Seroprevalence of infection by Coxiella burnetii in Canary Islands (Spain)

Objectives: The aims of our study were: (i) to know the seroprevalence of Coxiella burnetii infection in the Canary Islands, (ii) to evaluate its epidemiologic features and (iii) to compare the rates of seroprevalence using two different cut-offs (1:20 and 1:80) for the diagnosis of past infection. Methods: We analysed a representative sample of the canarian population. 662 sera were tested. For the detection of IgG and IgM antibodies against C. burnetii phase II antigens an immuofluorescence assay was used. The serologic screening for IgG detection begun with a 1:20 dilution. A titer of IgG 1:80 along with a negative IgM were used as criteria for previous infection. Results: At an IgG antibody titer against C. burnetii of 1:80 as diagnostic for past infection, the observed global seroprevalence was 21.5%. If the cut-off used was 1:20, the observed prevalence increased up to 35.8% (p = 0.001). Significantly different seroprevalence rates were obtained at these different cut-offs when results were analysed for groups of age and socioeconomic status, but not for either the island of origin or for farmers. Conclusion: Our results strongly suggest that Coxiella burnetii infection is endemic in all the Canary Islands. Although it is more frequent in males above 30 years old, it do affect people of all ages, and thus it should be borne in mind in the face of any acute febrile syndrome.     

Prevalence of antibodies to Rickettsia conorii Coxiella burnetii and Rickettsia typhi in Salamanca province (Spain). Serosurvey in the human population

The Salamanca Province of Spain is an endemic zone for Mediterranean spotted fever. In this area, only one case of Q fever has been reported and typhus group rickettsial diseases have never been diagnosed. To obtain a panoramic view of the presence of antibodies to the most ubiquitous rickettsial agents, 400 sera specimens from a statistically representative sample of the human population of Salamanca City and its surrounding province were subjected to indirect microimmunofluorescent test for antibodies against Rickettsia conorii, Coxiella burnetii, phase II, and Rickettsia typhi antigens. Titers 1:40 to R. conorii were found in 73.5% of the sera. Positivity was more common in subjects who reported closer contact with the natural environment and/or with domestic animals. Seropositivity to C. burnetii, phase II, was detected in 50.2% of sera. These positive cases were related to rural environmental factors and to prevoius contact with animals. The frequency of antibodies increased with age showing a progressive exposure to the rickettsial antigen. The prevalence of antibodies to R. conorii and C. burnetii in the human population of Salamanca Province is higher than that reported from any other geographic zone. The study of antibodies to R. typhi showed that 12.5% of the sera had titers 1:40. According to our results, seropositivity to this rickettsial antigen cannot be related to any particular group of population nor interpreted totally as cross reactivity with R. conorii. Our data show a wide distribution of R. conorii and C. burnetii antigens in Salamanca Province, and also indicate the presence of R. typhi antigens in this area.     

Low prevalence of diphtheria immunity in the population of Florence, Italy

A seroepidemiological study was conducted in 1994 on a representative sample of the population of Florence in order to verify the immunity coverage against diphtheria. Subjects were divided according to sex and age class. Sera from each selected class were at least 1.5/1000 of the residing population. Diphtheria antitoxin was titrated using a quantitative ELISA test. The results show an overall adjusted prevalence of diphtheria immunity ( 0.01 IU/ml) equal to 63.7%. Subjects of younger age classes have good protection levels (85.5% immune under 30 years), while only half individuals aged 50 years have antibody titres . 0.01 IU/ml. Full protection (antibody titre 0.1 IU/ml) was detected only in a very small proportion of those aged 40 years. Our data show (1) how a recrudescence of diphtheria could theoretically take place in older subjects living in Italy, and (2) stress the importance of periodical re-vaccination of adults.     

