skip to main content
Back to search results

Wuchereria Bancrofti

Wuchereria Bancrofti

PATHOGEN SAFETY DATA SHEET – INFECTIOUS SUBSTANCES

SECTION I – INFECTIOUS AGENT

NAME: Wuchereria bancrofti

SYNONYM OR CROSS REFERENCE: Bancroftian filariasis, Lymphatic filariasis, elephantiasis

CHARACTERISTICS: Wuchereria bancrofti is a filarial nematode that, as an adult, is a thread-like worm(1,2,3). The female nematodes are 10 cm long and 0.2 mm wide, while the males are only about 4 cm long(1,3). The adults reside and mate in the lymphatic system where they can produce up to 50 000 microfilaria per day(1). The microfilaria are 250-300 µm long, 8 µm wide and circulate in the peripheral blood. They can live in the host as microfilaria for up to 12 months(1,4). Adult worms take 6 to 12 months to develop from the larval stage and can live between 4 and 6 years(1,4).

SECTION II – HAZARD IDENTIFICATION

PATHOGENICITY/TOXICITY: In filarial endemic areas, there are three groups of patients recognized(5). The first group, considered endemic normals, are exposed to the nematode but have not been infected(5). The second group have been exposed, infected, and have microfilaria in their peripheral circulatory system, but remain asymptomatic.(5). Asymptomatic infections can go undetected for years, and with lymphatic filariasis (LF) it may eventually result in internal damage which is not easily diagnosed(5). The third group are those who are chronically infected and present with lymphoedema (which affects 16 million people), hydrocoele and elephantiasis(5,6). Acute (bacterial) dermato-lymphangio-adenitis (ADLA), another condition that can result from infection, presents with fever, chills, swelling and lymphoedema. ADLA usually occurs when an adult worm dies and the lymph vessels surrounding it are inflamed due to the host’s immunological response(2,5). ADLA normally occurs in older children and youth and remains with the infected individual throughout life(5). Chronic ADLA attacks can cause renal disease, haematuria, proteinuria, chyluria, nephritic syndrome and glomerulanephritis(2,5). Patients with LF can also have rheumatic problems, cystitis with urethral obstruction, fibrosing mediastinitis, tropical vaginal hydroceles and bladder pseudotumors(5). Another indication of LF is pulmonary eosinophila which is characterized by paroxysmal cough and wheezing and, even though the patient harbours adult worms, there are no microfilarias in the blood(5). The most disabling of health problems caused by LF is elephantiasis, a permanent swelling of a limb (usually lower limbs although it can effect arms, breasts and genitalia). Streptococci bacteria can infect the affected limb, worsening the condition(5,6). Certain markers predispose patients to chronic filarial disease, including a high dose of the infectious agent, a pre-existing bacterial infection, or a specific host response(7).

EPIDEMIOLOGY: Wuchereria bancrofti is endemic in 78 countries and affects 128 million people worldwide(1). This nematode is widespread throughout humid and tropical zones of Asia, Africa, the Americas and the Pacific islands, and is common in areas with poor socioeconomic levels(1,2,7). Wuchereria bancrofti is the infectious agent in 91 % of LF cases. LF is also recognized as the second most disabling mosquito-borne disease next to malaria(1,4,5,6). To date, 44 million people experience clinical disease; however, 76 million suffer pre-clinical damage to their renal and lymphatic systems(5). An estimated 1.3 billion people in endemic regions are at risk of developing LF each year and, even though not fatal, it still remains the leading cause of infirmity, permanent disability, and chronic morbidity(1). Vector control and the mass distribution of pharmaceuticals have proven the most effective measures in containing this epidemic(1,4).

HOST RANGE: Humans are the only known host(1,4).

INFECTIOUS DOSE: Infection usually involves numerous exposures to this organism. It is not uncommon that an individual receive 2700 to 1,000,000 bites from infected mosquitoes (approximately equivalent to 10 to 20 years of exposure) before becoming infected(1).

MODE OF TRANSMISSION: The disease is usually transmitted through the bite of an infectious mosquito. Overall there are 6 genera and 70 species of mosquitoes responsible for the spread of Wuchereria bancrofti(1).

INCUBATION PERIOD: The incubation period is variable and often difficult to determine. Both microfilaria and adult worms have been observed in patients as early as 6 months and as late as 12 months after infection(4).

COMMUNICABILITY: This disease is not transmitted from person-to-person. Mosquitoes, however, can be infected by humans if they ingest microfilaria during a blood meal of an infected individual(1). The mosquito remains infectious for only 10-14 days after consuming an infected blood meal(1).

SECTION III – DISSEMINATION

RESERVOIR: Humans are the only known reservoir for Wuchereria bancrofti(1).

ZOONOSIS: Humans are infected by mosquitoes who act as vectors, as well as a developmental reservoir(1).

VECTORS: Mosquitoes are the vector for this nematode and certain genera and species appear to transmit the infectious agent in particular geographical locations(1). At least 43 species of Anopheles mosquitoes are responsible for the infection of people in West Africa, rural Southeast Asia and parts of the Southern Pacific(1). Anopheles mosquitoes, in particular, transmit the nocturnal periodic form of the worm(1). Other genera like Aedes, Ochleratus, and Downsyomia, which have 20 different species among them, spread both the nocturnal and diurnal supperiodic forms of the nematode, particularly in the Pacific islands and parts of Southeast Asia(1). Like the Anopheles genus, 6 species of the Culex genus infect humans with the nocturnal periodic form of Wuchereria Bancrofti, but in East Africa, the Middle East, urban Southeast Asia and Latin America(1).

SECTION IV – STABILITY AND VIABILITY

DRUG SUSCEPTIBILITY: A combination of both albendazole and ivermectin, or albendazole and diethylcarbamazine are effective in eliminating of microfilaria, but only disrupt the adult female’s reproductive ability(1,4,5). Drug treatment regimes may not get rid of the adult worms so long term therapeutic courses are often employed(2). These nematodes have also shown susceptibility to avermectin, piperazines and suramin (Bayer 205)(8).

