Isolation of non-tuberculous mycobacteria at three rural settings in Zambia; a pilot study.

To assess the role of non-tuberculous mycobacteria (NTM) as a cause of tuberculosis-like diseases in Zambia, 167 chronically ill patients, hospitalized in three rural hospitals in Katete, Sesheke and Chilonga, were examined by microscopy and liquid culture for the presence of NTM. The percentages of patients with a positive culture for Mycobacterium tuberculosis complex were similar in the three geographical locations (19-25%). In contrast, the percentage of NTM ranged from 78% in Katete and 65% in Sesheke to 21% in Chilonga. Furthermore, the distribution of NTM species was different at the three geographical sites. In seven patients, true NTM-associated disease was suspected: five with Mycobacterium lentiflavum and two with Mycobacterium intracellulare. Analysis of possible risk factors indicated that the OR for NTM culture-positive sputum was significantly higher for patients living in Katete and Sesheke. Female gender and chest X-ray appearances of tuberculosis were independently associated with NTM culture-positive sputum. NTM colonization and disease in hospitalized, chronically ill patients in rural Zambia appear to be common.

Device-independent, real-time identification of bacterial pathogens with a metal oxide-based olfactory sensor.

A novel olfactory method for bacterial species identification using an electronic nose device called the MonoNose was developed. Differential speciation of micro-organisms present in primary cultures of clinical samples could be performed by real-time identification of volatile organic compounds (VOCs) produced during microbial replication. Kinetic measurements show that the dynamic changes in headspace gas composition are orders of magnitude larger than the static differences at the end of fermentation. Eleven different, clinically relevant bacterial species were included in this study. For each of the species, two to eight different strains were used to take intra-species biodiversity into account. A total of 52 different strains were measured in an incubator at 37 degrees C. The results show that the diagnostic specificities varied from 100% for Clostridium difficile to 67% for Enterobacter cloacae with an overall average of 87%. Pathogen identification with a MonoNose can be achieved within 6-8 h of inoculation of the culture broths. The diagnostic specificity can be improved by broth modification to improve the VOC production of the pathogens involved.

Polymorphism in CC-chemokine ligand 2 associated with tuberculosis in Zambia.

Polymorphism in various genes that may influence susceptibility to tuberculosis (TB) was examined in 46 TB patients and 119 healthy tuberculin-positive controls in Zambia. The odds of having TB was 2.8-fold higher in carriers of the -2518 AG single-nucleotide polymorphism in the promoter region of the CC-chemokine ligand 2 than in those carrying the homozygous genotype AA (95%CI 1.3-5.5).

Rapid identification of mycobacteria by Raman spectroscopy.

A number of rapid identification methods have been developed to improve the accuracy for diagnosis of tuberculosis and to speed up the presumptive identification of Mycobacterium species. Most of these methods have been validated for a limited group of microorganisms only. Here, Raman spectroscopy was compared to 16S rRNA sequencing for the identification of Mycobacterium tuberculosis complex strains and the most frequently found strains of nontuberculous mycobacteria (NTM). A total of 63 strains, belonging to eight distinct species, were analyzed. The sensitivity of Raman spectroscopy for the identification of Mycobacterium species was 95.2%. All M. tuberculosis strains were correctly identified (7 of 7; 100%), as were 54 of 57 NTM strains (94%). The differentiation between M. tuberculosis and NTM was invariably correct for all strains. Moreover, the reproducibility of Raman spectroscopy was evaluated for killed mycobacteria (by heat and formalin) versus viable mycobacteria. The spectra of the heat-inactivated bacteria showed minimal differences compared to the spectra of viable mycobacteria. Therefore, the identification of mycobacteria appears possible without biosafety level 3 precautions. Raman spectroscopy provides a novel answer to the need for rapid species identification of cultured mycobacteria in a clinical diagnostic setting.

[A patient with fever following a visit to the tropics: tick-borne relapsing fever discovered in a thick blood smear preparation]. / Een patiënt met koorts na een bezoek aan de tropen: 'tick-borne relapsing fever' ontdekt in een dikkedruppelpreparaat.

A 26-year-old woman presented with a 2-day history of fever peaking to 39 degrees C and cold shivers that developed after a 2-weeks trip to Guatemala and Belize. Prior to the fever the patient had felt symptoms of a common cold and general malaise. Moreover, she complained of generalised myalgia and nausea. She had taken paludrine as a prophylactic against malaria. Borrelia spirochaetes, the pathogen of relapsing fever, were detected in a thick blood smear preparation. On the basis of the anamnesis, geography and specific exposure, the patient had a form of relapsing fever that is transmitted by ticks and not by lice: tick-borne relapsing fever. She was treated with doxycycline, 100 mg b.i.d. for 7 days. She could be discharged home in good condition after 2 days.

