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PubMed1980

A study of small mammals in the Ciloto field station area, West Java, Indonesia, with special reference to vectors of plague and scrub typhus.

From June 1977 to June 1978 a study of smal mammals was carried out in the Ciloto field station area, West Java, Indonesia by the WHO Vector Biology and Control Research Unit-II. The objectives of the investigations were to determine the diversity and density of rodent species, to find potential plague and scrub typhus vectors and to study their host-parasite relationships. In the 13 month period a total of 6 species of murids were identified; two species of campestral rats (R. tiomanicus and R. argentiventer), one species of peri-domestic (R. exulans), one species of domestic (R.r. diardii), and two species of forest rats (R. bartelsii and R. bukit). In addition, three species of insectivores (Suncus murinus, Hylomys suillus and Crocidura monticola), and one species of carnivore were found. Of the three habitats studies (mixed, ricefield and lalang), 10 species of small mammals were found in the mixed while four species of commensal murids were found in both the ricefield and the lalang. Of the four commensal murid species R. exulans had the highest density. R. tiomanicus was common but not abundant, and least common was R. argentiventer. R.r. diardii was occasionally found in the field. The mean litter size of gravid R. tiomanicus was 7.1, R. exulans 4.3, R. argentiventer 7.5 and R.r. diardii 9. Male R. tiomanicus, R. argentiventer and R.r. diardii with spermatozoa present in animals over 55 gm. Animals of less than 50 gm had no sperm. In R. exulans spermatozoa were present in specimens weighing 24-66 gm. No sperm were detected in those below 20 gm. The flea index of Xenopsylla cheopis and Stivalius cognatus as determined for R. tiomanicus was 0.3 and 2.3;l for R.r. diardii 2.2 and 1.7; for R. exulans 0.3 and 0.5; and for R. argentiventer 0.4 and 1.7 respectively. S. cognatus had a significantly higher density than X. cheopis among the campestral and peridomestic rats, but the density of X. cheopis was significantly in the domestic rat. Overall infestation rates were equally high in both mixed and lalang habitats, but low in the ricefield. Flea indices were highest in the mixed habitat, lower in lalang, and lowest in ricefield. The putative vector of scrub typhus (Leptotrombidium (L.) deliense) was quite prevalent on campestral rats, less so on domestic ones and least on peridomestic. Overall infestation rates were equally high in both mixed and lalang habitats and low in the ricefield. Chiggers load per animal was significantly higher in the mixed habitat, lower in lalang and lowest in the ricefield.

Animals↗
PubMed1976

Siphonaptera collected by Dr. M. Daniel in Nepal.

During the Third Czechoslovak Expedition to the Himalayas, in the spring of 1973, Dr. M. Daniel collected 244 specimens of fleas belonging to 19 different taxa, including four hitherto undescribed ones, from mammals and birds in the Barun Khola valley at the foot of the Makalu mountain just south-east of Mt. Everest. Data and comments are given in this paper for the fleas collected and the new taxa are described.

Animals↗
PubMed1994

[Plague in Zaire].