Electrophoretic protein typing of Campylobacter jejuni subspecies ≪ Doylei ≫ (nitrate-negative campylobacter-like organisms) from human faeces and gastric mucosa

Twenty-seven strains comprising 23 clinical isolates of nitrate negative campylobacters (NNC) from Australia, South Africa, the United Kingdom and the Federal Republic of Germany, a representative of the CNW (catalase negative/weak) group and reference strains of three other Campylobacter species, were ckaracterized by one-dimensional SDS-polyacrylamide gel electrophoresis of cellular proteins. The protein patterns were highly reproducible, and were used as the basis for a numerical analysis which showed that the reference strain (NCTC 11951) of Campylobacter jejuni subspecies doylei , and 20 NNC isolates formed a distinct group at the 74% similarity level. The protein patterns showed unexpectedly low similarity between subspecies doylei and the type strain of Campylobacter jejuni and revealed that some NNC strains were quite distinct from subspecies doylei . Four electrophoresic (EP) types (I–IV) were identified from phenons formed at the 81% similarity level. Three of these (I, III, IV) corresponded to geographical location of strain isolation but the type II strains were from diverse locations. The correlation observed between EP-type, catalase production and sensitivity to 2, 3, 5, triphenyltetrazolium chloride indicated these latter two tests might be useful for biotyping within the subspecies.     

Prevalence ofLegionella pneumophila serogroup 1 antibodies in blood donors

The prevalence of anti-Legionella pneumophila serogroup 1 antibodies in 777 blood donors of the Turin area was determined by the indirect immunofluorescence assay (IFA) and by the microagglutination test (MA). Low titers (IFA of 1/16 and MA of 1/8) were found in 0.3% of the subjects. A statistically significant difference was not observed by sex and by age for IFA titers, but was noted by sex for MA titers of 1/4 (p<0.05). The upper limit of normal titer was <1/8 by IFA and <1/4 by MA at 15% cutoff level and 1/8 by IFA and 1/4 by MA at 1% cutoff level. In conclusion, the prevalence of antibodies in the Turin area was very low; IFA titers of 1/64 and MA titers of >1/16 can be considered as presumptive of infection in a single serum specimen of a patient with pneumonia; no change in the epidemiology of the disease was observed in the recent years.     

Aeromonads in acute diarrhoea and asymptomatic infections in Nigerian children

Stool samples of 616 asymptomatic and 296 diarrhoeic school children were compared for the recovery rate ofAeromonas spp. on ampicillin (10 µg/ml) sheep blood agar. Culture filtrates of isolates were tested for heat-stable enterotoxin by the infant mouse test and haemolysin production with 1% freshly washed rabbit erythrocytes. Stools of 9 (3.0%) diarrhoeic children yielded five strains ofA. hydrophila and four ofA. veronii (two each of biotypessobria andveronii), compared to 12 (1.9%) (p>0.01) asymptomatic children who harbored sevenA. hydrophila and fiveA. caviae strains. Isolates from-diarrhoeic stools were exclusively from children 5 years, while all infected asymptomatic children were 6 years. Culture filtrates of all nine diarrhoeic strains were uniformly enterotoxigenic (intestinal weight ratio >0.083) and produced haemolysin titres >128. These phenotypes where variable in carriage strains ofA. hydrophila but were not detected inA. caviae. The recovery ofA. hydrophila, andA. veronii biotypes from diarrhoeic stools of children 5 years may suggest their involvement in diarrhoea causation in the absence of other diarrhoeagenic agents.     

Seroepidemiology of rickettsial infections in Morocco

The prevalence of antibodies reactive withRickettsia conorii, Rickettsia typhi, Coxiella burnetii andEhrlichia chaffeensis was investigated using indirect immunofluorescence (IFA) test on human sera obtained from 300 blood donors in Casablanca and 126 sera obtained from clinical laboratories in Fez. In sera from Casablanca, antibodies reactive at titers >=1: 32 were found againstR. conorii (7%), andR. typhi (1.7%), but not againstE. chaffeensis. In the sera from Fez, antibodies were also detected againstR. conorii (5.6%),R. typhi (4%), but not againstE. chaffeensis. By Western immunoblotting, seroprevalence forR. conorii was in Casablanca and 4.8% in Fez. Antibodies reactive at titers >=1:50 againstC. burnetii (phase II) were present in sera from Casablanca (1%) and Fez (18.3%).Abbreviations IFA Immunofluorescence assay - MSF Mediterranean spotted fever - PBS Phosphate-buffered saline     

