ABSTRACT
BACKGROUND: Lack of dependable morbidity and mortality data complicates efforts to measure the demographic or population-level impact of the global HIV/AIDS epidemic. Mortuary-based mortality surveillance can address gaps in vital statistics in low-resource settings by improving accuracy of measuring HIV-associated mortality and indicators of access to treatment services among decedents. This paper describes the process and considerations taken in conducting mortuary and hospital-based HIV mortality surveillance among decedents in Kenya. MAIN TEXT: We conducted HIV mortuary and hospital-based mortality surveillance at two of the largest mortuaries in Kisumu County, Kenya (April 16-July 12, 2019). Medical charts were reviewed for documentation of HIV status among eligible decedents. HIV testing was done on blood and oral fluid samples from decedents with undocumented HIV status and those whose medical records indicated HIV-negative test results > 3 months before death. A panel of experts established the cause of death according to the International Classification of Diseases, 10th Revision rules. Civil registry data for the year 2017 were abstracted and coded to corresponding ICD-10 codes. Of the 1004 decedents admitted to the two mortuaries during the study period, 49 (4.9%) were unavailable because they had been transferred to other facilities or dispatched for burial before enrolment. Of the 955 available decedents, 104 (10.9%) were ineligible for the study. Blood samples were collected from 659 (77.4%) decedents, and 654 (99.2%) were tested for HIV. Of the 564 decedents eligible for the OraQuick® validation sub-study, 154 were eligible for oral sample collection, and 132 (85.7%) matched pre- and post-embalming oral samples were collected and tested. Of the 851 eligible decedents, 241 (28.3%) had evidence of HIV infection: 119 had a diagnosis of HIV infection recorded in their patient files, and 122 had serological evidence of HIV infection. CONCLUSION: This study shows that in low-resource settings, conducting hospital and mortuary-based surveillance is feasible and can be an alternative source of mortality data when civil registry data are inadequate.
Subject(s)
Acquired Immunodeficiency Syndrome , HIV Infections , HIV Infections/epidemiology , Hospital Mortality , Hospitals , Humans , Kenya/epidemiologyABSTRACT
BACKGROUND: Pneumococci are spread by persons with nasopharyngeal colonization, a necessary precursor to invasive disease. Pneumococcal conjugate vaccines can prevent colonization with vaccine serotype strains. In 2011, Kenya became one of the first African countries to introduce the 10-valent pneumococcal conjugate vaccine (PCV10) into its national immunization program. Serial cross-sectional colonization surveys were conducted to assess baseline pneumococcal colonization, antibiotic resistance patterns, and factors associated with resistance. METHODS: Annual surveys were conducted in one urban and one rural site during 2009 and 2010 among children aged <5 years. To reflect differences in vaccine target population, recruitment was age-stratified in Kibera, whereas a simple random sample of children was drawn in Lwak. Nasopharyngeal swabs were collected from eligible children. Pneumococci were isolated and serotyped. Antibiotic susceptibility testing was performed using the 2009 isolates. Antibiotic nonsusceptibility was defined as intermediate susceptibility or resistance to ≥1 antibiotics (i.e., penicillin, chloramphenicol, levofloxacin, erythromycin, tetracycline, cotrimoxazole, and clindamycin); multidrug resistance (MDR) was defined as nonsusceptibility to ≥3 antibiotics. Weighted analysis was conducted when appropriate. Modified Poisson regression was used to calculate factors associated with antibiotic nonsusceptibility. RESULTS: Of 1,087 enrolled (Kibera: 740, Lwak: 347), 90.0% of these were colonized with pneumococci, and 37.3% were colonized with PCV10 serotypes. There were no differences by survey site or year. Of 657 (of 730; 90%) isolates tested for antibiotic susceptibility, nonsusceptibility to cotrimoxazole and penicillin was found in 98.6 and 81.9% of isolates, respectively. MDR was found in 15.9% of isolates and most often involved nonsusceptibility to cotrimoxazole and penicillin; 40.4% of MDR isolates were PCV10 serotypes. In the multivariable model, PCV10 serotypes were independently associated with penicillin nonsusceptibility (Prevalence Ratio: 1.2, 95% CI 1.1-1.3), but not with MDR. CONCLUSIONS: Before PCV10 introduction, nearly all Kenyan children aged <5 years were colonized with pneumococci, and PCV10 serotype colonization was common. PCV10 serotypes were associated with penicillin nonsusceptibility. Given that colonization with PCV10 serotypes is associated with greater risk for invasive disease than colonization with other serotypes, successful PCV10 introduction in Kenya is likely to have a substantial impact in reducing vaccine-type pneumococcal disease and drug-resistant pneumococcal infection.
