Sarala Malla

Typhoid Fever: A Massive, Single-Point Source, Multidrug-Resistant Outbreak in Nepal

BACKGROUND In the summer of 2002, a total of 5963 cases of typhoid fever were recorded in Bharatpur, Nepal (population, 92,214) during a 7-week period. A team from the Armed Forces Research Institute of Medical Sciences in Bangkok, Thailand, and the CIWEC Travel Medicine Clinic (Kathmandu, Nepal) assisted the Nepal National Public Health Laboratory (Kathmandu, Nepal) in the further investigation of this large, explosive febrile disease outbreak. METHODS Investigators conducted a thorough epidemiologic and laboratory investigation to assess the size and scope of the outbreak. In addition to subculturing of previously collected samples, blood samples were obtained from 100 febrile patients, and culture and susceptibility testing were done by standard laboratory methods. Pulsed field gel electrophoresis (PFGE) and plasmid analysis were done. RESULTS The majority of the isolates, including 1 from the municipal water supply, were multidrug resistant. The minimum inhibitory concentrations (MICs) of ciprofloxacin ranged from 0.19 microg/mL to 0.125 microg/mL. With use of PFGE, all isolates, including isolates from the water supply, showed an analytical similarity of 96%-100%. Multidrug-resistant isolates had a plasmid encoding for resistance, and those with resistance to nalidixic acid had a single-point mutation. CONCLUSIONS To the best of our knowledge, this outbreak is the largest single-point source outbreak of multidrug-resistant typhoid fever yet reported, and it was molecularly traced to the citys single municipal water supply. Isolates were uniformly resistant to nalidixic acid, there was a decrease in their susceptibility as measured by MIC of fluoroquinolones, and 90% of isolates obtained were resistant to >1 antibiotic.

Identification of all dengue serotypes in Nepal.

To the Editor: Nepal is situated on the southern slopes of the Himalayas, surrounded by India on 3 sides and China to the north. Nepal’s altitude ranges from 8,848 m in the Himalayas to 90 m in the Terai, the southern, low, flatland bordering India. Nepal is a disease-endemic area for many vector-borne diseases, including malaria, kala-azar, Japanese encephalitis, and lymphatic filariasis. Because of the porous border between Nepal and India, social, cultural, and economic activities in cross-border areas are common. Dengue is an emerging disease in Nepal; presumably transmission is moving north from India into the Terai (1–5). The first report of dengue virus isolation or RNA (serotype 2 with nucleotide homology closest to a dengue virus type 2 isolate from India) was in 2008 involving a Japanese patient returning from Nepal in October 2004 (5). Entomologic investigations from the 1980s showed Aedes albopictus in the Terai plains, but Ae. aegypti has not been previously reported. After Indian outbreaks now known to include all 4 dengue serotypes (6), a team from the Epidemiology and Disease Control Division, Kathmandu, investigated suspected cases of dengue fever during September–October 2006 in Banke, the district bordering Uttar Pradesh, India. The team collected blood samples from persons in Banke and, subsequently, from persons in a number of other districts and sent them to the National Public Health Laboratory in Kathmandu or the Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand for analysis with ELISA, reverse transcription–PCR, (RT-PCR), or both. Case definitions for dengue fever were adopted based on World Health Organization guidelines (7). Blood samples were obtained from patients with an acute febrile illness of 2–7 days’ duration and with >2 of the following manifestations: headache, retro-orbital pain, muscular or joint pain, and rash. If laboratory tests were positive, cases were confirmed. Results were confirmed by ELISA performed at the Armed Forces Research Institute of Medical Sciences as previously described (8). Positive results were immunoglobulin (Ig) M >40 units or IgG >100 units. RT-PCR was performed by extracting RNA from 140 μL of each serum sample using QIAGEN Viral RNA Extraction Kit per manufacturer’s instructions (QIAGEN, Germantown, MD, USA). RT-PCR and nested PCR were conducted according to the Lanciotti protocol (9) with the following modifications. Reverse transcriptase from avian myeloblastosis virus (Promega, Madison, WI, USA) was used in the first round RT-PCR. The concentrations of the primers used in the RT-PCR and nested reactions were reduced from 50 pmol to 12.5 pmol per reaction, and the number of nested PCR amplification cycles was increased to 25. Serum specimens were obtained from 70 suspected case-patients from 16 districts from October 13 through December 3, 2006; 25 confirmed cases (13 by ELISA, 10 by RT-PCR, and 2 by both tests) came from 9 districts (Table). The average age was 29 years (range 5–65 years); 80% of the case-patients were men. Three patients had a history of travel to India, but clusters of dengue fever cases reported in October (Banke and Dang districts) indicated local transmission was occurring among patients with no travel history. The Terai districts accounted for 80% of cases. Entomologic collections done indoors and outside at 5 different sites reporting suspected cases identified Ae. albopictus and Ae. aegypti in all 5 districts. Table Dengue laboratory test results, National Public Health Laboratory, Nepal, and AFRIMS, Bangkok, 2006* These clinical and laboratory test results confirmed the presence of all 4 dengue serotypes. Notably, patients from the Dang district had no travel history outside the Dang valley. Because Aedes spp. have been identified in Dang, the data strongly suggest the existence of an endemic cycle of dengue. Underreporting is expected in the absence of diagnostic facilities at the field level. It is unclear whether the predominance of male patients is indicative of greater outdoor as opposed to indoor transmission. Of note, Ae. albopictus has been found in the country since the 1980s; in this study, we found Ae. aegypti in Nepal. Men typically wear short-sleeved clothes due to hot and humid conditions and, therefore, are frequently exposed to mosquito bites. However, men may also access the healthcare system more frequently. The ages of case-patients point to a relative lack of dengue immunity among the older population, and this finding is consistent with a new introduction of dengue. Because dengue hemorrhagic fever appears when >1 serotype becomes endemic to an area (10), the presence of all 4 serotypes portends the emergence of more severe dengue disease in Nepal.