Hemorrhagic Fevers : Few Clues after 25 Years

There is a high prevalence of Ebola antibodies found in the Kenya population; related to geographical area and season; although the clinical disease was never found and the virus was not isolated. A field study was carried out in 7 hospitals in western Kenya; 1986 -1987 (including surveillance studies in suspect areas); to intensify collection and transport of samples; testing facilities; patient observation with record keeping and follow-up. This study involved 1109 admitted patients with fever and/or bleeding; 155 contacts of haemorrahagic fever antibody (Hfab) patients; and 916 people in suspect areas. Respectively 160;44 and 80 persons were found Hfab positive mainly to Ebola; using an indirect immunofluorescent assay. From 676 viral cultures no virus was isolated. A relationship between antibody titres and ecological factors; social habitat; age; sex or season was not found. The non-specificity of IF testing was demonstrated by: 1) the disagreement between the results of two reference laboratories; 2) the unpredictability of the titre conversation course; and 3) by proving a significant cross-reactivity with Borrelia burgdorferii antibodies; Plasmodium falcparum antibodies and Salmonella typhi antibodies. Renewed testing in 1995 of 90 positive sera (with low titres) showed 19 sera to be positive by Elisa (2 in Zaire; 1 in Sudan; 9 in Reston and 7 in Cote d'Ivoire) from which 4 were confirmed by IFI 2 in Reston and 2 in Cote d'Ivoire. These findings are more proof that non-human virulent strains of Filoviridae; especially Ebola virus; are around in Kenya

Analysis of infectious diseases in rural tropical areas.

A study of 256 annual reports from 17 rural tropical hospitals in 4 African countries over a period of 16 years showed an absolute increase in the number of patients admitted with infectious diseases. Admissions were highest for malaria, followed by pneumonia and gastroenteritis. Admissions for immunisable diseases are decreasing in all countries. Fever remains the most important indicator of infectious diseases. Analysis of fever patients in rural tropical hospitals relies on knowledge of the epidemiology of diseases, plus expertise in physical examination. In this study, a detailed analysis of 900 fever patients indicated that 4% showed no infection, 21% of infections could be diagnosed by physical examination, 35% were diagnosed with the help of additional laboratory tests and 40% of patients were diagnosed as FUO (fever of unknown origin). 17% of FUO patients had a short, self limiting fever, but the remaining 23% were severely ill, suggesting bacterial sepsis, as was indicated by earlier studies. Undiagnosed fevers with resulting over-treatment and high resistance are costly and dangerous. These effects stress the need for better and more laboratory facilities, including possibilities for bacterial cultures. At present, patients are generally over-treated with antimalarials and antibiotics, since further diagnostic facilities are not available. Resistance is high for antimalatials ( Malaria) and for Amoxycillin, Cotrimoxazole and Gentamicin (Gram-bacteria from urine and blood).

Analysis of Infectious Diseases in Rural Tropical Areas

A study of 256 annual reports from 17 rural tropical hospitals in 4 African countries over a period of 16 years showed an absolute increase in the number of patients admitted with infectious diseases. Admissions were highest for malaria; followed by pneumonia and gastroenteritis. Admissions for immunisable diseases are decreasing in all countries. Fever remains the most important indicator of infectious diseases. Analysis of fever patients in rural tropical hospitals relies on knowledge of the epidemiology of diseases; plus expertise in physical examination. In this study; a detailed analysis of 900 fever patients indicated that 4showed no infection; 21of infections could be diagnosed by physical examination; 35were diagnosed with the help of additional laboratory tests and 40of patients were diagnosed as FUO (fever of unknown origin). 17of FUO patients had a short; self limiting fever; but the remaining 23were severely ill; suggesting bacterial sepsis; as was indicated by earlier studies. Undiagnosed fevers with resulting over-treatment and high resistance are costly and dangerous. These effects stress the need for better and more laboratory facilities; including possibilities for bacterial cultures. At present; patients are generally over-treated with antimalarials and antibiotics; since further diagnostic facilities are not available. Resistance is high for antimalatials ( Malaria) and for Amoxycillin; Cotrimoxazole and Gentamicin (Gram-bacteria from urine and blood)