SUSCEPTIBILITY TO DISINFECTANTS: Most microorganisms are susceptible to 1 % sodium hypochlorite and 2 % glutaraldehyde, including Wuchereria bancrofti(9).

PHYSICAL INACTIVATION: The microfilaria of Wuchereria bancrofti has been observed to be susceptible to freezing(10).

SURVIVAL OUTSIDE HOST: Not known.

SECTION V – FIRST AID / MEDICAL

SURVEILLANCE: To monitor suspected cases of LF, laboratories use Giemsa-stained peripheral blood films, phosphatise detection of microfilaria, Knott concentration procedure and membrane filtration techniques(1). More recently, ELISA, PCR, Lymphoscintigraphy, and ICT tests have been used to detect the organism(1,11). The new technology has enabled epidemiologist to monitor the presence of this agent in the mosquito vector. Vector analysis in combination with patient diagnosis has allowed a more comprehensive picture of Wuchereria bancrofti and its relevance to human health.

Note: All diagnostic methods are not necessarily available in all countries.

FIRST AID/TREATMENT: Appropriate drug therapy, such as ivermectin and albendazole or diethylcarbamazine (DEC) and albendazole, to treat LF(1,2). A medical follow-up should be done after the treatment to ensure the elimination of both microfilaria and adult worms in the patient(12).

IMMUNIZATION: None(12).

PROPHYLAXIS: While a combination of either albendazole and ivermectin or albendazole and diethylcarbamazine (DEC) is given once a year in endemic areas, it has no effect on transmission by mosquito(1,12). It is recommended to stay away from mosquito breeding sites, particularly at key feeding periods, and to protect oneself with sprays or lotions that contain active ingredients like deet that repel mosquitoes, or by using bed nets impregnated with insecticides such as permethrin(12).

SECTION VI – LABORATORY HAZARDS

LABORATORY-ACQUIRED INFECTIONS: No laboratory-acquired infections have been reported to date.

SOURCES/SPECIMENS: Blood, infective eggs and larvae(1,13).

PRIMARY HAZARDS: Accidental ingestion of infected eggs or parenteral inoculation with infective larvae are the primary hazards(13). Arthropods used routinely in laboratory research that are contaminated with filariasis also pose a risk(13,14).

SPECIAL HAZARDS: Certain sensitized individuals can have allergic reactions to some antigenic components of nematodes(13).

SECTION VII – EXPOSURE CONTROLS / PERSONAL PROTECTION

RISK GROUP CLASSIFICATION: Risk group 2.

CONTAINMENT REQUIREMENTS: Containment Level 2 facilities, equipment, and operational practices for work involving infectious or potentially infectious materials, animals, cultures.

PROTECTIVE CLOTHING: Lab coat. Gloves when direct skin contact with infected materials is unavoidable. Eyes protection must be used where there is a known or potential risk of exposure to splashes(15).

OTHER PRECAUTIONS: All procedures that may produce aerosols, or involve high concentrations or large volumes should be conducted in a biological safety cabinet (BSC). The use of needles, syringes and other sharp objects should be strictly limited. Additional precautions should be considered with work involving large scale activities(15).

SECTION VIII – HANDLING AND STORAGE

SPILLS: Allow aerosols to settle and, wearing protective clothing, gently cover spill with paper towels and apply appropriate disinfectant, starting at the perimeter and working towards the centre. Allow sufficient contact time before clean up (30 min)(15).

DISPOSAL: All wastes should be decontaminated before disposal either by steam sterilization, incineration or chemical disinfection(15).

STORAGE: The infectious agent should be stored in a sealed and identified container(15).

SECTION IX – REGULATORY AND OTHER INFORMATION

REGULATORY INFORMATION: The import, transport, and use of pathogens in Canada is regulated under many regulatory bodies, including the Public Health Agency of Canada, Health Canada, Canadian Food Inspection Agency, Environment Canada, and Transport Canada. Users are responsible for ensuring they are compliant with all relevant acts, regulations, guidelines, and standards.

UPDATED: August 2010

PREPARED BY: Pathogen Regulation Directorate, Public Health Agency of Canada.

Although the information, opinions and recommendations contained in this Pathogen Safety Data Sheet are compiled from sources believed to be reliable, we accept no responsibility for the accuracy, sufficiency, or reliability or for any loss or injury resulting from the use of the information. Newly discovered hazards are frequent and this information may not be completely up to date.

Copyright ©

Public Health Agency of Canada, 2010

Canada

Vesicular Stomatitis Virus

PATHOGEN SAFETY DATA SHEET – INFECTIOUS SUBSTANCES

SECTION I – INFECTIOUS AGENT

NAME: Vesicular stomatitis virus (VSV)

SYNONYM OR CROSS REFERENCE: Vesiculovirus(1,2), vesicular stomatitis(1,2,3,4,5), VS(1,2,3,4,5,6), vesicular stomatitis virus disease(3,7), vesicular stomatitis fever, and Indiana fever(3).

CHARACTERISTICS: A member of the Vesiculovirus genus, in the family Rhabdoviridae(3,6). VSV is a bullet-shaped, enveloped virus, approximately 70 nm in diameter and 170 nm in length(3), and has a single-stranded, negative-sense RNA genome(5,8). VSV has two main serotypes: VSV serotype Indiana (with its subtypes Cocal virus and Alagoas virus), and VSV serotype New Jersey(1,2,3,5,6,8).

SECTION II – HAZARD IDENTIFICATION

PATHOGENICITY/TOXICITY: Most human infections with VSV appear to be subclinical(1,6,8). In patients that show clinical manifestations, the initial symptom is high fever that is often biphasic. Subsequent symptoms are “flu-like” including severe malaise, headaches, myalgia, arthralgia, retrosternal pain, eye aches, and nausea(1,3,6,7). Occasionally a disease course with haemorrhages similar to dengue fever has been seen(6). Vesicle formation on the oral mucosa, lips, and nose is possible, but these are rare symptom of vesicular stomatitis (VS)(3,6,7). Most human cases of VS have been diagnosed in laboratory workers(3). In the laboratory, VSV has been engineered to target cancer cells or to stimulate immunity against diseases such as AIDS or influenza(8).

