A Snapshot of Drug-Resistant M. tuberculosis Strains in Croatia.

Tuberculosis caused by resistant M. tuberculosis strains poses a serious threat as it requires prolonged and costly treatment and has high mortality rate. In order to investigate resistance to antituberculous drugs in Croatia, we analysed all resistant M. tuberculosis strains isolated from patients' samples in period 2010-2014 (1 strain per patient). Out of 2384 M. tuberculosis strains, we identified 88 (3.69 %) resistant strains. The analysis included resistance patterns, resistance conferring mutations and, according to MIRU-VNTR analysis, clustering and global lineages distribution. Relatively high number of strains was monoresistant, especially to isoniazid, while there were only six multiresistant strains. Among 59 strains with any pattern that includes resistance to isoniazid, a total of 22 (37.29 %) had resistance conferring mutation in katG gene (S315T), 23 (38.98 %) in inhA promoter region (C-15T) and 14 (23.73 %) had none of these mutations. The observed clustering rate of resistant strains was 28.41 %, and the most common global lineage was Euro-American (75 %).

Nosocomial pseudo-outbreak of Mycobacterium gordonae associated with a hospital's water supply contamination: a case series of 135 patients.

Nontuberculous mycobacteria (NTM) are opportunistic pathogens found in natural and human-engineered waters. In 2009, a relative increase in the isolation of Mycobacterium gordonae from pulmonary samples originating from General Hospital Zabok was noted by the National Mycobacteria Reference Laboratory. An epidemiological survey revealed a contamination of the cold tap water with M. gordonae and guidelines regarding sputum sample taking were issued. In addition, all incident cases of respiratory infection due to NTM reported from 2007 to 2012 at General Hospital Zabok were included in a retrospective review. Out of 150 individual NTM isolates, M. gordonae was the most frequently isolated species (n = 135; 90%) and none of the cases met the criteria of the American Thoracic Society for pulmonary NTM disease. While concomitant Mycobacterium tuberculosis infection was confirmed in only 6 (4%) patients, anti-tuberculosis treatment was initiated for a significant portion of patients (n = 64; 42.6%) and unnecessary contact tracing was performed. This study points out the need to enhance the knowledge about NTM in our country and indicates the importance of faster NTM identification, as well as the importance of good communication between laboratory personnel and physicians when evaluating the significance of the isolated NTM.

First insights into the molecular epidemiology of tuberculosis in Croatia during a three-year period, 2009 to 2011.

BACKGROUND: Mycobacterium tuberculosis still represents a serious cause of morbidity and mortality worldwide. The aim of this study was to determine the transmission rate and genetic lineages of M. tuberculosis circulating in Croatia during a 3-y period, between 2009 and 2011. METHODS: A total of 1587 M. tuberculosis strains (1 strain per tuberculosis patient) isolated in Croatia from 2009 to 2011 were genotyped using 15-locus mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR) analysis. RESULTS: The majority of tested isolates (66.73%) belonged to the Euro-American global lineage. The most prevalent sub-lineages were Haarlem (48.64%), followed by S (6.05%), Cameroon (3.72%), and Latin American-Mediterranean (3.4%). Among the total 1587 tested isolates, 996 (63%) were included in 1 of 236 clusters. The cluster size ranged from 2 (114 clusters) to 45 (1 cluster) patients, the mean cluster size being 4.2. These results indicate that 47.83% of tuberculosis cases during the period analyzed were the result of recent transmission. CONCLUSIONS: The most prevalent global lineage in Croatia is Euro-American (sub-lineages Haarlem, S, Cameroon, and Latin American-Mediterranean). The high clustering rate and high medium clustering size of 4.2 tuberculosis cases could indicate a possible failure in interrupting the transmission of infection and points to the need for improvements in national and local tuberculosis control activities. This is the first study describing the molecular epidemiology of tuberculosis in Croatia.

SARS-CoV-2 Omicron Variant in Croatia-Rapid Detection of the First Case and Cross-Border Spread.

BACKGROUND: Due to rapid spread, the Omicron variant has become the dominant SARS-CoV-2 variant responsible for infections worldwide. We present the first detection of the Omicron variant in Croatia which resulted in rapid cross-border spreading. METHODS: Whole-genome sequencing was performed using the Illumina MiniSeq sequencing system. SARS-CoV-2 lineages were identified using the PANGOLIN and GISAID databases. RESULTS: The first case of the Omicron variant (BA.1.17) emerged in Croatia after a workshop held in Zagreb in November 2021. The patient reported a history of previous COVID-19 and received two doses of an mRNA vaccine. Three additional cases were detected among Croatian participants of the workshop. At the beginning of December, SARS-CoV-2 infection was confirmed in one participant from Montenegro and her husband. Phylogenetic analysis showed that the detected Omicron variants were closely related to the first Croatian case, confirming the connection with the workshop outbreak and rapid cross-border spreading. Subsequent analyses of SARS-CoV-2 positive samples in Croatia showed the rapid introduction of the Omicron variant and depletion of the Delta variant resulting in the fifth pandemic wave. CONCLUSIONS: Genomic monitoring and early detection of novel SARS-CoV-2 variants are essential to implement timely epidemiological interventions and reduce further transmission in the population.

