Transactions of the Royal Society of Tropical Medicine and Hygiene

Editorial Board

2010-08-01

Prevalence of multi-drug resistant tuberculosis in Karachi, Pakistan: identification of at risk groups

2010-08-01

Summary: Multidrug-resistant tuberculosis (MDR-TB) is a possible threat to global tuberculosis control. Despite a disease prevalence of 263/100 000 population Pakistan lacks information on prevalence of drug resistant TB. Our objective was to estimate prevalence of MDR and associated risk factors in patients with pulmonary tuberculosis in Karachi. Six hundred and forty consenting adult patients were enrolled from field clinics from July 2006 to August 2008 through passive case finding. Prevalence of MDR-TB with 95% confidence interval (CI) was calculated with Epi-Info. Logistic Regression analyses were performed for risk factors associated with MDR. Overall MDR rate was 5.0%, 95% CI: 3.3-6.6% (untreated 2.3%, treated 17.9%). Mean age was 32.5 (±15.6) years and there were 292 (45.6%) females and 348 (54.4%) males. Factors independently associated with MDR were: female gender (OR 3.12; 95% CI: 1.40–6.91), and prior history of incomplete treatment (OR 10.1; 95% CI: 4.71–21.64). Ethnic groups at higher risk for MDR included Sindhis (OR 4.5; 95% CI: 1.42–14.71) and Pashtoons (OR 3.6, 95% CI: 1.12–11.62). This study reports an overall MDR rate of 5.0% in our study population. It further highlights the need for MDR prevention through re-focusing Directly Observed Treatment, Short-course DOTS delivery with emphasis on women and certain high risk sub groups.

The prevalence and correlates of self-reported hearing impairment in the Ibadan Study of Ageing

Akeem O. Lasisi, Taiwo Abiona, Oye Gureje — 2010-08-01

Abstract: This cohort study of 1302 persons aged ≥65 years, conducted in the Yoruba-speaking regions of Nigeria, determines the prevalence and correlates of hearing impairment (HI) in the elderly population. Self-reports of HI and its putative risk factors among several indices were obtained using face-to-face interviews, and confirmed by observer's evaluation. Hearing impairment was found in 79 respondents, giving a prevalence of 6.1%. Gender difference was not significant but increasing age was associated with higher prevalence. Logistic regression analysis, adjusted for age and sex, revealed that history of recurrent suppurative otitis media [odds ratio (OR)=4.6, 95% CI 2.34–8.99, P=0.01], head injury (OR=2.2, 95% CI 1.14–4.26, P=0.02) and current hypertension (OR=2.1, 95% CI 1.18–3.57, P=0.01) were significantly associated with HI. No identifiable risk factors were found in 32 (40.5%) of the 79 respondents with HI. We conclude that the prevalence of HI among the elderly in Nigeria is comparable to reports from other countries. Identified risk factors were preventable or controllable. The large proportion of elderly with no identifiable risk factors, presumably presbyacusis, suggests a need for further study. The strategies for control of these risk factors and hearing aid support should be integrated into health care policy initiatives for elderly persons in sub-Saharan Africa.

Filarial selenium glutathione peroxidase: a probable immunodiagnostic marker for lymphatic filariasis

Anchal Singh, Shaukat Kamal, Sushma Rathaur — 2010-08-01

Summary: Lymphatic filariasis (LF) caused by Wuchereria bancrofti is widely prevalent in tropical and subtropical countries. Night blood film examination is most commonly used for diagnosis of filariasis but is cumbersome and labour intensive. In order to develop an indirect ELISA-based immunodiagnostic test, the importance of antifilarial IgG subclasses was evaluated in bancroftian filariasis patients. Blood samples from healthy individuals and different categories of LF patients were used to estimate the diagnostic potential of selenium glutathione peroxidase antigen purified from the bovine filarial parasite Setaria cervi. This antigen reacted with both IgG1 and IgG4; however, the IgG1 response was greater in microfilaraemic patients and the IgG4 response was higher in chronic filarial patients. The diagnostic sensitivity of IgG1 and IgG4 was 97% and 96% whereas specificity was determined to be 95% and 98% respectively. Our observations suggest that SeGSHPx could be an alternative diagnostic marker for the detection of bancroftian filariasis in an endemic area.