EPIDEMIOLOGY: VS exists in North and South America, Africa and Asia but not in central Europe(6). Serological surveys indicate that the prevalence of infection may be high among some populations in enzootic areas. For example, in a rural locality in Panama, more than 90% of the adult population is affected(3); however, the precise frequency of VS is not well established, as the disease often goes unnoticed due to its benign course.

HOST RANGE: Humans(1,2,4,5,6,8), horses(2,4,6,8), cattle, pigs, mules(2,6), sand flies(5,6), grasshoppers(4), and rodents(2).

INFECTIOUS DOSE: Unknown.

MODE OF TRANSMISSION: Bite of an infected sand fly(1,5,7,8); by direct contact with abrasions on the skin; by contact with infected domestic animals; or by inhaling aerosols via the nasopharyngeal route(1,3). The virus has also been transmitted via accidental autoinoculation or inhalation of aerosols in a laboratory setting(3,8).

INCUBATION PERIOD: A wide range of incubation periods have been reported from 30 hours(1,6) to 6 days(7).

COMMUNICABILITY: There is no documented evidence of person-to-person transmission of VSV.

SECTION III – DISSEMINATION

RESERVOIR: The main reservoir is the sand fly, although arboreal rodents and non-human primates may also harbour VSV(7). Grasshoppers have also been implicated as a potential reservoir for VSV(4).

ZOONOSIS: Yes, humans can contract VSV through direct contact with infected animals, or indirectly through the bite of an infected fly(1,5,7,8).

VECTORS: Sand fly ( Phlebotomus spp.) appears to be the most important vector for VSV(2,6,8). Black flies ( Simuliidae )(2,5,6), midges ( Culicoides spp.), mosquitoes ( Aedes spp.)(2,5,8) and other diptera(2,5,6) have also been implicated.

SECTION IV – STABILITY AND VIABILITY

DRUG SUSCEPTIBILITY: Unknown.

SUSCEPTIBILITY TO DISINFECTANTS: VSV is inactivated by 1% cresylic acid, phenolics, chlorinated phenol, 2.5% phenol, 0.4% HCl, 2% sodium orthophenylphenate(9), and sodium hypochlorite(1,9).

PHYSICAL INACTIVATION: Inactivated at low pH (1.5)(9), and immediately upon heating to 60 °C(10,11). VSV in stroma-free haemoglobin can also be inactivated by phototreatment (for example, with red light-emitting diode (655 nm), 1,9-dimethylmethylen blue (DMMB), or methylen blue (MB))(11).

SURVIVAL OUTSIDE HOST: VSV can survive for 3 to 4 days in infected saliva on milking pails, mangers and hay(1).

SECTION V – FIRST AID / MEDICAL

SURVEILLANCE: Monitor for symptoms. Human VSV infections are confirmed by virus isolation from throat swabs or blood(1,2,6). Other methods of detection include PCR(1,2,6), ELISA(1,2), neutralisation(2), compliment fixation, immunofluorescence, and electron microscopy(1).

Note: All diagnostic methods are not necessarily available in all countries.

FIRST AID/TREATMENT: No specific therapy is currently available. Symptomatic treatment and prevention of secondary infections is important(6).

IMMUNIZATION: None currently available for use in humans.

PROPHYLAXIS: None.

SECTION VI – LABORATORY HAZARDS

LABORATORY-ACQUIRED INFECTIONS: 46 recorded cases (with no deaths) until 1980(12).

SOURCES/SPECIMENS: Blood(3,4,6), throat secretions(1,3,6), saliva(1,3,4), exudates, or epithelium from open vesicles(1,3,4).

PRIMARY HAZARDS: Exposure of skin and mucous membranes to VSV via infectious aerosols and/or droplets(3).

SPECIAL HAZARDS: Handling infected livestock is a well documented hazard(1,2,3,6,7).

SECTION VII – EXPOSURE CONTROLS / PERSONAL PROTECTION

RISK GROUP CLASSIFICATION: Risk Group 3.

CONTAINMENT REQUIREMENTS: Containment Level 3 facilities, equipment, and operational practices for work involving infectious or potentially infectious materials, animals, or cultures.

PROTECTIVE CLOTHING: Personnel entering the laboratory should remove street clothing and jewellery, and change into dedicated laboratory clothing and shoes, or don full coverage protective clothing (i.e., completely covering all street clothing). Additional protection may be worn over laboratory clothing when infectious materials are directly handled, such as solid-front gowns with tight fitting wrists, gloves, and respiratory protection. Eye protection must be used where there is a known or potential risk of exposure to splashes(13).

OTHER PRECAUTIONS: All activities with infectious material should be conducted in a biological safety cabinet (BSC) or other appropriate primary containment device in combination with personal protective equipment. Centrifugation of infected materials must be carried out in closed containers placed in sealed safety cups, or in rotors that are loaded or unloaded in a biological safety cabinet. The use of needles, syringes, and other sharp objects should be strictly limited. Open wounds, cuts, scratches, and grazes should be covered with waterproof dressings. Additional precautions should be considered with work involving animals or large scale activities(13).

SECTION VIII – HANDLING AND STORAGE

SPILLS: Allow aerosols to settle and, wearing protective clothing, gently cover spill with paper towels and apply appropriate disinfectant, starting at the perimeter and working towards the centre. Allow sufficient contact time before clean up (30 min)(13).

DISPOSAL: Decontaminate all materials for disposal by steam sterilisation, chemical disinfection, and/or incineration(13).

STORAGE: In sealed, leak-proof containers that are appropriately labelled and locked in a Containment Level 3 laboratory(13).

SECTION IX – REGULATORY AND OTHER INFORMATION

REGULATORY INFORMATION: The import, transport, and use of pathogens in Canada is regulated under many regulatory bodies, including the Public Health Agency of Canada, Health Canada, Canadian Food Inspection Agency, Environment Canada, and Transport Canada. Users are responsible for ensuring they are compliant with all relevant acts, regulations, guidelines, and standards.

