PCR-based detection of the Mycobacterium tuberculosis complex in urine of HIV-infected and uninfected pulmonary and extrapulmonary tuberculosis patients in Burkina Faso.
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To evaluate a one-tube nested PCR-based analysis of urine for diagnosing pulmonary tuberculosis (PTB) and extrapulmonary tuberculosis (EPTB) in Bobo-Dioulasso, Burkina Faso, a prospective analysis of urine samples from HIV- and non-HIV-infected adults with PTB and EPTB (case patients) and with pathology other than tuberculosis (TB) (control patients) was performed. Three groups of patients were classified as microbiological-positive and -negative PTB and EPTB on the basis of clinical signs and microbiological results. Urine from patients was analysed using the DNA extraction and Sechi's methods, both modified, for the detection of Mycobacterium tuberculosis. The sensitivity, specificity, positive predictive value and negative predictive value were calculated. The sensitivity of the test for the microbiological-positive PTB, microbiological-negative PTB and EPTB was 40.5 % (88/217), 66.7 % (20/30) and 57.1 % (48/84), respectively. The specificity was 98.2 %. Differences were observed in the two populations infected and not infected by HIV. This method is not appropriate for detection of new TB cases in the routine laboratory, but it can be useful for cases where the clinical and bacteriological diagnosis of TB is not conclusive. (+info)
The spread of the Leu-Phe kdr mutation through Anopheles gambiae complex in Burkina Faso: genetic introgression and de novo phenomena.
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During extensive sampling in Burkina Faso and other African countries, the Leu-Phe mutation producing the kdr pyrethroid resistance phenotype was reported in both Anopheles gambiae ss and A. arabiensis. This mutation was widely distributed at high frequency in the molecular S form of A. gambiae while it has been observed at a very low frequency in both the molecular M form and A. arabiensis in Burkina Faso. While the mutation in the M form is inherited through an introgression from the S form, its occurrence is a new and independent mutation event in A. arabiensis. Three nucleotides in the upstream intron of the kdr mutation differentiated A. arabiensis from A. gambiae ss and these specific nucleotides were associated with kdr mutation in A. arabiensis. Ecological divergences which facilitated the spread of the kdr mutation within the complex of A. gambiae ss in West Africa, are discussed. (+info)
Bacterial meningitis in Burkina Faso: surveillance using field-based polymerase chain reaction testing.
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BACKGROUND: In addition to frequent epidemics of group A meningococcal disease, endemic bacterial meningitis due mostly to Neisseria meningitidis, pneumococcus, and Haemophilus influenzae type b is a serious problem in sub-Saharan Africa. The improved ability to identify the etiologic agent in cases of bacterial meningitis will facilitate more rapid administration of precise therapy. METHODS: To describe the epidemiology of bacterial meningitis and evaluate the usefulness of field-based polymerase chain reaction (PCR) testing, we implemented population-based meningitis surveillance in Burkina Faso during 2002-2003 by use of PCR, culture, and antigen detection tests. RESULTS: Among persons aged 1 month to 67 years, the incidences of meningococcal meningitis, pneumococcal meningitis, and Haemophilus influenzae type b meningitis were 19 cases (n=179), 17 cases (n=162), and 7.1 cases (n=68) per 100,000 persons per year, respectively. Of the cases of meningococcal meningitis, 72% were due to N. meningitidis serogroup W135. Pneumococcal meningitis caused 61% of deaths and occurred in a seasonal pattern that was similar to that of meningococcal meningitis. Of cases of pneumococcal meningitis and N. meningitidis serogroup W135 meningitis, 71% occurred among persons >2 years of age. Most patients, regardless of the etiology of their illness and the existence of an epidemic, received short-course therapy with oily chloramphenicol. Compared with culture as the gold standard, the sensitivity and specificity of PCR in the field were high; this result was confirmed in Burkina Faso and Paris. CONCLUSIONS: Precise and rapid identification of etiologic agents is critical for improvement in the treatment and prevention of meningitis, and, thus, PCR should be considered for wider use in Africa. Vaccines against Streptococcus pneumoniae, N. meningitidis (including serogroup W135), and H. influenzae type b all will have a major impact on the bacterial meningitis burden. Antibiotic recommendations need to consider the importance of S. pneumoniae, even during the epidemic season. (+info)
Interlaboratory comparison of PCR-based identification and genogrouping of Neisseria meningitidis.
