Prospective, observational study to assess the performance of CAA measurement as a diagnostic tool for the detection of Schistosoma haematobium infections in pregnant women and their child in Lambaréné, Gabon: study protocol of the freeBILy clinical trial in Gabon.

BACKGROUND: Schistosoma antigen detection in urine is a valuable diagnostic approach for schistosomiasis control programmes because of the higher sensitivity compared to parasitological methods and preferred sampling of urine over stool. Highly accurate diagnostics are important in low Schistosoma transmission areas. Pregnant women and young children could particularly benefit from antigen testing as praziquantel (PZQ) can be given to only confirmed Schistosoma cases. This prevents the unborn baby from unnecessary exposure to PZQ. We present here the protocol of a diagnostic study that forms part of the freeBILy project. The aim is to evaluate the accuracy of circulating anodic antigen (CAA) detection for diagnosis of Schistosoma haematobium infections in pregnant women and to validate CAA as an endpoint measure for anti-Schistosoma drug efficacy. The study will also investigate Schistosoma infections in infants. METHODS: A set of three interlinked prospective, observational studies is conducted in Gabon. The upconverting phosphor lateral flow (UCP-LF) CAA test is the index diagnostic test that will be evaluated. The core trial, sub-study A, comprehensively evaluates the accuracy of the UCP-LF CAA urine test against a set of other Schistosoma diagnostics in a cross-sectional trial design. Women positive for S. haematobium will proceed with sub-study B and will be randomised to receive PZQ treatment immediately or after delivery followed by weekly sample collection. This approach includes comparative monitoring of CAA levels following PZQ intake and will also contribute further data for safety of PZQ administration during pregnancy. Sub-study C is a longitudinal study to determine the incidence of S. haematobium infection as well as the age for first infection in life-time. DISCUSSION: The freeBILy trial in Gabon will generate a comprehensive set of data on the accuracy of the UCP-LF CAA test for the detection of S. haematobium infection in pregnant women and newborn babies and for the use of CAA as a marker to determine PZQ efficacy. Furthermore, incidence of Schistosoma infection in infants will be reported. Using the ultrasensitive diagnostics, this information will be highly relevant for Schistosoma prevalence monitoring by national control programs as well as for the development of medicaments and vaccines. TRIAL REGISTRATION: The registration number of this study is NCT03779347 ( clinicaltrials.gov , date of registration: 19 December 2018).

Fast and reliable easy-to-use diagnostics for eliminating bilharzia in young children and mothers: An introduction to the freeBILy project.

Schistosoma antigen detection tests have a large potential for schistosomiasis control programs due to their ability to detect active and ongoing Schistosoma infections, their much higher sensitivity compared to microscopical methods, and the possibility to use non-invasive urine samples. Pregnant women and young children could especially benefit from affordable and easy-to-use antigen tests as inclusion of these vulnerable groups in mass drug administration campaigns will always require higher justification hurdles, especially in low to middle endemic regions with a higher proportion of individuals who are not infected and thus unnecessarily exposed to praziquantel. The overall objective of the 'fast and reliable easy-to-use diagnostics for eliminating bilharzia in young children and mothers' (freeBILy, www.freeBILy.eu) project is to thoroughly evaluate the point-of-care circulating cathodic antigen (POC-CCA) and the up-converting phosphor reporter particle, lateral flow circulating anodic antigen (UCP-LF CAA) urine strip tests to diagnose Schistosoma infections in pregnant women and young children and to assess their potential as a schistosomiasis control tool in test-and-treat strategies. The freeBILy project will generate valuable, evidence-based findings on improved tools and test-and-treat strategies to reduce the burden of schistosomiasis in pregnant women and young children.

Evaluation of the multiplex real-time PCR assays RealStar malaria S&T PCR kit 1.0 and FTD malaria differentiation for the differentiation of Plasmodium species in clinical samples.