Exposure of cats in southern Africa to Coxiella burnetii, the agent of Q fever

Recently, the domestic cat has been implicated in numerous outbreaks of Q fever in humans. To determine if cats in southern Africa are infected with the agent of Q fever we tested sera from cats in South Africa and Zimbabwe by indirect fluorescence for antibodies reactive with phase II Coxiella burnetii antigen (Nine Mile strain). Reactive antibodies were detected at titres of 1/40 in sera from cats in South Africa (1/52, 2%) and Zimbabwe (15/119, 13%). Our results indicate that cats in southern Africa are infected with C. burnetii and should be considered as sources of infection for humans.     

Diagnostic criteria for carbaryl poisoning in sheep

Sheep were used to study the effect of carbaryl in liver, heart, and brain and on cholinesterase activity. Carbaryl residues 0.01 ppm in the brain were present in all sheep dying after dosing. Sheep dying acutely had higher levels of carbaryl and 50% inhibition of brain cholinesterase activity, while sheep with prolonged death had lower carbaryl levels and less cholinesterase inhibition. Prolonged deaths were associated with pulmonary embarrassment, enteritis, hyperthermia, and metabolic acidosis. Carbaryl was rapidly degraded in stored blood samples but was stable in dead brain tissue.This project was partially funded by the Animal Health Division, U.S. Department of Agriculture.     

Behaviour of some indicators of biological effect in female lead workers

Summary The relationships between certain indicators of internal dose and of biological effect were studied in 93 adult women with varying degrees of exposure to lead (PbB levels ranging from 8 to 74 g/ 100 ml). The results were compared with those obtained in a group of 95 males with more of less similar exposure. In both groups a good correlation was found between PbB and ALAD, EP, CPU taken singularly and the trend of the indicators of effect, depending on PbB levels, was similar: the decrease in ALAD values was already clear at PbB levels which do not cause an elevation of EP and the erythrocyte metabolite increased earlier than CPU. Considering the same levels of internal lead load (measured by both PbB and PbU-EDTA) in women, EP values were higher than in the men. No significant difference was established between the two sexes regarding ALAD and CPU values, when considered at the same PbB levels. Validity of ALAD and EP in the females, as already shown in our previous studies on males, was moderate in predicting PbB levels 40 g/100 ml, while it clearly improved at PbB levels 50–60 g/ 100 ml. This indicates that for screening women of child-bearing age the two indicators of effect must be used with caution, since a value of 40 g/100 ml has been proposed as the permissible PbB limit.Abbreviations PbB blood lead (g/100 ml) - PbU-EDTA amount of chelatable lead excreted with 24 hours urine after administration of CaNa₂ EDTA (1 g intravenously) - ALAD -aminolevulinic acid dehydratase activity of erythrocytes (mU/ml RBC) - EP erythrocyte protoporphyrin (g/100 ml RBC) - ALAU urinary -aminolevulinic acid (mg/1) - CPU urinary coproporphyrin (g/1)     

Bioaccumulation and toxicity of selenium in Chironomus decorus larvae fed a diet of seleniferous Selenastrum capricornutum

The bioaccumulation and toxicity of selenium in a simple aquatic food chain was investigated by feeding a diet of seleniferous algae (Selenastrum capricornutum) to fourth instar midge (Chironomus decorus) larvae. Treatment diets consisted of S. capricornutum cultured in three concentrations of selenite (0, 10, and 40 g Se/L) and four concentrations of selenate (0, 4, 10, and 40 g Se/L). The seleniferous algae was freeze-dried and utilized as a diet for the midge larvae. The data show that, under laboratory conditions, a 96 h dietary exposure of 2.11 g Se/g dry weight significantly reduced larval growth at tissue concentrations 2.55 g Se/g dry weight. The results demonstrate that some invertebrates are very sensitive to dietary selenium exposure. When compared to similar studies with Daphnia magna, the data suggest that invertebrate primary consumers differ in the metabolism of dietary selenium.     