Two endemic foci of plague have been discovered in Zaïre, the first in the Ituri in 1928, the other in North-Kivu in 1938. They are situated in the region of the great East-African Rift and are adjacent to the Ugandan focus, identified in 1877. A strict surveillance of these endemic foci makes it possible to state that, between 1928 and 1959, 632 cases of plague have been diagnosed in the Ituri, or 20 a year, and 190 in the N-Kivu, or 8 a year. Since then several flare ups have been notified. This situation is very remote from the "black death" concept. Yersinia pestis presents, besides its bipolar staining, many other characteristics such as the indispensable presence of iron to produce virulence, or the fermentation of glycerine and reduction of nitrates as parameters for the identification of 3 biovars, corresponding with a specific geographic distribution: antiqua, medievalis, orientalis or maritima. The antigenic structure has been discussed and also the role of plasmids. Plague is a disease of rats, a variegated gathering of rodents with different degrees of tolerance and sensitiveness to Y.pestis, living in a frail equilibrium. The multimammate houserat was in the Ituri the principal agent until the black rat Rattus rattus invaded the region and a new balance came into being. The frequent changes in taxonomy of Mastomys caused uncertainties. The transmission is due to fleas subject to a blocking of their ventriculum by Y.pestis. Fleas play an active part in the process. Man is only a casual intruder. The pathogenicity is related to its invasiveness and its intracellular localization in macrophages and other R.E. cells, in which Y.pestis can survive. The bubo is characteristic of the disease. In Zaïre a septicaemic tendency has been observed, with a possible involvement of the C.N.S. and of the lungs. The latter may produce among the surrounding relatives primary pneumonic plague. The clinical diagnosis ought to be confirmed by bacteriologic investigation of the puncture fluid of the bubo, the blood, and when necessary the C.S.F. or the sputum by culture and/or animal inoculation. The treatment became very efficient since the availability of sulfamides and later antibiotics: aminoglycosides, chloramphenicol, tetracyclines. A timely administration ensures practically recovery. As soon as Y.pestis was identified vaccination was put into practice and in the first place by killed germs (Haffkine's lymph) to day with formalized F1, for mass vaccination live attenuated strains were used: Tjiwidej (Otten), E.V. (Girard), K120 (Grasset).(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1993

Zoonoses of dermatological interest.

The zoonoses are those diseases transmitted from animals to humans. Although commonly thought to be infectious in origin such as scabies or dermatophytosis, inflammatory processes may also be zoonotic. Contact dermatitis may result from allergens being carried from animals to humans. Although the scabies mite is somewhat species specific, various mites sometimes have the opportunity of producing skin disease on man (ie, canine scabies, porcine scabies, and feline scabies [notoedric mange]); cheyletiellosis is caused by a similar mite, often found in rabbits. The index case of superficial fungal infections may be the household pet, whereas the cause of flea bite dermatitis (papular urticaria) may be the lack of an animal, resulting in the flea choosing a human for feeding. Understanding zoonotic skin diseases will improve the clinician's diagnostic skills. Both the human and animal patient will then receive more effective treatment in a quicker fashion.

Animals↗
PubMedDate not supplied

[Human diffusion of arthropod disease vectors throughout the world].

The present distribution of animals and plants throughout the world is the result of an evolutionary process involving tectonic, climatic and biotic factors. Humans, since their appearance, have contributed to the spreading of many species including disease vectors and pests. When humans left their native African home, they brought with them ectoparasites such as lice and acarids. During the neolithic era, humans were leading domesticated animals which carried their own parasites into new areas. Dwelling commensals, flea, bugs, triatomids, flies, and cockroaches followed human migrations. In the second millennium, sailboats transported mosquito species which were resistant and reproduced on board, including Culex quinquefasciatus, Aedes aegypti, and Ae. albopictus. Steamers further shortened the length of trips and allowed the transport of anophelines. The opening of the Tamatave-Port-Louis line was immediately followed by the transport of An. gambiae from Madagascar to Mauritius and Reunion, and epidemics of malaria occurred on the two islands which had been free of the disease. Also, An. gambiae was transported from Senegal to Brazil. Old tires destined for recycling carried Ae. albopictus to the USA, Brazil, and then Italy. The pandemic of the plague at the end of the nineteenth century was propagated from harbour to harbour by steamers carrying both infected rats and their fleas Xenopsylla cheopsis. Aircrafts have reduced the travel time so much that in less than two days an insect could reach every point of the world. As soon as the airports had been built on the islands of French Polynesia, they were all colonized by Ae. aegypti. The same phenomenon occurred with midges (Fig. 2). Also, the construction of the airport on a Galapagos Island coincided with the importation of the blackfly Simulium bipunctatum from the continent. In addition, infected malaria mosquitos imported from tropical countries reached Europe and contaminated airport employees and local inhabitants. Six cases of malaria were recorded during the summer of 1994 around the Charles de Gaulle Airport, north of Paris, suggesting that the anophelines could have been imported from West and Central African countries which are served by this airport. The serious threat of vector importation is moderated by the vector's difficulty in adapting to new conditions. However any prediction is questionable.