A fatal Mycobacterium chelonae infection in an immunosuppressed patient with systemic lupus erythematosus and concomitant Fahr's syndrome.

We present a case of systemic Mycobacterium chelonae infection in an immunosuppressed patient with systemic lupus erythematosus (SLE), idiopathic hypoparathyroidism, and hypothyroidism. The patient was treated for 3 months for skin infection with clarithromycin monotherapy. Since her condition deteriorated, the antibiotic therapy was switched to intravenously administered clindamycin, cloxacillin, and meropenem. Due to further deterioration and isolation of M. chelonae from the blood culture, antimicrobial therapy was changed to azithromycin and amikacin. Drug-test sensitivity was performed, and the isolate was susceptible to clarithromycin only. The patient's deteriorating status prevented orally administered medication with clarithromycin (parenteral formulation is not registered in Croatia). The same antibiotic regime was continued until the isolation of Pseudomonas aeruginosa and Candida albicans. In addition, extensive calcifications in her brain were found on a computed tomography (CT) scan, which suggested Fahr's syndrome. Despite all measures and supportive care, the patient developed multiorgan failure and eventually died. There has been an increase in the number of infections by rapidly growing mycobacteria, but only a few cases of severe systemic infection with M. chelonae have been described. If the infection is diagnosed early and a patient is treated with appropriate drugs, dissemination can be avoided despite immunosuppression. For serious skin, bone, and soft-tissue disease, a minimum of 4 months of a combined drug therapy is necessary. This is the first report of M. chelonae infection in Croatia and the first-described M. chelonae infection in a patient with concomitant Fahr's syndrome.

Epidemiological patterns of tuberculosis in Croatia in the period 1996-2005.

The last comprehensive publication on tuberculosis in Croatia and the earliest impact of war, besides the yearly routine reports, was done in 1996 in Croatian. We were, therefore, interested to explore incidence trends and to highlight the early post-war tuberculosis epidemiological patterns in the next ten years period (1996-2005). A retrospective analysis of epidemiological data on all registered tuberculosis cases in Croatia searching the databases of 21 Croatian Public Health Institutes and the National Tuberculosis Registry was made. During the study period, the total tuberculosis incidence rates in Croatia dropped from 45 to 25.8/100 000 inhabitants. The average highest age-specific rates were recorded in the age group > or = 65 years being in decrease in all age groups. Paediatric cases (0-14 years) represented 4.5% of all cases. Tuberculosis cases among males were recorded in 64% cases, and 83.6% were indigenous population. Tuberculosis was bacteriologically confirmed in 67.7% cases. A low proportion of drug resistance (3.3%) was recorded. During 1985-2005, 56 tuberculosis cases among 242 AIDS cases were reported. Tuberculosis mortality showed a decreasing trend (p < 0.001). However, tuberculosis has still had the highest mortality rates among infectious diseases in Croatia. Despite the War chain of events and tuberculosis programmatic changes, tuberculosis incidence rates in Croatia have been decreasing but they are still far away from national target, incidence rate of 10/100 000 declared in 1998 and much higher than in European Union and Western Europe. Tuberculosis among children, resistance to tuberculosis drugs and HIV prevalence, significant problems in many European countries, have not caused problems in tuberculosis control in Croatia. This favourable epidemiological situation must be kept and improved through strengthened tuberculosis control measures.

[Significance of laboratory statistics in tuberculosis control in Medimurje County]. / Znacenje laboratorijskih podataka u nadzoru nad tuberkulozom u Medimurskoj zupaniji.

UNLABELLED: Microbiological diagnosis of tuberculosis is the axis of any national tuberculosis control program. Tuberculosis notification rate in Medimurje County has been equivalent to the national average, except in 2009 when it (23/100,000) surpassed the national rate of 19.3/100,000. The aim of this study was to analyze laboratory results (age, sex, site of the disease, drug susceptibility test results, and genotyping results) in tuberculosis control in Medimurje County. MATERIAL, METHODS AND RESULTS: A prospective study of genotyping all newly isolated Mycobacterium tuberculosis strains is currently conducted at the Croatian National Institute of Public Health, Tuberculosis Diagnostic Department. The genotyping method used is determining variable number of tandem repeats of mycobacterial repetitive interspersed unit. Between 2007 and 2009, a total of 59 strains from patients coming from Medimurje County were genotyped, 27 (45.8%) of which had a unique genotype in the national database, while 32 (54.2%) were grouped in 22 clusters with 2 to 22 pertaining strains. Two of 22 clusters, one with two and one with five members each, were made up from strains isolated solely in Medimurje County. These strains are not only characteristic of the County, but the patients they originated from had most likely been exposed to the same route of transmission. The remaining 25 strains were grouped in 20 clusters. The patients they came from were from different parts of Croatia, while the number of Medimurje natives in these clusters varied between 1 and 3. A relatively high percentage of strains of unique genotype pointed to a relatively low degree of recent transmission. The results of molecular epidemiology analysis as part of monitoring the routes of tuberculosis transmission, showed the efficiency of counter epidemic measures by detection of unexpected routes of transmission and by identification of strains present in a given community, which more often than others cause disease.

