Aeromonas hydrophila infection associated with the use of medicinal leeches.

The use of medicinal leeches (Hiruda medicinalis) is becoming more common after plastic surgery to control venous congestion of skin grafts. We describe a patient with Aeromonas hydrophila infection whose graft was treated with medicinal leeches. The infection required systemic antibiotic therapy. A. hydrophila is the predominant bacterial flora in the gut of the leech, where it plays an essential role for the animal in the digestion of blood. The potential for A. hydrophila wound infection, and appropriate antibiotic prophylaxis of the leech or patient, should be considered when medicinal leeches are used.

Serologic analyses of Peromyscus leucopus, a rodent reservoir for Borrelia burgdorferi, in northeastern United States.

An enzyme-linked immunosorbent assay (ELISA) and indirect fluorescent-antibody test were used to detect antibodies to Borrelia burgdorferi, the causative agent of Lyme disease, in Peromyscus leucopus (white-footed mouse). Of the 661 mice captured in Connecticut, Rhode Island, and New York during 1980 and 1983 to 1987, 166 (25.1%) had antibodies to B. burgdorferi by ELISA. Comparative analyses of 210 serum specimens, collected in areas where Lyme disease is endemic, revealed a threefold difference in sensitivity between the ELISA (38.1% positive) and the indirect fluorescent-antibody method (12.4%). Although prevalence of seropositive P. leucopus was highest during June, elevated amounts of antibody (1:1,280 to 1:2,560) were detected in mice that harbored spirochetes during all seasons. Being reservoirs for B. burgdorferi, these rodents are suitable for monitoring spirochete infections at foci and should be included in field evaluations of control programs aimed at suppressing Lyme disease.

[The rodent. Akodon arviculoides, Wagner, 1842 (Cricetidae)--importance in plague foci in Brazil]. / Estudo do roedor Akodon arviculoides, Wagner, 1842 (Cricetidae)--importância nos focos pestosos do Brasil.

The occurrence of the rodent Akodon arviculoides Wagner, 1842 in the plague focus of the "Agreste" region of the State of Pernambuco and a report on its ability for survival, reproduction and development in captivity, its susceptibility to Yersinia pestis infection and the role of this rodent species in Brazilian plague foci are reported.

Tularemia: a 30-year experience with 88 cases.

Drawing upon our experience with 88 cases and a survey of the English literature, we reviewed the clinical, pathophysiological, and epidemiological aspects of tularemia. Tularemia can be thought of as two syndromes--ulceroglandular and typhoidal. This dichotomy simplifies earlier nomenclature and emphasizes the obscure typhoidal presentation. Clinical manifestations suggest that the two syndromes reflect differences in host response. In ulceroglandular tularemia the pathogen appears to be well contained by a vigorous inflammatory reaction. Pneumonia is less common and the patient's prognosis is good. In typhoidal disease there are few localizing signs; pneumonia is more common; and the mortality without therapy is much higher, suggesting that the host response is somehow deficient. Francisella tularensis is an extremely virulent pathogen capable of initiating infection with as few as 10 organisms inoculated subcutaneously. During an incubation period of 3 to 6 days the host responds first with polymorphonuclear leukocytes and then macrophages. Granulocytes are unable to kill the pathogen without opsonizing antibody leaving cellular immunity to play the major role in host defense. One to 2 weeks after infection, a vigorous T-lymphocyte response can be detected in vitro with lymphocyte blast transformation assays and in vivo with an intradermal skin test, which, unfortunately, is not commercially available. Humoral immunity, often used as a diagnostic modality, appears 2 to 3 weeks into the illness. Cellular immunity is long-lasting, accounting for the common reoccurrence of localized disease upon repeated exposures to the pathogen. There are no symptoms that distinguish the ulceroglandular from the typhoidal syndrome. A pulse-temperature dissociation is seen in less than half of the patients. The location of ulcers and enlarged lymph nodes give a clue to the likely vector since lesions located on the upper extremities are more commonly associated with mammalian, and those of the head and neck and lower extremities with arthropod, vectors. Pharyngitis, pericarditis, and pneumonia can complicate both syndromes, although the latter is much more common in typhoidal disease. Hepatitis, usually of a mild degree, is common and occasionally erythema nodosum is seen. No specific laboratory tests characterize tularemia, and cultures of the pathogen are often difficult to obtain because of the special growth requirements of Francisella tularesis and the inability of many clinical laboratories to handle the dangerous pathogen.(ABSTRACT TRUNCATED AT 400 WORDS)

Epidemiological studies on the background of the endemic occurrence of tsutsugamushi disease in Toyama Prefecture. I. Epidemiology of infection with Rickettsia tsutsugamuchi among field rodents in endemic and nonendemic areas.

