Detection of flea-borne Rickettsia species in the Western Himalayan region of India.

Human infections by various rickettsial species are frequently reported globally. We investigated a flea-borne rickettsial outbreak infecting 300 people in Western Himalayan region of India. Arthropod vectors (ticks and fleas) and animal and human blood samples from affected households were analysed by gltA and ompB genes based polymerase chain reaction (PCR). Rat flea (Ceratophyllus fasciatus) samples were found harbouring a Rickettsia sp. Phylogenetic analysis based on gltA gene using PHYLIP revealed that the detected Rickettsia sp. has 100% identity with SE313 and RF2125 strains of Rickettsia sp. of flea origin from Egypt and Thai-Myanmar border, respectively and cf1 and 5 strains from fleas and lice from the USA. But, the nucleotide sequence of genetically variable gene ompB of R14 strain was found closely related to cf9 strain, reported from Ctenocephalides felis fleas. These results highlight the public health importance of such newly discovered or less recognised Rickettsia species/strains, harboured by arthropod vectors like fleas.

Isolation of Brucella melitensis from a human case of chronic additive polyarthritis.

Brucellar arthritis remains under diagnosed owing to non-specific clinical manifestations. Here, we report isolation of Brucella melitensis from synovial fluid of 5th metatarsophalangeal joint of a 39-year-old lady having unusually chronic asymmetric, additive, peripheral polyarthritis. This isolation was confirmed by Bruce-Ladder polymerase chain reaction (PCR). The patient had a history of contact with an aborted goat. Rose Bengal Plate Agglutination Test (RBPT) and Standard Tube Agglutination Test (SAT) were positive for Brucella-specific antibodies both for patient and in contact with sheep and goats. The patient was treated with doxycycline and rifampicin for 16 weeks and was recovered fully.

Unique combined penA/mtrR/porB mutations and NG-MAST strain types associated with ceftriaxone and cefixime MIC increases in a 'susceptible' Neisseria gonorrhoeae population.

OBJECTIVES: To determine which mutations in penA, mtrR and porB are implicated in increasing minimum MICs of ceftriaxone and cefixime in a susceptible gonococcal population and to ascertain associations with gonococcal strain types (STs). METHODS: One hundred and forty-six Neisseria gonorrhoeae isolates formed two extended-spectrum cephalosporin susceptibility groups: group 1 isolates with cefixime and ceftriaxone MICs of 0.0005-0.016 mg/L; and group 2 isolates with cefixime MICs of 0.03-0.125 mg/L (n = 24) and ceftriaxone MICs of 0.03-0.06 mg/L (n = 23). Mutation patterns in penicillin-binding protein 2 (PBP2; penA), multiple transfer resistance repressor (MtrR; mtrR) and porin B (PorB; porB) were ascertained by DNA sequence and bioinformatic analysis. STs were determined using N. gonorrhoeae multiantigen sequence typing (NG-MAST). RESULTS: Most isolates carried PBP2 mutation pattern IX (D345a, F504L, A510V, A516G and P551L; 50/146, 34.2%), a G45D substitution in MtrR (37.7%) and a wild-type (WT) sequence for PorB (43.2%). Group 2 gonococcal isolates were significantly associated with: penA pattern IX; dual mutations in the promoter (A-) and DNA dimerization domain (H105Y) of MtrR; and G120K;A121D substitutions in PorB. There were 50 combined penA/mtrR/porB mutation patterns, with corresponding patterns I/WT/WT and IX/G45D/G120K;A121D predominating. Gonococci susceptible to ceftriaxone and cefixime were significantly associated with NG-MAST ST 25 (33/36; 92%) and the combined penA/mtrR/porB mutation pattern I/WT/WT. No combined mutation pattern or specific ST was associated with elevated ceftriaxone MICs. NG-MAST ST 3654 was significantly associated with the pattern IX/G45D/G120K;A121D and cefixime group 2 isolates. CONCLUSIONS: Specific single or combined mutation patterns in penA, mtrR and porB and specific STs were associated with differences in susceptibility to ceftriaxone and cefixime.

Laboratory investigation of drinking water sources of Kangra, Himachal Pradesh.

