Trends in Neisseria meningitidis serogroups amongst patients with suspected cerebrospinal meningitis in the meningitis belt of Ghana: a 5-year retrospective study.

BACKGROUND: Serogroup A Neisseria meningitidis was the major cause of meningococcal meningitis epidemics in the African meningitis belt before 2010 when the monovalent meningococcal A conjugate vaccine (MenAfriVac) was introduced in the region. Therefore, this study aimed to establish the trends in N. meningitidis serogroups from 2016 to 2020 in Ghana's meningitis belt. METHODS: Polymerase chain reaction (PCR) confirmed laboratory results of suspected cases of cerebrospinal meningitis from January, 2016 to March, 2020 were obtained from the Tamale Public Health Laboratory. The data were subjected to trend analysis using Statistical Package for the Social Sciences version 25. Differences between discrete variables were analyzed using the Cochran-Armitage trend test. RESULTS: Of the 2,426 suspected cases, 395 (16.3%) were confirmed positive for N. meningitidis using PCR. Serogroup X showed a significant upward trend (P < 0.01), and serogroup W showed a downward trend (P < 0.01). However, no significant trend was observed for any other serogroup. CONCLUSION: This study showed the emergence of serogroup X, a non-vaccine type, as the predominant N. meningitidis serogroup in the wake of a declining serogroup W in Ghana's meningitis belt.

Enhancing Meningococcal Genomic Surveillance in the Meningitis Belt Using High-Resolution Culture-Free Whole-Genome Sequencing.

Rollout of meningococcal serogroup A conjugate vaccine in Africa started in 2010, aiming to eliminate meningitis outbreaks, in meningitis belt countries. Since then, studies have been conducted, primarily using isolates, to assess the vaccine impact on the distribution of meningococcal strains in the region. Here, we implemented an innovative, culture-free whole-genome sequencing approach on almost 400 clinical specimens collected between 2017 and 2019 from meningococcal meningitis cases in 6 African countries. About 50% of specimens provided high-quality whole-genome sequence data for comprehensive molecular profiling of the meningococcal pathogen. Three major clonal complexes were identified: CC11 associated with serogroup W, CC181 associated with serogroup X, and CC10217 associated with serogroup C, which continues to rise as a predominant clonal complex in the region. Genomic surveillance for meningococcal meningitis can be significantly improved using culture-free methods to increase data representativeness and monitor changes in epidemiological landscape, especially for countries with low culture rate.

Meningitis Outbreak Caused by Vaccine-Preventable Bacterial Pathogens - Northern Ghana, 2016.

Bacterial meningitis is a severe, acute infection of the fluid surrounding the brain and spinal cord that can rapidly lead to death. Even with recommended antibiotic treatment, up to 25% of infected persons in Africa might experience neurologic sequelae (1). Three regions in northern Ghana (Upper East, Northern, and Upper West), located in the sub-Saharan "meningitis belt" that extends from Senegal to Ethiopia, experienced periodic outbreaks of meningitis before introduction of serogroup A meningococcal conjugate vaccine (MenAfriVac) in 2012 (2,3). During December 9, 2015-February 16, 2016, a total of 432 suspected meningitis cases were reported to health authorities in these three regions. The Ghana Ministry of Health, with assistance from CDC and other partners, tested cerebrospinal fluid (CSF) specimens from 286 patients. In the first 4 weeks of the outbreak, a high percentage of cases were caused by Streptococcus pneumoniae; followed by an increase in cases caused by Neisseria meningitidis, predominantly serogroup W. These data facilitated Ghana's request to the International Coordinating Group* for meningococcal polysaccharide ACW vaccine, which was delivered to persons in the most affected districts. Rapid identification of the etiologic agent causing meningitis outbreaks is critical to inform targeted public health and clinical interventions, including vaccination, clinical management, and contact precautions.

Providing specimen transport through an online marketplace in the Northern region of Ghana.