Subject(s)
Anti-Bacterial Agents/pharmacology , Pneumococcal Infections/microbiology , Streptococcus pneumoniae/drug effects , Child, Preschool , Cross-Sectional Studies , Drug Resistance, Bacterial/drug effects , Female , Humans , Immunization Programs , Infant , Kenya , Male , Microbial Sensitivity Tests , Nasopharynx/microbiology , Pneumococcal Infections/epidemiology , Pneumococcal Vaccines/therapeutic use , Rural Population , Serogroup , Streptococcus pneumoniae/isolation & purification , Surveys and Questionnaires , Urban PopulationABSTRACT
BACKGROUND: Streptococcus pneumoniae is a leading cause of pneumonia, meningitis and sepsis in developing countries, particularly among children and HIV-infected persons. Pneumococcal oropharyngeal (OP) or nasopharyngeal (NP) colonization is a precursor to development of invasive disease. New conjugate vaccines hold promise for reducing colonization and disease. METHODS: Prior to introduction of 10-valent pneumococcal conjugate vaccine (PCV10), we conducted a cross-sectional survey among HIV-infected parents of children <5 years old in rural Kenya. Other parents living with an HIV-infected adult were also enrolled. After broth enrichment, NP and OP swabs were cultured for pneumococcus. Serotypes were identified by Quellung. Antimicrobial susceptibility was performed using broth microdilution. RESULTS: We enrolled 973 parents; 549 (56.4%) were HIV-infected, 153 (15.7%) were HIV-uninfected and 271 (27.9%) had unknown HIV status. Among HIV-infected parents, the median age was 32 years (range 15-74) and 374/549 (68%) were mothers. Pneumococci were isolated from 237/549 (43.2%) HIV-infected parents and 41/153 (26.8%) HIV-non-infected parents (p = 0.0003). Colonization with PCV10 serotypes was not significantly more frequent in HIV-infected (12.9%) than HIV-uninfected parents (11.8%; p = 0.70). Among HIV-infected parents, cooking site separate from sleeping area and CD4 count >250 were protective (OR = 0.6; 95% CI 0.4, 0.9 and OR = 0.5; 95% CI 0.2, 0.9, respectively); other associations were not identified. Among 309 isolates tested from all parents, 255 (80.4%) were penicillin non-susceptible (MIC ≥0.12 µg/ml). CONCLUSIONS: Prevalence of pneumococcal colonization is high among HIV-infected parents in rural Kenya. If young children are the pneumococcal reservoir for this population, PCV10 introduction may reduce vaccine-type colonization and disease among HIV-infected parents through indirect protection.