Animals↗
PubMed1996

The comparative host status of red veld rats (Aethomys chrysophilus) and bushveld gerbils (Tatera leucogaster) for epifaunal arthropods in the southern Kruger National Park, South Africa.

Red veld rats (Aethomys chrysophilus) and bushveld gerbils (Tatera leucogaster) were trapped at monthly intervals, when possible, over a 2-year period, in the southern Kruger National Park, Mpumalanga Province. Forty-six specimens of each species were caught, euthenased and microscopically examined for fleas, lice, ticks and mites. Clear differences existed between the two rodent hosts in infestation intensity and also parasite species. The flea, Xenopsylla brasiliensis, commonly and exclusively utilized red veld rats, whereas Xenopsylla frayi was common and specific to bushveld gerbils. T. leucogaster were commonly infested with the lice Hoplopleura biseriata and Polyplax biseriata, while only a single A. chrysophilus hosted the louse, Hoplopleura patersoni. Red veld rats harboured small numbers of the immature stages of Haemaphysalis leachi/spinulosa and relatively large numbers of Rhipicephalus simus. The larvae of R. simus were irregularly collected from February to September and the nymphs from March to November. Bushveld gerbils hosted fewer ticks than did the rats, with a single specimen of H. leachi/spinulosa and low numbers of immature Hyalomma truncatum, the latter erratically present from June to October. Miles were abundant on both rodent hosts, A. chrysophilus hosting 13 species in six families, and T. leucogaster hosting 12 species representing seven families, with clear differences in mite assemblages between the two rodents. As the rats and gerbils were collected from the same trap lines at the same times, the differences in species composition and infestation intensity of their parasites, suggest that immunological behavioural or other segregating mechanisms are in operation to maintain discrete parasite assemblages.

Animals↗
PubMed1996

A case of tungiasis.

Tunga penetrans is a burrowing flea that is prevalent in Central and South America, the Caribbean, tropical Africa, India, and Pakistan, and rarely is imported to the United States. Tungiasis results from the cutaneous infestation of humans by the gravid female flea, T. penetrans. We report a case of tungiasis in a female who had been on a missionary expedition along the Brazilian Amazon River. The clinical presentation, life cycle, differential diagnosis, military and historical aspects, and treatment are discussed.

Animals↗
PubMed1998

[Epidemiology and epizootiology of plague: the major role of the surveillance of reservoir populations of wild rodents in the control of permanent foci].

Plague is a bacterial infection, due to Yersinia pestis. It is essentially a zoonosis of rodents, communicable from rodent to rodent and from rodent to man by flea bite. From the first human case, acquired from rodents, interhuman transmission occurs by means of flea bite (bubonic plague) or is airborne (primary pulmonary plague). Long term implantation of plague amongst wild rodents populations after the third pandemic (1894 to present), created inveterate foci in all continents, except Europe. Those wild rodents settlements in arid biotopes, preserved from human activities, represent the main reservoir of plague. Their determination is mandatory for the surveillance of epizootics and the prevention of epidemics.

Animals↗
PubMedDate not supplied

[Bartonellosis: I. Bartonella henselae].

