National Institute of Hygiene
National Institute of Hygiene
Mascari T.M.,Louisiana State University |
Hanafi H.A.,United States Naval Medical Research Unit No 3 |
Jackson R.E.,Syngenta |
Ouahabi S.,National Institute of Hygiene |
And 5 more authors.
PLoS Neglected Tropical Diseases | Year: 2013
Background:Leishmaniasis remains a global health problem because of the substantial holes that remain in our understanding of sand fly ecology and the failure of traditional vector control methods. The specific larval food source is unknown for all but a few sand fly species, and this is particularly true for the vectors of Leishmania parasites. We provide methods and materials that could be used to understand, and ultimately break, the transmission cycle of zoonotic cutaneous leishmaniasis.Methods and Findings:We demonstrated in laboratory studies that analysis of the stable carbon and nitrogen isotopes found naturally in plant and animal tissues was highly effective for linking adult sand flies with their larval diet, without having to locate or capture the sand fly larvae themselves. In a field trial, we also demonstrated using this technique that half of captured adult sand flies had fed as larvae on rodent feces. Through the identification of rodent feces as a sand fly larval habitat, we now know that rodent baits containing insecticides that have been shown in previous studies to pass into the rodents' feces and kill sand fly larvae also could play a future role in sand fly control. In a second study we showed that rubidium incorporated into rodent baits could be used to demonstrate the level of bloodfeeding by sand flies on baited rodents, and that the elimination of sand flies that feed on rodents can be achieved using baits containing an insecticide that circulates in the blood of baited rodents.Conclusions:Combined, the techniques described could help to identify larval food sources of other important vectors of the protozoa that cause visceral or dermal leishmaniasis. Unveiling aspects of the life cycles of sand flies that could be targeted with insecticides would guide future sand fly control programs for prevention of leishmaniasis.
Benhafid M.,National Institute of Hygiene |
Benhafid M.,Mohammed V University |
Elomari N.,National Institute of Hygiene |
Elqazoui M.,National Institute of Hygiene |
And 4 more authors.
Journal of Medical Virology | Year: 2013
Rotavirus vaccine was introduced in Morocco during 2010. In anticipation of introducing rotavirus vaccines, the Ministry of Health in Morocco established a rotavirus surveillance network in June 2006 at four hospitals in Morocco to obtain baseline data on rotavirus disease burden and prevalent strains. From June 2006 to May 2009, stool samples were collected from children under 5 years of age admitted for diarrhea to four sentinel hospitals serving different regions of Morocco. Rotaviruses were detected in stools using enzyme immunoassay, then genotyped by reverse-transcriptase polymerase chain reaction. Samples with adequate stool in which the P or G types could not be determined by RT-PCR were subjected to nucleotide sequence analysis. Overall, 42% (579 of 1,388) of the stools samples tested were positive for rotavirus. Genotyping of 548 (95%) samples demonstrated that G1P (55%) was the most prevalent strain, followed by G9P (11.3%), G2P (9.1%), G4P (0.9%), and G3P (0.4%). Several other strains were identified including G1P (0.2%), G1P (0.9%), G2P (4.3%), G2P (0.2%), G3P (0.4%), G3P (0.2%), and G9P (0.2%). A high prevalence of mixed infections was found (15% of all samples) of which G1G2P (4%) and G1G3P (3.6%) accounted for the majority. Considerable diversity of rotavirus genotypes was present among strains circulating in Morocco prior to the introduction of the vaccine. This study highlighted the need for maintaining active surveillance to monitor changes in rotavirus disease burden and strain dynamics and to detect changes over time that could impact the effectiveness of the vaccination program. J. Med. Virol. 85:354-362, 2013. © 2012 Wiley Periodicals, Inc. Copyright © 2012 Wiley Periodicals, Inc.
El Qazoui M.,National Institute of Hygiene |
Oumzil H.,National Institute of Hygiene |
Baassi L.,Office of the Laboratories of the National Institute of Hygiene |
El Omari N.,National Institute of Hygiene |
And 4 more authors.