Background: Integrated diagnostic networks, which are themselves dependent on robust specimen transport solutions, are fundamental to effective healthcare systems. Objective: This study aimed to pilot an online marketplace for the transport of specimens throughout a laboratory network in Ghana. Methods: Independent drivers were matched with health facilities that required specimen transport using a suite of mobile applications and web portals developed for this study. This marketplace was piloted with seven drivers, two laboratories, and five health facilities in Ghana's Northern region from March 2019 to October 2019. Results: During the pilot, 182 deliveries were completed for 691 patients, including 4118 laboratory tests for antenatal care, disease surveillance, and clinical testing. Testing included 34 tests for communicable and non-communicable diseases. All but two specimens (laboratory cancellations) were successfully delivered and tested. The median time from request to encrypted emailing of results was 19.7 h, while that for a drop-off request was 0.9 h. In the midwife registry, the median time from patient visit to result recording was 1 day, compared to 4 days in the same months in 2018, and the number of mothers without documented testing decreased from 41 to 3. Similarly, the proportion of tuberculosis specimen deliveries from Buipe Polyclinic to Tamale Zonal Laboratory taking over 1 day fell from 62% at baseline to 3% during the pilot. Conclusion: An online marketplace successfully orchestrated the delivery of laboratory specimens under a variety of clinical circumstances, reducing overall turn-around time without diminution of the overall specimen delivery process. What this study adds: This study established the efficacy of an online marketplace to orchestrate timely and high-quality delivery of specimens within a laboratory network.

Predictive signs and symptoms of bacterial meningitis isolates in Northern Ghana.

Cerebrospinal meningitis (CSM) is a public health burden in Ghana that causes up to 10% mortality in confirmed cases annually. About 20% of those who survive the infection suffer permanent sequelae. The study sought to understand the predictive signs and symptoms of bacterial meningitis implicated in its outcomes. Retrospective data from the Public Health Division, Ghana Health Service on bacterial meningitis from 2015 to 2019 was used for this study. A pre-tested data extraction form was used to collect patients' information from case-based forms kept at the Disease Control Unit from 2015 to 2019. Data were transcribed from the case-based forms into a pre-designed Microsoft Excel template. The data was cleaned and imported into SPSS version 26 for analysis. Between 2015 and 2019, a total of 2446 suspected bacterial meningitis cases were included in the study. Out of these, 842 (34.4%) were confirmed. Among the confirmed cases, males constituted majority with 55.3% of the cases. Children below 14 years of age were most affected (51.4%). The pathogens commonly responsible for bacterial meningitis were Neisseria meningitidis (43.7%) and Streptococcus pneumoniae (53.0%) with their respective strains Nm W135 (36.7%), Nm X (5.1%), Spn St. 1 (26.2%), and Spn St. 12F/12A/12B/44/4 (5.3%) accounting for more than 70.0% of the confirmed cases. The presence of neck stiffness (AOR = 1.244; C.I 1.026-1.508), convulsion (AOR = 1.338; C.I 1.083-1.652), altered consciousness (AOR = 1.516; C.I 1.225-1.876), and abdominal pains (AOR = 1.404; C.I 1.011-1.949) or any of these signs and symptoms poses a higher risk for testing positive for bacterial meningitis adjusting for age. Patients presenting one and/or more of these signs and symptoms (neck stiffness, convulsion, altered consciousness, and abdominal pain) have a higher risk of testing positive for bacterial meningitis after statistically adjusting for age.

Availability and Prices of WHO Essential Diagnostics in Laboratories in West Africa: A Landscape Survey of Diagnostic Testing in Northern Ghana.

BACKGROUND: We determined the availability and pricing of laboratory testing in the Northern Region of Ghana to identify current gaps with respect to the WHO's Essential Diagnostics List (EDL). METHODS: A representative sample of facilities offering diagnostic testing within the Northern Region was geographically mapped and evaluated, with random sampling stratified by population density. Data were collected on testing menus, volumes, turn-around times, and out-of-pocket test prices. A total of 27 health centers and 39 clinical laboratories were surveyed between June and August 2019. RESULTS: Health centers offered a median of 2 of 20 tests recommended by the WHO for facilities without laboratories. The most common tests offered included point-of-care tests for malaria, HIV, and pregnancy. Clinical laboratories offered a median of 11 of 72 tests on the EDL. These facilities most commonly provided testing for malaria, HIV, pregnancy, HBsAg, urinalysis, HCV Ab, syphilis, glucose, and CBC. Urban laboratories had a total of 36 EDL tests available while rural laboratories had 12. Test prices were higher in private compared to public laboratories. National Health Insurance reimbursements were lower than out-of-pocket prices (38%), and when controlling for test price, test availability was negatively associated with this gap in reimbursement. CONCLUSIONS: Availability of diagnostic testing in Ghana's Northern Region is severely limited compared to the WHO's EDL. The disparity is pronounced in rural facilities. Reimbursement rates should be reset to more closely match out-of-pocket test prices in order to achieve the Universal Health Coverage target of the Sustainable Development Goals.

