Jeevan B. Sherchand

Molecular Epidemiology of Rotavirus Diarrhea among Children and Adults in Nepal: Detection of G12 Strains with P[6] or P[8] and a G11P[25] Strain

ABSTRACT In anticipation of a rotavirus vaccine in Nepal, this study was undertaken to determine the distribution of the G and P serotypes and electropherotypes of rotaviruses in order to examine if there is any emerging serotype or unusual strain circulating in children and adults in Nepal. Of 1,315 diarrheal stool specimens, rotavirus was detected by an enzyme-linked immunosorbent assay in 116 (17%) of 666 patients less than 5 years of age, in 18 (7%) of 260 patients 5 to 14 years of age, and in 19 (5%) of 358 patients 15 years of age and older. Approximately 75% of rotavirus diarrhea occurred in children less than 5 years of age. Approximately 70% of rotaviruses found in each of the three age groups belonged to serotype G1P[8]. Interestingly, there were 29 (20%) G12 rotaviruses carrying either P[8] or P[6] and one (0.7%) G11 rotavirus carrying an unusual P[25] genotype. RNA polyacrylamide gel electrophoresis discriminated 19 strains (electropherotypes), among which there were three codominant strains carrying G1P[8] and long RNA patterns. Five electropherotypes were discriminated among G12 rotaviruses, all of which had long RNA patterns. The fact that 20% of rotaviruses were G12 strains carrying either P[8] or P[6] and had multiple electropherotypes suggest that G12 strains are not more rare strains but that they pose an emerging challenge to current and future vaccines. The presence of multiple strains as defined by electropherotypes suggests the richness of the rotavirus gene pool in Nepal, where unusual strains may continue to emerge.

Mumbai disease in far western Nepal: HIV infection and syphilis among male migrant-returnees and non-migrants.

Objective To measure the seroprevalence of human immunodeficiency virus (HIV) infection and syphilis, and to assess the behavioural risk factors for these infections among migrant‐returnees and non‐migrants in far western Nepal.

Molecular characterization of Blastocystis isolates from children and rhesus monkeys in Kathmandu, Nepal.

To investigate the possible transmission of Blastocystis organisms between local rhesus monkeys and children in Kathmandu, Nepal, we compared the subtype (ST) and sequence of Blastocystis isolates from children with gastrointestinal symptoms and local rhesus monkeys. Twenty and 10 Blastocystis isolates were established from 82 and 10 fecal samples obtained from children and monkeys, respectively. Subtype analysis with seven sequence-tagged site (STS) primers indicated that the prevalence of Blastocystis sp. ST1, ST2 and ST3 was 20%, 20% and 60% in the child isolates, respectively. In contrast to human isolates, ST3 was not found in monkey isolates and the prevalence of ST1 and ST2 was 50% and 70%, respectively, including three mixed STs1 and 2 and one isolate not amplified by any STS primers, respectively. Since Blastocystis sp. ST2 has been reported as the most dominant genotype in the survey of Blastocystis infection among the various monkey species, sequence comparison of the 150bp variable region of the small subunit rRNA (SSU rRNA) gene was conducted among ST2 isolates of humans and monkeys. Sequence alignment of 24 clones developed from ST2 isolates of 4 humans and 4 monkeys showed three distinct subgroups, defined as ST2A, ST2B and ST2C. These three subgroups were shared between the child and monkey isolates. These results suggest that the local rhesus monkeys are a possible source of Blastocystis sp. ST2 infection of humans in Kathmandu.

Detection of G12 human rotaviruses in Nepal

Of 731 stool specimens collected from children with diarrhea in Kathmandu, Nepal, from August 2004 through July 2005, 170 (23.3%) tested positive for rotavirus. Reverse transcription–PCR, including a revised G12-specific primer set, identified 56 (32.9%) as G2P[4] and 39 (23.0%) as G12 with P[6], P[8], or P[4].

A Multi-Country Non-Inferiority Cluster Randomized Trial of Frontloaded Smear Microscopy for the Diagnosis of Pulmonary Tuberculosis

Luis Cuevas and colleagues report findings from a multicenter diagnostic clinical trial in tuberculosis, showing that the sensitivity and specificity of a “front-loaded” diagnostic scheme is not inferior to that of a standard diagnostic scheme.

LED Fluorescence Microscopy for the Diagnosis of Pulmonary Tuberculosis: A Multi-Country Cross-Sectional Evaluation

This study, nested within a clinical trial, by Luis Cuevas and colleagues finds that LED-FM microscopy has higher sensitivity but lower specificity than Zn microscopy for detecting tuberculosis in sputum samples.