Transmission of antibodies to Chlamydia Psittaci and Coxiella Burnetii through eggs and “crop milk” in pigeons

Young semi-domesticated pigeons captured or hatched from eggs gathered in Bratislava during 1989–1991 were examined for complement fixing antibodies to Chlamydia psittaci and agglutinating antibodies to Coxiella burnetii. Antibodies to Ch. psittaci were present in 76% of birds younger than 24 h, in 47.7% between 1 and 10 days of age and in 12% of nestlings over 10 days old. Antibodies to Ch. psittaci were also detected in crop milk of 4.1% of 1 to 10 day old birds and in 4.5% of specimens older than 10 days. Antibodies to C. burnetii were not found in juvenile birds under 24 h old, but antibodies against this agent were present in 16.4% birds between 1 and 10 days old and in 18% over 10 days old. Antibodies to C. burnetii were also detected in crop milk collected from crops of 2% of the young birds between 1 and 10 days.     

Brain acetylcholinesterase activity in forest songbirds exposed to a new method of UULV fenitrothion spraying

Brain acetylcholinesterase (AChE) activity was measured in forest songbirds exposed to Ultra Ultra Low Volume (UULV) aerial spraying of fenitrothion in New Brunswick for spruce budworm control. Brain AChE activity was determined in 324 songbirds from the sprayed blocks and 47 from an unsprayed control area, and represented four species. In most cases, more than half of the individuals of any species sampled were diagnosed as exposed (20% inhibition) to the fenitrothion sprays and had a mean percent level of inhibition of 40% or greater, relative to mean control values. The proportion of birds with life-threatening levels of inhibition (50%) was usually less than 20%. The largest proportion of birds with life-threatening inhibition was found after the first 210 g AI/ha spray. The White-throated Sparrow had the highest proportion (25–55%) of individuals with life-threatening inhibition after all sprays. Brain AChE inhibition was greater in exposed birds collected after the first 210 g AI/ha spray than after the second one. Variation among species' responses to the sprays is discussed in relation to habitat and foraging preferences. Several sampling biases which may contribute to underestimation of the impact of fenitrothion spraying on birds are identified.     

In vitro susceptibility of mycelial and yeast forms of Penicillium marneffei to amphotericin B,fluconazole, 5-fluorocytosine and itraconazole

The mycelial (25°C) and yeast-like (37°C) forms of Penicillium marneffei clinical and type strains were investigated for their in vitro susceptibility to amphotericin B (AmB), 5-fluorocytosine (5-FC), fluconazole (FLU) and itraconazole (ITZ), using Bacto antibiotic medium 3, yeast-nitrogen, Sabouraud's dextrose (pH 5.7) and high resolution (pH 7.1) broth media (1ml/tube), respectively. Results indicated that the minimal inhibitory and minimal fungicidal concentrations (MICs and MFCs) for the mycelial cultures of P. marneffei to AmB were in the range 0.78–1.56 and 0.78–3.125 g/ml, respectively, as against 3.125–25 g (MICs) for the yeast form cultures. The MFCs to AmB for the yeast form were one dilution higher. The MICs to FLU were generally lower for the yeast form (6.25–25 g) than the mycelial form (25–50 g/ml), whereas MFCs for the mycelial cultures were > 100 g as compared to 6.25–100 g for their yeast form. The MICs for the mycelial form to 5-FC ranged from < 0.195–0.39 g. Higher MICs (6.25 g) were recorded for their yeast form. The MFCs to 5-FC for the yeast form were 25–100 g/ml. The MICs for the mycelial form to ITZ ranged from < 0.195 to 3.125 g/ml. Higher values (< 0.195–50 g) were recorded for their yeast-like form. The MFCs to ITZ for mycelial and yeast forms ranged from < 0.195–0.39 and 25–100 g/ml, respectively. Results indicate that P. marnefei's yeast form is more sensitive to FLU and ITZ (8 of 10 strains) while the mycelial form displayed greater susceptibility to AmB and 5-FC. The MICs for ITZ remained steady in SD medium, pH 5.7 to 7.1. However, some strains gave higher MIC values (0.39–1.56 g/ml) when tested in the HR.     