UPDATED: September 2010.

PREPARED BY: Pathogen Regulation Directorate, Public Health Agency of Canada.

Although the information, opinions and recommendations contained in this Pathogen Safety Data Sheet are compiled from sources believed to be reliable, we accept no responsibility for the accuracy, sufficiency, or reliability or for any loss or injury resulting from the use of the information. Newly discovered hazards are frequent and this information may not be completely up to date.

Copyright © Public Health Agency of Canada, 2010 Canada

Trichomonas Vaginalis

PATHOGEN SAFETY DATA SHEET – INFECTIOUS SUBSTANCES

SECTION I – INFECTIOUS AGENT

NAME: Trichomonas vaginalis

SYNONYM OR CROSS REFERENCE: Trichomoniasis, vaginitis.

CHARACTERISTICS: Trichomonas vaginalis is a parasitic protozoan flagellate, and organisms vary in size but are usually around 10 μm in length and 7 μm in width(1,2). It usually has an oval or pear-like shape, but can assume an amoeboid form when attached to vaginal epithelial cells. T. vaginalis has a total of 5 flagella, four of which are located at its anterior portion. The fifth flagellum is incorporated within the undulating membrane(1,3). The anaerobic parasite can only exist as a trophozoite and lacks a cystic stage, reproducing by longitudinal binary fission. Growth is optimized at 37°C at pH 6.0 – 6.3, but can survive at up to pH 7(4).

SECTION II – HAZARD IDENTIFICATION

PATHOGENICITY/TOXICITY: T. vaginalis is generally restricted to the genitourinary tract by the host’s immune system, and is the etiological agent of human trichomoniasis(2). Infection has been associated with an increased risk of human immunodeficiency syndrome in both sexes(4).

In women: Symptoms of infection include vaginal secretion that is scanty and mixed with mucus; malodorous discharge that is frothy, yellow or green, mycopurulent, and copious(4). The protozoan can be found in the vagina, cervix, bladder, Bartholin’s, Skene’s, and periurethral glands. Complications may result in cervical erosion, cervical cancer, infertility, adnexitis, pyosalpinx, and endometritis. Premature rupture of the placental membranes can occur in pregnant women, resulting in premature birth and low-birth weight(5). Acute infections are characterised by severe pruritus, vaginitis, vulvitis with dysuria and dyspareunia, and hemorrhagic spots on the mucosa (in 2% of patients) which results in colpitis macularis or petechiae (strawberry cervix). In females, 50% of cases are asymptomatic. Infection can persist for long periods of time in the urogenital tract of women. 25 – 50% are asymptomatic for the first 6 months of infection, and organisms can survive indefinitely in the lower urogenital tract if left untreated(1,6).

In men: Prevalence is lower in men, and infection is often asymptomatic(7). Infection in men can be present in the prostate, seminal vesicles, and epididymis. Complications are rare, but can potentially lead to genitourinary inflammation disease, sterility, scanty, clear to mucopurulent discharge, dysuria, non-gonococcal urethritis, prostatitis, balanoposthitis, epididymitis, and urethral disease(4). Infection is usually mild with no symptoms, thus making men potential carriers. Spontaneous resolution of infection is common as the oxidative nature of the male genital tract is speculated to be inhibitory to pathogenic factors of infection, which usually remains for 10 days or less(1).

EPIDEMIOLOGY: Worldwide – trichomoniasis caused by T. vaginalis is one of the most common non-viral sexually transmitted diseases with an estimated 170 million cases occurring annually (no seasonal variability)(1), and incidence has been found to be high in non-hispanic black women(5). Infection usually occurs in women during reproductive years, and occurrence before menarche or after menopause is rare(4). Fourteen to 60% of male infections are associated with known infected female partners(1).

HOST RANGE: Humans(1).

INFECTIOUS DOSE: Experimental studies have shown that urogenital inoculation with 10,000 to 120,000 organisms has resulted in transmission, although epidemiological examinations have shown that the infective dose in women is low and the infection rate is high(8-10).

MODE OF TRANSMISSION: Commonly spread through sexual contact with vaginal or urethral discharges of infected persons(1), and transmission of organisms via artificial insemination of infected cryobanked semen is also possible(11). Non-sexual transmission is rare but has been observed in cases involving contaminated douche nozzles, moist wash-clothes, specula, or toilet seats(1,12,13). Transmission to newborn infants from infected mothers is possible and is observed in 2 – 17% of cases, and can result in urinary tract or vaginal infections(1).

INCUBATION PERIOD: Ranges from 3 – 28 days with an average of 7 days(4,14).

COMMUNICABILITY: Infection can persist for a significant period of time in asymptomatic cases(14), from months to years. SECTION III – DISSEMINATION

RESERVOIR: Humans, typically females, while men may act as a reservoir for infection(4).

ZOONOSIS: None.

VECTORS: None.

SECTION IV – STABILITY AND VIABILITY

DRUG SUSCEPTIBILITY: The only drugs that have been approved by the FDA for use in the United States are metronidazole (although the use of this drug can increase the incidence of preterm birth)(15), and Tinidazole (trade name known as Tindamax)(16). Ornidazole, secnidazole, and nimorazole can be used in countries outside of the US. In vitro testing has shown that nitroimidazole EU11100 also has similar efficacy as metronidazole(15).

DRUG RESISTANCE: Studies have shown that at least 5% of clinical cases of trichomoniasis are caused by metronidazole-resistant T. vaginalis, and cross-resistance to tinidazole is a concern as the two drugs are similar in modes of action (4).

SUSCEPTIBILITY TO DISINFECTANTS: Susceptible to 1% sodium hypochlorite, and 70% ethanol(17).

PHYSICAL INACTIVATION: Inactivated below pH 5(4). Organisms cannot survive long (several hours) in dry conditions(1).