BMC Infectious Diseases | Year: 2014
Background: Acute gastroenteritis is a serious cause of child mortality and morbidity in resource-limited countries. A viral etiology is most common, and rotavirus and norovirus are reported to be the leading causative agents. There are still few epidemiological data on the simultaneous occurrence of these viruses in Morocco. The aim of this study was to provide useful epidemiological data on the gastroenteritis associated with rotavirus and norovirus among children aged less than 5 years.Methods: From January to December 2011, 335 samples were tested for rotavirus and norovirus using enzyme-linked immunosorbent assay, reverse-transcription-polymerase chain reaction (RT-multiplex PCR) and real-time RT-PCR. Partial sequences of the norovirus were phylogenetically analyzed to determine the genotype.Results: The overall rates of rotavirus and norovirus infections were 26.6% and 16.1%, respectively. Mixed viral infections were detected in 9 of 335 stool specimens (2.7%).The most common genotype combination in the rotavirus strains was G1[P8] (51.7%), followed by G2[P4] (10.1%), G2[P8] (4.5%), G9[P8] (3.4%), G4[P8] (3.4%), and G1[P6] (2.3%). Among patients positive for norovirus, 42 (77.8%) tested positive for GII and 12 (22.2%) for GI. Thirty-three (78.6%) of the norovirus GII-positive cases were successfully characterized. Genotype GII.4 was the most prevalent (n = 27; 81.8%), followed by GII.3 (n = 2; 6.1%), GII.13 (n = 2; 6.1%), GII.16 (n = 1; 3%), and GII.17 (n = 1; 3%).Conclusion: This study suggests that in Morocco, norovirus is the most frequent cause of acute gastroenteritis after rotavirus, but further enteric viruses need to be integrated in the surveillance system so that a conclusion could be drawn. © 2014 El Qazoui et al.; licensee BioMed Central Ltd.
Dooley K.E.,Johns Hopkins University |
Lahlou O.,National Institute of Hygiene |
Ghali I.,Sina |
Knudsen J.,Johns Hopkins University |
And 3 more authors.
BMC Public Health | Year: 2011
Background: Patients with tuberculosis require retreatment if they fail or default from initial treatment or if they relapse following initial treatment success. Outcomes among patients receiving a standard World Health Organization Category II retreatment regimen are suboptimal, resulting in increased risk of morbidity, drug resistance, and transmission. In this study, we evaluated the risk factors for initial treatment failure, default, or early relapse leading to the need for tuberculosis retreatment in Morocco. We also assessed retreatment outcomes and drug susceptibility testing use for retreatment patients in urban centers in Morocco, where tuberculosis incidence is stubbornly high. Methods. Patients with smear- or culture-positive pulmonary tuberculosis presenting for retreatment were identified using clinic registries in nine urban public clinics in Morocco. Demographic and outcomes data were collected from clinical charts and reference laboratories. To identify factors that had put these individuals at risk for failure, default, or early relapse in the first place, initial treatment records were also abstracted (if retreatment began within two years of initial treatment), and patient characteristics were compared with controls who successfully completed initial treatment without early relapse. Results: 291 patients presenting for retreatment were included; 93% received a standard Category II regimen. Retreatment was successful in 74% of relapse patients, 48% of failure patients, and 41% of default patients. 25% of retreatment patients defaulted, higher than previous estimates. Retreatment failure was most common among patients who had failed initial treatment (24%), and default from retreatment was most frequent among patients with initial treatment default (57%). Drug susceptibility testing was performed in only 10% of retreatment patients. Independent risk factors for failure, default, or early relapse after initial treatment included male gender (aOR = 2.29, 95% CI 1.10-4.77), positive sputum smear after 3 months of treatment (OR 7.14, 95% CI 4.04-13.2), and hospitalization (OR 2.09, 95% CI 1.01-4.34). Higher weight at treatment initiation was protective. Male sex, substance use, missed doses, and hospitalization appeared to be risk factors for default, but subgroup analyses were limited by small numbers. Conclusions: Outcomes of retreatment with a Category II regimen are suboptimal and vary by subgroup. Default among patients receiving tuberculosis retreatment is unacceptably high in urban areas in Morocco, and patients who fail initial tuberculosis treatment are at especially high risk of retreatment failure. Strategies to address risk factors for initial treatment default and to identify patients at risk for failure (including expanded use of drug susceptibility testing) are important given suboptimal retreatment outcomes in these groups. © 2011 Dooley et al; licensee BioMed Central Ltd.
Kartoglu U.,World Health Organization |
Ozguler N.K.,Karaman Hayat Medical Center |
Wolfson L.J.,World Health Organization |
Kurzatkowski W.,National Institute of Hygiene
Bulletin of the World Health Organization | Year: 2010
Objective: To determine the validity of the shake test for detecting freeze damage in aluminium-based, adsorbed, freeze-sensitive vaccines. Methods A double-blind crossover design was used to compare the performance of the shake test conducted by trained health-care workers (HCWs) with that of phase contrast microscopy as a "gold standard". A total of 475 vials of 8 different types of World Health Organization prequalified freeze-sensitive vaccines from 10 different manufacturers were used. Vaccines were kept at 5 °C. Selected numbers of vials from each type were then exposed to-25 °C and-2 °C for 24-hour periods. Findings: There was complete concordance between HCWs and phase-contrast microscopy in identifying freeze-damaged vials and non-frozen samples. Non-frozen samples showed a fine-grain structure under phase contrast microscopy, but freeze-damaged samples showed large conglomerates of massed precipitates with amorphous, crystalline, solid and needle-like structures. Particles in the non-frozen samples measured from 1 μm (vaccines against diphtheria-tetanus-pertussis; Haemophilus influenzae type b; hepatitis B; diphtheria-tetanus-pertussis-hepatitis B) to 20 μm (diphtheria and tetanus vaccines, alone or in combination). By contrast, aggregates in the freeze-damaged samples measured up to 700 μm (diphtheria-tetanus-pertussis) and 350 μm on average. Conclusion: The shake test had 100% sensitivity, 100% specificity and 100% positive predictive value in this study, which confirms its validity for detecting freeze damage to aluminium-based freeze-sensitive vaccines.
