Hepatitis in slaughterhouse workers

Table 1 Various microorganisms responsible for causing hepatitis among slaughterhouse workers along with their reservoirs, routes of transmission, diagnostic tools, clinical features treatment and preventive strategies

Microorganisms	Reservoirs of infection	Routes of transmission	Laboratory diagnosis	Common clinical features	Treatment options	Preventive strategies
HBV	(1) Gorillas; (2) Chimpanzees; and (3) Cows[77]	(1) Parenterally; (2) Perinatally; (3) Sexually; and (4) Horizontally[5]	Serology: (1) HBsAg; (2) HBeAg; (3) Anti-HBc IgM; (4) Anti-HBc IgG; (5) Anti-HBe; and (6) HBV DNA[77]	(1) Constitutional symptoms; (2) Anorexia; (3) Nausea; (4) Vomiting; (5) Low-grade fever; (6) Myalgia; (7) Disordered gustatory acuity and smell; (8) RUQ pain; (9) Hepatic encephalopathy; (10) Ascites; (11) Gastrointestinal bleeding; and (12) Coagulopathy[77]	(1) NtRTIs: (a) Tenofovir; and (b) Adefovir; (2) NRTIs: (a) Entecavir; (b) Elbivudine; (c) Lamivudine; and (3) PEG- interferon -a 2a, interferon alfa-2b[78]	(1) Pre-exposure vaccination; and (2) Post exposure prophylaxis with vaccination and immunoglobulin’s depending on clinical status[3]
HEV	(1) Wild boar; (2) Camels; (3) Cows; (4) Goats; and (5) Pigs[13]	Fecal-oral route[14]	Anti-HEV IgM[14]	(1) Prodromal-phase; (2) Myalgia; (3) Arthralgia; (4) Fever; (5) Anorexia; (6) Nausea/vomiting; (7) Weight loss; (8) Right upper quadrant pain; (9) Icteric-phase; (10) Jaundice; (11) Dark urine; (12) Light-colored stools; (13) Pruritus; and (14) Right upper quadrant tenderness and hepatomegaly[12,14]	(1) Mostly are self-limited; and (2) Current treatment options: (a) Ribavirin; (b) Pegylated interferon for chronic infection in immune-compromised[79]	(1) Hygiene; and (2) Recombinant vaccines have demonstrated efficacy against HEV. (Available in China)[79]
RVF	Livestock[15]	(1) Contact with the blood and the fluids of the animals; and (2) Infected mosquitoes[15]	(1) Both IgM and IgG antibodies are specific to RVF virus; and (2) PCR of the antigens[17]	Mostly the patients are asymptomatic or have mild flu like disease, but a small percentage of patients may develop life threatening illness with ocular disease, hepatitis, encephalitis or hemorrhagic fever[16,17]	(1) Most human cases of RVF are mild and self-limiting; and (2) A specific treatment for RVF has not established[80]	(1) Avoid contact with blood, body fluids, or tissues of infected animals and protecting themselves against mosquitoes and other bloodsucking insects; and (2) Use of mosquito repellents and bed nets are two effective methods[80]
Q fever	(1) Domestic mammals, especially ungulates (cattle, sheep, and goats); and (2) Also has been found in wild mammals, birds, and arthropods[21]	(1) Transmitted via the urine, feces, milk and parturition products of infected animals; and (2) Aerosolized breathing in dust that has been contaminated by infected animal feces, urine, milk, and birth products[22]	(1) Serologic testing with PCR in the early stages of acute illness[81]; and (2) A fourfold rise in IgG antibody titer between acute and convalescent samples	(1) Acute: (a) Fever; (b) Pneumonia; (c) Hepatitis; and (d) Neurologic manifestations ranging from a simple headache to meningitis, encephalitis or both; and (2) Chronic infection: (a) Endocarditis; and (b) Chronic fatigue syndrome[21,23]	(1) Acute illness: Self-limited but 2 wk of doxycycline recommender; and (2) Chronic Q fever: Requires several months of antibiotics with a combination of antibiotics including doxycycline and hydroxychloroquine[81]	(1) Avoiding contact with animals, especially while animals are giving birth; and (2) Do not consume raw milk or raw milk products[81]
Salmonella	Intestinal tracts of humans and other animals, including poultry, other birds, amphibians, and reptiles[82]	Foodborne illness associated with contaminated poultry meat and pork[28-30]	(1) Serotyping and DNA fingerprinting; (2) Blood cultures; (3) PCR using H1-d primers; and (4) The Widal test or Typhidot for serology is rarely used now[82]	(1) Systemic disease involving multiple body organs; and (2) Liver can also be affected resulting in hepatomegaly and transaminitis[27,28]	Antibiotics based on sensitivities[82]	(1) Do not eat or drink foods containing raw eggs, or raw (unpasteurized) milk; and (2) Wash hands, kitchen work surfaces, and utensils with soap and water immediately after they have been in contact with raw meat or poultry[82]