BACKGROUND: Two commercial PCR assays were assessed in a retrospective study to determine their reliability as tools for the differentiation of Plasmodium species in human blood. METHODS: A total of 1022 blood samples from 817 patients with suspected or confirmed malaria submitted to the German National Reference Centre for Tropical Pathogens were subjected to malaria microscopy using thick and thin blood films as well as to a genus-specific malaria real-time PCR. Parasite-positive samples were analysed by RealStar Malaria S&T PCR Kit 1.0 (altona Diagnostics) and FTD Malaria Differentiation (Fast Track Diagnostics) multiplex real-time PCR assays targeting species-specific Plasmodium DNA. RESULTS: Out of the 1022 blood samples, 247 (24.2%) tested positive for Plasmodium spp. The two multiplex assays showed rather similar performance characteristics and provided concordant species information in 98.9% of samples positive by malaria microscopy and in 95.1% (RealStar) and 96.8% (FTD) of samples positive by genus-specific PCR. Compared to FTD, RealStar revealed slightly reduced sensitivity for submicroscopic, low-level P. falciparum infections, while FTD was unable to detect P. knowlesi. CONCLUSIONS: The two commercial malaria PCR assays assessed are suitable for discriminating Plasmodium species in clinical samples, and can provide additional information in cases of microscopically uncertain findings.

Detection of Tropheryma whipplei in stool samples by one commercial and two in-house real-time PCR assays.

OBJECTIVE: Tropheryma whipplei, the causative agent of Whipple's disease, can also be identified in stool samples of humans without systemic disease. It is much more frequently detected in human stool samples in tropical environments than in industrialized countries. PCR-screening has been applied for point prevalence studies and environmental assessments in tropical settings, but results depend on the applied assay. We compared one commercial qPCR kit with two well-described in-house assays for detection of T. whipplei from stool. METHODS: Residual materials from nucleic acid extractions of stool samples from two groups with presumably different prevalences and increased likelihood of being colonized or infected by T. whipplei were tested. One group comprised 300 samples from study participants from western Africa (group 1); the second group was of 300 returnees from tropical deployments (group 2). Each sample was assessed with all three qPCR assays. Cycle threshold (Ct ) values were descriptively compared. RESULTS: Based solely on mathematical modeling, the three PCR assays showed considerably different detection rates of T. whipplei DNA in stool samples (kappa 0.67 (95% confidence interval [0.60, 0.73])). Considering the calculated test characteristics, prevalence of 28.3% for group 1 and 5.0% for group 2 was estimated. Discordant test results were associated with later Ct values. The study did not validate the assays for the detection of T. whipplei in Whipple's disease and for diagnostic purposes since clinical specificity and sensitivity were not investigated. CONCLUSIONS: In spite of the observed diagnostic uncertainty, PCR-based screening approaches can be used for epidemiological purposes and environmental samples to define the source and reservoir in resource-limited tropical settings if prevalence is calculated using diagnostic accuracy-adjusted methods.

Serological approaches for the diagnosis of schistosomiasis - A review.

Schistosomiasis is a common disease in endemic areas of Sub-Saharan Africa, South America and Asia. It is rare in Europe, mainly imported from endemic countries due to travelling or human migration. Available methods for the diagnosis of schistosomiasis comprise microscopic, molecular and serological approaches, with the latter detecting antigens or antibodies associated with Schistosoma spp. infection. The serological approach is a valuable screening tool in low-endemicity settings and for travel medicine, though the interpretation of any diagnostic results requires knowledge of test characteristics and a patient's history. Specific antibody detection by most currently used assays is only possible in a relatively late stage of infection and does not allow for the differentiation of acute from previous infections for therapeutic control or the discrimination between persisting infection and re-infection. Throughout the last decades, new target antigens have been identified, and assays with improved performance and suitability for use in the field have been developed. For numerous assays, large-scale studies are still required to reliably characterise assay characteristics alone and in association with other available methods for the diagnosis of schistosomiasis. Apart from S. mansoni, S. haematobium and S. japonicum, for which most available tests were developed, other species of Schistosoma that occur less frequently need to be taken into account. This narrative review describes and critically discusses the results of published studies on the evaluation of serological assays that detect antibodies against different Schistosoma species of humans. It provides insights into the diagnostic performance and an overview of available assays and their suitability for large-scale use or individual diagnosis, and thus sets the scene for serological diagnosis of schistosomiasis and the interpretation of results.

Antibiotic resistance and clonal diversity of invasive Staphylococcus aureus in the rural Ashanti Region, Ghana.

