Milagros Moreno

Knockdown resistance mutations (kdr) and insecticide susceptibility to DDT and pyrethroids in Anopheles gambiae from Equatorial Guinea

Objectives  To determine the frequency of knockdown resistance (kdr) mutations in the malaria vector Anopheles gambiae s.s. from continental Equatorial Guinea; and to relate kdr genotypes with susceptibility to DDT and pyrethroid insecticides in this vector.

Tuberculosis diagnosed in a rural setting in Angola. Accuracy of follow-up sputum smears to predict outcome

Abstract Objective: To analyze treatment outcome and the accuracy of positive sputum smear at 2 months to predict treatment failure in a cohort of patients with tuberculosis (TB) in a rural setting in Angola. Design: Observational study of patients with TB from January 2009 to August 2010 in Hospital Nossa Senhora da Paz in Angola. A multivariate analysis was performed to identify variables associated with treatment failure and death. Sensitivity, specificity, positive and negative predictive values and likelihood ratios to define the accuracy of a positive sputum smear at 2 months to predict treatment failure were calculated. Results: One thousand four hundred and twenty-five patients were diagnosed with TB. Overall, 526 patients were cured from TB and 419 had treatment completed, so 945 (66·3%) patients achieved treatment success. The outcomes of the remaining patients were: 91 (6·4%) had treatment failure, 100 (7%) died, 49 (3·4%) interrupted treatment, and 240 (16·8%) were transferred out. Variables associated with a higher risk of treatment failure were previously treated patients (odds ratio, 2·36; 95% confidence interval, 1·32–4·2) and positive sputum smear at 2 months (odds ratio, 9·81; 95% confidence interval, 5·88–16·36). Among the group of 551 patients with sputum smear confirmed at diagnosis and specimens taken at 2 and 5 months, the positive predictive value (31%) and the positive likelihood ratio (3·21) of a positive sputum smear taken at 2 months to predict treatment failure were low. Conclusions: Patients with positive sputum smear at 2 months have a higher risk of treatment failure. However, this by itself is a poor predictor of treatment failure.

Epidemiology of Schistosomiasis and Usefulness of Indirect Diagnostic Tests in School-Age Children in Cubal, Central Angola

Introduction Schistosomiasis remains a public health major problem and little is known in many areas, mainly in Sub-Saharan Africa Objectives To assess the burden and risk factors of schistosomiasis and intestinal parasitic helminthes in the children of Cubal, Angola, and to compare different diagnostic approaches for urinary schistosomiasis under field conditions. Methods A cross-sectional study was conducted. Urine and faeces samples of school children were microscopically studied. A random sample of children was obtained from an alphabetically arranged list of children, taking one of two children. Urine dipstick, colorimetric test and macrohaematuria were considered as indirect diagnostic methods and compared to direct urine examination. Possible risk factors for the infection were sex, age, distance to the river and previous treatment with praziquantel; the assessment was performed using Chi-square test. Results A total of 785 (61.18%) children showed S. haematobium eggs in urine; children living within 500 meters from the river had a higher odds for infection: Odds ratio 1.97 (1.45–2.7 CI 95%); urine dipstick showed sensitivity of 96% and specificity of 61.3%, with a positive predictive value; colorimetric test showed sensitivity of 52.5%, specificity of 74.6% and a positive predictive value of 77%. Proteinuria was present in 653 (51.1%) children, being more frequent in children with S. haematobium in urine (75.2%); 32 of 191 stool samples (16%) showed the presence of other intestinal parasites and 8 (4%) for S. haematobium. Conclusions Prevalence of urinary schistosomiasis in our study area is much higher than the national average, considering it as a high-risk community. Proximity to a source of water was a risk factor for the infection. Indirect tests, as urine dipstick and colorimetric test, were useful tools for diagnosis, due to ease of use and low cost. Proteinuria was a common finding, probably showing an early structural damage due to schistosomiasis in this group of children.

Changes in malaria epidemiology in a rural area of Cubal, Angola

BackgroundScarce information about malaria epidemiology in Angola has been published. The objective of this study is to describe the epidemiology of malaria at the Hospital Nossa Senhora da Paz (Cubal, Angola) and the fatality rate due to malaria (total and in children under five years) in the last five years.MethodsA retrospective, observational study was performed at the Hospital Nossa Senhora da Paz, a 400-bed rural hospital located in Benguela Province of Angola. The study population included all patients who attended the hospital from January 2009 to December 2013. Outcome variables were calculated as follows: the percentage of malaria cases (number of positive thick blood films, divided by the total thick blood films performed); the percentage of in-patients for malaria (number of in-patients diagnosed with malaria, divided by the total number of in-patients); and, the fatality rate (number of deaths due to malaria divided by the number of positive thick blood films).ResultsOverall, 23,106 thick blood films were performed, of which 3,279 (14.2%) were positive for Plasmodium falciparum infection. During this five-year period, a reduction of 40% (95% CI 37-43%, p < 0.001) in the malaria-positive slides was detected. Distribution of positive-malaria slides showed a seasonal distribution with a peak from December to March (rainy season). An average annual reduction of 52% (95% CI 50-54%, p < 0.001) in the admissions due to malaria was observed. The overall fatality rate due to malaria was 8.3%, and no significant differences in the annual fatality rate were found (p = 0.553).ConclusionsA reduction in the number of malaria cases and the number of admissions due to malaria has been observed at the Hospital Nossa Senhora da Paz, during the last five years, and incidence along the study period showed a seasonal distribution. All this information could be useful when deciding which malaria control strategies have to be implemented in this area.

