Background: Dengue is a growing problem both in its geographical spread and in its intensity, and yet current global distribution remains highly uncertain. Challenges in diagnosis and diagnostic methods as well as highly variable national health systems mean no single data source can reliably estimate the distribution of this disease. As such, there is a lack of agreement on national dengue status among international health organisations. Here we bring together all available information on dengue occurrence using a novel approach to produce an evidence consensus map of the disease range that highlights nations with an uncertain dengue status. Methods/Principal Findings: A baseline methodology was used to assess a range of evidence for each country. In regions where dengue status was uncertain, additional evidence types were included to either clarify dengue status or confirm that it is unknown at this time. An algorithm was developed that assesses evidence quality and consistency, giving each country an evidence consensus score. Using this approach, we were able to generate a contemporary global map of national-level dengue status that assigns a relative measure of certainty and identifies gaps in the available evidence. Conclusion: The map produced here provides a list of 128 countries for which there is good evidence of dengue occurrence, including 36 countries that have previously been classified as dengue-free by the World Health Organization and/or the US Centers for Disease Control. It also identifies disease surveillance needs, which we list in full. The disease extents and limits determined here using evidence consensus, marks the beginning of a five-year study to advance the mapping of dengue virus transmission and disease risk. Completion of this first step has allowed us to produce a preliminary estimate of population at risk with an upper bound of 3.97 billion people. This figure will be refined in future work.

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Refining the global spatial limits of dengue virus transmission by evidence-based consensus

The 22q11.2 deletion syndrome.

Summary: To date, most Leishmania and human immunodeficiency virus (HIV) coinfection cases reported to WHO come from Southern Europe. Up to the year 2001, nearly 2,000 cases of coinfection were identified, of which 90% were from Spain, Italy, France, and Portugal. However, these figures are misleading because they do not account for the large proportion of cases in many African and Asian countries that are missed due to a lack of diagnostic facilities and poor reporting systems. Most cases of coinfection in the Americas are reported in Brazil, where the incidence of leishmaniasis has spread in recent years due to overlap with major areas of HIV transmission. In some areas of Africa, the number of coinfection cases has increased dramatically due to social phenomena such as mass migration and wars. In northwest Ethiopia, up to 30% of all visceral leishmaniasis patients are also infected with HIV. In Asia, coinfections are increasingly being reported in India, which also has the highest global burden of leishmaniasis and a high rate of resistance to antimonial drugs. Based on the previous experience of 20 years of coinfection in Europe, this review focuses on the management of Leishmania-HIV-coinfected patients in low-income countries where leishmaniasis is endemic.

https://www.who.int/leishmaniasis/burden/hiv_coinfection/Clinical_Microbiology_Reviews_2008.pdf

The Relationship between Leishmaniasis and AIDS: the Second 10 Years

In India, 320 patients with visceral leishmaniasis (209 in the state of Bihar and 11 in the neighboring state of Uttar Pradesh) received identical pentavalent antimony (Sb) treatment. Sb induced long-term cure in 35% (95% confidence interval [CI], 28%-42%) of those in Bihar versus 86% (95% CI, 79%-93%) of those in Uttar Pradesh. In Bihar, the center of the Indian epidemic, traditional Sb treatment should be abandoned.

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Failure of Pentavalent Antimony in Visceral Leishmaniasis in India: Report from the Center of the Indian Epidemic

Dengue viral infections are one of the most important mosquito borne diseases in the world. They may be asymptomatic or may give rise to undifferentiated fever, dengue fever, dengue haemorrhagic fever (DHF), or dengue shock syndrome. Annually, 100 million cases of dengue fever and half a million cases of DHF occur worldwide. Ninety percent of DHF subjects are children less than 15 years of age. At present, dengue is endemic in 112 countries in the world. No vaccine is available for preventing this disease. Early recognition and prompt initiation of appropriate treatment are vital if disease related morbidity and mortality are to be limited. This review outlines aspects of the epidemiology of dengue infections, the dengue virus and its mosquito vector, clinical features and pathogenesis of dengue infections, and the management and control of these infections.

https://pmj.bmj.com/content/postgradmedj/80/948/588.full.pdf

Dengue viral infections

One hundred and ten adult patients hospitalized with dengue haemorrhagic fever (DHF) during the recent outbreak in North India were prospectively studied. Of these, 48 (43.6%) were grade I, 40 (36.4%) grade II, 10 (9.1%) grade III and 12 (10.9%) grade IV DHF. Dengue shock syndrome (DSS) was seen in 22 (20%) patients. Fever, headache, myalgias and arthralgias were the common symptoms seen in 100%, 80.9%, 76.2% and 52.3% patients, respectively. Spontaneous bleeding was seen in 62 patients (56.4%) with mucocutaneous bleeding being the most common (46 patients). Gastrointestinal bleeding was seen in 38 (34.5%) patients. In as many as 40 patients, the haemorrhagic manifestations occurred after the fever had come down. Fifty-five patients (50%) required platelet transfusions. Twelve patients died, giving a mortality rate of 10.9% in the present study. Prompt recognition and supportive treatment can be lifesaving.

Dengue haemorrhagic fever in adults: a prospective study of 110 cases.