BACKGROUND: Staphylococcus aureus is among the most common pathogens isolated from blood cultures in Ghana; yet the epidemiology of blood infections in rural settings is poorly described. This study aims to investigate antimicrobial susceptibility and clonal diversity of S. aureus causing bloodstream infections in two hospitals in the Ashanti Region, Ghana. METHODS: Blood cultures were performed for all febrile patients (≥37.5 °C) on hospital admission. Antibiotic susceptibility testing for S. aureus isolates was carried out by the VITEK 2 system. Multiplex polymerase chain reaction (PCR) was used to detect S. aureus-specific nuc gene, Panton-Valentine leukocidin (PVL), and methicillin-resistant S. aureus (MRSA)-specific mecA and mecC genes. The population structure of S. aureus was assessed by spa typing. RESULTS: In total, 9,834 blood samples were cultured, out of which 0.6% (n = 56) were positive for S. aureus. Multidrug resistance (MDR) was detected in 35.7% (n = 20) of the S. aureus strains, of which one was a MRSA. The highest rate of antibiotic resistance was seen for commonly available antibiotics, including penicillin (n = 55; 98.2%), tetracycline (n = 32; 57.1%) and trimethoprim/sulfamethoxazole (n = 26; 46.4%). Of all S. aureus strains, 75.0% (n = 42) carried the PVL-encoding genes. We found 25 different spa types with t355 (n = 11; 19.6%), t314 (n = 8; 14.3%), t084 (n = 8; 14.3%) and t311 (n = 5; 8.9%) being predominant. CONCLUSION: The study exhibited an alarmingly large level of antibiotic resistance to locally available antibiotics. The frequency of genetically diverse and PVL-positive methicillin-sensitive S. aureus (MSSA) was high and could represent a reservoir for the emergence of virulent PVL-positive MRSA clones.

Influenza A and Parvovirus B19 Seropositivity Rates in Gabonese Infants.

Clinical and epidemiological data from Central Africa on influenza A and parvovirus B19 infections are limited. We analyzed 162 blood samples of infants 3, 9, 15, and 30 months of age for IgG antibodies against both pathogens. Antibody responses were 0, 3.7%, 12.3%, and 20.4% against influenza A; and 1.2%, 2.5%, 3.1%, and 9.3% against parvovirus B19, respectively. Seropositivity rates were 89.5 (95% confidence interval [CI]: 59-120.1) and 38.2 (95% CI: 18.9-57.6)/1,000 person-years at risk for influenza A and parvovirus B19, respectively. Our data add to the understanding of the epidemiology of both conditions.

Molecular epidemiology and seroprevalence in asymptomatic Plasmodium falciparum infections of Malagasy pregnant women in the highlands.

BACKGROUND: Malaria epidemiology in Madagascar is classified into four different areas, ranging from unstable seasonal transmission in the highlands to hyperendemic perennial transmission areas in the costal level. Most malaria studies in Madagascar are focused on symptomatic children. However, because of the low transmission in some areas with correspondingly low level of semi-immunity, adults are also at risk, in particular pregnant women. The objective of this study was to gain information on the genetic epidemiology of malarial infections in pregnant women in order to provide information for malaria control and elimination programmes in Madagascar. METHODS: Between May and August 2010, we carried out cross-sectional surveys targeting healthy pregnant women in six locations, three in the coastal area and three in the highlands at 850-1300 m. 1244 blood samples were screened for anti-Plasmodium falciparum antibodies by immunofluorescence test and for malarial infection by realtime-PCR. The prevalence of chloroquine and sulphadoxine-pyrimethamine resistance markers was also determined in all Plasmodium falciparum samples by PCR-RFLP as well as the multiplicity of infection through genotyping six neutral microsatellites. RESULTS: In the highlands, 67.4% of the women presented antibodies against Plasmodium falciparum and 9.2% were carrying parasites, at the coast 95.6% and 14.8%, respectively. In the mean, 1.2 clones were detected in infected pregnant woman in the highlands and 1.5 at the coast. A higher level of monoclonal infections was found in the highlands (85.4%) compared to the coast (61.8%). Resistance markers for sulphadoxine-pyrimethamine were present only in two sites. CONCLUSION: Immunity is triggered in Malagasy highland populations when they are infected with malaria parasites, but these populations could also serve as a reservoir for epidemics.

PCR for enteric pathogens in high-prevalence settings. What does a positive signal tell us?