Subject(s)
HIV Infections/complications , Pneumococcal Infections/microbiology , Pneumococcal Vaccines/administration & dosage , Streptococcus pneumoniae/growth & development , Adolescent , Adult , Aged , Child , Child, Preschool , Cross-Sectional Studies , Female , HIV Infections/epidemiology , Humans , Infant , Kenya/epidemiology , Male , Middle Aged , Nasopharynx/immunology , Pneumococcal Infections/epidemiology , Pneumococcal Infections/etiology , Pneumococcal Infections/prevention & control , Pneumococcal Vaccines/immunology , Pneumonia/immunology , Prevalence , Rural Population , Serogroup , Streptococcus pneumoniae/immunology , Young AdultABSTRACT
BACKGROUND: The epidemiology and burden of influenza remain poorly defined in sub-Saharan Africa. Since 2005, the Kenya Medical Research Institute and Centers for Disease Control and Prevention-Kenya have conducted population-based infectious disease surveillance in Kibera, an urban informal settlement in Nairobi, and in Lwak, a rural community in western Kenya. METHODS: Nasopharyngeal and oropharyngeal swab specimens were obtained from patients who attended the study clinic and had acute lower respiratory tract (LRT) illness. Specimens were tested for influenza virus by real-time reverse-transcription polymerase chain reaction. We adjusted the incidence of influenza-associated acute LRT illness to account for patients with acute LRT illness who attended the clinic but were not sampled. RESULTS: From March 2007 through February 2010, 4140 cases of acute LRT illness were evaluated in Kibera, and specimens were collected from 1197 (27%); 319 (27%) were positive for influenza virus. In Lwak, there were 6733 cases of acute LRT illness, and specimens were collected from 1641 (24%); 359 (22%) were positive for influenza virus. The crude and adjusted rates of medically attended influenza-associated acute LRT illness were 6.9 and 13.6 cases per 1000 person-years, respectively, in Kibera, and 5.6 and 23.0 cases per 1000 person-years, respectively, in Lwak. In both sites, rates of influenza-associated acute LRT illness were highest among children <2 years old and lowest among adults ≥50 years old. CONCLUSION: In Kenya, the incidence of influenza-associated acute LRT illness was high in both rural and urban settings, particularly among the most vulnerable age groups.
Subject(s)
Influenza, Human/epidemiology , Influenza, Human/virology , Pneumonia, Viral/epidemiology , Pneumonia, Viral/virology , Adolescent , Adult , Aged , Child , Child, Preschool , Female , Humans , Incidence , Infant , Infant, Newborn , Kenya/epidemiology , Male , Middle Aged , Nasopharynx/virology , Oropharynx/virology , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , Rural Population , Seasons , Young AdultABSTRACT
To determine previous exposure and incidence of rickettsial infections in western Kenya during 2007-2010, we conducted hospital-based surveillance. Antibodies against rickettsiae were detected in 57.4% of previously collected serum samples. In a 2008-2010 prospective study, Rickettsia felis DNA was 2.2× more likely to be detected in febrile than in afebrile persons.
Subject(s)
Fever/epidemiology , Rickettsia Infections/epidemiology , Rickettsia felis/isolation & purification , Adolescent , Adult , Antibodies, Bacterial/blood , Bacterial Proteins/genetics , Case-Control Studies , Child , Child, Preschool , Female , Fever/blood , Fever/immunology , Fever/microbiology , Humans , Incidence , Infant , Kenya/epidemiology , Male , Middle Aged , Molecular Typing , Rickettsia Infections/blood , Rickettsia Infections/immunology , Rickettsia Infections/microbiology , Rickettsia felis/genetics , Sequence Analysis, DNA , Seroepidemiologic Studies , Young AdultABSTRACT