Molecular Epidemiology of Rotavirus Diarrhea among Children Aged <5 Years in Nepal: Predominance of Emergent G12 Strains during 2 Years

A 2-year surveillance was performed in Kathmandu, Nepal, by collection of stool specimens from 1139 children aged <5 years who were hospitalized for acute diarrhea from November 2005 through October 2007. Of the 1139 samples, 379 (33%) had rotavirus strains identified by enzyme-linked immunosorbent assay; the most prevalent G type was G12, accounting for 50% of typed strains in 2005-2006 and 29% in 2006-2007, followed by G1 (26%) in 2005-2006 and by G9 (28%) and G2 (20%) in 2006-2007. The most prevalent P type was P[8], accounting for 47% of strains in 2005-2006 and 35% in 2006-2007, followed by P[6] (37% in 2005-2006 and 33% in 2006-2007) and P[4] (10% in 2005-2006 and 24% in 2006-2007). Of combined genotypes, G12P[6] was the most prevalent, accounting for 34% of strains in 2005-2006 and 24% in 2006-2007, followed by G1P[8] (23%) in 2005-2006 and G2P[4] (20%) in 2006-2007. An unusually high detection of G12 strains underscores the importance of continued surveillance of rotavirus strains.

Interferon gamma, interferon-gamma-induced-protein 10, and tuberculin responses of children at high risk of tuberculosis infection.

Background: Children in contact with adults with pulmonary tuberculosis (TB) are at risk for infection and disease progression, and chemoprophylaxis may reduce this risk. The identification of infection is based on the tuberculin skin test (TST) and interferon-γ (INF-γ) release assays. Other biomarkers such as interferon-γ-induced-protein 10 (IP-10) may have potential for the diagnosis of latent TB infections. Objectives: To describe IP-10 concentrations and their association to TST and INF-γ responses in children recently exposed to adults with smear-positive TB in Brazil and Nepal. Methods: Two surveys using the same design were undertaken to describe TST, INF-γ, and IP-10 responses in 146 children in Nepal and 113 children in Brazil. Results: The concordance of TST and QuantiFERON-TB gold in-tube (QFT-IT) was high (&kgr; 0.73 in Brazil and 0.80 in Nepal). IP-10 responses were higher in children with both positive TST and positive QFT-IT (medians 1434 pg/mL in Brazil and 1402 pg/mL in Nepal) and lowest in children with both negative TST and negative QFT-IT (medians 206 pg/mL in Brazil and 81 pg/mL in Nepal). Children with negative TST and positive QFT-IT had higher IP-10 concentrations than children with positive TST but negative QFT-IT. Conclusions: IP-10 is a potential marker to identify latent TB infections that is expressed in large quantities and with good agreement with QFT-IT. The reasons for the discrepant results observed are discussed.

Front-Loading Sputum Microscopy Services: An Opportunity to Optimise Smear-Based Case Detection of Tuberculosis in High Prevalence Countries

Setting. Ethiopia, Nepal, Nigeria, and Yemen. Objective. To reduce the time to complete sputum microscopy. Design. Cross-sectional surveys enrolling 923 patients with chronic cough in the 4 countries and using similar protocols. Spot-morning-spot sputum specimens were collected. An additional sputum specimen (Xspot) was collected one hour after the first, and the yields of the first two or the three specimens collected as spot-morning-spot or spot-Xspot-morning were compared. Results. 216 patients had ≥ one positive smear. 210 (97%) were identified by the spot-morning-spot, and 210 (97%) were identified by the spot-Xspot-morning specimens, with 203 and 200 identified by the first 2 specimens of each approach, respectively. Neither difference was significant. Conclusions. The time to complete smear microscopy could be reduced.

A randomized controlled trial of the impact of chlorhexidine skin cleansing on bacterial colonization of hospital-born infants in Nepal.

Background: Chlorhexidine skin cleansing might substantially reduce neonatal infection and mortality in developing countries. Few data exist on the impact of chlorhexidine cleansing on skin colonization of infants during the first day of life or on the absorption potential of chlorhexidine during newborn skin cleansing. Methods: Hospital-born newborns in Kathmandu, Nepal were randomly allocated to full-body skin cleansing with 0.25%, 0.50%, or 1.00% chlorhexidine solution. Skin swabs were collected from the axilla, inguinal, and peri-umbilical areas before cleansing (baseline), and at 2 and 24 hours after treatment. Skin flora was quantified and organisms identified. In a subsample, heel prick blood was collected 24 hours after the cleansing and percutaneous absorption of chlorhexidine was assessed. Results: Among 286 enrolled newborns, no adverse effects on skin were reported and body temperature was minimally reduced (mean reduction, 0.33°C). In all groups, positive skin culture rates were significantly reduced at 2 hours but generally not at 24 hours; greater reductions were observed with higher concentrations of chlorhexidine. Effect at 24 hours was highest in the 1.00% group (37% lower positive skin culture rate). For 15 of 75 infants with heel pricks, chlorhexidine was detected at trace concentrations (<8 ng/mL, n = 14; 25.8 ng/mL, n = 1). Conclusions: Chlorhexidine skin cleansing seemed safe and reduced skin flora in newborns in a dose-dependent manner 2 hours after treatment. Greater residual effect at the highest concentration (1%) might provide broader benefit and may simplify combined maternal and neonatal regimens by matching the concentration used for vaginal cleansing during labor.