BACKGROUND: Molecular methods, in particular PCR, are increasingly used for the diagnosis of enteric pathogens in stool samples. In high-endemicity settings, however, asymptomatic carriage or residual DNA from previous infections will hamper the interpretation of positive test results. We assessed the quantitative dimension of this problem in schoolchildren in the rural highlands of Madagascar. METHODS: Stool samples were collected from 410 apparently healthy Madagascan schoolchildren and analysed by multiplex real-time PCR for enteroinvasive bacteria (Salmonella spp., Shigella spp./enteroinvasive Escherichia coli (EIEC), Campylobacter jejuni, Yersinia spp.), enteric protozoa (Entamoebea histolytica, Giardia duodenalis, Cryptosporidium spp., Cyclospora spp.), and helminths (Ascaris lumbricoides, Ancylostoma spp., Necator americanus, Strongyloides stercoralis). Symptoms of gastrointestinal disease were assessed. RESULTS: Among the 410 samples, we detected Giardia duodenalis in 195, Campylobacter jejuni in 91, Ascaris lumbricoides in 72, Cyclospora cayetanenesis in 68, Shigella spp./EIEC in 56, and Strongyloides stercoralis and Cryptosporum spp. in 1 case each. Salmonella spp., Yersinia spp. and hookworms were not observed. Relative risk assessment suggested few and incoherent associations with pathogen detections, indicating asymptomatic carriage or DNA residuals. Only 26.1% of the schoolchildren were tested negative for all analysed pathogens. CONCLUSIONS: The very high risk of detecting traces of asymptomatic carriage or residual DNA from previous infections limits the value of highly sensitive PCR for the causal attribution of detected enteric pathogens from stool samples to an infectious gastrointestinal disease in the high-endemicity setting. Evaluated standards for the interpretation of such results are needed both for the diagnostic routine and for epidemiological assessments.

Schistosoma mansoni in schoolchildren in a Madagascan highland school assessed by PCR and sedimentation microscopy and Bayesian estimation of sensitivities and specificities.

Madagascar is an endemic area for schistosomiasis, but recent prevalence data are scarce. We investigated stool samples of 410 children aged 4-18 years from a combined primary and secondary school in a Madagascan highland village near Ambositra in order to assess the prevalence of Schistosoma mansoni using microscopy and real-time polymerase chain reaction (PCR). A high prevalence of S. mansoni of 77.1% was detected by PCR, while only 15.2% of microscopic examinations of sedimentation-enriched stools were positive. We estimated the sensitivity and specificity of stool sedimentation microscopy (19.7% and 98.8%) and of PCR (98.9% and 89.3%) using a Bayesian approach for two dependant tests in one population without a reference standard. Our Bayesian posterior estimate of the prevalence is 80.2%. Simple sedimentation technique misses about 4/5 of all PCR-confirmed infections and is insufficient to determine the prevalence of S. mansoni. A survey comparing PCR with a classical standard technique (KatoKatz) is desirable.

Influence of parasite density and sample storage time on the reliability of Entamoeba histolytica-specific PCR from formalin-fixed and paraffin-embedded tissues.

We report on the reliability of polymerase chain reaction (PCR) for the detection of Entamoeba histolytica from formalin-fixed, paraffin-embedded tissue in comparison with microscopy and have determined predictors that may influence PCR results. E. histolytica-specific and Entamoeba dispar-specific real-time PCR and microscopy from adjacent histologic sections were performed using a collection of formalin-fixed, paraffin-embedded tissue specimens obtained from patients with invasive amebiasis. Specimens had been collected during the previous 4 decades. Association of sample age, parasite density, and reliability of PCR was analyzed. E. histolytica PCR was positive in 20 of 34 biopsies (58.8%); 2 of these 20 were microscopically negative for amebae in neighboring tissue sections. PCR was negative in 9 samples with visible amebae in neighboring sections and in 5 samples without visible parasites in neighboring sections. PCR was negative in all specimens that were older than 3 decades. Low parasite counts and sample ages older than 20 years were predictors for false-negative PCR results. All samples were negative for E. dispar DNA. PCR is suitable for the detection of E. histolytica in formalin-fixed, paraffin-embedded tissue samples that are younger than 2 decades and that contain intermediate to high parasite numbers. Negative results in older samples were due to progressive degradation of DNA over time as indicated by control PCRs targeting the human 18S rRNA gene. Moreover, our findings support previous suggestions that only E. histolytica but not E. dispar is responsible for invasive amebiasis.