As dolutegravir (DTG)-containing HIV regimens are scaled up globally, monitoring for HIV drug resistance (HIVDR) will become increasingly important. We designed a partially multiplexed HIVDR assay using Sanger sequencing technology to monitor HIVDR mutations in the protease, reverse-transcriptase (PRRT), and integrase (INT). A total of 213 clinical and analytical plasma and dried blood spot (DBS) samples were used in the evaluation. The assay detected a wide range of known HIV-1 subtypes and circulating recombinant forms (CRFs) of group M from 139 samples. INT accuracy showed that the average nucleotide (nt) sequence concordance was 99.8% for 75 plasma samples and 99.5% for 11 DBS samples compared with the reference sequences. The PRRT accuracy also demonstrated the average nucleotide sequence concordance was 99.5% for 57 plasma samples and 99.2% for 33 DBS samples. The major PRRT and INT DR mutations of all samples tested were concordant with those of the reference sequences using the Stanford HIV database (db). Amplification sensitivity of samples with viral load (VL) >5000 copies/mL showed plasma exceeded 95% of positivity, and DBS exceeded 90% for PRRT and INT. Samples with VL (1000 to 5000 copies/mL) showed plasma exceeded 90%, and DBS reached 88% positivity for PRRT and INT. Assay precision and reproducibility showed >99% nucleotide sequence concordance in each set of replicates for PRRT and INT. In conclusion, this HIVDR assay met WHO HIVDR assay performance criteria for surveillance, worked for plasma and DBS, used minimal sample volume, was sensitive, and was a potentially cost-effective tool to monitor HIVDR mutations in PRRT and INT. IMPORTANCE This HIVDR genotyping assay works for both plasma and DBS samples, requires low sample input, and is sensitive. This assay has the potential to be a user-friendly and cost-effective HIVDR assay because of its partially multiplexed design. Application of this genotyping assay will help HIVDR monitoring in HIV high-burdened countries using a DGT-based HIV drug regimen recommended by the U.S. President's Emergency Plan for AIDS Relief and the WHO.
Subject(s)
Anti-HIV Agents , Drug Resistance, Viral , HIV Infections , HIV-1 , Anti-HIV Agents/therapeutic use , DNA-Directed RNA Polymerases , Drug Resistance, Viral/genetics , Genotype , HIV Infections/drug therapy , HIV-1/genetics , Humans , Integrases/genetics , Mutation , Peptide Hydrolases/genetics , RNA-Directed DNA Polymerase/genetics , Reproducibility of Results , Viral LoadABSTRACT
Background: Since 2010, Kenya has used SLIPTA to prepare and improve quality management systems in medical laboratories to achieve ISO 15189 accreditation. However, less than 10% of enrolled laboratories had done so in the initial seven years of SLMTA implementation. Objective: We described Kenya's experience in accelerating medical laboratories on SLMTA to attain ISO 15189 accreditation. Methods: From March 2017 to July 2017, an aggressive top-down approach through high-level management stakeholder engagement for buy-in, needs-based expedited SLIPTA mentorship and on-site support as a rapid results initiative (RRI) was implemented in 39 laboratories whose quality improvement process had stagnated for 2-7 years. In July 2017, SLIPTA baseline and exit audit average scores on quality essential elements were compared to assess performance. Results: After RRI, laboratories achieving greater than a 2-star SLMTA rating increased significantly from 15 (38%) at baseline to 33 (85%) (p < 0.001). Overall, 34/39 (87%) laboratories received ISO 15189 accreditation within two years of RRI, leading to a 330% increase in the number of accredited laboratories in Kenya. The most improved of the 12 quality system essentials were Equipment Management (mean increase 95% CI: 5.31 ± 1.89) and Facilities and Biosafety (mean increase [95% CI: 4.05 ± 1.78]) (both: p < 0.0001). Information Management and Corrective Action Management remained the most challenging to improve, despite RRI interventions. Conclusion: High-level advocacy and targeted mentorship through RRI dramatically improved laboratory accreditation in Kenya. Similar approaches of strengthening SLIPTA implementation could improve SLMTA outcomes in other countries with similar challenges.