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Twenty clinical samples (18 cerebrospinal fluid samples and 2 articular fluid samples) were sent to 11 meningococcus reference centers located in 11 different countries. Ten of these laboratories are participating in the EU-MenNet program (a European Union-funded program) and are members of the European Monitoring Group on Meningococci. The remaining laboratory was located in Burkina Faso. Neisseria meningitidis was sought by detecting several meningococcus-specific genes (crgA, ctrA, 16S rRNA, and porA). The PCR-based nonculture method for the detection of N. meningitidis gave similar results between participants with a mean sensitivity and specificity of 89.7 and 92.7%, respectively. Most of the laboratories also performed genogrouping assays (siaD and mynB/sacC). The performance of genogrouping was more variable between laboratories, with a mean sensitivity of 72.7%. Genogroup B gave the best correlation between participants, as all laboratories routinely perform this PCR. The results for genogroups A and W135 were less similar between the eight participating laboratories that performed these PCRs. (+info)
Migration as a risk factor for measles after a mass vaccination campaign, Burkina Faso, 2002.
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BACKGROUND: Shortly after a measles supplementary immunization activity (SIA) targeting children from 9 months to 14 years of age that achieved high coverage, Burkina Faso had a large, serologically confirmed measles outbreak. To investigate the causes of this first reported failure of a widely successful measles control strategy we conducted a case-control study. METHODS: Serologically confirmed measles cases aged > or =9 months at the time of the SIA in 6 heavily affected districts were frequency matched on age to 3 controls recruited from people frequenting health centres in the same districts. RESULTS: Between January and July 2002, 1287 measles cases were reported throughout Burkina Faso. Of the 707 cases that were serologically confirmed, 358 (51%) were from 9 months to 14 years of age and 265 (37%) were > or =15 years of age. Among cases and controls from 9 months to 14 years of age significant risk factors for measles were lack of measles vaccination and, in the unvaccinated, recent travel to Cote d'Ivoire. Of the recent measles cases in Cote d'Ivoire 54% were there when exposed to measles. Among adults, risk factors included non-vaccination and the lack of school attendance during childhood. Vaccine effectiveness was estimated to be 98%. CONCLUSIONS: Migration of children between Cote d'Ivoire and Burkina Faso played a major role in the failure of the SIA to interrupt measles transmission. Synchronization of measles control activities should be a high priority in countries with regions where much migration occurs. (+info)
The elasticity of demand for health care in Burkina Faso: differences across age and income groups.
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Like many other developing countries, Burkina Faso has been exploring how community resources can be tapped to co-finance health services. Although revenue generation is important for the viability of health services, effects on utilization and on equity of access to health care must also be considered. The authors present a logistic regression model to derive price elasticities of demand for health care based on cross-sectional survey data. While demand for health care appears inelastic overall (-0.79), subgroup analysis reveals differences in elasticity across age and income groups. Elasticities of demand for infants and children (-3.6 and -1.7) and for the lowest income quartile (-1.4) are substantially greater than overall elasticity. The method used is unusual in that it allows estimation of elasticities before the introduction of user fees. This increases the value of the information to policy makers. (+info)
Association of Plasmodium falciparum isolates encoding the p. Falciparum chloroquine resistance transporter gene K76T polymorphism with anemia and splenomegaly, but not with multiple infections.
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The aim of the study was to assess whether infections with Plasmodium falciparum isolates encoding the P. falciparum chloroquine resistance transporter (pfcrt) gene K76T polymorphism, a molecular marker for chloroquine resistance, are associated with multiple infections, age, or clinical signs of malaria in a semi-immune population in a holoendemic area of Burkina Faso. The parameters of interest were investigated in 210 P. falciparum-positive inhabitants. Logistic regression analysis showed that pfcrt K76T-carrying isolates are significantly more likely to cause anemia and splenomegaly. Furthermore, we found that infections with P. falciparum isolates encoding pfcrt K76T are dependent on age rather than multiple infections. Our findings suggest that pfcrt K76T might serve as a valuable marker for assessing the long-term clinical effect of chronic infections with chloroquine-resistant P. falciparum isolates in populations, without the need of drug efficacy trials. (+info)
Reliability of data on caesarean sections in developing countries.
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OBJECTIVE: To examine the reliability of reported rates of caesarean sections from developing countries and make recommendations on how data collection for surveys and health facility-based studies could be improved. METHODS: Population-based rates for caesarean section obtained from two sources: Demographic and Health Surveys (DHS) and health facility-based records of caesarean sections from the Unmet Obstetric Need Network, together with estimates of the number of live births, were compared for six developing countries. Sensitivity analyses were conducted using several different definitions of the caesarean section rate, and the rates obtained from the two data sources were compared. FINDINGS: The DHS rates for caesarean section were consistently higher than the facility-based rates. However, in three quarters of the cases, the facility-based rates for caesarean sections fell within the 95% confidence intervals for the DHS estimate. CONCLUSION: The importance of the differences between these two series of rates depends on the analyst's perspective. For national and global monitoring, DHS data on caesarean sections would suffice, although the imprecision of the rates would make the monitoring of trends difficult. However, the imprecision of DHS data on caesarean sections precludes their use for the purposes of programme evaluation at the regional level. (+info)