Estimating the economic burden of pneumococcal meningitis and pneumonia in northern Ghana in the African meningitis belt post-PCV13 introduction.

BACKGROUND: Ghana introduced 13-valent pneumococcal conjugate vaccine (PCV13) into the routine infant immunization program in 2012, using a three-dose primary series without a booster. Despite ≥ 88% reported three-dose vaccination coverage since 2013, PCV13-type pneumococcal meningitis outbreaks have occurred. We estimated the ongoing economic burden of PCV13-type pneumococcal meningitis and pneumonia in northern Ghana, an area within the African meningitis belt with seasonal increases of pneumococcal meningitis post-PCV13 introduction, to inform PCV13 vaccination policy. METHODS: We performed a cross-sectional survey among patients with pneumonia or meningitis at three hospitals in northern Ghana to determine patient-level costs (direct medical and nonmedical, indirect patient and caregiver costs) incurred in household, outpatient, and inpatient settings. Pneumonia burden was estimated using 2017-2018 administrative records. Pneumococcal meningitis burden was estimated using 2017-2018 case-based surveillance data. Economic burden was reported in 2019 U.S. dollars ($) from the societal perspective. RESULTS: For an area with a total population of 5,068,521, our model estimated 6,441 PCV13-type pneumonia cases and 286 PCV13-type meningitis cases occurred in a typical year post-PCV13. In the base case scenario, the total economic burden was $5,230,035 per year ($777 per case). By age group, cost per PCV13-type pneumonia case was $423 (<5 years), $911 (5-14 years), and $784 (≥15 years); cost per PCV13-type meningitis case was $2,128 (<5 years), $3,247 (5-14 years), and $2,883 (≥15 years). Most (78.0-93.4%) of the total societal cost was due to indirect costs related to deaths from PCV13-type diseases. CONCLUSIONS: The estimated economic burden of PCV13-type disease in northern Ghana remains substantial, especially in older children and adults who were expected to have benefited from indirect effects from infant immunization. Additional interventions such as changes in the infant immunization schedule, reactive vaccination, or catch-up PCV13 vaccination may be needed to control remaining vaccine-type disease.

Common bacteria in sputum or gastric lavage of patients presenting with signs and symptoms of lower respiratory tract infections.

INTRODUCTION: lower respiratory tract infections (LRTIs) are infections involving the trachea, primary bronchi and lungs. People with LRTIs typically experience coughs as the primary symptoms; however, shortness of breath, weakness, fever and fatigue may be coupled with the cough. It is common among the aged, children under five and the immune-suppressed. Persons with symptoms suggestive of pulmonary tuberculosis (TB) may have tuberculosis, other respiratory tract infection or co-infection of tuberculosis and other respiratory pathogens. This study aimed to identify the presence of pathogens in sputum of suspected tuberculosis cases and their antimicrobial resistance patterns. METHODS: this was a retrospective study conducted from September 2018 to November 2019 at Tamale Public Health Laboratory. Sputum or gastric lavage samples were collected from persons with suspected clinical presentations of TB and/or LRTI. These samples were cultured using standard microbiological protocols and antimicrobial susceptibility test performed on the positive cultures by Kirby-Bauer disc diffusion method. Molecular identification of M. tuberculosis was performed on all the suspected TB cases using GeneXpert mycobacterium tuberculosis/rifampin (MTB/RIF) assay. RESULTS: during the study period, there were 264 cases of which 49.2% were males and 50.8% were females. Positive cases for culture were 47.3%. Out of the 264 cases, 186 (70.5%) were suspected TB with 51.6% being positive for culture, 6.5% positive for M. tuberculosis (GeneXpert confirmed) and 3.8% co-infection of TB with other bacteria pathogens. Klebsiella spp. (35/125; 28%) and Pseudomonas spp. (19/125; 15.2%) were the most predominant pathogens isolated. There was no significant difference in detection of bacteria in males and females (p=0.89), however individuals with suspected TB were significantly infected with other bacterial species than the unsuspected individuals (p=0.03). Almost all the isolates showed high susceptibility towards carbapenem (meropenem) and high resistance towards the third generation cephalosporins (cefotaxime and ceftriaxone). CONCLUSION: this study highlights the need to test individuals with classical symptoms of LRTIs for other bacterial infections other than TB only. Sputum culture is recommended for all suspected tuberculosis cases to provide accurate laboratory diagnosis to LRTIs and mitigate unnecessary use of antimicrobials.