A total of 70 drinking water sources including piped water supply (n = 36), ground water sources (n = 24, hand pumps and bore wells) and natural water sources (n = 10, springs/step-wells) from various parts of district Kangra, Himachal Pradesh were investigated for their suitability for drinking purpose by presumptive coliform test. Three samples were collected from each source during different parts of the year. Piped water sources (91.7%) were most contaminated followed by natural water sources (90%) and ground water sources (62.5%). 70.5% of the total water samples (n = 210) were positive for coliforms. All the three samples from 8.3% (n = 3), 37.5% (n = 9) and 10% (n = 1) piped water, ground water and natural sources respectively, were negative for coliform organisms. A variety of organisms including Proteus, Klebsiella, Citrobacter, Escherichia coli (E. coli), Pasteurella, Enterobacter and Serratia liquefaciens were isolated from water samples positive for coliforms in presumptive coliform test. Thermo-tolerant coliform organisms; Escherichia coli, Citrobacter, Klebsiella and Enterobacter were 71.2% (n = 52) of the total bacterial isolations. These findings suggest absence of adequate treatment and disinfection of the water sources supplying drinking water in district Kangra.

Rabies: control strategies for Himalayan states of the Indian subcontinent.

Rabies remains to be one of the most important direct zoonosis and is invariably fatal once the clinical symptoms appear. The disease can be prevented but still people continue to die of infection. India alone accounts to 81 per cent of the total deaths occurring due to rabies across the world. Dog is major reservoir of the infection, although other domestic and wild reservoirs also play an important role in the spread of the disease. A large population of stray dogs, availability of susceptible hosts, close proximity of animals and man and lack of effective control strategies might have led to endemic status of the disease in India. The effective control of rabies can be achieved through reduction of the stray dogs and stray livestock populations through implementation of animal birth control (ABC) programme and the proper induction of "herd immunity" by mass vaccination and awareness health programme. The increase in human population, changes in the environment, increased transportation, development of human habitations in new places and seasonal migration of the animals have resulted in the introduction of the infection to new territories and changes in the epidemiology of the disease in hills. Therefore, it is essential to design area specific control programmes so that the disease can be eliminated effectively.

Human brucellosis: review of an under-diagnosed animal transmitted disease.

Human brucellosis is an important animal transmitted disease of man. Although, the cases have been recorded all over the world, the prevalence is higher in developing countries. Lack of sufficient knowledge about the disease among the physicians, its under-diagnosis or misdiagnosis and absence of effective prevention and management strategies are attributed to the widespread of the disease. Increase in the occurrence of animal brucellosis has also resulted indirectly in an increase in the prevalence of human infection. Absence of characteristic clinical symptoms, chronic nature of the infection and difficulty in isolation of the causal agent from the patients make the diagnosis of the disease more difficult. The serological tests employed for diagnosing human brucellosis vary in terms of their sensitivity and specificity. Therefore, a combination of serological tests is desirable. Currently no vaccine is available against human brucellosis, which could check the spread of the disease effectively. It is suggested that clinicians investigate the cases of pyrexia of unknown origin (PUO) for brucellosis. It is desirable that specimens from cases of tuberculosis, typhoid, rheumatoid arthritis, urogenital infections, kala-azar, cirrhosis, bacterial endocarditis, leukemia and filariasis should also be screened for brucellosis in man. The cases of meningitis of unestablished etiology as the cases of human brucellosis are often misdiagnosed as cases of typhoid or tuberculosis.

Seroprevalence of brucellosis in man.

A total of 352 human serum samples were screened for brucellosis. A combination of serological tests including Rose Bengal plate test (RBPT), standard tube agglutination test (STAT) and dot-enzyme linked immunosorbent assay (dot-ELISA) were employed for the purpose. The study revealed a prevalence rate of 4.97 per cent in samples that included specimens from persons occupationally exposed to animals. The number of seropositives through all tests used was higher among males (5.95 per cent) than females (3.15 per cent). A markedly higher prevalence of 17.39 per cent was recorded among field veterinarians. A low prevalence (2-6 per cent) was observed in humans with unknown history of animal contact. Dot-ELISA yielded 4.97 per cent positives compared to 1.38 and 0.82 per cent through RBPT and STAT respectively.