SURVIVAL OUTSIDE HOST: The organism grows best at 37°C, and specimens in urine should be considered viable for only 30 minutes to avoid false negatives (2 hours if PCR is used)(18). Live T. vaginalis have been found in swimming pool water, in urine, and semen after up to 6 – 24 hours, and up to 30 – 45 minutes when exposed to air(1,19,20). Studies have also shown that T. vaginalis organisms are able to survive through the cryopreservation process of human semen, making infection via artificial insemination possible(11).

SECTION V – FIRST AID / MEDICAL

SURVEILLANCE: Monitor for symptoms. Current laboratory diagnoses include direct microscopic observation, cell culture, immunological techniques, PCR assay, nucleic acid probe test, immunochromatographic capillary-flow dipstick technology, DNA probing and gene amplification, and in situ hybridization(2,9,16).

Note: All diagnostic methods are not necessarily available in all countries.

FIRST AID/TREATMENT: Topical vaginal medications and pessaries (such as clotrimazole, povidone-iodine, nonoxynol-9, and arsenical pessaries) may be prescribed for treatment in women to lessen the effects of symptoms; however, these do not consistently cure disease(4). Topical paromycin has been found to be effective, but side effects can be mild to severe(21). There are no topical medications available for men. Metronidazole can be administered orally or intravenously, with cure rates of 85-95%(1); Metronidazole should not be used by pregnant women in their first trimester as it has been linked to higher prevalence of preterm birth(22).

IMMUNISATION: No vaccinations are currently available. Two vaccines have progressed to the human clinical trials stage in the past 50 years (a heat-killed T. vaginalis vaccine, and SolcoTriovac), although they have not been proven to be effective against T. vaginalis(4).

PROPHYLAXIS: Since many males are asymptomatic and may be carriers, it is important to concurrently treat male partners of infected women to prevent re-infection(4).

SECTION VI – LABORATORY HAZARDS

LABORATORY-ACQUIRED INFECTIONS: None reported to date.

SOURCES/SPECIMENS: Vaginal and urethral secretions, urine, human semen(4,11,18).

PRIMARY HAZARDS: Droplet exposure to mucous membrane, accidental parenteral inoculation and sexual transmission(1,23).

SPECIAL HAZARDS: None.

SECTION VII – EXPOSURE CONTROLS / PERSONAL PROTECTION

RISK GROUP CLASSIFICATION: Risk Group 2(24).

CONTAINMENT REQUIREMENTS: Containment Level 2 facilities, equipment, and operational practices for work involving infected or potentially infected materials, animals, or cultures.

PROTECTIVE CLOTHING: Lab coat. Gloves when direct skin contact with infected materials or animals is unavoidable. Eye protection must be used where there is a known or potential risk of exposure to splashes(25).

OTHER PRECAUTIONS: All procedures that may produce aerosols, or involve high concentrations or large volumes should be conducted in a biological safety cabinet (BSC). The use of needles, syringes, and other sharp objects should be strictly limited. Additional precautions should be considered with work involving animals or large scale activities(25).

SECTION VIII – HANDLING AND STORAGE

SPILLS: Allow aerosols to settle and, while wearing protective clothing, cover spill with absorbent paper towel. Apply appropriate disinfectant, and starting from perimeter and wipe towards the center. Allow sufficient contact time with the disinfectant before cleaning up.

DISPOSAL: Decontaminate all wastes that contain or have come in contact with the infectious organism before disposing by autoclave, chemical disinfection, gamma irradiation, or incineration(25).

STORAGE: Properly labelled and sealed containers.

SECTION IX – REGULATORY AND OTHER INFORMATION

REGULATORY INFORMATION: The import, transport, and use of pathogens in Canada is regulated under many regulatory bodies, including the Public Health Agency of Canada, Health Canada, Canadian Food Inspection Agency, Environment Canada, and Transport Canada. Users are responsible for ensuring they are compliant with all relevant acts, regulations, guidelines, and standards.

UPDATED: November 2010

PREPARED BY: Pathogen Regulation Directorate, Public Health Agency of Canada

Although the information, opinions and recommendations contained in this Pathogen Safety Data Sheet are compiled from sources believed to be reliable, we accept no responsibility for the accuracy, sufficiency, or reliability or for any loss or injury resulting from the use of the information. Newly discovered hazards are frequent and this information may not be completely up to date.

Copyright © Public Health Agency of Canada, 2010 Canada

This MSDS / PSDS document, provided by Public Health Agency of Canada (PHAC), is offered here as a FREE public service to visitors of www.EHS.com. As outlined in this site’s Terms of Use, VelocityEHS is not responsible for the accuracy, content or any aspect of the information contained therein.

Trichomonas Vaginalis

PATHOGEN SAFETY DATA SHEET – INFECTIOUS SUBSTANCES

SECTION I – INFECTIOUS AGENT

NAME: Trichomonas vaginalis

SYNONYM OR CROSS REFERENCE: Trichomoniasis, vaginitis.

CHARACTERISTICS: Trichomonas vaginalis is a parasitic protozoan flagellate, and organisms vary in size but are usually around 10 μm in length and 7 μm in width(1,2). It usually has an oval or pear-like shape, but can assume an amoeboid form when attached to vaginal epithelial cells. T. vaginalis has a total of 5 flagella, four of which are located at its anterior portion. The fifth flagellum is incorporated within the undulating membrane(1,3). The anaerobic parasite can only exist as a trophozoite and lacks a cystic stage, reproducing by longitudinal binary fission. Growth is optimized at 37°C at pH 6.0 – 6.3, but can survive at up to pH 7(4).

SECTION II – HAZARD IDENTIFICATION

PATHOGENICITY/TOXICITY: T. vaginalis is generally restricted to the genitourinary tract by the host’s immune system, and is the etiological agent of human trichomoniasis(2). Infection has been associated with an increased risk of human immunodeficiency syndrome in both sexes(4).

