.

Whipple's disease

• Initial:

• Preferred regimen:(Doxycycline 100mg PO bid + Hydroxychloroquine 200 mg po tid) for 1 year, then Doxycycline 100mg PO bid for life.