Showing papers by "Philippe J Guerin published in 2007"

Prevalence, Determinants of Positivity, and Clinical Utility of Cryptococcal Antigenemia in Cambodian HIV-Infected Patients

Abstract: OBJECTIVES To determine the prevalence, determinants ofpositivity, and clinical utility of serum cryptococcal polysaccharide (CPS) antigen testing among HIV-infected patients in 2004 in Cambodia, an area highly endemic for cryptococcosis. METHODS All HIV-infected patients with a CD4+ count <200 cells/mm3 attending 1 of 2 Phnom Penh hospitals for the first time were systematically screened for serum CPS. Patients with positive test results were further investigated to identify those with cryptococcal meningitis (CM), pulmonary cryptococcosis, or isolated positive cryptococcal antigenemia (IPCA). RESULTS The median (interquartile range [IQR]) CD4+ count of 327 enrolled patients was 24 (IQR: 8 to 65) cells/mm3. The prevalence of cryptococcal infection was 59 (18.0%) of 327 cases, of which 41 were CM and 10 were IPCA. In the absence of serum CPS detection, 17 (28.8%) of 59 cryptococcal infections would have been missed on the day of consultation. In patients with no specific symptoms of meningoencephalitis, the prevalence of positive serum CPS detection was 32 (10.8%) of 295 cases. Countryside residence (adjusted odds ratio [AOR] = 3.6), headache (AOR = 3.2), body mass index <15.4 kg/m2 (AOR = 3.4), CD4+ count <50 cells/mm3 (AOR = 4.0), and male gender (marginally, AOR = 2.1) were all independently associated with a positive test results. CONCLUSION Serum CPS screening among AIDS patients with a CD4+ count <100 cells/mm3 is useful in areas highly endemic for cryptococcosis, allowing early diagnosis and treatment of this opportunistic infection.

Unacceptably High Mortality Related to Measles Epidemics in Niger, Nigeria, and Chad

Abstract: Background Despite the comprehensive World Health Organization (WHO)/United Nations Children’s Fund (UNICEF) measles mortality–reduction strategy and the Measles Initiative, a partnership of international organizations supporting measles mortality reduction in Africa, certain highburden countries continue to face recurrent epidemics. To our knowledge, few recent studies have documented measles mortality in sub-Saharan Africa. The objective of our study was to investigate measles mortality in three recent epidemics in Niamey (Niger), N’Djamena (Chad), and Adamawa State (Nigeria).

World Antimalarial Resistance Network I: Clinical efficacy of antimalarial drugs

Abstract: The proliferation of antimalarial drug trials in the last ten years provides the opportunity to launch a concerted global surveillance effort to monitor antimalarial drug efficacy. The diversity of clinical study designs and analytical methods undermines the current ability to achieve this. The proposed World Antimalarial Resistance Network (WARN) aims to establish a comprehensive clinical database from which standardised estimates of antimalarial efficacy can be derived and monitored over time from diverse geographical and endemic regions. The emphasis of this initiative is on five key variables which define the therapeutic response. Ensuring that these data are collected at the individual patient level in a consistent format will facilitate better data management and analytical practices, and ensure that clinical data can be readily collated and made amenable for pooled analyses. Such an approach, if widely adopted will permit accurate and timely recognition of trends in drug efficacy. This will guide not only appropriate interventions to deal with established multidrug resistant strains of malaria, but also facilitate prompt action when new strains of drug resistant plasmodia first emerge. A comprehensive global database incorporating the key determinants of the clinical response with in vitro, molecular and pharmacokinetic parameters will bring together relevant data on host, drug and parasite factors that are fundamental contributors to treatment efficacy. This resource will help guide rational drug policies that optimize antimalarial drug use, in the hope that the emergence and spread of resistance to new drugs can be, if not prevented, at least delayed.

Drug policy for visceral leishmaniasis: a cost-effectiveness analysis.

Abstract: Summary objective To facilitate the choice of the best visceral leishmaniasis (VL) treatment strategy for first-line health services in (VL)-endemic areas, we compared in a formal decision analysis the cost and the costeffectiveness of the different available options. methods We selected four drug regimens for VL on the basis of frequency of use, feasibility and reported efficacy studies. The point estimates and the range of plausible values of effectiveness and cost were retrieved from a literature review. A decision tree was constructed and the strategy minimizing the cost per death averted was selected. results Treatment with amphotericin B deoxycholate was the most effective approach in the baseline analysis and averted 87.2% of all deaths attributable to VL. The least expensive and the most costeffective treatment was the miltefosine regimen, and the most expensive and the least cost-effective was

Meningitis Serogroup W135 Outbreak, Burkina Faso, 2002.

Abstract: In 2002, the largest epidemic of Neisseria meningitidis serogroup W135 occurred in Burkina Faso. The highest attack rate was in children <5 years of age. We describe cases from 1 district and evaluate the performance of the Pastorex test, which had good sensitivity (84%) and specifi city (89%) compared with culture or PCR.