In women: Symptoms of infection include vaginal secretion that is scanty and mixed with mucus; malodorous discharge that is frothy, yellow or green, mycopurulent, and copious(4). The protozoan can be found in the vagina, cervix, bladder, Bartholin’s, Skene’s, and periurethral glands. Complications may result in cervical erosion, cervical cancer, infertility, adnexitis, pyosalpinx, and endometritis. Premature rupture of the placental membranes can occur in pregnant women, resulting in premature birth and low-birth weight(5). Acute infections are characterised by severe pruritus, vaginitis, vulvitis with dysuria and dyspareunia, and hemorrhagic spots on the mucosa (in 2% of patients) which results in colpitis macularis or petechiae (strawberry cervix). In females, 50% of cases are asymptomatic. Infection can persist for long periods of time in the urogenital tract of women. 25 – 50% are asymptomatic for the first 6 months of infection, and organisms can survive indefinitely in the lower urogenital tract if left untreated(1,6).

In men: Prevalence is lower in men, and infection is often asymptomatic(7). Infection in men can be present in the prostate, seminal vesicles, and epididymis. Complications are rare, but can potentially lead to genitourinary inflammation disease, sterility, scanty, clear to mucopurulent discharge, dysuria, non-gonococcal urethritis, prostatitis, balanoposthitis, epididymitis, and urethral disease(4). Infection is usually mild with no symptoms, thus making men potential carriers. Spontaneous resolution of infection is common as the oxidative nature of the male genital tract is speculated to be inhibitory to pathogenic factors of infection, which usually remains for 10 days or less(1).

EPIDEMIOLOGY: Worldwide – trichomoniasis caused by T. vaginalis is one of the most common non-viral sexually transmitted diseases with an estimated 170 million cases occurring annually (no seasonal variability)(1), and incidence has been found to be high in non-hispanic black women(5). Infection usually occurs in women during reproductive years, and occurrence before menarche or after menopause is rare(4). Fourteen to 60% of male infections are associated with known infected female partners(1).

HOST RANGE: Humans(1).

INFECTIOUS DOSE: Experimental studies have shown that urogenital inoculation with 10,000 to 120,000 organisms has resulted in transmission, although epidemiological examinations have shown that the infective dose in women is low and the infection rate is high(8-10).

MODE OF TRANSMISSION: Commonly spread through sexual contact with vaginal or urethral discharges of infected persons(1), and transmission of organisms via artificial insemination of infected cryobanked semen is also possible(11). Non-sexual transmission is rare but has been observed in cases involving contaminated douche nozzles, moist wash-clothes, specula, or toilet seats(1,12,13). Transmission to newborn infants from infected mothers is possible and is observed in 2 – 17% of cases, and can result in urinary tract or vaginal infections(1).

INCUBATION PERIOD: Ranges from 3 – 28 days with an average of 7 days(4,14).

COMMUNICABILITY: Infection can persist for a significant period of time in asymptomatic cases(14), from months to years. SECTION III – DISSEMINATION

RESERVOIR: Humans, typically females, while men may act as a reservoir for infection(4).

ZOONOSIS: None.

VECTORS: None.

SECTION IV – STABILITY AND VIABILITY

DRUG SUSCEPTIBILITY: The only drugs that have been approved by the FDA for use in the United States are metronidazole (although the use of this drug can increase the incidence of preterm birth)(15), and Tinidazole (trade name known as Tindamax)(16). Ornidazole, secnidazole, and nimorazole can be used in countries outside of the US. In vitro testing has shown that nitroimidazole EU11100 also has similar efficacy as metronidazole(15).

DRUG RESISTANCE: Studies have shown that at least 5% of clinical cases of trichomoniasis are caused by metronidazole-resistant T. vaginalis, and cross-resistance to tinidazole is a concern as the two drugs are similar in modes of action (4).

SUSCEPTIBILITY TO DISINFECTANTS: Susceptible to 1% sodium hypochlorite, and 70% ethanol(17).

PHYSICAL INACTIVATION: Inactivated below pH 5(4). Organisms cannot survive long (several hours) in dry conditions(1).

SURVIVAL OUTSIDE HOST: The organism grows best at 37°C, and specimens in urine should be considered viable for only 30 minutes to avoid false negatives (2 hours if PCR is used)(18). Live T. vaginalis have been found in swimming pool water, in urine, and semen after up to 6 – 24 hours, and up to 30 – 45 minutes when exposed to air(1,19,20). Studies have also shown that T. vaginalis organisms are able to survive through the cryopreservation process of human semen, making infection via artificial insemination possible(11).

SECTION V – FIRST AID / MEDICAL

SURVEILLANCE: Monitor for symptoms. Current laboratory diagnoses include direct microscopic observation, cell culture, immunological techniques, PCR assay, nucleic acid probe test, immunochromatographic capillary-flow dipstick technology, DNA probing and gene amplification, and in situ hybridization(2,9,16).

Note: All diagnostic methods are not necessarily available in all countries.

FIRST AID/TREATMENT: Topical vaginal medications and pessaries (such as clotrimazole, povidone-iodine, nonoxynol-9, and arsenical pessaries) may be prescribed for treatment in women to lessen the effects of symptoms; however, these do not consistently cure disease(4). Topical paromycin has been found to be effective, but side effects can be mild to severe(21). There are no topical medications available for men. Metronidazole can be administered orally or intravenously, with cure rates of 85-95%(1); Metronidazole should not be used by pregnant women in their first trimester as it has been linked to higher prevalence of preterm birth(22).

IMMUNISATION: No vaccinations are currently available. Two vaccines have progressed to the human clinical trials stage in the past 50 years (a heat-killed T. vaginalis vaccine, and SolcoTriovac), although they have not been proven to be effective against T. vaginalis(4).

PROPHYLAXIS: Since many males are asymptomatic and may be carriers, it is important to concurrently treat male partners of infected women to prevent re-infection(4).

SECTION VI – LABORATORY HAZARDS

LABORATORY-ACQUIRED INFECTIONS: None reported to date.

SOURCES/SPECIMENS: Vaginal and urethral secretions, urine, human semen(4,11,18).

PRIMARY HAZARDS: Droplet exposure to mucous membrane, accidental parenteral inoculation and sexual transmission(1,23).

SPECIAL HAZARDS: None.

SECTION VII – EXPOSURE CONTROLS / PERSONAL PROTECTION

RISK GROUP CLASSIFICATION: Risk Group 2(24).