ABSTRACT
BACKGROUND: Estimating cause-related mortality among the dead is not common, yet for clinical and public health purposes, a lot can be learnt from the dead. HIV/AIDS accounted for the third most frequent cause of deaths in Kenya; 39.7 deaths per 100,000 population in 2019. OraQuick Rapid HIV-1/2 has previously been validated on oral fluid and implemented as a screening assay for HIV self-testing in Kenya among living subjects. We assessed the feasibility and diagnostic accuracy of OraQuick Rapid HIV-1/2 for HIV screening among decedents. METHODS: Trained morticians collected oral fluid from 132 preembalmed and postembalmed decedents aged >18 months at Jaramogi Oginga Odinga Teaching and Referral Hospital mortuary in western Kenya and tested for HIV using OraQuick Rapid HIV-1/2. Test results were compared with those obtained using the national HIV Testing Services algorithm on matched preembalming whole blood specimens as a gold standard (Determine HIV and First Response HIV 1-2-O). We calculated positive predictive values, negative predictive values, area under the curve, and sensitivity and specificity of OraQuick Rapid HIV-1/2 compared with the national HTS algorithm. RESULTS: OraQuick Rapid HIV-1/2 had similar sensitivity of 92.6% [95% confidence interval (CI): 75.7 to 99.1] on preembalmed and postembalmed samples compared with the gold standard. Specificity was 97.1% (95% CI: 91.9 to 99.4) and 95.2% (95% CI: 89.2 to 98.4) preembalming and postembalming, respectively. Preembalming and postembalming positive predictive value was 89.3% (95% CI: 71.8 to 97.7) and 83.3% (95% CI: 65.3 to 94.4), respectively. The area under the curve preembalming and postembalming was 94.9% (95% CI: 89.6 to 100) and 93.9% (95% CI: 88.5 to 99.4), respectively. CONCLUSIONS: The study showed a relatively high-performance sensitivity and specificity of OraQuick Rapid HIV-1/2 test among decedents, similar to those observed among living subjects. OraQuick Rapid HIV-1/2 presents a convenient and less invasive screening test for surveillance of HIV among decedents within a mortuary setting.
Subject(s)
HIV Infections , HIV-1 , HIV Antibodies , HIV Infections/diagnosis , Humans , Infant , Kenya/epidemiology , Reagent Kits, Diagnostic , Sensitivity and SpecificityABSTRACT
BACKGROUND: Accurate data on HIV-related mortality are necessary to evaluate the impact of HIV interventions. In low- and middle-income countries (LMIC), mortality data obtained through civil registration are often of poor quality. Though not commonly conducted, mortuary surveillance is a potential complementary source of data on HIV-associated mortality. METHODS: During April-July 2019, we assessed HIV prevalence, the attributable fraction among the exposed, and the population attributable fraction among decedents received by two high-volume mortuaries in Kisumu County, Kenya, where HIV prevalence in the adult population was estimated at 18% in 2019 with high ART coverage (76%). Stillbirths were excluded. The two mortuaries receive 70% of deaths notified to the Kisumu East civil death registry; this registry captures 45% of deaths notified in Kisumu County. We conducted hospital chart reviews to determine the HIV status of decedents. Decedents without documented HIV status, including those dead on arrival, were tested using HIV antibody tests or polymerase chain reaction (PCR) consistent with national HIV testing guidelines. Decedents aged less than 15 years were defined as children. We estimated annual county deaths by applying weights that incorporated the study period, coverage of deaths, and mortality rates observed in the study. RESULTS: The two mortuaries received a total of 1,004 decedents during the study period, of which 95.1% (955/1004) were available for study; 89.1% (851/955) of available decedents were enrolled of whom 99.4% (846/851) had their HIV status available from medical records and post-mortem testing. The overall population-based, age- and sex-adjusted mortality rate was 12.4 per 1,000 population. The unadjusted HIV prevalence among decedents was 28.5% (95% confidence interval (CI): 25.5-31.6). The age- and sex-adjusted mortality rate in the HIV-infected population (40.7/1000 population) was four times higher than in the HIV-uninfected population (10.2/1000 population). Overall, the attributable fraction among the HIV-exposed was 0.71 (95% CI: 0.66-0.76) while the HIV population attributable fraction was 0.17 (95% CI: 0.14-0.20). In children the attributable fraction among the exposed and population attributable fraction were 0.92 (95% CI: 0.89-0.94) and 0.11 (95% CI: 0.08-0.15), respectively. CONCLUSIONS: Over one quarter (28.5%) of decedents received by high-volume mortuaries in western Kenya were HIV-positive; overall, HIV was considered the cause of death in 17% of the population (19% of adults and 11% of children). Despite substantial scale-up of HIV services, HIV disease remains a leading cause of death in western Kenya. Despite progress, increased efforts remain necessary to prevent and treat HIV infection and disease.