Field evaluation of specificity and sensitivity of a standard SARS-CoV-2 antigen rapid diagnostic test: A prospective study at a teaching hospital in Northern Ghana.

The testing capacity for SARS-CoV-2 in Africa is rather limited. Antigen detection rapid diagnostic tests (Ag-RDTs) are a cheap and rapid alternative to reverse transcriptase-polymerase chain reaction (RT-PCR) tests, but there is little data about their performance under real life conditions in tropical countries. The objective of this study is to evaluate the performance of a standard Ag-RDT in a population of a major hospital in northern Ghana. Prospective, cross-sectional, blinded verification of the performance of the SD Biosensor Standard Q SARS-CoV-2 Ag-RDT under real life conditions in 135 symptomatic patients and 58 contacts of RT-PCR positives at Tamale Teaching Hospital in February 2021. Nasopharyngeal samples were taken under standard conditions and tested against RT-PCR in the hospital laboratory. 193 participants (median age 35 years, 109 male) were included into the study for which both RT-PCR test and Ag-RDT results were available. A total of 42 (22%) were RT-PCR positive. Of the 42 RT-PCR positives, 27 were Ag-RDT positive, resulting in a sensitivity of 64% (95% CI 49-79). Sensitivity among symptomatic patients was 58% (95% CI 38-78). 123 were identified Ag-RDT negatives of the 151 RT-PCR negatives, resulting in a specificity of 81% (95% CI 75-87). SARS-CoV-2 Ag-RDTs appear to have a rather low sensitivity and particularly a low specificity under real life conditions in Africa. The role of existing Ag-RDTs in countries with high-temperature climates and limited resources still needs more data and discussion.

Socioeconomic characteristics associated with the introduction of new vaccines and full childhood vaccination in Ghana, 2014.

BACKGROUND: Childhood vaccination in Ghana has historically been high, but the impact of recently introduced vaccines on coverage is unknown. We calculate vaccine coverage of Ghanaian children- contrasting newly introduced vaccines and those long available - and describe associations between sociodemographic indicators and full vaccination. METHODS: Data from the 2014 Ghana Demographic and Health Survey was used to calculate full vaccination, defined as receipt of one dose bacillus Calmette-Guérin (BCG); two doses of rotavirus vaccine; 3 doses of pentavalent vaccine, oral polio vaccine (OPV), and pneumococcal conjugate vaccine (PCV); and one dose of measles-rubella vaccine and yellow fever vaccine, among children age 12-24 months. Logistic regression with survey procedures was used to estimate odds ratios for socioeconomic factors' association with full vaccination. RESULTS: The sample comprised a total of 1107 children 12-24 months. Full vaccination coverage was 70.8%. Vaccination coverage was higher for vaccines administered at younger ages (e.g., birth dose of BCG was 97.0%) than at older ages (e.g., yellow fever at 9 months was 88.2%). Newly introduced vaccines had lower coverage: at 10 weeks, pentavalent 2 was 95.4%, versus 91.2% for PCV 2 and 88.8% for rotavirus 2. Living outside of Greater Accra, home delivery, younger maternal age, urban residence, and more than one child under five in the home were all associated with decreased odds of full vaccination in the adjusted analysis whereas sex of the child, wealth, religion, and maternal education were not associated with full vaccination status. CONCLUSION: Ghana has high overall vaccination rates although disparities in full vaccination by sociodemographic status exist. As vaccine recommendations are revised, it will be important to insure equitable access to vaccination for all children regardless of demographic and socioeconomic background.