Food and drinking water hygiene and intestinal protozoa in deployed German soldiers.

This report analyzes the occurrence of Cryptosporidium spp., E. histolytica, and G. intestinalis in stool of returnees from military deployments and the impact of hygiene precautions. Between 2007 and 2010, stool samples of 830 returnees that were obtained 8-12 weeks after military deployments in Afghanistan, Uzbekistan, the Balkans, Democratic Republic of the Congo/Gabonese Republic, and Sudan and 292 control samples from non-deployed soldiers were analyzed by PCR for Cryptosporidium spp., E. histolytica, G. intestinalis, and the commensal indicator of fecal contamination E. dispar. Data on hygiene precautions were available. The soldiers were questioned regarding gastrointestinal and general symptoms. Among 1122 stool samples, 18 were positive for G. intestinalis, 10 for E. dispar, and no-one for Cryptosporidium spp. and E. histolytica. An increased risk of acquiring chronic parasitic infections in comparison with non-deployed controls was demonstrated only for G. intestinalis in Sudan, where standardized food and drinking water hygiene precautions could not be implemented. Standard food and drinking water hygiene precautions in the context of screened military field camps proved to be highly reliable in preventing food-borne and water-borne chronic infections and colonization by intestinal protozoa, leading to detection proportions similar to those in non-deployed controls.

Fluorescence in situ hybridization (FISH) for rapid identification of Salmonella spp. from agar and blood culture broth--an option for the tropics?

BACKGROUND: Salmonella enterica is an important cause of diarrhea with the potential to cause systemic infection including sepsis, particularly in the tropics. Sepsis in particular requires quick and reliable identification to allow a rapid optimization of antibiotic therapy. We describe the establishment and evaluation of fluorescence in situ hybridization (FISH) as a rapid and easy-to-perform molecular identification procedure from agar and blood culture broths. METHODS: Two newly developed FISH probes with specificity for Salmonella spp. were evaluated with 10 reference strains, 448 clinical isolates of Gram-negative bacteria from Germany and Ghana including 316 Salmonella spp. strains, and 39 environmental Salmonella spp. isolates from rivers and streams in Ghana. One FISH probe was further tested with 207 pre-incubated blood culture broths from Germany with Gram-negative rod-shaped bacteria in Gram stain. RESULTS: Evaluation of the newly designed FISH probes demonstrated sensitivity of 99.2% and specificity of 98.4% for clinical isolates, sensitivity of 97.4% for environmental Salmonella spp. isolates, and sensitivity of 100% and specificity of 99.5% for blood culture materials. CONCLUSIONS: FISH proved to be highly reliable for a rapid identification of Salmonella spp. directly from pre-incubated blood culture broths as well as after growth on agar. The inexpensive and easy-to-perform procedure is particularly suitable for resource-limited areas where more sophisticated procedures are not available.

Increased detection of invasive enteropathogenic bacteria in pre-incubated blood culture materials by real-time PCR in comparison with automated incubation in Sub-Saharan Africa.

BACKGROUND: Invasive enteropathogenic bacteria can cause systemic infections. Data from studies with PCR detection suggest, at least for Salmonella enterica, that blood culture may lead to underestimation in the tropics. Corresponding data are lacking for other invasive enteropathogenic bacteria. We compared classical blood culture and molecular methods for the diagnosis of blood infections. METHODS: A real-time multiplex PCR for Salmonella spp., Shigella spp./entero- invasive Escherichia coli (EIEC), Yersinia spp., and Campylobacter jejuni was applied to 2321 retained blood culture samples from Ghanaian patients, after enrichment by automated culture. RESULTS: PCR detected Salmonella DNA in 56 out of 58 pre-incubated Ghanaian blood cultures with growth of S. enterica. In 2 samples molecular diagnosis was only possible after 1:10 dilution. Twenty-two samples negative by blood culture and 1 positive with Micrococcus spp. were PCR-positive for Salmonella spp. In addition, 3 Shigella spp./EIEC, 2 Yersinia spp., and 1 C. jejuni were detected by PCR but not by culture growth. CONCLUSIONS: Real-time PCR was more sensitive in identifying invasive enteropathogenic bacteria than automated blood culture, which is hampered by a lack of evidence-based standardization of pre-analytic conditions in the tropics. Primary agar culture and Gram-staining prior to automated blood culture is advisable in cases where transportation times are long.