Reducing the number of sputum samples examined and thresholds for positivity: an opportunity to optimise smear microscopy.

Abstract: SETTING: Urban health clinic, Nairobi. OBJECTIVE: To evaluate the impact on tuberculosis (TB) case detection and laboratory workload of reducing the number of sputum smears examined and thresholds for diagnosing positive smears and positive cases. DESIGN: In this prospective study, three Ziehl-Neelsen stained sputum smears from consecutive pulmonary TB suspects were examined blind. The standard approach (A), � 2 positive smears out of 3, using a cut-off of 10 acid-fast bacilli (AFB)/100 high-power fields (HPF), was compared with approaches B, � 2 positive smears (� 4 AFB/100 HPF) out of 3, one of which is � 10 AFB/100 HPF; C, � 2 positive smears (� 4 AFB/100 HPF) out of 3; D, � 1 positive smear (� 10 AFB/100 HPF) out of 2; and E, � 1 positive smear (� 4 AFB/100 HPF) out of 2. The microscopy gold standard was detection of at least one positive smear (� 4 AFB/100 HPF) out of 3. RESULTS: Among 644 TB suspects, the alternative approaches detected from 114 (17.7%) (approach B) to 123 cases (19.1%) (approach E) compared to 105 cases (16.3%) for approach A (P � 0.005). Sensitivity ranged between 82.0% (105/128) for A and 96.1% (123/128) for E. The single positive smear approaches reduced the number of smears by 36% compared to approach A. CONCLUSION: Reducing the number of specimens and the positivity threshold to define a positive case increased the sensitivity of microscopy and reduced laboratory workload.

Outbreak of beriberi in a prison in Côte d'Ivoire.

Abstract: BackgroundA beriberi outbreak occurred in the Maison d'Arret et de Correction d'Abidjan (MACA), a detention center in Abidjan, Cote d'Ivoire, between October 2002 and April 2003.ObjectiveA retrospective investigation was conducted to document the outbreak in April 2003.MethodsA descriptive analysis and a case–control study were performed. A probable case patient was defined as a person detained in the center between October 2002 and April 2003 with at least two of the following symptoms: bilateral leg edema, dyspnea, positive squat test, motor deficiencies, and paresthesia. A definite case patient was defined as a probable case patient who showed clinical improvement under thiamin treatment.ResultsOf 712 cases reported, 115 (16%) were probable and 597 (84%) were definite. The overall attack rate was 14.1%, and the case fatality rate was 1.0% (7/712). The highest attack rate was reported in the building housing prisoners with long-term sentences (16.9%). All patients were male, and the mean age was 28 year...

Using European Travellers as an Early Alert to Detect Emerging Pathogens in Countries with Limited Laboratory Resources.

Abstract: The volume, extent and speed of travel have dramatically increased in the past decades, providing the potential for an infectious disease to spread through the transportation network. By collecting information on the suspected place of infection, existing surveillance systems in industrialized countries may provide timely information for areas of the world without adequate surveillance currently in place. We present the results of a case study using reported cases of Shigella dysenteriae serotype 1 (Sd1) in European travellers to detect "events" of Sd1, related to either epidemic cases or endemic cases in developing countries. We identified papers from a Medline search for reported events of Sd1 from 1940 to 2002. We requested data on shigella infections reported to the responsible surveillance entities in 17 European countries. Reports of Sd1 from the published literature were then compared with Sd1 notified cases among European travellers from 1990 to 2002. Prior to a large epidemic in 1999–2000, no cases of Sd1 had been identified in West Africa. However, if travellers had been used as an early warning, Sd1 could have been identified in this region as earlier as 1992. This project demonstrates that tracking diseases in European travellers could be used to detect emerging disease in developing countries. This approach should be further tested with a view to the continuous improvement of national health surveillance systems and existing European networks, and may play a significant role in aiding the international public health community to improve infectious disease control.

Clonal reconquest of antibiotic-susceptible salmonella enterica serotype typhi in son la province, vietnam

Abstract: In the last three decades, high rates of resistance to common first-line antimicrobial agents have been reported in Salmonella enterica serotype Typhi (Typhi), the causative organism of typhoid fever (TF), in many regions of the world, especially in South East Asia. Analysis of Typhi strains isolated from outbreaks and sporadic cases of TF in Son La province, northwest Vietnam, in 2002 revealed that 94.5% (85/90) of the isolates were fully susceptible to amoxicillin, chloramphenicol, cotrimoxazole, tetracycline, and nalidixic acid. There was a clear decline in the occurrence of multi-drug resistant (MDR) Typhi isolates collected in this province in 2002 (4.4%) compared with the period 1995-1999 in the same province (30.8-100%). By using molecular (IS200 profiling, PstI-ribotyping, XbaI-pulsed-field gel electrophoresis, and haplotyping) and phage-typing methods, we showed that the Typhi isolates from Son La province in 2002 were genetically related; however, they were unrelated to the previous MDR clones established in Vietnam.