Rosinska M.,National Institute of Hygiene |
Sieroslawski J.,Institute of Psychiatry and Neurology |
Wiessing L.,European Monitoring Center for Drugs and Drug Addiction
BMC Infectious Diseases | Year: 2015
People who inject drugs (PWID) are an important group at risk of blood borne infections in Poland. However, robust evidence regarding the magnitude of the problem and geographical variation is lacking, while coverage of prevention remains low. We assessed the potential of combining bio-behavioural studies and case-based surveillance of PWID to gain insight into preventive needs in Poland. Methods: Results of a bio-behavioural human immunodeficiency virus (HIV) and hepatitis C virus (HCV) prevalence study among ever injectors in six regions in Poland were compared with HIV case-based surveillance trends from 2000 to 2012. Logistic regression was used for multivariable analyses in the prevalence study. The case surveillance data were correlated with prevalence data, by region, to determine surveillance validity and identify any recent trends. Results: HIV seroprevalence (18% overall) differed more than ten-fold across regions (2.4% to 32%), but HCV seroprevalence and the proportion of PWID sharing needles/syringes in the past 12 months were similar, 44% to 68% and 22% to 29%, respectively. In multivariable models accounting for socio-demographic factors, duration of injecting history and needle sharing practices, regional differences were significant for both HIV and HCV seroprevalence with adjusted odds ratios varying up to a factor of 12.6 for HIV and 3.8 for HCV. The number of new cases of HIV diagnosed in each region during the bio-behavioural study period was strongly correlated (r = 0.93) with HIV prevalence. There was an overall decreasing trend in the number of new diagnoses of HIV over time. However, a transient increase in three regions was preceded by a higher proportion of people with short injecting history (≤5 years) and a high prevalence of HCV coinciding with a low prevalence of HIV in the bio-behavioural study. Conclusions: Bio-behavioural and case-based data were consistent with respect to the regional distribution of HIV and also provided complementary information, with the proportion of new injectors and high HCV prevalence predicting increases in HIV case rates. We identified three regions in Poland that appear to be at increased need for preventive measures. Data point to the need for a stronger investment in harm reduction programmes in Poland. © Rosińska et al.
Grabowski A.,Central Institute for Labour Protection |
Rosinska M.,National Institute of Hygiene
European Physical Journal B | Year: 2012
On the basis of experimental data on interactions between humans we have investigated the process of epidemic spreading in a social network.We found that the distribution of the number of contacts maintained in one day is exponential. Data on frequency and duration of interpersonal interactions are presented. They allow us to simulate the spread of droplet-/-air-borne infections and to investigate the influence of human dynamics on the epidemic spread. Specifically, we investigated the influence of the distribution of frequency and duration of those contacts on magnitude, epidemic threshold and peak timing of epidemics propagating in respective networks. It turns out that a large increase in the magnitude of an epidemic and a decrease in epidemic threshold are visible if and only if both are taken into account. We have found that correlation between contact frequency and duration strongly influences the effectiveness of control measures like mass immunization campaigns. © EDP Sciences, Societá Italiana di Fisica, Springer-Verlag 2012.
Kanobana K.,Institute of Tropical Medicine |
Vereecken K.,Institute of Tropical Medicine |
Junco Diaz R.,National Institute of Hygiene |
Sariego I.,Institute of Tropical Medicine |
And 3 more authors.