Prevalence of Strongyloides stercoralis and Other Intestinal Parasite Infections in School Children in a Rural Area of Angola: A Cross-Sectional Study

Strongyloides stercoralis is widely distributed in the tropics and subtropics. The aim of this study was to determine the prevalence of S. stercoralis and other intestinal parasites and identify the risk factors for infection with S. stercoralis in a rural area of Angola. A cross-sectional study was conducted in school-age children (SAC) in Cubal, Angola. A questionnaire collecting clinical and epidemiological variables was used, and two stool samples were collected. A concentration technique (Ritchie) and a technique for detection of larvae migration (Baermann) were performed. Of 230 SAC, 56.1% were female and the mean age was 9.3 years (SD 2.45). Severe malnutrition, according to body mass index (BMI)-for-age, was observed in 20.4% of the SAC, and anemia was found in 59.6%. Strongyloides stercoralis was observed in 28 of the 230 (12.8%) SAC. Eggs of other helminths were observed in 51 (22.2%) students: Hymenolepis spp. in 27 students (11.7%), hookworm in 14 (6.1%), Schistosoma haematobium in four (1.7%), Enterobius vermicularis in four (1.7%), Ascaris lumbricoides in three (1.3%), Taenia spp. in two (0.9%), and Fasciola hepatica in one (0.4%). Protozoa were observed in 17 (7.4%) students. Detection of S. stercoralis was higher using the Baermann technique versus using formol-ether (11.3 vs. 3%). Overall prevalence of S. stercoralis in the school population of 16 studied schools in the municipal area of Cubal was greater than 10%. This fact must be considered when designing deworming mass campaigns. The use of specific tests in larvae detection is needed to avoid overlooking this parasite.

Ultrasound findings and associated factors to morbidity in Schistosoma haematobium infection in a highly endemic setting

To evaluate the usefulness of the WHO classification of ultrasound pathological changes and to establish risk factors for morbidity in a highly endemic setting.

Field and laboratory comparative evaluation of a LAMP assay for the diagnosis of urogenital schistosomiasis in Cubal, Central Angola

To evaluate the performance of Rapid‐Heat LAMPellet assay in field conditions for diagnosis of urogenital schistosomiasis in an endemic area in Cubal, Angola, and to assess the reproducibility in a reference laboratory.

Ultrasound Evolution of Pediatric Urinary Schistosomiasis after Treatment with Praziquantel in a Highly Endemic Area

Urinary schistosomiasis causes damage to the urological system. Ultrasound is a method that detects the burden of secondary disease, individually and in epidemiological studies. In this study, the Schistosoma haematobium-associated urinary tract pathology is analyzed before and after treatment in a short period of time. Seventy children who had previously participated in an epidemiological study on schistosomiasis in the city of Cubal, Angola, and had also performed urinary ultrasound between August 2013 and February 2014 were cited 6-8 months later to assess the possible reinfection and repeat new urinary ultrasound, analyzing changes at the level of urinary pathology. The presence of hematuria and proteinuria was also analyzed. Of the 70 children analyzed, 29 (41.4%) were girls, with an average age of 10.4 years (standard deviation 2.3). Fifty-three (75.7%) had an improvement in their bladder and/or kidney scores, whereas 12 (17.1%) had no change and five (7.1%) had progression of the disease. None of the parameters analyzed completely disappeared. After one single course of treatment with praziquantel, all the analyzed parameters showed regression. Improvement was greater in the urinary bladder than in the upper urinary tract, though these lesions also reversed; the reversion of all parameters was greater among children older than 10 years old than the younger ones. Proteinuria was the parameter with a smaller reduction. Ultrasound should be a usual tool for diagnosis and follow-up in urinary schistosomiasis, particularly in children; more accurate recommendations about follow-up in the case of children whose lesions do not reverse should be established.

LARVAE STAGE DESCRIPTION OF ANOPHELES (CELLIA) CARNEVALEI FROM ADULT INDIVIDUALS COLLECTED IN EQUATORIAL GUINEA

ABSTRACT This is the first description of 3rd and 4th instars of Anopheles (Cellia) carnevalei. Adults were caught in the mainland region (Rio Muni) of Equatorial Guinea. Larvae present characteristic palmate setae different from Anopheles nili.