The recent discovery of the bacterium Bartonella henselae was mainly due to the development of molecular biology techniques adapted to microbial diagnosis and to the description of new human diseases linked to Aids. About 10% of pet cats and 33% of stray cats harbour that bacterium in their blood. In immunocompetent patients, that bacterium is responsible for human cat scratch disease, characterized essentially by a localized lymph nodes enlargement in the vicinity of the entry site of the bacteria. This disease occurs more likely in pet cats less than 1-year-old and infested with fleas. The bacterium is transmitted to humans by scratches or bites; the role of fleas is possible, but is not yet documented. In 5 to 13% of cases, the cat scratch disease appears as more severe, including health impairment, hepatitis, Parinaud's oculo-glandular syndrome, neurological complications or stellate retinitis. In immunocompromised patients, B. henselae is responsible for various clinical presentations: bacillary angiomatosis, bacillary peliosis, recurrent or persistent bacteremia or endocarditis. Diagnosis of infections due to B. henselae can be performed by serological specific testing with sensitivity and specificity values ranging from 75 to 100%. Cultivation of the bacterium is fastidious, particularly in cases of cat scratch disease. The most efficient diagnostic test is the in vitro DNA amplification which has the drawback to require a lymph node sample. Antibiotics are usually inefficient for the treatment of cat scratch disease. By contrast, in immunocompromised patients, these infections are successfully treated for a more or less long time by macrolides or tetracyclines or rifampin.

Animals↗
PubMed1998

Rodents, their seasonal activity, ecto- and blood-parasites in Saint Catherine area, South Sinai Governorate, Egypt.

Rodents are on the top of animal reservoirs of zoonotic parasites. Five species of wild rodents were trapped on monthly base from Saint Catherine area. The highest trap index was 0.5 in May and the lowest was zero in December, January and February. The dominant rodents were Acomys c. dimidiatus followed by Dipodillus d. dasyurus and then A. r. russatus. Sporadic numbers of Sekeetamys c. calurus (3) and Eliomys. qu. melanurus (2) were collected. The ectoparasites in a descending order of abundance were mites (45.6%), lice (30.3%) and then fleas (24.1%). The most abundant ectoparasites among the three groups were Polyplax spinulosa (lice). Allodermanyssus sanguineus (mites), and Xenopsylla dipodilli (fleas). Leishmania amastigotes and Babesia microti were detected in Acomys. Also, one pregnant female A. c. dimidiatus was infected with a nematode parasite, Syphacia obvelata. The results were discussed on the light of the previous work.

Animals↗
PubMed2006

Widened coronary arteries in a feverish child.

A 3-year-old girl with fever of unknown origin after a visit to Surinam was seen at our hospital. Signs and symptoms were indicative of either Kawasaki syndrome or an acute viral or (atypical) bacterial illness. No cardiac abnormalities were noted at echocardiography. She was treated with intravenous immunoglobulin and clarithromycin and made a quick recovery. Serologically, the diagnosis of murine typhus was made; a flea-borne rickettsiosis caused by Rickettsia typhi. A follow-up echocardiography 1 week later showed a dilated left coronary artery, which was normal again 4 weeks later. We suggest that this phenomenon was a manifestation of rickettsial vasculitis.

Anti-Bacterial Agents↗
PubMed2003

[Murine typhus in Tenerife. Clinicoepidemiological study and differential clinical features with Q fever].

BACKGROUND AND OBJECTIVE: Our aim was to conduct a study to define the clinical and epidemiological characteristics of patients with murine typhus in Tenerife island (Canary islands, Spain). Moreover, we investigated the differential clinical features of this disease with regard to Q fever. PATIENTS AND METHOD: 5-year prospective study of patients with murine typhus (1998-2002) admited in a reference hospital in Tenerife, Spain. RESULTS: Thirty two patients were included. Flea bite and rat exposure were iuncommon (6.25%). The monthly distribution showed a peak of incidence in January, August and September, without a clear seasonal prevalence. Fever and headache were the most common clinical features. Rash was present in 28% of the cases. Both an increase in liver enzyme levels (88%) and thrombocytopenia (37.5%) were the most relevant laboratory findings. Organ complications were uncommon (18.75%). Antibiotics were administered to 90% of patients and cure was achieved in all them. Compared with Q fever, patients with murine typhus more commonly had rash (p = 0.006) and thrombocytopenia (p < 0.001). CONCLUSION: Murine typhus is an emerging rickettsiosis in Tenerife and must be considered in the differential diagnosis with Q fever.