Impact of malaria and hepatitis B co-infection on clinical and cytokine profiles among pregnant women.

BACKGROUND: The overlap of malaria and chronic hepatitis B (CHB) is common in endemic regions, however, it is not known if this co-infection could adversely influence clinical and immunological responses. This study investigated these interactions in pregnant women reporting to antenatal clinics in Ghana. METHODS: Clinical parameters (hemoglobin, liver function biomarker, peripheral malaria parasitemia, and hepatitis B viremia) and cytokine profiles were assayed and compared across four categories of pregnant women: un-infected, mono-infected with Plasmodium falciparum (Malaria group), mono-infected with chronic hepatitis B virus (CHB group) and co-infected (Malaria+CHB group). RESULTS: Women with Malaria+CHB maintained appreciably normal hemoglobin levels (mean±SEM = 10.3±0.3 g/dL). That notwithstanding, Liver function test showed significantly elevated levels of alanine aminotransferase, aspartate aminotransferase and total bilirubin [P<0.001 for all comparisons]. Similarly, the Malaria+CHB group had significantly elevated pro-inflammatory cytokines, including tumour necrosis factor alpha (TNF-α), interleukin (IL)-1ß, and IL-6 [P<0.05 for all comparisons]. In women with Malaria+CHB, correlation analysis showed significant negative association of the pro-inflammatory cytokines responses with malaria parasitemia [IL-1ß (P<0.001; r = -0.645), IL-6 (P = 0.046; r = -0.394) and IL-12 (P = 0.011; r = -0.49)]. On the other hand, the pro-inflammatory cytokine levels positively correlated with HBV viremia [TNF-α (P = 0.004; r = 0.549), IL-1ß (P<0.001; r = 0.920), IL-6 (P<0.001; r = 0.777), IFN-γ (P = 0.002; r = 0.579), IL-2 (P = 0.008; r = 0.512) and IL-12 (P<0.001; r = 0.655)]. Also, for women in the Malaria+CHB group, parasitemia was observed to diminish HBV viremia [P = 0.003, r = -0.489]. CONCLUSION: Put together the findings suggests that Malaria+CHB could exacerbate inflammatory cytokine responses and increase susceptibility to liver injury among pregnant women in endemic settings.

Prevalence of Asymptomatic Malaria among Children in the Tamale Metropolis: How Does the PfHRP2 CareStart™ RDT Perform against Microscopy?

BACKGROUND: Asymptomatic carriage of the malaria parasites, likewise its misdiagnosis, especially false negatives, due to the use of substandard rapid diagnosis tests (RDTs) has been shown to hinder the progress of the fight against malaria. METHOD: The study assessed the prevalence of asymptomatic malaria as well as the performance of Plasmodium falciparum-specific protein and histidine-rich protein 2 (PfHRP2) CareStart™ RDT against standard microscopy in the detection of malaria infection among 345 children (1-15 yrs) from two (2) basic schools in Tamale Metropolis. RESULTS: From the microscopy (considered as gold standard), prevalence of malaria among the asymptomatic children was found to be 2.6%, with sensitivity and specificity of CareStart™ RDT in detecting P. falciparum infections found to be 55.6% and 93.8%, respectively. The positive predictive value (PPV) and negative predictive value (NPV) of CareStart™ RDT were found to be 19.23% and 98.45%, respectively. There was an evidence showing a significant relation between CareStart™ RDT and microscopy in determining malaria infection (χ 2 = 30.579, p < 0.001). CONCLUSION: Prevalence of asymptomatic malaria among children was found to be 2.6%. The study reported low sensitivity and PPV for PfHRP2 CareStart™ RDT in an asymptomatic population at instances of low parasitaemia.

Prevalence of malaria and hepatitis B among pregnant women in Northern Ghana: Comparing RDTs with PCR.