Serological survey of HIV and syphilis in pregnant women in Madagascar.

OBJECTIVES: Peripartal transmission of human immunodeficiency virus (HIV) and Treponema pallidum, the causative agent of syphilis, leads to severe consequences for newborns. Preventive measures require awareness of the maternal infection. Although HIV and syphilis testing in Madagascar could be theoretically carried out within the framework of the national pregnancy follow-up scheme, the required test kits are rarely available at peripheral health centres. In this study, we screened blood samples of pregnant Madagascan women for HIV and syphilis seroprevalence to estimate the demand for systemic screening in pregnancy. METHODS: Retrospective anonymous serological analysis for HIV and syphilis was performed in plasma samples from 1232 pregnant women that were taken between May and July 2010 in Ambositra, Ifanadiana, Manakara, Mananjary, Moramanga and Tsiroanomandidy (Madagascar) during pregnancy follow-up. Screening was based on Treponema pallidum haemagglutination tests for syphilis and rapid tests for HIV, with confirmation of positive screening results on line assays. RESULTS: Out of 1232 pregnant women, none were seropositive for HIV and 37 (3%) were seropositive for Treponema pallidum. CONCLUSIONS: Our findings are in line with previous studies that describe considerable syphilis prevalence in the rural Madagascan population. The results suggest a need for screening to prevent peripartal Treponema pallidum transmission, while HIV is still rare. If they are known, Treponema pallidum infections can be easily, safely and inexpensively treated even in pregnancy to reduce the risk of transmission.

Seroprevalence of antibodies against Chikungunya, Dengue, and Rift Valley fever viruses after febrile illness outbreak, Madagascar.

In October 2009, two-3 months after an outbreak of a febrile disease with joint pain on the eastern coast of Madagascar, we assessed serologic markers for chikungunya virus (CHIKV), dengue virus (DENV), and Rift Valley fever virus (RVFV) in 1,244 pregnant women at 6 locations. In 2 eastern coast towns, IgG seroprevalence against CHIKV was 45% and 23%; IgM seroprevalence was 28% and 5%. IgG seroprevalence against DENV was 17% and 11%. No anti-DENV IgM was detected. At 4 locations, 450-1,300 m high, IgG seroprevalence against CHIKV was 0%-3%, suggesting CHIKV had not spread to higher inland-altitudes. Four women had IgG against RVFV, probably antibodies from a 2008 epidemic. Most (78%) women from coastal locations with CHIKV-specific IgG reported joint pain and stiffness; 21% reported no symptoms. CHIKV infection was significantly associated with high bodyweight. The outbreak was an isolated CHIKV epidemic without relevant DENV co-transmission.

ABO blood group and the risk of placental malaria in sub-Saharan Africa.

BACKGROUND: In malarious areas of the world, a higher proportion of the population has blood group O than in non-malarious areas. This is probably due to a survival advantage conferred either by an attenuating effect on the course of or reduction in the risk of infection by plasmodial parasites. Here, the association between ABO blood group and incidence of placental malaria was assessed in order to determine the possible influence of the former on the latter. METHODS: Data from a study in Lambaréné, Gabon, and data from three previously published reports of studies in The Gambia, Malawi and Sudan, were compiled and compared. ABO blood groups were cross-tabulated with placental malaria stratified by parity. Odds ratios (OR), stratified by parity, were calculated for the outcome, placental parasitaemia, and compared between blood group O vs. non-O mothers in all four studies. Random effects meta-analysis of data from individual studies from areas with perennial hyper/holoendemic transmission was performed. RESULTS: In Gabon, the odds ratio (OR) for active placental parasitaemia in mothers with group O was 0.3 (95% CI 0.05-1.8) for primiparae and 0.7 (95% CI 0.3-1.8) for multiparae. The OR for primiparae in the published study from The Gambia was 3.0 (95% CI 1.2-7.3) and, in Malawi, 2.2 (95% CI 1.1-4.3). In the Sudanese study, no OR for primiparae could be calculated. The OR for placental parasitaemia in group O multiparae was 0.8 (95% CI 0.3-1.7) in the Gambia, 0.6 (95% CI 0.4-1.0) in Malawi and 0.4 (95% CI 0.1-1.8) in Sudan. Combining data from the three studies conducted in hyper-/holo-endemic settings (Gambia, Malawi, Gabon) the OR for placental malaria in blood group O multiparae was 0.65 (95% CI 0.44-0.96) and for primiparae 1.70 (95% CI 0.67-4.33). CONCLUSION: Studies conducted in The Gambia and Malawi suggest that blood group O confers a higher risk of active placental infection in primiparae, but a significantly lower risk in multiparae. These findings were not confirmed by the study from Gabon, in which statistically non-significant trends for reduced risk of placental parasitaemia in those with blood group O, regardless of parity, were observed.