Adolescent↗
PubMed1999

Serosurvey of wild rodents for Rickettsioses (spotted fever, murine typhus and Q fever) in Java Island, Indonesia.

The prevalence of antibodies against spotted fever group rickettsia (SFGR), murine typhus and Q fever were investigated in wild rats captured in Indonesia. Sera of 327 rats were collected from Jakarta and Boyolali on Java Island. The prevalences of antibodies against SFGR and murine typhus were 128 (39.1%) and 48 (14.7%), respectively. Antibodies against Q fever were not detected in these serum samples. Antibodies against SFGR were found in all species of rats (20.8-51.9%). The antibody positive rate against murine typhus in Rattus norvegicus (38.0%) was significantly higher than that in other rat species (0-4.8%, p<0.01). The antibody positive rates against SFGR and murine typhus in rats captured in Jakarta were significantly higher than those in rats captured in Boyolali (p<0.01). In this survey, all species of rats had antibodies against SFGR, indicating that the 4 species of tested rats (R. norvegicus, R. rattus, R. exulans, R. tiomanicus) were infected with SFGR and that SFGR may infest the whole of Java Island. Most of the rats that were antibody-positive against murine typhus were captured in Jakarta. Therefore, R. norvegicus and R. rattus are likely to be important hosts of murine typhus in Jakarta. The antibody-positive rates against SFGR and murine typhus in rats captured in the dry season were significantly higher than those in rats captured in the rainy season. This may coincide with the active periods of ticks and fleas in Indonesia.

Animals↗
PubMed1997

Retinal manifestations of acute murine typhus.

PURPOSE: To report the ocular manifestations of acute serologically confirmed murine typhus. METHODS: A retrospective analysis of the clinical history, photography and fluorescein angiography of two patients with acute murine typhus with ocular involvement was conducted. RESULTS: A 38 year old male and a 49 year old female were included in the study. Both complained of fever, headache, rash, night sweats and pulmonary symptoms. They had noted the recent onset of diminished visual acuity and floaters. Examination of the posterior pole revealed mild optic nerve head edema (in one patient), intraretinal hemorrhages and small localized areas of retinal whitening. The history confirmed that both patients had been exposed to fleas and the serologic testing was positive for Rickettsia typhi. The systemic and ocular findings resolved after the use of systemic antibiotics. CONCLUSION: Rickettsial diseases such as murine typhus should be included in the differential diagnosis of otherwise healthy individuals who present with an acute systemic febrile illness and retinitis or neuroretinitis. SUMMARY STATEMENT: The clinical features of two patients with serologically proven acute murine typhus with ocular involvement are presented. Both patients presented with a retinal whitening that resolved after treatment.

Acute Disease↗
PubMed2006

Murine typhus is a common cause of febrile illness in Bedouin children in Israel.

Murine typhus is known to be endemic among populations living in poverty and exposed to rats and their fleas. A prospective 2-y study was conducted to determine the contribution of murine typhus to undifferentiated febrile illnesses among Bedouin children attending an outpatient clinic in southern Israel. Children with fever > or = 38.5 degrees C lasting for > or = 3 d were enrolled in the study. Murine typhus was serologically confirmed by the microimmunofluorescence test. A total of 549 children met the inclusion criteria of whom 76 (13.8%) had serologically-confirmed murine typhus. The disease was diagnosed in 27 of 434 (6.2%) patients aged < 5 y and in 49 of 115 (42.6%) older children (p<0.001). Murine typhus was diagnosed in 54 of 288 (18.8%) patients between June and November and in 22 of 261 (8.4%) between December and May (p<0.001). Patients with murine typhus had significantly higher prevalence of anaemia, leukopenia, hyponatraemia, and elevated liver enzymes compared to children without the disease. A single child was hospitalized and all 76 patients recovered without complications. Murine typhus is an important cause of febrile illnesses among Bedouin children > or = 5 y of age living in southern Israel and usually runs a benign clinical course.