Field evaluation of commercial immunoglobulin M antibody capture ELISA diagnostic tests for the detection of Japanese encephalitis virus infection among encephalitis patients in Nepal.

OBJECTIVES Japanese encephalitis (JE) is a devastating disease with high rates of death and disability that occurs particularly in resource-limited, rural regions of Asia. Simple, accurate and inexpensive diagnostics tests are vital for quantifying the burden of illness. This field study evaluated two commercial JE immunoglobulin M antibody capture (MAC) ELISA kits using samples from routine JE surveillance. METHODS Positive (n=132) and negative (n=218) sera were randomly selected from patient samples collected as part of JE surveillance in Nepal in 2005. Samples were tested in a national public health laboratory with commercial kits produced by XCyton and Inverness (Panbio). Results were compared with those of the research lab-based reference standard, the Armed Forces Research Institute of Medical Sciences JE MAC ELISA. RESULTS Positive and negative predictive values and 95% confidence intervals were 90% (82-95%) and 85% (79-89%) for Panbio1, 94% (88-98%) and 89% (87-93%) for Panbio2, and 84% (77-90%) and 96% (92-98%) for XCyton kits, respectively. Sensitivities of Panbio1, Panbio2, and XCyton kits were 71% (63-79%), 80% (72-87%), and 93% (88-97%); specificities were 95% (91-98%), 97% (94-99%), and 89% (85-93%), respectively. Overall percent agreement was 86% for Panbio1 and 91% for both Panbio2 and XCyton. CONCLUSIONS Both commercial kits had good predictive values when single serum samples from encephalitis cases were tested in a national laboratory. Either kit can be used in similar JE-endemic settings where co-transmission of dengue virus, a flavivirus which has strong cross-reactivity with JE, is limited. These results can inform decisions by countries and the World Health Organization laboratory networks on national-level use of these kits for JE surveillance.

A pilot study on antimicrobial susceptibility of Neisseria gonorrhoeae isolates from Nepal.

Despite a sharp decline in the incidence of gonococcal infection in developed countries during the last decade gonorrhea remains one of the most common sexually transmitted infections (STIs) in developing countries and a global health problem. In the absence of effective vaccine control of gonococcal infection mainly depends on identification and treatment of the infected individuals and reductions in sexual risk behavior. Early and successful antibiotic treatment of gonococcal infection is important for cure of the patient prevention of complications and to reduce transmission. Strategies for control of gonorrhea have relied on the use of highly effective and often single-dose therapy administered at the time of diagnosis. Information on antimicrobial susceptibility of Neisseria gonorrhoeae is therefore important to guide selection of an appropriate antimicrobial agent. Antimicrobial resistance in gonococci often spreads rapidly between countries and infected travelers often appear for treatment in countries distant from the place of contact. Hence local and regional antimicrobial resistance data are important for management of gonorrhea. Specific data on the incidence of gonorrhea and antimicrobial resistance of N. gonorrhoeae in Nepal is lacking. A pilot study was conducted to assess the effectiveness of current recommendations for treatment for gonorrhea which is a single oral dose of 500 mg ciprofloxacin. (excerpt)

The challenges and successes of implementing a sustainable antimicrobial resistance surveillance programme in Nepal.

