[Show abstract][Hide abstract] ABSTRACT: 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.
[Show abstract][Hide abstract] ABSTRACT: In the acute phase of leptospirosis, the diagnosis can be established with high sensitivity by testing blood and urine samples with polymerase chain reaction (PCR). However, only few real-time PCR assays have been validated for diagnostic use. The diagnostic accuracy of a novel TaqMan® PCR (LipL32 real-time PCR) targeting the lipl32 gene (or hap-1) and a previously described TaqMan® PCR (16S real-time PCR) targeting the rrs gene coding for 16S rRNA was evaluated when applied to both urine and blood specimens from humans suspected of leptospirosis. Applied to at least two blood cultures LipL32 real-time PCR had a sensitivity of 86%, and a specificity of 100%; and 16S real-time PCR had a sensitivity of 100%, and a specificity of 97%. Applied to urine samples, patients that were positive by the reference methods were also positive by both real-time PCR assays (n=4). For LipL32 real-time PCR the specificity was 100%, while for 16S real-time PCR it was only 91.5% due to unexpected cross-reactions with other bacteria. The analytical sensitivity was close to the theoretical limit-of-detection for both assays detecting all described human pathogenic species. We report a specific real-time PCR assay for detection of Leptospira, i.e., LipL32 real-time PCR that has been validated for diagnostic application in both urine and blood specimens from humans. We further show that a previously described 16S real-time PCR no longer can be recommended for diagnostic use due to a low specificity.
[Show abstract][Hide abstract] ABSTRACT: We present two cases of rickettsial infections in travellers caused by Rickettsia typhi and R. africae respectively. The two cases illustrate the widely varying symptomatology and aetiology. Incidence and treatment of the disease are discussed. The diagnosis is complex, and we believe that rickettsiosis is an underestimated cause of fever in returned travellers from the tropics. In the past two years only 26 cases have been diagnosed in Denmark. Whenever rickettsiosis is clinically suspected, empiric treatment with doxycycline should be initiated.
[Show abstract][Hide abstract] ABSTRACT: Rickettsial diseases are increasingly reported in international travellers. Prospective studies have shown that 2-4 % of travellers returning with fever have a rickettsiosis. We discuss epidemiology, clinical findings, diagnostics, treatment and prevention of rickettsiosis. In conclusion, rickettsiosis should be considered in the returned traveller with fever, especially when malaria, dengue fever and typhoid fever have been excluded. There is a possibility that doxycycline may have a prophylactic effect on rickettsiosis, but this thesis is only imaginary and needs further investigation.
[Show abstract][Hide abstract] ABSTRACT: Query (Q) fever was virtually unknown in Denmark in 2005, when, after the introduction of new sensitive diagnostic methods for Coxiella burnetii, an increasing number of positive cattle created concern among people with frequent exposure. This led to a dramatic rise in examinations for Q fever among humans in the following 2 years. The aim of our study was to assess indication for testing and symptoms in individuals with serological signs of infection with C. burnetii. We performed a case-review study of seropositives among all humans tested for Q fever in 2006-07 in Denmark. Seropositive cases were categorized with acute infection: 4-fold increase in immunoglobulin G (IgG) phase II or concomitant IgM phase II ≥ 1 : 256 and IgG phase II ≥ 1 : 1024; and previous infection: IgG phase II ≥ 1 : 1024. A borderline result was defined as: IgG phase II = 1 : 512. Physicians completed a questionnaire retrospectively. Of the 1613 people tested, 177 (11%) were seropositive [37 (2%) acute infection, 140 (9%) previous infection], 180 had a borderline result. Among 127 seropositives responders, 31% were tested due to symptoms compatible with Q fever after a possible exposure to C. burnetii, 64% were asymptomatic and were tested following relevant exposure only; 64% were males, 43% farmers, 39% veterinarians, 84% had been exposed to cattle. The most frequently reported symptoms were asthenia (25%), myalgia (21%), fever (17%) and headache (13%). About two-thirds of seropositives reported asymptomatic infections, and were tested for Q fever because of concern for occupational exposure to cattle. One-third of the seropositives reported symptoms consistent with Q fever, the majority being mild. Our study provided important evidence that increased requests for Q fever testing in 2006-07 arose from heightened public awareness of the disease, and not from an outbreak of clinical disease. Nonetheless, Q fever should be considered endemic in Denmark.