Subject(s)
HIV Infections/epidemiology , HIV Infections/mortality , Morgue/statistics & numerical data , Adolescent , Adult , Autopsy , Cause of Death , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Kenya/epidemiology , Male , Middle Aged , Population Surveillance , Young AdultABSTRACT
BACKGROUND: HIV-1 incidence calculation currently includes recency classification by HIV-1 incidence assay and unsuppressed viral load (VL ≥ 1000 copies/mL) in a recent infection testing algorithm (RITA). However, persons with recent classification not virally suppressed and taking antiretroviral (ARV) medication may be misclassified. SETTING: We used data from 13 African household surveys to describe the impact of an ARV-adjusted RITA on HIV-1 incidence estimates. METHODS: HIV-seropositive samples were tested for recency using the HIV-1 Limiting Antigen (LAg)-Avidity enzyme immunoassay, HIV-1 viral load, ARVs used in each country, and ARV drug resistance. LAg-recent result was defined as normalized optical density values ≤1.5. We compared HIV-1 incidence estimates using 2 RITA: RITA1: LAg-recent + VL ≥ 1000 copies/mL and RITA2: RITA1 + undetectable ARV. We explored RITA2 with self-reported ARV use and with clinical history. RESULTS: Overall, 357 adult HIV-positive participants were classified as having recent infection with RITA1. RITA2 reclassified 55 (15.4%) persons with detectable ARV as having long-term infection. Those with detectable ARV were significantly more likely to be aware of their HIV-positive status (84% vs. 10%) and had higher levels of drug resistance (74% vs. 26%) than those without detectable ARV. RITA2 incidence was lower than RITA1 incidence (range, 0%-30% decrease), resulting in decreased estimated new infections from 390,000 to 341,000 across the 13 countries. Incidence estimates were similar using detectable or self-reported ARV (R2 > 0.995). CONCLUSIONS: Including ARV in RITA2 improved the accuracy of HIV-1 incidence estimates by removing participants with likely long-term HIV infection.
Subject(s)
Algorithms , Epidemiological Monitoring , HIV Infections/diagnosis , HIV-1 , Adolescent , Adult , Anti-HIV Agents/therapeutic use , Female , HIV Infections/drug therapy , Humans , Incidence , Male , Middle Aged , Young AdultSubject(s)
Carrier State/microbiology , Diagnostic Errors , Pneumococcal Infections/microbiology , Polymerase Chain Reaction/methods , Streptococcus pneumoniae/classification , Streptococcus pneumoniae/isolation & purification , Bacteriological Techniques/methods , Carrier State/diagnosis , Genotype , Humans , Molecular Diagnostic Techniques/methods , Pneumococcal Infections/diagnosis , Recombination, Genetic , SerotypingABSTRACT
BACKGROUND: The World Health Organization recommends viral load (VL) as the preferred method for diagnosing antiretroviral therapy failure; however, operational challenges have hampered the implementation of VL monitoring in most resource-limited settings. This study evaluated the accuracy of dried blood spot (DBS) VL testing under field conditions as a practical alternative to plasma in determining virologic failure (VF). METHODS: From May to December 2013, paired plasma and DBS specimens were collected from 416 adults and 377 children on antiretroviral therapy for ≥6 months at 12 clinics in Kenya. DBSs were prepared from venous blood (V-DBS) using disposable transfer pipettes and from finger-prick capillary blood using microcapillary tubes (M-DBS) and directly spotting (D-DBS). All samples were tested on the Abbott m2000 platform; V-DBS was also tested on the Roche COBAS Ampliprep/COBAS TaqMan (CAP/CTM) version 2.0 platform. VF results were compared at 3 DBS thresholds (≥1000, ≥3000, and ≥5000 copies/mL) and a constant plasma threshold of ≥1000 copies/mL. RESULTS: On the Abbott platform, at ≥1000-copies/mL threshold, sensitivities, specificities, and kappa values for VF determination were ≥88.1%, ≥93.1%, and ≥0.82%, respectively, for all DBS methods, and it had the lowest percentage of downward misclassification compared with higher thresholds. V-DBS performance on CAP/CTM had significantly poorer specificity at all thresholds (1000%-33.0%, 3000%-60.9%, and 5000%-77.0%). No significant differences were found between adults and children. CONCLUSIONS: VL results from V-DBS, M-DBS, and D-DBS were comparable with those from plasma for determining VF using the Abbott platform but not with CAP/CTM. A 1000-copies/mL threshold was optimal and should be considered for VF determination using DBS in adults and children.
