The Relationship between Disease Pattern and Disease Burden by Chest Radiography, <Emphasis Type="Italic">M. tuberculosis</Emphasis> Load,and HIV Status in Patients with Pulmonary Tuberculosis in Addis Ababa

Abstract Background: We evaluated the impact of HIV coinfection on the chest radiographic pattern and extent of disease and its relation to the load of Mycobacterium tuberculosis in Ethiopian out-patients with pulmonary tuberculosis. Patients and Methods: A total of 168 patients with cultureverified pulmonary tuberculosis had their chest X-rays (CXR) reviewed for the site, pattern, and extent of disease and the findings were correlated to (a) the mycobacterial culture count and bacillus load after sputum concentration and (b) the HIV status of the patients. Results: HIV-positive patients were less likely to have cavitary disease (p < 0.001) and more likely to have pleural effusion (p = 0.08), miliary (p < 0.05), and interstitial (p < 0.01) patterns. A total of 15 (9.2%) patients had normal chest X-rays. HIV-infected patients had a CXR classified as normal or with minimal involvement (p = 0.059) and a reduced mycobacterial colony count (p = 0.002) compared to HIV-negative patients. Middle and lower lung involvement were more common in HIV-positive patients. Conclusion: CXR findings in the setting of an underlying HIV infection tend to be more atypical and could present as either normal or with minimal involvement. In general, HIV-positive patients had lower colony count of M. tuberculosis than HIV-negative patients. Of particular interest is the finding of a large number of normal chest X-rays in HIV-infected patients. With the rising incidence of both tuberculosis and HIV infection in Ethiopia, the finding of a normal chest X-ray and a negative smear poses a challenge for the diagnosis of pulmonary tuberculosis.     

Ultrasound evaluation of abdominal masses in Ethiopian child patients

The aim of this study was to assess the pattern of abdominal masses and evaluate the value of ultrasound in paediatric abdominal masses. We used a cross-sectional study of abdominal masses in children attending a university teaching hospital. The common abdominal masses were: Wilms' tumour, 12 (14.8%); lymphoma, 11 (13.6%); appendiceal mass/abscess, 11 (13.6%); neuroblastoma, 7 (8.6%); TB, 6 (7.4%); hydronephrosis, 5 (6.2%); abdominal wall abscess, 6 (7.4%); hydatidcyst, 4 (4.9%); mesenteric cyst, 3 (3.7%); and intussusceptions, 3 (3.7%). Identification of a purely cystic mass was suggestive of benign lesion (odds ratio [OR] = 118, P = 0.0001) and masses found in the <5 years age group tend to be malignant (OR = 2.77). The most common sites of origin were kidneys, retroperitoneal extra renal and gastrointestinal tract. The overall diagnostic accuracy of ultrasound was 88.9%.     

Population genomic structure and adaptation in the zoonotic malaria parasite Plasmodium knowlesi