A prospective study on the dynamics of the clinical and immunological evolution of human Leishmania (L.) infantum chagasi infection in the Brazilian Amazon region

2010-08-01

Summary: This prospective study was carried out from October 2003 to December 2005 and involved a cohort of 946 individuals of both genders, aged 1–89 years, from an endemic area for American visceral leishmaniasis (AVL), in Pará State, Brazil. The aim of the study was to analyze the dynamics of the clinical and immunological evolution of human Leishmania (L.) infantum chagasi infection represented by the following clinical-immunological profiles: asymptomatic infection (AI); symptomatic infection (SI=AVL); subclinical oligosymptomatic infection (SOI); subclinical resistant infection (SRI); and indeterminate initial infection (III). Infection diagnosis was determined by the indirect fluorescent antibody test and leishmanin skin test. In total, 231 cases of infection were diagnosed: the AI profile was the most frequent (73.2%), followed by SRI (12.1%), III (9.9%), SI (2.6%) and SOI (2.2%). The major conclusion regarding evolution dynamics was that the III profile plays a pivotal role from which the cases evolve to either the resistant, SRI and AI, or susceptible, SOI and SI, profiles; only one of the 23 III cases evolved to SI, while most evolved to either SRI (nine cases) or SOI (five cases) and eight cases remained as III.

Intermittent preventive treatment of malaria in pregnancy (IPTp): do frequent antenatal care visits ensure access and compliance to IPTp in Ugandan rural communities?

Richard Ndyomugyenyi, James Katamanywa — 2010-08-01

Summary: The relationship between antenatal care (ANC) visits and coverage of intermittent preventive treatment of malaria in pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP), and barriers to IPTp-SP access were examined. Four hundred and fifty-three women who had given birth during the study period were interviewed using a semi-structured questionnaire. Of these, 425 (93.8%) attended ANC at least once, but only 90 (21.2%) made four or more visits. Primigravidae 25 (29.8%) were more likely than multigravidae 65 (17.6%) to make more than four visits (P=0.012). Only 237 (52.3%) women accessed two or more doses of IPT-SP, which increased with the number of ANC visits (X2 for linear trends, 117.7, P<0.001). However, 131 (28.9%) women made two or more ANC visits, which were sufficient for them to access two or more doses of IPTp-SP, but they did not. The main reasons were: not given SP by the midwife for unknown reasons 36 (27.5%), SP stock-outs 34 (26%) and irregular ANC attendance 18 (13.7%). Frequent ANC visits do not seem to ensure access to IPTp-SP in the presence of other barriers. The Roll Back Malaria target of 80% of women accessing two or more doses of IPTp-SP by 2010 appears unachievable unless alternative channels of delivery are found.

Comparison of the effects of oral hydration and intravenous fluid replacement in adult patients with non-shock dengue hemorrhagic fever in Taiwan

Ing-Kit Lee, Wen-Huei Lee, Kuender D. Yang, Jien-Wei Liu — 2010-08-01

Abstract: The level of plasma leakage is mild to moderate in patients with non-shock dengue hemorrhagic fever (DHF grade I and grade II), and the necessity of intravenous fluid replacement for these patients remains controversial. We conducted an observational study in adult patients (>18 years) with non-shock DHF admitted to a medical centre in southern Taiwan comparing the effects of oral hydration [group 1 (n=19); age (mean±SD) 54.6±15.5 years] and intravenous fluid replacement, with a volume of >40ml/kg/day in the first 72h of hospitalization [group 2 (n=30); age 55.9±11.6 years]. No significant difference was found in demographics, clinical manifestations, and mean peak level of hematocrit between the two groups. Patients in group 2 had a significantly longer hospital stay compared to those in group 1 (P=0.007), and there was a trend suggesting patients in group 2 were prone to develop pleural effusion and/or pulmonary edema. No difference was found in daily mean pulse pressure, mean hematocrit level, and mean platelet count between the groups for the duration of the 7 days in hospital. All 49 patients survived. Our data suggest that oral hydration may be as effective as intravenous fluid replacement for adults with non-shock DHF and this warrants investigation in a larger series of patients.

Correlation between ELISA and ML Flow assays applied to 60 Brazilian patients affected by leprosy

2010-08-01

Abstract: Serological tests can be helpful in classifying leprosy patients as having either the paucibacillary or the multibacillary form. The aim of this study was to evaluate the concordance between two serological assays, i.e. ML Flow and ELISA, in a population of leprosy patients in Brazil. The investigation involved 60 patients with newly diagnosed leprosy. Together with the application of the serological assays, selected demographic, clinical and epidemiological data relating to the study population were recorded. ML Flow detected anti-PGL1 antibodies in 70% of the leprosy patients, while ELISA was positive in 53.3%. The degree of concordance between the tests was substantial (83.3%). A positive correlation was demonstrated between the results obtained in the semi-quantitative ML Flow test and ELISA absorbance values. We concluded that both serological assays were found to be efficient in detecting anti-PGL1 antibodies. The ML Flow test may be a cheaper and easier to perform alternative to ELISA in leprosy patients.