CONTAINMENT REQUIREMENTS: Containment Level 2 facilities, equipment, and operational practices for work involving infected or potentially infected materials, animals, or cultures.

PROTECTIVE CLOTHING: Lab coat. Gloves when direct skin contact with infected materials or animals is unavoidable. Eye protection must be used where there is a known or potential risk of exposure to splashes(25).

OTHER PRECAUTIONS: All procedures that may produce aerosols, or involve high concentrations or large volumes should be conducted in a biological safety cabinet (BSC). The use of needles, syringes, and other sharp objects should be strictly limited. Additional precautions should be considered with work involving animals or large scale activities(25).

SECTION VIII – HANDLING AND STORAGE

SPILLS: Allow aerosols to settle and, while wearing protective clothing, cover spill with absorbent paper towel. Apply appropriate disinfectant, and starting from perimeter and wipe towards the center. Allow sufficient contact time with the disinfectant before cleaning up.

DISPOSAL: Decontaminate all wastes that contain or have come in contact with the infectious organism before disposing by autoclave, chemical disinfection, gamma irradiation, or incineration(25).

STORAGE: Properly labelled and sealed containers.

SECTION IX – REGULATORY AND OTHER INFORMATION

REGULATORY INFORMATION: The import, transport, and use of pathogens in Canada is regulated under many regulatory bodies, including the Public Health Agency of Canada, Health Canada, Canadian Food Inspection Agency, Environment Canada, and Transport Canada. Users are responsible for ensuring they are compliant with all relevant acts, regulations, guidelines, and standards.

UPDATED: November 2010

PREPARED BY: Pathogen Regulation Directorate, Public Health Agency of Canada

Although the information, opinions and recommendations contained in this Pathogen Safety Data Sheet are compiled from sources believed to be reliable, we accept no responsibility for the accuracy, sufficiency, or reliability or for any loss or injury resulting from the use of the information. Newly discovered hazards are frequent and this information may not be completely up to date.

Copyright © Public Health Agency of Canada, 2010 Canada

Trichomonas Vaginalis

PATHOGEN SAFETY DATA SHEET – INFECTIOUS SUBSTANCES

SECTION I – INFECTIOUS AGENT

NAME: Trichomonas vaginalis

SYNONYM OR CROSS REFERENCE: Trichomoniasis, vaginitis.

CHARACTERISTICS: Trichomonas vaginalis is a parasitic protozoan flagellate, and organisms vary in size but are usually around 10 μm in length and 7 μm in width(1,2). It usually has an oval or pear-like shape, but can assume an amoeboid form when attached to vaginal epithelial cells. T. vaginalis has a total of 5 flagella, four of which are located at its anterior portion. The fifth flagellum is incorporated within the undulating membrane(1,3). The anaerobic parasite can only exist as a trophozoite and lacks a cystic stage, reproducing by longitudinal binary fission. Growth is optimized at 37°C at pH 6.0 – 6.3, but can survive at up to pH 7(4).

SECTION II – HAZARD IDENTIFICATION

PATHOGENICITY/TOXICITY: T. vaginalis is generally restricted to the genitourinary tract by the host’s immune system, and is the etiological agent of human trichomoniasis(2). Infection has been associated with an increased risk of human immunodeficiency syndrome in both sexes(4).

In women: Symptoms of infection include vaginal secretion that is scanty and mixed with mucus; malodorous discharge that is frothy, yellow or green, mycopurulent, and copious(4). The protozoan can be found in the vagina, cervix, bladder, Bartholin’s, Skene’s, and periurethral glands. Complications may result in cervical erosion, cervical cancer, infertility, adnexitis, pyosalpinx, and endometritis. Premature rupture of the placental membranes can occur in pregnant women, resulting in premature birth and low-birth weight(5). Acute infections are characterised by severe pruritus, vaginitis, vulvitis with dysuria and dyspareunia, and hemorrhagic spots on the mucosa (in 2% of patients) which results in colpitis macularis or petechiae (strawberry cervix). In females, 50% of cases are asymptomatic. Infection can persist for long periods of time in the urogenital tract of women. 25 – 50% are asymptomatic for the first 6 months of infection, and organisms can survive indefinitely in the lower urogenital tract if left untreated(1,6).

In men: Prevalence is lower in men, and infection is often asymptomatic(7). Infection in men can be present in the prostate, seminal vesicles, and epididymis. Complications are rare, but can potentially lead to genitourinary inflammation disease, sterility, scanty, clear to mucopurulent discharge, dysuria, non-gonococcal urethritis, prostatitis, balanoposthitis, epididymitis, and urethral disease(4). Infection is usually mild with no symptoms, thus making men potential carriers. Spontaneous resolution of infection is common as the oxidative nature of the male genital tract is speculated to be inhibitory to pathogenic factors of infection, which usually remains for 10 days or less(1).

EPIDEMIOLOGY: Worldwide – trichomoniasis caused by T. vaginalis is one of the most common non-viral sexually transmitted diseases with an estimated 170 million cases occurring annually (no seasonal variability)(1), and incidence has been found to be high in non-hispanic black women(5). Infection usually occurs in women during reproductive years, and occurrence before menarche or after menopause is rare(4). Fourteen to 60% of male infections are associated with known infected female partners(1).

HOST RANGE: Humans(1).

INFECTIOUS DOSE: Experimental studies have shown that urogenital inoculation with 10,000 to 120,000 organisms has resulted in transmission, although epidemiological examinations have shown that the infective dose in women is low and the infection rate is high(8-10).

MODE OF TRANSMISSION: Commonly spread through sexual contact with vaginal or urethral discharges of infected persons(1), and transmission of organisms via artificial insemination of infected cryobanked semen is also possible(11). Non-sexual transmission is rare but has been observed in cases involving contaminated douche nozzles, moist wash-clothes, specula, or toilet seats(1,12,13). Transmission to newborn infants from infected mothers is possible and is observed in 2 – 17% of cases, and can result in urinary tract or vaginal infections(1).