Zoonoses and Public Health 05/2011; 59(1):61-8. DOI:10.1111/j.1863-2378.2011.01419.x · 2.07 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Leptospirosis is a neglected zoonosis of ubiquitous distribution. Symptoms are often non-specific and may range from flu-like symptoms to multi-organ failure. Diagnosis can only be made by specific diagnostic tests like serology and PCR. In non-endemic countries, leptospirosis is often not suspected before antibiotic treatment has been initiated and consequently, relevant samples for diagnostic PCR are difficult to obtain. Blood cultures are obtained from most hospitalized patients before antibiotic therapy and incubated for at least five days, thus providing an important source of blood for PCR diagnosis. However, blood cultures contain inhibitors of PCR that are not readily removed by most DNA-extraction methods, primarily sodium polyanetholesulfonate (SPS).
In this study, two improved DNA extraction methods for use with blood cultures are presented and found to be superior in recovering DNA of Leptospira interrogans when compared with three previously described methods. The improved methods were easy and robust in use with all tested brands of blood culture media. Applied to 96 blood cultures obtained from 36 patients suspected of leptospirosis, all seven patients with positive convalescence serology were found positive by PCR if at least one anaerobic and one aerobic blood culture, sampled before antibiotic therapy were tested.
This study suggests that a specific and early diagnosis can be obtained in most cases of severe leptospirosis for up to five days after initiation of antimicrobial therapy, if PCR is applied to blood cultures already sampled as a routine procedure in most septic patients.
PLoS ONE 08/2010; 5(8):e12095. DOI:10.1371/journal.pone.0012095 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We report a patient with Q fever endocarditis in a settlement in eastern Greenland (Isortoq, Ammassalik area). Likely animal sources include sled dogs and seals. Q fever may be underdiagnosed in Arctic areas but may also represent an emerging infection.
[Show abstract][Hide abstract] ABSTRACT: Q fever is a ubiquitous zoonosis caused by Coxiella burnetii. The disease is emerging in many parts of the world, likely because of increased awareness and availability of better diagnostics. The diagnosis is primarily based on serology. Because the prevalence of the disease varies worldwide, the establishment of local cutoff values is needed. A baseline for antibodies against C. burnetii in Denmark was defined by testing sera from healthy Danish volunteers using a commercially available immunofluorescence antibody test. Cross-reactivity was studied on sera obtained from patients experiencing clinically related diseases. The cutoff titers suggested by the manufacturer were found to result in very low specificity of the test. The specificity was, however, effectively increased by using cutoff titers based on the local baseline and equal to immunoglobulin M (IgM) phase I > or =128, IgM phase II > or =256, IgG phase I > or =512, and IgG phase II > or =1024.
[Show abstract][Hide abstract] ABSTRACT: Clin Microbiol Infect 2010; 16: 1285–1288
Until recently, Q fever was notified in very low numbers annually in Denmark and it was always considered to be acquired abroad. Preliminary reports now describe Coxiella burnetii in milk samples from Danish dairy cattle. Serum samples of a large cohort of farmers, veterinarians, inseminators and hoof trimmers, all having occupational contact with dairy cattle, were tested for the presence of IgG to phase I and phase II antigens of C. burnetii. In 39 of 359 individuals studied (11%), the presence of antibodies to C. burnetii was found. Veterinarians had the highest seropositivity rate (36%). This survey suggests that C. burnetii is a recently recognized domestic infection in Denmark and that risk of infection is associated with occupation.
[Show abstract][Hide abstract] ABSTRACT: Earlier studies on the ecology of leptospirosis in temperate regions focused mainly on free-ranging rats in rural areas. Here we report on the occurrence of Leptospira spp. in Rattus norvegicus living in sewers in a suburban area in Copenhagen, Denmark. In 2006-2007, about 30 rats were captured in sewers at each of six different locations. Rat kidneys were screened by PCR for pathogenic Leptospira spp. In one location no infected rats were found, whereas the prevalence in the remaining five locations ranged between 48% and 89%. Micro-agglutination tests showed that serogroup Pomona, Sejroe, and Icterohaemorrhagiae were the most common. Infection was related to age with the highest prevalence observed for adult rats but there was no difference in infection rate between sexes, suggesting primarily environmental transmission. Since most reported rat problems in urban areas are related to sewer rats, the surprisingly high level of infection calls for an increased public health concern.
Epidemiology and Infection 05/2009; 137(11):1586-92. DOI:10.1017/S0950268809002647 · 2.49 Impact Factor