Incidence of leptospirosis in a select population in Nepal

2010-08-01

Abstract: The geographic distribution of leptospirosis is widespread but no national surveillance program exists in Nepal to establish the incidence of leptospirosis or the disease burden. This study reports the incidence of symptomatic leptospirosis in military personnel participating in an efficacy study of a hepatitis E virus vaccine in Nepal. Among the 1566 study volunteers who completed follow-up, we evaluated 271 illnesses over 2.2 years for the presence of leptospira IgM antibodies by ELISA. Positive ELISA results were confirmed by the microscopic agglutination test. The annual incidence of disease was between 3.5 and 6.1 cases/1000. The prevalence of confirmed leptospirosis was 9% among hepatitis cases and 8% among febrile cases. The most reactive serovars were Bratislava, Autumnalis, Icterohaemorrhagiae, and Sejroe. Leptospirosis should be considered in the differential diagnosis of febrile illnesses and icteric syndromes in Nepal. Additional studies are needed to establish the broader distribution and the spectrum of disease in Nepal.

Increasing incidence of malaria in the Negro River basin, Brazilian Amazon

A.C. Cabral, N.F. Fé, M.C. Suárez-Mutis, M.N. Bóia, F.A. Carvalho-Costa — 2010-08-01

Abstract: Malaria in Brazil is virtually restricted to the Amazon Region, where it has a heterogeneous geographic distribution. We reviewed secondary data in order to describe the regional and temporal distribution of 8018 malaria cases seen between 2003 and 2007 in Santa Isabel do Rio Negro, a municipality in the northwest Brazilian Amazon. A significant rise in malaria incidence, mainly in the Yanomami Indian reservation, was observed during this time. Anopheline breeding sites were also mapped and entomological data were obtained through the capture of larval and adult mosquitoes. Thirty-three potential breeding sites were identified in the urban and periurban areas, 28 of which were positive for anopheline larvae. Anopheles darlingi specimens were captured in both intra- and peridomicile locations in the urban areas. Demographic data were also assessed via a sectional survey, revealing that the majority of dwellings were vulnerable to mosquitoes. This study suggests that urban and periurban areas of this municipality are highly susceptible to epidemic malaria, which is endemic in the Yanomami Indian reservation near the city. In addition, transmission can be perpetuated autochthonously in the urban area, drawing attention to the continuous need for preventative measures such as controlling adult and aquatic stages of mosquitoes and improving housing.

Vibrio cholerae O1 bacteremia in Pakistan: analysis of eight cases

2010-08-01

Abstract: Bacteremia caused by Vibrio cholerae O1 has been a rare phenomenon. We report on eight cases of V. cholerae O1 bacteremia from Pakistan which occurred during 1992–2008. Six of the cases were seen in children (two neonates and four infants) and seven of the eight patients were female. Urogenital malignancy, hepatitis B virus-associated end-stage liver disease, concurrent Campylobacter enteritis and prematurity were the underlying conditions in four patients. Two of the eight patients died and one was lost to follow up and this outcome may be due to prior immunity leading to less severe illness.

Insulin-like growth factor-I induced and constitutive arginase activity differs among isolates of Leishmania derived from patients with diverse clinical forms of Leishmania braziliensis infection

2010-08-01

Summary: Arginase activity has been related to leishmaniasis development, thus we studied the constitutive and insulin-like growth factor (IGF) I-induced arginase activity of Leishmania (Viannia) braziliensis isolates from patients with different clinical forms of American tegumentary leishmaniasis (ATL). Isolates from mucosal leishmaniasis presented higher basal levels of arginase activity than isolates from other clinical forms of ATL. Isolates from disseminated leishmaniasis that present mucosal lesion in some cases reached the arginase activity similar to that of isolates from mucosal leishmaniasis upon IGF-I stimulation. Differences in arginase activity may influence disease outcomes such as evolution to mucosal lesion in patients with L. (V.) braziliensis infection.

Is PCR testing on blood samples useful or not in the diagnosis of Toxoplasma encephalitis?

Daniel Ajzenberg — 2010-08-01

Sir, I read with great interest the paper by Correia et al. In this well-designed study, the authors mainly focused on the sensitivity and specificity of PCR assay in cerebrospinal fluid (CSF) samples for the diagnosis of Toxoplasma encephalitis (TE) in Brazilian AIDS patients in the city of Recife. However, I was concerned by the results of the very low sensitivity (1.5%) of PCR assay observed in blood samples from these patients.