Tropical Medicine and International Health | Year: 2013
Introduction: Evidence suggests that human toxocariasis (HT) could stimulate the onset of allergic diseases such as asthma. More specifically, in subjects having a hypothetical 'atopic genotype', HT could boost preexistent allergy symptoms. We tested the latter hypothesis in Cuba, a country where both asthma and HT are prevalent. Material and methods: In a group of Cuban school-aged children (n = 958), we investigated the association of Toxocara seropositivity and atopic status with asthma. Toxocara seropositivity was diagnosed with ELISA and atopy by allergen skin prick test. Both physician-diagnosed asthma and current wheeze, as determined by International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire, were considered. Associations were assessed using multivariable logistic regression analyses, with either 'physician-diagnosed asthma' or 'current wheeze' as outcome variable. Results: 40.1% of the children were Toxocara seropositive. Prevalences were 21.7% for current wheeze and 32.7% for physician-diagnosed asthma. The odds of having asthma were almost two times higher in atopic children, but only reached borderline significance (OR=1.90, CI 95%: 0.95-3.80 for physician-diagnosed asthma and OR=1.94, CI 95%: 0.98-3.85 for current wheeze). Toxocara seropositivity and physician-diagnosed asthma were associated (OR=1.51, CI 95%: 1.01-2.26). Moreover, in children without antibodies to Toxocara, being atopic was significantly associated with having physician-diagnosed asthma (OR=2.53, CI 95%: 1.63-3.90), while this association was not present in Toxocara positives (OR=1.38, CI 95%: 0.82-2.37). Conclusion: Our data confirm previous observations of higher Toxocara seropositivity rates in asthmatic children. Toxocara seropositivity appeared to abrogate the apparent association between atopy and asthma in Cuban children. Although this observation was limited to physician-diagnosed asthma, it challenges the hypothesis that HT stimulates the onset of allergic diseases such as asthma in atopic individuals. © 2013 Blackwell Publishing Ltd.
De Vos P.,Institute of Tropical Medicine |
Garcia-Farinas A.,National Institute of Hygiene |
Alvarez-Perez A.,National Institute of Hygiene |
Rodriguez-Salva A.,National Institute of Hygiene |
And 2 more authors.
Tropical Medicine and International Health | Year: 2012
During the 1990s, Cuba was able to overcome a severe crisis, almost without negative health impacts. This national retrospective study covering the years 1989-2000 analyses the country's strategy through essential social, demographic, health process and health outcome indicators. Gross domestic product (GDP) diminished by 34.76% between 1989 and 1993. In 1994 slow recuperation started. During the crisis, public health expenses increased. The number of family doctors rose from 9.22 to 27.03 per 104 inhabitants between 1989 and 2000. Infant mortality rate and life expectancy exemplify a series of health indicators that continued to improve during the crisis years, whereas low birth weight and tuberculosis incidence are among the few indicators that suffered deterioration. GDP is inversely related to tuberculosis incidence, whereas the average salary is inversely related to low birth weight. Infant mortality rate has a strong negative correlation with the health expenses per inhabitant, the number of maternal homes, the number of family doctors and the proportion of pregnant women receiving care in maternal homes. Life expectancy has a strong positive correlation with health expenses, the number of nursing personnel and the number of medical contacts per inhabitant. The Cuban strategy effectively resolved health risks during the crisis. In times of serious socio-economic constraints, a well conceptualized public health policy can play an important role in maintaining the overall well-being of a population. © 2012 Blackwell Publishing Ltd.
Kosik-Bogacka D.I.,Pomeranian Medical University |
Kalisinska E.,Pomeranian Medical University |
Henszel L.,National Institute of Hygiene |
Kuzna-Grygiel W.,Pomeranian Medical University
Zoonoses and Public Health | Year: 2012
The most common families of mites found in house dust are Pyroglyphidae, Glycyphagidae and Acaridae; all are a source of many antigens responsible for allergic diseases. The aim of this study was to examine the seasonal dynamics of allergenic mite populations in dust samples collected from sleeping places in apartments in north-western Poland. The mites were isolated from the dust using a saturated saline floating method. In 132 dust samples we determined: Dermatophagoides farinae, Dermatophagoides pteronyssinus, Euroglyphus maynei, Hirstia sp., Chortoglyphus arcuatus, Lepidoglyphus destructor, Gohieria fusca and Cheyletus sp. The greatest frequency was observed for D. farinae, D. pteronyssinus, Ch. arcuatus and Cheyletus sp., in the fourth quarter and D. farinae in the third quarter. Smaller coefficients of dominance were found for D. pteronyssinus, Ch. arcuatus and Cheyletus sp., and their greatest mean concentrations were found in the first and fourth quarters. Given the division of the year into heating and non-heating seasons, mites D. farinae and D. pteronyssinus achieved the highest mean concentration in the first season, and Cheyletus sp. in the second season. The analysis of the participation of developmental stages showed that the adults of D. farinae were more prevalent than juveniles in the first, second and third quarters, and imago stages of D. pteronyssinus were more numerous in relation to juveniles in the first, third and fourth quarters. The results confirm the high incidence of house dust mites in sleeping places in north-western Poland dwellings; the best conditions for the development of these mites, mainly D. farinae and D. pteronyssinus, occur in the fourth quarter and are the least favourable in the second quarter. In many cases, these results are consistent with data from other parts of Poland collected by various authors. © 2011 Blackwell Verlag GmbH.