Campylobacter jejuni	Wildlife reservoirs: (a) Wild birds species include migratory birds—ranes, ducks, geese and seagulls; and (b) Rodents and insects[83]	(1) Eating and handling of contaminated poultry, water and milk; and (2) Contact through the feces of a dog or cat[33]	(1) Serological diagnosis with ELISA; (2) PCR to detect Campylobacter jejuni in stool; and (3) Detection of antigens in stool specimens[84]	(1) Food borne gastroenteritis; (2) Extra intestinal manifestations; (3) Meningitis; (4) Hepatitis; (5) Bacteremia; and (6) Cardiac complications[31,32]	(1) Azithromycin and Fluoroquinolones; and (2) Antimicrobial susceptibility testing is essential before treatment[84]	Good hygiene[84]
Leptospirosis	(1) Domestic animals; (2) Cattle; (3) Pigs; and (4) Sheep[37]	Humans are infected through the broken skin or exposure to contaminated water and soil from infected urine of animals[38]	(1) DNA PCR; (2) Urine is the most reliable body fluid to study because the urine contains leptospires paired; (3) Antileptospira antibodies; and (4) MAT of acute and convalescent serum specimens[85]	(1) Most of the infected cases are mild; (2) Severe disease; (2) Hepatitis; and (3) Weil’s disease with renal failure and jaundice[42]	(1) Mild leptospirosis; (2) Doxycycline; (3) Ampicillin; (4) Amoxicillin; (5) Severe leptospirosis; (6) Intravenous penicillin G; (7) Third generation cephalosporin i.e. cefotaxime and ceftriaxone; and (8) Alternative regimens include ampicillin, amoxicillin, or erythromycin[86]	Good hygiene[42]
Bovine tuberculosis	(1) Both domestic and domesticated animals; (2) Cattle; (3) Sheep; (4) Pigs; (5) Goats; (7) Cats; (8) Dogs; and (9) Horses[45]	(1) Animals to humans; (2) Ingestion of animal products; and (3) Airborne inhalation of spores[44]	(1) AFB staining; (2) Mycobacterial cultures; (3) Molecular testing for mycobacterial DNA; (4) TST; and (5) IGRAs[87]	(1) Fever; (2) Night sweats; (3) Weight loss; and (4) The other symptoms depend on the tissue of the body infected by the organism[46]	Two months of isoniazid, rifampin, and ethambutol , followed by seven months of isoniazid and rifampin[46]	(1) Immunization with BCG vaccine; and (2) Treatment of latent infection[88]
Brucellosis	(1) Domestic animals; (2) B. abortus in cattle; (3) B. melitensis in sheep, goats, and camels; and (4) B. suis in swine[47,48]	(1) Intake of contaminated milk products; (2) Physical contact with infected tissues of the animals; and (3) Inhalation of contaminated aerosols[48]	(1) Cultures; (2) Serology; and (3) PCR[48]	(1) It commonly infects the GI tract but brain, nerves, GU, skin and hepatobiliary systems can also be involved; and (2) Brucella hepatitis usually occurs in the chronic granulomatous form with mild transaminitis but acute cases have been reported also[48-50]	(1) Combination of antibiotics is used; (2) Doxycycline and streptomycin; and (3) Based on the severity and location of infection, multiple combinations and longer durations are needed[89]	(1) Vaccination of domestic livestock, serologic testing, quarantine of herds, and slaughter of infected animals; (2) Protection of slaughterhouse workers; (3) Separated areas for killing from other processing areas; (4) Use of protective clothing and disinfectants; (5) Control of air circulation; and (6) Pasteurization of milk[89]