Seroepidemiology of Q fever in Nova Scotia: Evidence for age dependent cohorts and geographical distribution

To determine the incidence of Q fever in Nova Scotia, a randomly selected sample of 492 volunteers aged 18–70 years was recruited by mail from all 18 urban and rural counties in this province. Volunteers were followed from 1988 to 1991 for antibody titres toCoxiella burnetii antigens. Analysis of seroprevalence by age revealed two statistically different cohorts. Those younger than 35 years had a low, stable seroprevalence while those 35 years and older had a seroprevalence statistically correlated with increasing age. The finding of age related cohorts suggests a sporadic or cyclical infection rate. An age-independent geographical clustering was also noted, with higher seroprevalence in a major agricultural area of the province. No seroconversions were observed, but four subjects had seroreversions. At baseline, 72 (14.6%) of the 492 subjects were considered seropositive (>/1:8C. burnetii phase II antibody titre by microimmunofluorescence). Of 47 seropositive subjects who provided yearly serum samples, two (4.3%) showed >/4-fold increase in antibody titre and did not react to antigens of the 11 other respiratory pathogens tested, suggesting a reactivation of Q fever. All 22 subjects positive to phase I antigen were positive to phase II antigen. This study suggests that the rate of infection in Nova Scotia has been low since the 1960's and that risk of infection is associated more with a geographically clustered reservoir of infection than with occupation or gender.     

Toxicity of iodine,iodide, and iodate to Daphnia magna and rainbow trout (Oncorhynchus mykiss)

The acute toxicity (96-h LC₅₀) of aqueous stable iodine species (I^–, IO ₃ ^– , I₂) to rainbow trout and Daphnia magna were measured at three individual concentrations of hardness, total organic carbon, and chloride. Rainbow trout were most sensitive to I₂ (LC₅₀0.53 mg/L), and much less sensitive to IO ₃ ^– (LC₅₀220 mg/L) or I^– (LC₅₀860 mg/L). Daphnia magna were equally sensitive to I₂ (LC₅₀0.16 mg/L) and I^– (LC₅₀0.17 mg/L), but were less sensitive to IO ₃ ^– (LC₅₀10.3 mg/L). The external and internal radiological dose imparted by equivalent molar quantities of radioactive ¹²⁵I, ¹²⁹I, and ¹³¹I were calculated for both the Daphnia and trout using the LC₅₀ values obtained from a standard water treatment. As expected, the dose from ¹²⁵I and ¹³¹I would exceed the expected lethal dose rate long before a chemically toxic level is reached. In contrast, a molar concentration of ¹²⁹I likely to cause death by chemical toxicity would impart a radiological dose less than that expected to be lethal. Thus, for short-lived aquatic organisms, risks due to chemical toxicity of ¹²⁹I may exceed risks due to its radioactive emissions.     

Prevalence of antimicrobial resistance ofStreptococcus pneumoniae in Southwest Germany as determined by the E test

We have studied the prevalence of antimicrobial resistance ofStreptococcus pneumoniae in Southwest Germany. One hundred seventy-four clinical isolates of pneumococci collected from hospitalized patients between October 1992 and April 1994 were used for MIC determinations. MICs for penicillin, ceftriaxone, erythromycin, and rifampicin were assessed by the E test. Eleven of the 174 strains (6.3%) were intermediately resistant to penicillin (MIC between 0.1 and 1.0 µg/ml) and four of the 174 strains (2.3%) were intermediately resistant to ceftriaxone (MIC between 0.1 and 1.0 µg/ml). All four isolates with a reduced susceptibility to ceftriaxone also demonstrated intermediate resistance to penicillin. Six of the 174 strains (3.5%) were highly resistant (MIC 8 µg/ml) to erythromycin. Resistance to rifampicin was not observed. Our results demonstrate that pneumococcal resistance to penicillin and erythromycin has increased markedly in Germany over the last decade. Our findings underline the need for continuous surveillance of antimicrobial resistance ofStreptococcus pneumoniae.     