The currently prescribed tests for asthma diagnosis require compulsory patient compliance, and are usually not sensitive to mild asthma. Development of an objective test using minimally invasive samples for diagnosing and monitoring of the response of asthma may help better management of the disease. Raman spectroscopy (RS) has previously shown potential in several biomedical applications, including pharmacology and forensics. In this study, we have explored the feasibility of detecting asthma and determining treatment response in asthma patients, through RS of serum. Serum samples from 44 asthma subjects of different grades (mild, moderate, treated severe and untreated severe) and from 15 reference subjects were subjected to Raman spectroscopic analysis and YKL-40 measurements. The force expiratory volume in 1 second (FEV1) values were used as gold standard and the serum YKL-40 levels were used as an additional parameter for diagnosing the different grades of asthma. For spectral acquisition, serum was placed on a calcium fluoride (CaF2) window and spectra were recorded using Raman microprobe. Mean and difference spectra comparisons indicated significant differences between asthma and reference spectra. Differences like changes in protein structure, increase in DNA specific bands and increased glycosaminoglycans-like features were more prominent with increase in asthma severity. Multivariate tools using Principal-component-analysis (PCA) and Principal-component based-linear-discriminant analysis (PC-LDA) followed by Leave-one-out-cross-validation (LOOCV), were employed for data analyses. PCA and PC-LDA results indicate separation of all asthma groups from the reference group, with minor overlap (19.4%) between reference and mild groups. No overlap was observed between the treated severe and untreated severe groups, indicating that patient response to treatment could be determined. Overall promising results were obtained, and a large scale validation study on random subjects is warranted before the routine clinical usage of this technique.

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Serum based diagnosis of asthma using Raman spectroscopy: an early phase pilot study.

A case of mixed infection due to leptospira, dengue and hepatitis E is reported. Similar clinical presentation and simultaneous transmission of these diseases during rainy season can cause substantial misdiagnosis. Serological tests play a mainstay in diagnosis. Early detection by appropriate serological tests and institution of therapy is crucial and life saving.

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Co-infections due to leptospira, dengue and hepatitis E: a diagnostic challenge.

The aims of the present study were to carry out surveillance for dengue virus infection in adults with short-duration fever, and serological study of dengue virus infection in persons without fever. Patients were divided into two groups. Group 1 included patients above 12 years of age with fever of 2-12 days duration without any apparent cause. Of these, patients who presented with fever for 2-5 days were included for virus isolation (group 1a) while those who presented within 6-12 days of the onset of fever were included for the dengue-specific IgM serology (group 1b). Group 2 included a sample of population belonging to all age groups but without pyrexia and blood was collected for dengue-specific IgG serology. Twenty-six patients were enrolled in group 1a over a period of 4 months (September to December, 1997). Of these, DEN1 was isolated in 5 cases. Group 1b included 182 patients, out of which 34 (18.68%) were positive for dengue-specific IgM antibodies. Significantly, all the positive cases were detected during the months of September to November. Retro-orbital pain was present in a significantly more number of IgM-positive cases as compared to IgM-negative cases. Group 2 included 125 cases without fever. The overall positivity for dengue-specific IgG antibodies was 77.6%, with the highest positivity of 100% in the age group of 31-40 years. It was concluded that dengue virus infection is endemic in and around Delhi with peak incidence between September and Novemver. The prevalent serotype during September and December 1997 was DEN1. Since previous epidemic of DHF was due to DEN2 type, isolation of DEN1 serotype indicates changes of another epidemic of DHF due to DEN1 serotype. The stresses the urgent need for implementation of measures to control the transmission of dengue infection.

Seroepidemiology and active surveillance of dengue fever/dengue haemorrhagic fever in Delhi.

Objective Tuberculous lymphadenitis is the commonest form of extra-pulmonary tuberculosis. It is most often caused by M. tuberculosis though several reports from other countries have shown mycobacteria other than tuberculosis (MOTT) to be responsible for a significant proportion of tuberculous lymphadenitis cases. The present study was conducted to find the prevalence of M. tuberculosis and MOTT as aetiological agents in patients with peripheral tuberculous lymphadenitis. Methods A total of 138 patients with tuberculous lymphadenitis were included in the study. Diagnosis of tuberculosis was established on the basis of fine needle aspiration cytology, histopathology, presence of mycobacteria on Ziehl Neelson stain or auramine rhodamine stain, or aspiration of pus with negative Gram's stain and pyogenic cultute with radiologic evidence of pulmonary tuberculosis. Mycobacterial cultures were performed on aspirated material and species identified using standard methods. Results Of 138 patients, single lymph nodal enlargement was found in 48.6% patients while others had more than one lymph nodes. Lymph nodes were matted in 26.8% cases while fluctuation could be elicited in 12.3% patients. Chest X-ray showed evidence of active pulmonary lesions or mediastinal lymphadenopathy in 28.3% cases. The fine needle aspiration cytology was positive for tuberculous lymphadenitis in 41.3% cases while it revealed granulomas or necrosis in another 13% cases. The Ziehl-Neelson and the auramine-rhodamine staining were positive in 19.6% and 26.8% patients, respectively. On culture, the lymph node aspirate was positive for Mycobacterium species in 40.6% patients. In all but two cases, the culture revealed presence of Mycobacterium tuberculosis. The other two cultures revealed growth of Mycobacterium fortuitum chelonae complex. Of the two HIV-positive patients, M. tuberculosis could be isolated in one case. Conclusion Findings of this study suggest that M. tuberculosis is still the most common cause of tuberculous lymphadenitis and MOTT are responsible for very few cases. However, such studies need to be carried out frequently at various centres so as to see any periodic and geographic variations within India.

P Aggarwal

Papers

Dengue haemorrhagic fever in adults: a prospective study of 110 cases.

Serum based diagnosis of asthma using Raman spectroscopy: an early phase pilot study.

Co-infections due to leptospira, dengue and hepatitis E: a diagnostic challenge.

Seroepidemiology and active surveillance of dengue fever/dengue haemorrhagic fever in Delhi.

A clinico-bacteriological study of peripheral tuberculous lymphadenitis.