C. perfringens	(1) Soil; (2) Water; (3) Air; (4) Feces of healthy and infected individuals; (5) Gastrointestinal tract of humans and animals; and (7) Variety of dehydrated and processed foods[90]	(1) Food Poisoning; (2) Ingestion of large number of C. perfringens vegetative cells present in the contaminated food; (3) Gas gangrene; and (4) Contamination of wounds with dirt or any foreign material contaminated with C. perfringens[90]	(1) Cultures; (2) Imaging of the infected sites; and (3) Tissue biopsy with culture and Gram stain[90]	(1) Gastroenteritis[54,55]; (2) Gas gangrene; (3) Necrosis of the soft tissue; (4) Septicemia; (5) It rarely involves internal solid viscera like liver, kidneys, heart, etc.; and (6) Hepatic infection possibly results from the extension of infection into the biliary tree and then into the liver[56]	(1) Treatment of gas gangrene; (2) Surgical debridement; (3) Antibiotic therapy; and (4) Supportive measures[90]	(1) Protective materials like Lab coat, gloves and eye protection when dealing with infected materials[90]; and (2) Vaccination of non-immunized trauma individuals
Chlamydia psittaci	(1) Infected birds; (2) Parrots; (3) Pigeons; and (4) Sparrows[91]	(1) Aerosolized respiratory secretions; (2) Dried feces; and (3) Contact from the infected tissues of the birds[62,63]	(1) Complement fixation; (2) Micro immunofluorescence; and (3) PCR[91]	(1) Mild disease; (2) Influenza-like illness; (3) Severe disease; (4) Pneumonia; (5) Transaminitis with hepatomegaly and jaundice; and (6) Cardiac involvement[62,64]	(1) Antibiotics; (2) Tetracycline; and (3) Macrolides[91]	Follow precautions when handling and cleaning birds and cage[91]
Echinococcosis	(1) Sheep; (2) Goats; (3) Pigs; (4) Camels; (5) Horses; (6) Cattle; and (7) Human Liver is mainly affected by the sheep strain (G1) resulting in echinococcal cysts[65,69]	Ingestion of Echinococcal eggs excreted within the feces of the definitive host[92]	(1) Indirect hemagglutination test; (2) ELISA; and (3) Imaging tests for the location and size of the cysts[92]	(1) Development of cysts, primarily in the lungs and liver; and (2) This causes damage as they enlarge resulting in hepatitis and pneumonitis[65]	(1) Surgical removal of intact cysts; (2) Chemotherapy; (3) Albendazole and/or Praziquantel; (4) Chemotherapy is recommended 4 wk before, and for 1 mo after the surgery; and (5) Percutaneous aspiration, injection, re-aspiration is used in patients with inoperable intra-parenchymatous cysts[92]	Protective materials like Lab coat, gloves and eye protection when dealing with infected materials[92]
Toxoplasma gondii	(1) The definitive hosts are cats; and (2) The intermediate hosts are warm-blooded animals, including most mammals and birds[93]	(1) Consumption of poorly-cooked infected meat; (2) Ingestion of water, food, or milk contaminated with oocysts; (3) Inhalation of aerosols containing oocysts; (4) Contact with sand or soil contaminated by cat feces; (5) Transmission is also possible through blood transfusions and organ transplants; and (6) Transplacental if mother is infected[72]	(1) Positive serology for IgM and IgG antibodies; and (2) PCR[93]	(1) Fever; (2) Lymphadenopathy; (3) Multiorgan involvement; (4) Hepatitis; (5) Encephalomyelitis; and (6) Myocarditis[70,71]	(1) Spiramycin; (2) Can be taken by women in their first trimester to prevent transplacental transmission; (3) Sulfadiazine and folinic acid; and (4) For pregnant women in their third trimester[93]	(1) Protective materials like Lab coat, gloves and eye protection when dealing with infected materials[92]; and (2) Testing for toxoplasmosis in females before pregnancy[93]
Trichinosis	Different species are found world-wide in carnivorous and omnivorous animals like bears, foxes, walruses, hyenas, Pigs and cougars[94]	Ingestion of partially cooked/ uncooked or raw pork contaminated with the cysts or larvae[69]	(1) ELISAs; (2) Indirect immunofluorescence; (3) Latex agglutination; (4) Western blot; (5) Muscle biopsy; and (6) PCR[94]	(1) Diarrhea; (2) Fever; (3) Muscle aches; (4) Cardiac, neurological, and thromboembolic disease; and (5) Hepatic involvement is rare but has been reported in the literature[69]	(1) Albendazole; and (2) Mebendazole[94]	Consumption of properly cooked meat[94]

PCR: Polymerase chain reaction; ELISAs: Enzyme-linked immunosorbent assays; NtRTIs: Nucleotide analog reverse-transcriptase inhibitors; NRTIs: Nucleoside analog reverse-transcriptase inhibitors; MAT: Microscopic agglutination test; BCG: Bacillus Calmette-Guérin; TST: Tuberculin skin test; IGRAs; Interferon-gamma release assays; HBV: Hepatitis B virus; RVF: Rift Valley fever virus; HEV: Hepatitis E virus; C. Perfringens: Clostridium Perfringens.