BACKGROUND: High prevalence of malaria and hepatitis B has been reported among pregnant women in Ghana. In endemic areas, the diagnoses of malaria and hepatitis B among pregnant women on antenatal visits are done using histidine-rich protein 2 (HRP2) and hepatitis B surface antigen (HBsAg) rapid diagnostic tests (RDTs), respectively, which are, however, reported to give some false positive results. Also, socio-economic determinants have been drawn from these RDTs results which may have questionable implications. Thus, this study was aimed at evaluating the prevalence of malaria and hepatitis B by comparing RDTs with polymerase chain reaction (PCR) outcomes, and relating the PCR prevalence with socio-economic status among pregnant women in Northern Ghana. METHODS: We screened 2071 pregnant women on their first antenatal visit for Plasmodium falciparum and hepatitis B virus (HBV) using HRP2 and HBsAg RDTs, and confirming the infections with PCR. Socio-economic and obstetric information were collected using a pre-tested questionnaire, and associations with the infections were determined using Pearson's chi-square and multinomial logistic regression analyses at a significance level of p<0.05. RESULTS: The prevalence of the infections by RDTs/PCR was: 14.1%/13.4% for P. falciparum mono-infection, 7.9%/7.5% for HBV mono-infection, and 1.9%/1.7% for P. falciparum/HBV co-infection. No statistical difference in prevalence rates were observed between the RDTs and PCRs (χ2 = 0.119, p = 0.73 for malaria and χ2 = 0.139, p = 0.709 for hepatitis B). Compared with PCRs, the sensitivity/specificity of the RDTs was 97.5%/99.1% and 97.9%/99.4% for HRP2 and HBsAg respectively. Socio-economic status was observed not to influence HBV mono-infection among the pregnant women (educational status: AOR = 0.78, 95% CI = 0.52-1.16, p = 0.222; economic status: AOR = 1.07, 95% CI = 0.72-1.56, p = 0.739; financial status: AOR = 0.66, 95% CI = 0.44-1.00, p = 0.052). However, pregnant women with formal education were at a lower risk for P. falciparum mono-infection (AOR = 0.48, 95% CI = 0.32-0.71, p<0.001) and P. falciparum/HBV co-infection (AOR = 0.27, 95% CI = 0.11-0.67, p = 0.005). Also those with good financial status were also at a lower risk for P. falciparum mono-infection (AOR = 0.52, 95% CI = 0.36-0.74, p<0.001). CONCLUSION: Our data has shown that, the RDTs are comparable to PCR and can give a representative picture of the prevalence of malaria and hepatitis B in endemic countries. Also, our results support the facts that improving socio-economic status is paramount in eliminating malaria in endemic settings. However, socio-economic status did not influence the prevalence of HBV mono-infection among pregnant women in Northern Ghana.

Diagnosis of bacterial meningitis in Ghana: Polymerase chain reaction versus latex agglutination methods.

Bacterial meningitis is a public health crisis in the northern part of Ghana, where it contributes to very high mortality and morbidity rates. Early detection of the causative organism will lead to better management and effective treatment. Our aim was to evaluate the diagnostic accuracy of Pastorex and Wellcogen latex agglutination tests for the detection of bacterial meningitis in a resource-limited setting. CSF samples from 330 suspected meningitis patients within the northern zone of Ghana were analysed for bacterial agents at the zonal Public Health Reference Laboratory in Tamale using polymerase chain reaction (PCR) and two latex agglutination test kits; Pastorex and Wellcogen. The overall positivity rate of samples tested for bacterial meningitis was 46.4%. Streptococcus pneumoniae was the most common cause of bacterial meningitis within the sub-region, with positivity rate of 25.2%, 28.2% and 28.8% when diagnosed using Wellcogen, Pastorex and PCR respectively. The Pastorex method was 97.4% sensitive while the Wellcogen technique was 87.6% sensitive. Both techniques however produced the same specificity of 99.4%. Our study revealed that the Pastorex method has a better diagnostic value for bacterial meningitis than the Wellcogen method and should be the method of choice in the absence of PCR.

Continued occurrence of serotype 1 pneumococcal meningitis in two regions located in the meningitis belt in Ghana five years after introduction of 13-valent pneumococcal conjugate vaccine.