Malaria cases caused by the zoonotic parasite Plasmodium knowlesi are being increasingly reported throughout Southeast Asia and in travelers returning from the region. To test for evidence of signatures of selection or unusual population structure in this parasite, we surveyed genome sequence diversity in 48 clinical isolates recently sampled from Malaysian Borneo and in five lines maintained in laboratory rhesus macaques after isolation in the 1960s from Peninsular Malaysia and the Philippines. Overall genomewide nucleotide diversity (π = 6.03 × 10⁻³) was much higher than has been seen in worldwide samples of either of the major endemic malaria parasite species Plasmodium falciparum and Plasmodium vivax. A remarkable substructure is revealed within P. knowlesi, consisting of two major sympatric clusters of the clinical isolates and a third cluster comprising the laboratory isolates. There was deep differentiation between the two clusters of clinical isolates [mean genomewide fixation index (F_ST) = 0.21, with 9,293 SNPs having fixed differences of F_ST = 1.0]. This differentiation showed marked heterogeneity across the genome, with mean F_ST values of different chromosomes ranging from 0.08 to 0.34 and with further significant variation across regions within several chromosomes. Analysis of the largest cluster (cluster 1, 38 isolates) indicated long-term population growth, with negatively skewed allele frequency distributions (genomewide average Tajima’s D = −1.35). Against this background there was evidence of balancing selection on particular genes, including the circumsporozoite protein (csp) gene, which had the top Tajima’s D value (1.57), and scans of haplotype homozygosity implicate several genomic regions as being under recent positive selection.The zoonotic malaria parasite Plasmodium knowlesi is a significant cause of human malaria, with a wide spectrum of clinical outcomes including high parasitemia and death (1–4). Long known as a malaria parasite of long-tailed and pig-tailed macaques (5), the first large focus of human cases was described only in 2004 in the Kapit Division of Sarawak in Malaysian Borneo (6). Since then infections have been described from almost all countries in Southeast Asia (2, 7). Travelers to the region from Europe, North America, and Australasia also have recently acquired P. knowlesi malaria (7, 8). Until the application of molecular assays for specific detection, human P. knowlesi malaria was largely misdiagnosed as Plasmodium malariae, a morphologically similar but distantly related species (1, 6, 9, 10). Studies in the Kapit Division of Sarawak in Malaysian Borneo have indicated that P. knowlesi malaria is primarily a zoonosis with macaques as reservoir hosts (11) and that the forest-dwelling mosquito species Anopheles latens is the local vector for P. knowlesi (12). Other members of the Anopheles leucosphyrus group are vectors in different parts of Southeast Asia and may determine the geographical distribution of transmission (13, 14).Although P. knowlesi malaria is regarded as an emerging infection, there clearly have been increased efforts in detection made since its existence as a significant zoonosis was discovered, and specific detection has been enhanced by the declining numbers of human cases caused by other malaria parasites in Southeast Asia (15). Aside from the first two human cases described several decades ago (5), there is direct evidence of human P. knowlesi infections from ∼20 y ago in Malaysian Borneo and Thailand obtained by retrospective molecular analysis of material from archived blood spots and slides (10, 16), and molecular population genetic evidence indicates the zoonosis has been in existence for a much longer time (11). The genetic diversity of P. knowlesi is high within humans as well as macaques, with sequence data on three loci [the circumsporozoite protein (csp) gene, 18S rRNA, and mtDNA genome] indicating extensive shared polymorphism and no fixed differences between P. knowlesi parasites from humans and monkeys sampled in the same area in Sarawak, Malaysian Borneo (6, 11). Analysis of samples from a smaller number of humans and monkeys in Thailand showed alleles of the P. knowlesi merozoite surface protein 1 (msp1) gene to be similarly diverse in both hosts (16), and there were shared polymorphisms of the csp gene in parasites from a few infections examined in humans and macaques in Singapore (17). Recent multilocus microsatellite analysis has indicated a deep population subdivision in P. knowlesi associated with long-tailed and pig-tailed macaques; both major types infect humans and occur sympatrically at most sites in Malaysia, but the two types show some additional geographical differentiation across sites (18).Human populations have grown very rapidly in the Southeast Asian region and encroach on most of the wild macaque habitats, so it is vital to know if P. knowlesi parasites are adapting to human hosts or to anthropophilic mosquito vector species, either of which could cause human–mosquito–human transmission. Initial analysis of the P. knowlesi reference genome sequence (strain H) highlighted some unique features of the genome of this species (19), namely, schizont infected cell agglutination variant (SICAvar) and knowlesi interspersed repeat (KIR) variant antigen genes, which were widely dispersed instead of being predominantly localized in subtelomeric regions as seen in large gene families in Plasmodium falciparum and Plasmodium vivax (20). Here, we analyzed genomewide diversity in P. knowlesi and conducted scans for signatures of balancing and directional selection, revealing extremely high genetic diversity and significant structuring of this species into subpopulation clusters that appear to be reproductively isolated as well as loci that show evidence of recent strong selection.     

A Three Year Retrospective Study on Seroprevalence of Syphilis among Pregnant Women at Gondar University Teaching Hospital,Ethiopia

Background

Sexually transmitted infections (STIs) are a serious public health problem in low income countries, including Ethiopia. Syphilis caused by Treponema pallidum remains a major cause of reproductive morbidity and poor pregnancy outcomes in low income countries. Stillbirth, perinatal death, serious neonatal infection and low-birth weight babies are common among seropositive mothers.

Objective

To assess the seroprevalence of syphilis and risk factor correlates of this infection at Gondar University Teaching Hospital, Ethiopia.

Methods

The study was done on 2385 pregnant women attending the antenatal care clinic (ANC) from January 2009 to December 2011. Data was abstracted from the antenatal care clinic medical database. Chi-square test was used, using SPSS version 16 and significance level was chosen at 0.05 level with a two-tailed test.

Results

Of the total, 69(2. 9%) of pregnant women were confirmed as seropositive for syphilis. Pregnant women with an age group of 21–25 years of old were the most seropositive (3.4%), followed by 26–30 years of old (3.1%). The prevalence of syphilis infection was 3.2% in urban and 2.2% in rural pregnant women. Relatively high prevalence of syphilis infection were identified among students (4.2%) followed by governmental employees (3.8%).

Conclusion

The seroprevalence of syphilis among pregnant women attending ANC is declining. However, syphilis is more prevalent in the young and urban pregnant women. Emphasis on education to young people on STI risk behavioral change and partner follow up and notification for exposure to syphilis and treatment should be given.     

Factors related to the use of antenatal care services in Ethiopia: Application of the zero-inflated negative binomial model

The major causes for poor health in developing countries are inadequate access and under-use of modern health care services. The objective of this study was to identify and examine factors related to the use of antenatal care services using the 2011 Ethiopia Demographic and Health Survey data. The number of antenatal care visits during the last pregnancy by mothers aged 15 to 49 years (n = 7,737) was analyzed. More than 55% of the mothers did not use antenatal care (ANC) services, while more than 22% of the women used antenatal care services less than four times. More than half of the women (52%) who had access to health services had at least four antenatal care visits. The zero-inflated negative binomial model was found to be more appropriate for analyzing the data. Place of residence, age of mothers, woman’s educational level, employment status, mass media exposure, religion, and access to health services were significantly associated with the use of antenatal care services. Accordingly, there should be progress toward a health-education program that enables more women to utilize ANC services, with the program targeting women in rural areas, uneducated women, and mothers with higher birth orders through appropriate media.