In order to clarify the epidemiological background of the endemic occurrence of tsutsugamushi disease in Toyama Prefecture, Japan, since 1978, comparative surveys have been carried out between endemic and nonendemic areas. Rickettsia tsutsugamushi (Rt) was isolated at a rate of about 36% (158/439) from field rodents in the endemic area while it was not isolated from any of 280 in nonendemic areas. In all of six stations in the endemic area, a significantly high proportion of rodents were found to be Rt carriers. However, no Rt was isolated from rodents captured from July to September. The organism was isolated from rodents captured in the other months, especially in a high proportion in November when infestation of rodents with Leptotrombidium pallidum was at its peak. When the rodents were examined by indirect immunofluorescence staining, the rate of anti-Rt antibody-positive animals was about 55% (157/287) and about 17% (62/368) in endemic and nonendemic areas, respectively. Larvae of mites collected from the rodents were found to belong to four genera and 11 species. Among them L. pallidum was the only mite that had been known to be a vector of Rt. L. pallidum was found most frequently and in abundance from rodents in the endemic area, whereas it was present in very small numbers in rodents in nonendemic areas. The infestation of rodents with L. pallidum showed a seasonal variation, i.e. two peaks per year, in spring and autumn, and the number of mites detected was markedly greater in November than in spring. Rt was isolated from L. pallidum on rodents captured in the endemic area.

The herring gull Larus argentatus as a carrier of salmonella.

The proportion of salmonella carriers among town-nesting herring gulls increased significantly from 2.1% in 1975-6 to 8.4% in 1979. The range of serotypes carried by herring gulls was similar to that causing infection in man, and it is likely that the gulls ingest these serotypes when feeding at untreated sewage outfalls on the coast. This is supported by the proportion of salmonella carriers being higher among first-year birds (9.7%) than among older birds (2.0%), as it is known that higher proportions of immature herring gulls feed on the coast. Herring gulls carrying salmonellas appeared healthy at the time of capture and at a later date it was assumed that they were not themselves infected. However, their habit of congregating in large numbers on reservoirs and rubbish tips and also at resting sites on farmland often far from feeding and roosting areas, multiplies the pollution problem and increases the potential health hazard for both man and farm stock. Herring gulls feed at a variety of sites and fly many miles from food source to food source and from feeding areas to the roost. Thus, even within the same day, there is the possibility of the transfer of salmonellas over a much wider area than previously considered.

The herring gull Larus argentatus as a likely transmitting agent of Salmonella montevideo to sheep and cattle.

This paper presents evidence for the involvement of herring gulls (Larus argentatus) as vectors in the recent outbreaks of Salmonella montevideo in sheep and cattle in Scotland and suggests that the transfer can take place over considerable distances. The breeding area in Scotland of herring gulls which overwinter in N.E. England is remarkably similar to the geographical distribution of the outbreaks. This pattern, together with the feeding behaviour of herring gulls on farmland, the presence of S. montevideo in herring gulls just before their departure from the wintering area and the timing of the return just before the peak of outbreaks are all circumstantial evidence implicating this gull in the outbreaks. The rapid return of these gulls to their breeding areas means that S. montevideo can be transported long distances in one day and raises the possibility that the original source of S. montevideo could have been in N.E. England rather than in Scotland.

Arbovirus studies in an evergreen seasonal marsh forest in Trinidad, West Indies

Studies carried out in Turure Forest, north-eastern Trinidad, from March, 1966, to March, 1969, resulted in the isolation of 462 arbovirus strains: 198 Venezuelan equine encephalitis (VEE), 42 eastern equine encephalitis (EEE), 75 group C, 136 Guama group, 2 Ilheus, 1 St. Louis encephalitis, 5 Wyeomyia, 1 Maguari, 1 Cocal, and 1 Aruac, Strains of VEE were recovered most frequently from sentinel mice (109) and Culex portesi (82), and the same was true for the group C and Guana group isolates. EEE strains came from sentinel mice (30), C. pedroi (11), and C. portesi (1). Forest rodents yielded only 9 isolates, all group C and Guana group and all from Proechimys guyannensis and Oryzomys capito; however, 21 percent of 639 rodent sera had haemagglutination-inhibiting (HI) antibodies to one or more viruses. VEE HI antibodies were more common in O. capito that in P. guya nnensis. In complement-fixation (CF) tests, 32 percent of O. capito and 8 percent of P. guyannensis reacted with a Guama group antigen. Birds yielded 3 isolates, 2 Iheus and 1 St. Louis, but 10 percent of 1,414 Manacus manacus sera reacted with EEE antigen in HI test. Three of 4 horses had CF antibodies to EEE, and 54 percent of 158 human sera wer HI-positive for one or more of 9 antigens used, including VEE and EEE (AU)