BackgroundAntimicrobial resistance (AMR) is a major global public health concern and its surveillance is a fundamental tool for monitoring the development of AMR. In 1998, the Nepalese Ministry of Health (MOH) launched an Infectious Disease (ID) programme. The key components of the programme were to establish a surveillance programme for AMR and to develop awareness among physicians regarding AMR and rational drug usage in Nepal.MethodsAn AMR surveillance programme was established and implemented by the Nepalese MOH in partnership with the International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR, B) from 1998 to 2003. From 2004 to 2012, the programme was integrated and maintained as a core activity of the National Public Health Laboratory (NPHL) and resulted in an increased number of participating laboratories and pathogens brought under surveillance. The main strategies were to build national capacity on isolation, identification and AMR testing of bacterial pathogens, establish laboratory networking and an External Quality Assessment (EQA) programme, promote standardised recording and reporting of results, and to ensure timely analysis and dissemination of data for advocacy and national policy adaptations. The programme was initiated by nine participating laboratories performing AMR surveillance on Vibrio cholerae, Shigella spp., Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria gonorrhoeae.ResultsThe number of participating laboratories was ultimately increased to 13 and the number of pathogens under surveillance was increased to seven (Salmonella spp. was added to the surveillance programme in 2002 and extended spectrum β-lactamase producing Escherichia coli in 2011). From 1999 to 2012, data were available on 17,103 bacterial isolates. During the AMR programme, we observed changing trends in serovars/ species for Salmonella spp., Shigella spp. and V. cholerae and changing AMR trend for all organisms. Notably, N. gonorrhoeae isolates demonstrated increasing resistance to ciprofloxacin. Additionally, the performance of the participating laboratories improved as shown by annual EQA data evaluation.ConclusionsThis Nepalese AMR programme continues and serves as a model for sustainable surveillance of AMR monitoring in resource limited settings.

Intestinal parasitic infection among the HIV-infected patients in Nepal.

INTRODUCTION Intestinal parasitic infection has been a significant problem in HIV patients, worldwide. In this study, we aimed to measure the prevalence and identify the factors associated with intestinal parasitic infection in people infected with HIV and attending National Public Health Laboratory in Kathmandu, Nepal, for CD4 T-cell count. METHODOLOGY An analytical cross-sectional study in 745 HIV-infected people attending for CD4 T-cell count was conducted. RESULTS The prevalence of intestinal parasitic infection was 22.4% (95% CI 19.5 to 25.5). In univariate analysis, age, sex, longer time since diagnosis of HIV, CD4 T-cell count of <200/µL, diarrhoea, marital status, and being under tuberculosis (TB) treatment were significantly associated with increased odds of intestinal parasite infection. However, in the logistic regression model, only the CD4 T-cell count of <200/µL (adjusted OR=4.2, 95% CI 2.5 to 7.0), diarrhoea (adjusted OR=2.8, 95% CI 1.8 to 4.3) and being under TB treatment (adjusted OR=2.9, 95% CI 1.8 to 4.6) remained as significant predictors. On stratification, CD4 T-cell count of <200/ µL was independently associated with higher odds of protozoal as well as helminthes infection. The parasites Cryptosporidium and Cyclospora were observed only in participants with CD4 T-cell counts <200/µL. CONCLUSIONS Both protozoal and helminthic intestinal parasitic infections are common in HIV-infected people seeking care in healthcare facilities. The poor immune status as indicated by low CD4 T-cell count and TB may account for such a high risk of parasitic infection.

Factors associated with high prevalence of pulmonary tuberculosis in HIV-infected people visiting for assessment of eligibility for highly active antiretroviral therapy in Kathmandu, Nepal

Background: Tuberculosis is the leading cause of deaths among HIV patients. In this study, we estimated the prevalence of pulmonary tuberculosis (PTB) and identified the factors/co-morbidities associated with active PTB in HIV-infected people visiting the national public health laboratory to assess their eligibility to receive highly active antiretroviral therapy. Methods: A cross-sectional study was conducted to measure the prevalence of pulmonary tuberculosis. Data on probable risk factors in patients with and without PTB were compared, calculating the odds ratio as a measure of association. Factors showing significant association in univariate analyses were included in a stepwise backward logistic regression model to adjust for confounding. Results: The prevalence of pulmonary tuberculosis was 32.4 % (95% confidence interval (CI) 30.25–34.56). In the univariate analysis, patients with PTB were more likely to be older, married, and have a longer duration since the diagnosis of HIV, diarrhoea, parasitic infection, lower CD4 T-cell counts, and lower CD4/CD8 ratio. However, the backward stepwise logistic regression revealed that only the CD4 T-cell count < 200/μL (AOR 11.69, 95% CI 6.23–21.94), CD4 T-cell count 200–350/μL (AOR 2.52, 95% CI 1.30–4.89), diarrhoea (AOR 2.77, 95% CI 1.78–4.31), parasitic infection (AOR 3.34, 95% CI 2.02–5.50) and ‘sex with partner’ as probable modes of transmission (AOR 0.44, 95% CI 0.20–0.93) were independently associated with pulmonary tuberculosis. Conclusion: A high prevalence of pulmonary tuberculosis was observed. Participants with tuberculosis were significantly more likely to have lower CD4 counts, diarrhoea, and parasitic infections. HIV treatment programmes should consider these factors for better outcomes.