Subject(s)
Dried Blood Spot Testing/methods , HIV Infections/drug therapy , HIV Infections/virology , HIV-1/isolation & purification , Viral Load/methods , Adult , Child , HIV Infections/blood , HIV-1/drug effects , HIV-1/genetics , Health Resources , Humans , Kenya , Mass Screening/methods , RNA, Viral/blood , Sensitivity and Specificity , Specimen Handling/methods , Treatment FailureABSTRACT
When used in an area of rural western Kenya, the BinaxNOW® urine antigen test had a sensitivity of 67% (95% Confidence Interval [CI]: 43-85%) among 21 adults ≥15 years old with acute respiratory illnesses and pneumococcal bacteremia and a specificity of 98% (95% CI: 96-99%) among 660 adults ≥15 years old without fever or cough. The specificity of the test was not significantly affected by pneumococcal colonization, regardless of patients' HIV status, age, or sex. Use of the pneumococcal urine antigen test in clinical assessments of adults in Africa with acute respiratory illness is a viable option regardless of whether a patient is colonized by pneumococci, even among HIV-infected adults, although the moderate sensitivity of the urine antigen test indicates that the test is probably best used clinically as part of a panel with other tests that can detect pneumococci.
Subject(s)
Antigens, Bacterial/urine , Diagnostic Tests, Routine/methods , Immunoassay/methods , Pneumococcal Infections/diagnosis , Adolescent , Adult , Africa , Aged , Aged, 80 and over , Antigens , Female , Humans , Kenya , Male , Middle Aged , Sensitivity and Specificity , Young AdultABSTRACT
We conducted serological surveys for Coxiella burnetii in archived sera from patients that visited a rural clinic in western Kenya from 2007 to 2008 and in cattle, sheep, and goats from the same area in 2009. We also conducted serological and polymerase chain reaction-based surveillance for the pathogen in 2009-2010, in human patients with acute lower respiratory illness, in ruminants following parturition, and in ticks collected from ruminants and domestic dogs. Antibodies against C. burnetii were detected in 30.9% (N = 246) of archived patient sera and in 28.3% (N = 463) of cattle, 32.0% (N = 378) of goats, and 18.2% (N = 159) of sheep surveyed. Four of 135 (3%) patients with acute lower respiratory illness showed seroconversion to C. burnetii. The pathogen was detected by polymerase chain reaction in specimens collected from three of six small ruminants that gave birth within the preceding 24 hours, and in five of 10 pools (50%) of Haemaphysalis leachi ticks collected from domestic dogs.