BACKGROUND: Increases in pneumococcal meningitis were reported from Ghanaian regions that lie in the meningitis belt in 2016-2017, despite introduction of 13-valent pneumococcal conjugate vaccine (PCV13) in 2012 using a 3-dose schedule (6, 10, and 14 weeks). We describe pneumococcal meningitis epidemiology in the Ghanaian Northern and Upper West regions across two meningitis seasons. METHODS: Suspected meningitis cases were identified using World Health Organization standard definitions. Pneumococcal meningitis was confirmed if pneumococcus was the sole pathogen detected by polymerase chain reaction, culture, or latex agglutination in cerebrospinal fluid collected from a person with suspected meningitis during December 2015-March 2017. Pneumococcal serotyping was done using PCR. Annual age-specific pneumococcal meningitis incidence (cases per 100,000 population) was calculated, adjusting for suspected meningitis cases lacking confirmatory testing. FINDINGS: Among 153 pneumococcal meningitis cases, 137 (89.5%) were serotyped; 100 (73.0%) were PCV13-type, including 85 (62.0%) that were serotype 1, a PCV13-targeted serotype. Persons aged ≥5 years accounted for 96.7% (148/153) of cases. Comparing 2015-2016 and 2016-2017 seasons, the proportion of non-serotype 1 PCV13-type cases decreased from 20.0% (9/45) to 4.1% (3/74) (p = 0.008), whereas the proportion that was serotype 1 was stable (71.1% (32/45) vs. 58.1% (43/74); p = 0.16). Estimated adjusted pneumococcal meningitis incidence was 1.8 in children aged <5 years and ranged from 6.8-10.5 in older children and adults. CONCLUSIONS: High pneumococcal meningitis incidence with a large proportion of serotype 1 disease in older children and adults suggests infant PCV13 vaccination has not induced herd protection with this schedule in this high-transmission setting.

Genetic Diversity of Plasmodium falciparum Populations in Malaria Declining Areas of Sabah, East Malaysia.

Malaysia has a national goal to eliminate malaria by 2020. Understanding the genetic diversity of malaria parasites in residual transmission foci can provide invaluable information which may inform the intervention strategies used to reach elimination targets. This study was conducted to determine the genetic diversity level of P. falciparum isolates in malaria residual foci areas of Sabah. Malaria active case detection was conducted in Kalabakan and Kota Marudu. All individuals in the study sites were screened for malaria infection by rapid diagnostic test. Blood from P. falciparum-infected individuals were collected on filter paper prior to DNA extraction. Genotyping was performed using merozoite surface protein-1 (MSP-1), merozoite surface protein-2 (MSP-2), glutamate rich protein (GLURP) and 10 neutral microsatellite loci markers. The size of alleles, multiplicity of infection (MOI), mean number of alleles (Na), expected heterozygosity (He), linkage disequilibrium (LD) and genetic differentiation (FST) were determined. In Kalabakan, the MSP-1 and MSP-2 alleles were predominantly K1 and FC27 family types, respectively. The GLURP genotype VI (751-800 bp) was predominant. The MOI for MSP-1 and MSP-2 were 1.65 and 1.20, respectively. The Na per microsatellite locus was 1.70. The He values for MSP-1, MSP-2, GLURP and neutral microsatellites were 0.17, 0.37, 0.70 and 0.33, respectively. In Kota Marudu, the MSP-1 and MSP-2 alleles were predominantly MAD20 and 3D7 family types, respectively. The GLURP genotype IV (651-700 bp) was predominant. The MOI for both MSP-1 and MSP-2 was 1.05. The Na per microsatellite locus was 3.60. The He values for MSP-1, MSP-2, GLURP and neutral microsatellites were 0.24, 0.25, 0.69 and 0.30, respectively. A significant LD was observed in Kalabakan (0.495, p<0.01) and Kota Marudu P. falciparum populations (0.601, p<0.01). High genetic differentiation between Kalabakan and Kota Marudu P. falciparum populations was observed (FST = 0.532). The genetic data from the present study highlighted the limited diversity and contrasting genetic pattern of P. falciparum populations in the malaria declining areas of Sabah.