INCUBATION PERIOD: Ranges from 3 – 28 days with an average of 7 days(4,14).

COMMUNICABILITY: Infection can persist for a significant period of time in asymptomatic cases(14), from months to years. SECTION III – DISSEMINATION

RESERVOIR: Humans, typically females, while men may act as a reservoir for infection(4).

ZOONOSIS: None.

VECTORS: None.

SECTION IV – STABILITY AND VIABILITY

DRUG SUSCEPTIBILITY: The only drugs that have been approved by the FDA for use in the United States are metronidazole (although the use of this drug can increase the incidence of preterm birth)(15), and Tinidazole (trade name known as Tindamax)(16). Ornidazole, secnidazole, and nimorazole can be used in countries outside of the US. In vitro testing has shown that nitroimidazole EU11100 also has similar efficacy as metronidazole(15).

DRUG RESISTANCE: Studies have shown that at least 5% of clinical cases of trichomoniasis are caused by metronidazole-resistant T. vaginalis, and cross-resistance to tinidazole is a concern as the two drugs are similar in modes of action (4).

SUSCEPTIBILITY TO DISINFECTANTS: Susceptible to 1% sodium hypochlorite, and 70% ethanol(17).

PHYSICAL INACTIVATION: Inactivated below pH 5(4). Organisms cannot survive long (several hours) in dry conditions(1).

SURVIVAL OUTSIDE HOST: The organism grows best at 37°C, and specimens in urine should be considered viable for only 30 minutes to avoid false negatives (2 hours if PCR is used)(18). Live T. vaginalis have been found in swimming pool water, in urine, and semen after up to 6 – 24 hours, and up to 30 – 45 minutes when exposed to air(1,19,20). Studies have also shown that T. vaginalis organisms are able to survive through the cryopreservation process of human semen, making infection via artificial insemination possible(11).

SECTION V – FIRST AID / MEDICAL

SURVEILLANCE: Monitor for symptoms. Current laboratory diagnoses include direct microscopic observation, cell culture, immunological techniques, PCR assay, nucleic acid probe test, immunochromatographic capillary-flow dipstick technology, DNA probing and gene amplification, and in situ hybridization(2,9,16).

Note: All diagnostic methods are not necessarily available in all countries.

FIRST AID/TREATMENT: Topical vaginal medications and pessaries (such as clotrimazole, povidone-iodine, nonoxynol-9, and arsenical pessaries) may be prescribed for treatment in women to lessen the effects of symptoms; however, these do not consistently cure disease(4). Topical paromycin has been found to be effective, but side effects can be mild to severe(21). There are no topical medications available for men. Metronidazole can be administered orally or intravenously, with cure rates of 85-95%(1); Metronidazole should not be used by pregnant women in their first trimester as it has been linked to higher prevalence of preterm birth(22).

IMMUNISATION: No vaccinations are currently available. Two vaccines have progressed to the human clinical trials stage in the past 50 years (a heat-killed T. vaginalis vaccine, and SolcoTriovac), although they have not been proven to be effective against T. vaginalis(4).

PROPHYLAXIS: Since many males are asymptomatic and may be carriers, it is important to concurrently treat male partners of infected women to prevent re-infection(4).

SECTION VI – LABORATORY HAZARDS

LABORATORY-ACQUIRED INFECTIONS: None reported to date.

SOURCES/SPECIMENS: Vaginal and urethral secretions, urine, human semen(4,11,18).

PRIMARY HAZARDS: Droplet exposure to mucous membrane, accidental parenteral inoculation and sexual transmission(1,23).

SPECIAL HAZARDS: None.

SECTION VII – EXPOSURE CONTROLS / PERSONAL PROTECTION

RISK GROUP CLASSIFICATION: Risk Group 2(24).

CONTAINMENT REQUIREMENTS: Containment Level 2 facilities, equipment, and operational practices for work involving infected or potentially infected materials, animals, or cultures.

PROTECTIVE CLOTHING: Lab coat. Gloves when direct skin contact with infected materials or animals is unavoidable. Eye protection must be used where there is a known or potential risk of exposure to splashes(25).

OTHER PRECAUTIONS: All procedures that may produce aerosols, or involve high concentrations or large volumes should be conducted in a biological safety cabinet (BSC). The use of needles, syringes, and other sharp objects should be strictly limited. Additional precautions should be considered with work involving animals or large scale activities(25).

SECTION VIII – HANDLING AND STORAGE

SPILLS: Allow aerosols to settle and, while wearing protective clothing, cover spill with absorbent paper towel. Apply appropriate disinfectant, and starting from perimeter and wipe towards the center. Allow sufficient contact time with the disinfectant before cleaning up.

DISPOSAL: Decontaminate all wastes that contain or have come in contact with the infectious organism before disposing by autoclave, chemical disinfection, gamma irradiation, or incineration(25).

STORAGE: Properly labelled and sealed containers.

SECTION IX – REGULATORY AND OTHER INFORMATION

REGULATORY INFORMATION: The import, transport, and use of pathogens in Canada is regulated under many regulatory bodies, including the Public Health Agency of Canada, Health Canada, Canadian Food Inspection Agency, Environment Canada, and Transport Canada. Users are responsible for ensuring they are compliant with all relevant acts, regulations, guidelines, and standards.

UPDATED: November 2010

PREPARED BY: Pathogen Regulation Directorate, Public Health Agency of Canada

Although the information, opinions and recommendations contained in this Pathogen Safety Data Sheet are compiled from sources believed to be reliable, we accept no responsibility for the accuracy, sufficiency, or reliability or for any loss or injury resulting from the use of the information. Newly discovered hazards are frequent and this information may not be completely up to date.

Copyright © Public Health Agency of Canada, 2010 Canada

This MSDS / PSDS document, provided by Public Health Agency of Canada (PHAC), is offered here as a FREE public service to visitors of www.EHS.com. As outlined in this site’s Terms of Use, VelocityEHS is not responsible for the accuracy, content or any aspect of the information contained therein.


Need an SDS? Search our entire SDS database containing millions of documents.