Subject(s)
Cattle Diseases/epidemiology , Coxiella burnetii/isolation & purification , Goat Diseases/epidemiology , Q Fever/veterinary , Sheep Diseases/epidemiology , Ticks/microbiology , Animals , Cattle , Cattle Diseases/microbiology , Goat Diseases/microbiology , Goats , Humans , Kenya/epidemiology , Q Fever/epidemiology , Q Fever/microbiology , Seroepidemiologic Studies , Sheep , Sheep Diseases/microbiologyABSTRACT
We performed culture-based and PCR-based tests for pneumococcal identification and serotyping from carriage specimens collected in rural and urban Kenya. Nasopharyngeal specimens from 237 healthy children <5 years old (C-NPs) and combined nasopharyngeal/oropharyngeal specimens from 158 adults (A-NP/OPs, 118 HIV-positive) were assessed using pneumococcal isolation (following broth culture enrichment) with Quellung-based serotyping, real-time lytA-PCR, and conventional multiplexed PCR-serotyping (cmPCR). Culture-based testing from C-NPs, HIV-positive A-NP/OPs, and HIV-negative A-NP/OPs revealed 85.2%, 40.7%, and 12.5% pneumococcal carriage, respectively. In contrast, cmPCR serotypes were found in 93.2%, 98.3%, and 95.0% of these sets, respectively. Two of 16 lytA-negative C-NPs and 26 of 28 lytA-negative A-NP/OPs were cmPCR-positive for 1-10 serotypes (sts) or serogroups (sgs). A-NP/OPs averaged 5.5 cmPCR serotypes/serogroups (5.2 in HIV-positive, 7.1 in HIV-negative) and C-NPs averaged 1.5 cmPCR serotypes/serogroups. cmPCR serotypes/serogroups from lytA-negative A-NP/OPs included st2, st4, sg7F/7A, sg9N/9L, st10A, sg10F/10C/33C, st13, st17F, sg18C/18A/18B/18F, sg22F/22A, and st39. Nine strains of three non-pneumococcal species (S. oralis, S. mitis, and S. parasanguinis) (7 from A-OP, 1 from both A-NP and A-OP, and 1 from C-NP) were each cmPCR-positive for one of 7 serotypes/serogroups (st5, st13, sg15A/15F, sg10F/10C/33C, sg33F/33A/37, sg18C/18A/18B/18F, sg12F/12A/12B/ 44/46) with amplicons revealing 83.6-99.7% sequence identity to pneumococcal references. In total, 150 cmPCR amplicons from carriage specimens were sequenced, including 25 from lytA-negative specimens. Amplicon sequences derived from specimens yielding a pneumococcal isolate with the corresponding serotype were identical or highly conserved (>98.7%) with the reference cmPCR amplicon for the st, while cmPCR amplicons from lytA-negative specimens were generally more divergent. Separate testing of 56 A-OPs and 56 A-NPs revealed that â¼94% of the positive cmPCR results from A-NP/OPs were from OP microbiota. In contrast, A-NPs yielded >2-fold more pneumococcal isolates than A-OPs. Verified and suspected non-pneumococcal cmPCR serotypes/serogroups appeared to be relatively rare in C-NPs and A-NPs compared to A-OPs. Our findings indicate that non-pneumococcal species can confound serotype-specific PCR and other sequence-based assays due to evolutionarily conserved genes most likely involved in biosynthesis of surface polysaccharide structures.
ABSTRACT
Leishmania-induced macrophage dysfunctions have been correlated with altered signaling events. In this work, we report that SB203580, a specific inhibitor of p38 mitogen-activated protein kinases (MAPK), increases Leishmania donovani survival in human peripheral blood mononuclear macrophages. Consistent with this finding, activation of p38 and c-jun N-terminal kinase (JNK) MAPK signaling pathways by anisomycin significantly reduced parasite survival within these cells. However, the majority of the effect was seen in a 50% reduction in the percentage of macrophages infected, with little effect on the highly infected macrophages. The observed effect was likely to be due to the p38 MAPK pathway since SB203580 was able to completely reverse the effect of anisomycin. These findings suggest that the previously reported p38 MAPK inhibition by Leishmania infection may be partially overcome by anisomycin. Similar effects were observed in pretreated macrophages or in treatment of infected macrophages. These results suggests that p38 MAPK activation may have a potential therapeutic value in the treatment of visceral leishmaniasis.