Animals↗
PubMed1992

Epidemiologic classics of Carter, Maxcy, Trudeau, and Smith.

Four great epidemiologists whose work so concisely linked clinical observations, epidemiologic clues, and logical preventive measures are discussed. Henry Rose Carter set the stage for the Walter Reed successes in Cuba by showing that 9-16 days must elapse after contact before yellow fever develops. This provided the link for the Reed group to allow the "virus" to incubate in the mosquito before becoming infectious. Kenneth Maxcy clarified the controversy between endemic typhus fever and Brill's disease in the southeastern United States. His clinical, epidemiologic, and laboratory findings led him to propose that the causative organism (Rickettsia typhi) was in rodents and the probable vector, fleas. When confirmed, effective control measures were applied. Two other American investigators, Edward L. Trudeau and Theobald Smith, helped prove Robert Koch wrong on three counts: (1) Tuberculin is not an effective therapeutic agent for tuberculosis; (2) there are two distinct types of tubercle bacillus, human and bovine; and (3) the bovine form of Mycobacterium tuberculosis is remarkably pathogenic for humans. The significance of these findings is unlimited.

History, 19th Century↗
PubMed2003

An experimental model of human body louse infection with Rickettsia typhi.

Murine (endemic) typhus caused by Rickettsia typhi, one of the most widely distributed arthropod-borne diseases, is transmitted to humans mainly by the oriental rat flea. The human body louse, Pediculus humanus corporis, has been suspected to have a role in the transmission of R. typhi to humans. To evaluate the potential role of Pediculus humanus corporis as a vector of murine typhus, we used R. typhi in an experimental model of human body louse infection previously used with R. prowazekii. A rabbit was made bacteremic by inoculating it with 2 x 10(6) plaque-forming units of R. typhi; it remained bacteremic for at least 59 hours. Two hundred body lice infected by feeding on the bacteremic rabbit were compared to 200 uninfected control lice. Each louse population was fed once a day on the abdomen of a seronegative rabbit. On day 8 post-infection, as a result of disruption of the gut cells and leakage of the blood meal into the hemolymph, four infected lice became bright red and died within four hours. The life span of infected lice was 20 days less than that of the controls. Infected lice did not transmit R. typhi to their progeny (eggs and larvae) as demonstrated by PCR amplification and cell culture. With an immunofluorescence assay, R. typhi was detected in feces from day 7 post-infection, and the organism remained viable in feces for up to 80 days as demonstrated by cell culture. From the 21st day post-infection, the rabbit used to feed the R. typhi-infected lice developed an immunoglobulin response with a titer of 1:50 increasing to 1:200 at the 42nd day post-infection. It showed no clinical signs of infection. The rabbit that was used to feed uninfected lice remained seronegative. Although body lice are not clearly identified vectors of R. typhi, it seems that under certain circumstances they could transmit R. typhi.

Animals↗
PubMed1994

Identification of a novel rickettsial infection in a patient diagnosed with murine typhus.

Identification of ELB agent-infected fleas and rodents within several foci of murine typhus in the United States has prompted a retrospective investigation for this agent among human murine typhus patients. This agent is a recently described rickettsia which is indistinguishable from Rickettsia typhi with currently available serologic reagents. Molecular analysis of the 17-kDa antigen gene and the citrate synthase gene has discriminated this bacterium from other typhus group and spotted fever group rickettsiae. Current sequencing of its 16S ribosomal DNA gene indicates a homology of 98.5% with R. typhi and 99.5% with R. rickettsii. Through a combination of restriction fragment length polymorphism and Southern hybridization analysis of rickettsia-specific PCR products, one of five tested patient blood samples was shown to be infected with ELB while R. typhi infections were confirmed in the remaining samples. This is the first reported observation of a human infection by the ELB agent and underscores the utility of PCR-facilitated diagnosis and discrimination of these closely related rickettsial infections.

Adult↗