Chlamydia specific IgG and IgA antibodies in women with obstructive infertility as determined by immunoblotting and assays

The prevalence rate of IgG and IgA antibodies to Chlamydia was analyzed in 50 women with laparoscopy-verified tubal infertility and in 50 age-matched control women by single serovar (L₂) inclusion immunoperoxidase assay (IPA) and by immunoblotting technique (IB) Women with tubal infertility had significantly (p < 0.001) elevated IPA Chlamydia IgG antibody titer 128 and 256 than controls (64% vs 16%. Odds ratio = 9.3 and 50% vs 10%, Odds ratio = 9 respectively). The prevalence rate of IPA IgA antibody titer ( 16) to Chlamydia was also significantly higher (p < 0.001) in women with tubal infertility than controls (48% vs 8%, Odds ratio = 10:6).Antibodies to at least 19 chlamydial structural polypeptides ranging in molecular weight from 30 kD to 204 kD, were detected by the IB technique in the IPA seropositive sera. Antibodies to 57-60 kD were detectable in almost all the IPA IgG and IgA seropositive sera. The prevalence rate of IgG antibody to 57 kD-60 kD was significantly higher in women with obstructive infertility than healthy woman (84% vs. 56% p < 0.01; Odds ratio = 3.8). More significantly, higher differences to 57–60 kD polypeptide were found in the case of IgA between the infertile women and controls (52% vs. 10%, p < 0.001;; Odds ratio = 9.7). The significance of IPA and IB technique for screening of infertile women is discussed.Corresponding author.     

Adverse Pregnancy Outcomes and Coxiella burnetii Antibodies in Pregnant Women,Denmark

A high risk for obstetric complications has been reported among women infected with Coxiella burnetii, the causative agent of Q fever, but recent studies have failed to confirm these findings. We reviewed national data collected in Denmark during 2007–2011 and found 19 pregnancies in 12 women during which the mother had a positive or equivocal test for antibodies to C. burnetii (IgM phase I and II titers >64, IgG phase I and II titers >128). Of these 12 women, 4 experienced obstetric complications (miscarriage, preterm delivery, infant small for gestational age, oligohydramnion, fetal growth restriction, or perinatal death); these complications occurred in 9 pregnancies (47% of the 19 total pregnancies identified). Our findings suggest an association between Q fever and adverse pregnancy outcomes, but complications were identified in only 9 pregnancies during the study’s 5-year period, indicating that the overall risk is low.     

Epidemic of Q fever in Leszno district in Poland

In 1988 an epidemic of Q fever was detected in Leszno district. During 1973–1985 all 28,066 cattle tested for C. burnetii antibodies were found to be negative. The first seroconversions were found in cows which produced stillborn young. In the following years the number of seropositive cattle increased from 8.4% in 1987 to 21.6% in 1989. In 1988 all animal workers in the district were tested for C. burnetii antibodies. Of 4,264 persons tested, 1,451 (34%) were seropositive. A detailed study of workers and animals on one farm were performed. A herd of animals was found to be seropositive (32.1%), 68% of workers in direct contact with infected animals were seropositive and 29% of persons drinking raw milk. C. burnetii strains have been isolated from ticks, wild animals and birds hunted in close proximity of the farm. The dynamics of C. burnetii infection among animals and humans in this district and the fact that there is no importation of animal herds suggests that the possible route of introduction of Q fever in this area may be with imported semen or breeding bulls. The presence of C. burnetii in ticks and wild animals indicates the transfer of Q fever to the natural environment and its maintenance in this territory.Presented at the 4th International Symposium on Rickettsia and Rickettsial Disease, Pieany, CSFR, 1–6 October 1990.