Legionella pneumophila: The Journey from the Environment to the Blood

An outbreak of a potentially fatal form of pneumonia in 1976 and in the annual convention of the American Legion was the first time that Legionella spp. was identified. Thereafter, the term Legionnaires’ disease (LD) was established. The infection in humans is transmitted by the inhalation of aerosols that contain the microorganisms that belong to the Legionellaceae family and the genus Legionella. The genus Legionella contains genetically heterogeneous species and serogroups. The Legionella pneumophila serogroup 1 (Lp1) is the most often detected strain in outbreaks of LD. The pathogenesis of LD infection initiates with the attachment of the bacterial cells to the host cells, and subsequent intracellular replication. Following invasion, Legionella spp. activates its virulence mechanisms: generation of specific compartments of Legionella-containing vacuole (LCV), and expression of genes that encode a type IV secretion system (T4SS) for the translocation of proteins. The ability of L. pneumophila to transmigrate across the lung’s epithelium barrier leads to bacteremia, spread, and invasion of many organs with subsequent manifestations, complications, and septic shock. The clinical manifestations of LD depend on the bacterial load in the aerosol, the virulence factors, and the immune status of the patient. The infection has two distinct forms: the non- pneumatic form or Pontiac fever, which is a milder febrile flu-like illness, and LD, a more severe form, which includes pneumonia. In addition, the extrapulmonary involvement of LD can include heart, brain, abdomen, and joints.

Cervical Viral Infections among Asymptomatic Bulgarian Women

AIM

Although sexually transmitted viral infections are significant and increasing public health concern, little is known about their prevalence among Bulgarian women. The aim of this study was to investigate cervical viral infections in asymptomatic women.

METHODS

The study group included 52 randomly selected asymptomatic female volunteers from Bulgarian border town Kardzhali. Cervical specimens were tested by real-time PCR for human papillomaviruses (HPV), herpes simplex virus (HSV) types 1 and 2, cytomegalovirus (CMV), Epstein-Barr virus (EBV), and human immunodeficiency virus (HIV).

RESULTS

The investigation demonstrated a high rate (61.5%) of infection with one or more viruses of uterine cervix of participating women considered at low risk. The most prevalent was HPV, found in 32.7% of all women. The genotyping of high-risk (HR) HPV positive specimens showed that HPV16 was the most prevalent HR type. HSV prevalence (30.8%) was almost as high as that of HPV and most women were HSV1 infected. 9.6% and 5.8% of all specimens were positive for EBV and CMV, respectively.

CONCLUSIONS

Our results indicate that women from Kardzhali region, involved in this study, might be at risk for development of genital tract pathology, including cervical cancer, and for transmission of virus infection sexually and perinatally.

Health assessment of populations living close to the airport of Bourgas, Bulgaria

The aim of this follow-up performed in a period of three years (1997-1999) was to assess the morbidity rate among children (0-17 years) and adults (18 years and above) from housing estates Sarafovo, Izgrev, Zornitsa and party Slaveykov, located close to the airport of Bourgas and compare it to population living at more distance from the airport (town centre). It was found that the prevalence of all diseases in children and the incidence in adults were higher in populations living close to the airport than in matching population living in the town centre. Specific groups of diseases which may be considered more closely associated with the adverse health effects of noise included diseases of the nervous system and of the sense organs, mental disorders, cardiovascular diseases, particularly arterial hypertension, and diseases of the digestive system. It is worth noting, however, that some diseases whose relationship with the effects of aircraft noise was not expected to be that of cause and effect were also found in higher prevalence or incidence rate in exposed populations. This indicates that other factors, which were not sufficiently analysed in this study, deserve full consideration in the evaluation of the results obtained.

Preserving the environment in the resort of Bankya

The town of Bankya is a balneological resort (spa) situated in a picturesque valley 17 km west from Sofia. It is a place suitable for the treatment of cardiovascular diseases and certain functional diseases of the nervous system. As a national resort, it applies stricter environmental regulations for activities that might endanger the environment, including road transport. The aim of this study was to establish the health status of Bankya townspeople before the pending construction of a highway. The morbidity of the population of Bankya and neighbouring towns and villages was compared to that of the capital Sofia for the period between 1997 and 1999. The data were statistically processed using the non-parametric, chi-square analysis. The results showed similar morbidity in children from Bankya and neighbouring towns and villages, but it was significantly lower than in children from Sofia. The results for adults were also in favour of Bankya--lower morbidity than in the neighbouring towns and villages, and less than 50% of disease cases recorded for Sofia.