ABSTRACT
Reports of increasing false-negative HRP2-based rapid diagnostic test results across Africa require constant monitoring of factors associated with these false-negative outcomes, as failure of this diagnostic tool will have severe consequences on malaria treatment and control programs. This study characterized the extent of genetic diversity in the Plasmodium falciparum histidine-rich protein 2 (Pfhrp2) gene in P. falciparum isolates from symptomatic malaria patients across the regions of Ghana. Exon 2 of Pfhrp2 was amplified from gDNA using polymerase chain reaction. All Pfhrp2-negative samples were subjected to Pf18S rRNA and Pfmsp2 gene amplifications. The amplified Pfhrp2 exon 2 fragments from clonal samples were sent for commercial Sanger sequencing. The type and number of PfHRP2 repeats, classified based on repeat types previously reported, were estimated from the sequence data and compared among geographical regions. About 81% (2,333/2,890) of the original microscopy positive DBS were available and used in this study. The Pfhrp2 exon 2 amplification was successful in 98.5% (2,297/2,333) of the tested samples, with band size ranging from 400 bp to 1,050 bp. A total of 13 out of the 24 previously reported repeat types were identified among the samples, with three samples lacking both type 2 and type 7 repeat motifs. This study suggested that the genetic diversity of Pfhrp2 exon 2 identified in P. falciparum circulating in symptomatic malaria patients in Ghana is unlikely to influence the sensitivity and specificity of HRP2 RDT-based diagnosis.
ABSTRACT
BACKGROUND: Evaluate the Tuberculosis (TB) surveillance system in the Ga West Municipality to determine if it is achieving its objectives, and to assess its attributes and usefulness. DESIGN: Descriptive analysis of primary and secondary data. DATA SOURCE: Stakeholder interviews and record reviews on the objectives and operation of the surveillance system at all levels of the system. INTERVENTION: We evaluated the system's operation from 2011-2015 using the Centers for Disease Control and Prevention (CDC) updated guidelines for evaluating public health surveillance systems and the World Health Organisation (WHO) TB surveillance checklist for assessing the performance of national surveillance systems. RESULTS: The TB surveillance system in the municipality was functional and operated at all levels for timely detection of cases, accurate diagnosis, and case management. The system improved management of TB/HIV co-infections. The average time taken to confirm a suspected TB case was one day. The registration of a confirmed case and subsequent treatment happen immediately after confirmation. The municipality detected 109 of 727 TB cases in 2015 (case detection rate=15%). The positive predictive value (PPV) was 6.4%. There was one diagnostic centre in the municipality. Private facilities involvement in TB surveillance activities was low (1/15). CONCLUSION: The Tuberculosis surveillance system in the Ga West Municipality is well structured but partially meeting its objectives. The system is timely, stable and acceptable by most stakeholders and useful at all levels. It has no major data quality issues. Private health facilities in the municipality should be well incorporated into TB surveillance. FUNDING: This work was supported by Ghana Field Epidemiology and Laboratory Training Program (GFELTP), University of Ghana through the support of the West Africa Health Organization (Ref.: Prog/A17IEpidemSurveillN° 57212014/mcrt) to B-YA.
Subject(s)
Population Surveillance/methods , Public Health Surveillance/methods , Tuberculosis/epidemiology , Ghana/epidemiology , Humans , Public Health , World Health OrganizationABSTRACT
BACKGROUND: We evaluated the pneumonia surveillance system in Tema Metropolis to determine whether it is meeting its objectives and to assess its attributes. DESIGN: Descriptive primary and secondary data analysis. DATA SOURCE: We interviewed health staff on the system's operation and resources. We also extracted 2012-2016 surveillance dataset for under-five pneumonia cases and deaths from the District Health Information Management System for review. PARTICIPANTS: Health staff. INTERVENTION: The Centers for Disease Control (CDC) updated guidelines for evaluating surveillance systems was used to assess system attributes. MAIN OUTCOME MEASURE: state of the pneumonia surveillance system in Tema. RESULTS: A suspected case was defined as fast breathing in any child < 5 years old. The case definition was easy to apply, even at the community level. From 2012 to 2016, a total of 3,337 cases and 54 deaths (case fatality rate 1.6%) was recorded from 13 (23.6%) of 55 health facilities. Two epidemics were missed by the district because data were not being analysed. There were no laboratory data on antimicrobial resistance. Although reporting timeliness increased from 28.1% in 2012 to 83% in 2016, data inconsistencies existed between reporting levels. CONCLUSION: The surveillance system for under-five pneumonia in Tema Metropolis is simple, stable, flexible, timely, but of low sensitivity and acceptability, and only partly meeting its objectives. Major shortcomings are lack of laboratory data, non-use of data and low representativeness. FUNDING: The study was supported by a grant to author DB by the President's Malaria Initiative (PMI) -CDC CoAg 6NU2GGH001876.