Systemic bacteraemia in children presenting with clinical pneumonia and the impact of non-typhoid salmonella (NTS).

BACKGROUND: The diagnosis and antimicrobial treatment of pneumonia in African children in the absence of diagnostic means such as x-ray facilities or microbiological laboratories relies primarily on clinical symptoms presented by the patients. In order to assess the spectrum of bacterial pathogens, blood cultures were performed in children fulfilling the clinical criteria of pneumonia. METHODS: In total, 1032 blood cultures were taken from children between 2 months and 5 years of age who were admitted to a rural hospital in Ghana between September 2007 and July 2009. Pneumonia was diagnosed clinically and according to WHO criteria classified as "non-severe pneumonia" and "severe pneumonia" ("severe pneumonia" includes the WHO categories "severe pneumonia" and "very severe pneumonia"). RESULTS: The proportion of bacteriaemia with non-typhoid salmonella (NTS) was similar in children with pneumonia (16/173, 9.2%) compared to children hospitalized for other reasons (112/859, 13%). NTS were the predominant organisms isolated from children with clinical pneumonia and significantly more frequent than Streptococcus pneumoniae (8/173, 4.6%). Nine percent (9/101) of children presenting with severe pneumonia and 10% (7/72) of children with non-severe pneumonia were infected with NTS. Nineteen out of 123 NTS isolates (15%) were susceptible to aminopenicillins (amoxycillin/ampicillin), 23/127 (18%) to chlorampenicol, and 23/98 (23%) to co-trimoxazole. All NTS isolates were sensitive to ceftriaxone and ciprofloxacin. CONCLUSION: In Sub-saharan Africa, sepsis with NTS should be considered in children with symptoms of pneumonia and aminopenicillins might often not be the adequate drugs for treatment.

Mumps outbreak in the Republic of Moldova, 2007-2008.

BACKGROUND: Moldova experienced a nationwide mumps outbreak between 2007 and 2008. Single-dose monovalent mumps vaccination at 15 to 18 months was introduced in 1983, replaced by a 2-dose MMR schedule at age 1 and 6 to 7 years in 2002. We investigated the outbreak to quantify its extent, explore the role of primary and secondary vaccine failure, and provide control recommendations. METHODS: We analyzed national mumps surveillance and vaccination coverage data to estimate vaccine effectiveness (VE) using the screening method. A retrospective cohort study in 5 educational institutions was conducted to determine age-specific attack rates (ARs) and VE. We compared vaccine strain-specific ARs. Isolation and genotyping of mumps virus strains were performed. RESULTS: Of 31,142 cases reported during October 2007 and July 2008, 80% were in 15- to 24-year-olds. Of cases with information (66%), 92% were vaccinated once, 4% twice. One-dose mumps VE estimates based on surveillance data over 1997-2001 declined from 91% (95% CI: 88%-92%) in 2-year-olds to 72% (70%-74%) in 15- to 19-year-olds. In the cohort study (n = 1589), VE was -40% (-120% to 20%) for 1 dose. For 2 doses it was 62% (-43% to 90%) in 13- to 15-year-olds. ARs were higher in individuals vaccinated with Urabe strains (43%) than with Leningrad-Zagreb strains (14%, P < 0.001). Mumps virus genotype G5 was identified. CONCLUSIONS: Low effectiveness of single-dose mumps vaccination was the main cause of the outbreak. Waning immunity may have contributed to this. The risk of mumps in 2-dose vaccinees was low. Other countries in which large population groups have received <2 doses of mumps vaccine may face similar outbreaks.