[Infections due to nontuberculous mycobacteria]. / Infekcije izazvane netuberkuloznim mikobakterijama.

The best known members of genus Mycobacterium belong to M. tuberculosis complex. Other mycobacteria are known as nontuberculous mycobacteria (NTM). NTM less commonly cause a disease (mycobacteriosis), more often colonising respiratory tract. The presence of NTM is more common in immunocompromised patients and in those with a previous lung disease. The decrease in the incidence of tuberculosis is followed by increased incidence of NTM. Since tuberculosis has been declining in Croatia over the last 50 years, increasing incidence of NTM is expected. Growing incidence of chronic obstructive pulmonary disease (COPB) is contributing to this increase. NTM are ubiquitous and inhaling of aerosol particles constitutes the dominant route of infection. They are not transmitted via interhuman contact. In addition to pulmonary and skin infections, disseminated infections are also described. The treatment of mycobacteriosis is difficult and long. Besides using antituberculotic drugs such as rifampin and ethambutol, the therapies use fluoroquinolones; the introduction of macrolides has significantly improved the outcome of treatment.

Neglected disease in mentally ill patients: Major tuberculosis outbreak in a psychiatric hospital.

As tuberculosis incidence decreases, the possibility of overlooking the disease increases, especially in vulnerable populations. We describe here a major tuberculosis outbreak among mentally ill patients in Croatia, focusing on 1 regional hospital where most patients were hospitalized. The outbreak emphasizes the vulnerability of mentally ill patients to tuberculosis infection and the complexity of infection control measures in psychiatric institutions. The awareness of tuberculosis in these settings should be maintained to interrupt prolonged exposure and avoid unnecessary infection.

[Drug-resistant tuberculosis: resistance mechanisms and drug susceptibility of Mycobacterium tuberculosis]. / Rezistentna tuberkuloza: mehanizmi rezistencije i ispitivanje osjetljivosti M. tuberculosis.

Mycobacterium (M.) tuberculosis is the most common individual causative agent of infectious disease in the world. It is responsible for 26% of preventable deaths in adulthood. Because the number of new cases grows at an annual rate of 2%, in 1993 WHO proclaimed tuberculosis a global health problem. The immediate cause for this was coinfection with causative agents of tuberculosis and human immunodeficiency virus, and spread of resistant and multiresistant strains of M. tuberculosis (MDR TB). It is estimated that 50 million people are infected with resistant strains of M. tuberculosis. Tuberculosis has emerged as a major public health problem for its high mortality (50%-80%) in the first 4-16 weeks of the disease and 100 times more expensive therapy for drug-resistant than for drug-susceptible tuberculosis. Mycobacteriologic laboratories play a fundamental role in the detection, combat and control of tuberculosis, especially in preventing the spread of drug-resistant tuberculosis. In this connection, there is an increased need of a rapid and reliable determination of the susceptibility of isolated strains of M. tuberculosis to the first- and second-line antituberculotic drugs.

[Drug resistant tuberculosis: ten years of surveillance in Croatia]. / Rezultati desetogodisnjeg laboratorijskog pracenja rezistentne tuberkuloze u Hrvatskoj.

Drug resistant and multidrug resistant tuberculosis is a consequence of human activity. Resistant strains of M. tuberculosis are mainly prevalent in regions with weak national TB programs or poor socioeconomic environment. Therefore an effective surveillance of the resistance patterns of TB bacilli is an essential tool for the quality of tuberculosis control programs and a demanding task in all countries. Surveillance of tuberculosis in Croatia is based on individual notifications of every newly diagnosed patient by the physicians, followed by laboratory notifications. Data are collected at the Epidemiology Service, National Institute of Public Health Tuberculosis Register (TR). TR is part of the World Health Organization informational system and Surveillance of Tuberculosis in Europe (EuroTB). The results of the ten-year surveillance of the prevalence of drug resistant (5.7%) and multidrug resistant (1.6%) tuberculosis show that Croatia has a favorable situation which should be kept up strictly following the measures of the national TB program.