Dengue outbreak in Karachi, Pakistan, 2006: experience at a tertiary care center

Dengue Cases Presenting to the Emergency Department of a Tertiary Care Hospital in Late 2021: A Cross-Sectional Study in Karachi

Objectives: Dengue Fever (DF) is an arboviral disease caused by the Dengue virus (DENV). This study aims to assess the association of dengue prevalence with patients' residential areas and hematological laboratory findings (Total platelet count, immunoglobulins, and dengue antigens) during COVID-19 pandemic. Methods: A retrospective study was conducted at the Emergency department of Jinnah Postgraduate Medical Center, Karachi from October to December 2021. All the patients irrespective of their ages presenting to the ED with either of the following complaints: fever; GIT problems; vomiting; body ache; bleeding were included in our study. Results: Our study comprised 189 patients in total in which the females (n = 172) outnumbered the males (n = 17). Out of all, 84.7% of the patients were febrile having a low-grade fever on average. Korangi district had the most dengue cases, while Keamari had the fewest. There was no significant association reported between mean platelet count, mean TLC, and mean hemoglobin levels with dengue positivity. Conclusion: There is a concerning rise in DF cases in Karachi, particularly in the Korangi district. Despite the COVID-19 pandemic, DF demands urgent attention.

Modelling the impact of climate change on dengue outbreaks and future spatiotemporal shift in Pakistan

Climate change has a significant impact on the intensity and spread of dengue outbreaks. The objective of this study is to assess the number of dengue transmission suitable days (DTSD) in Pakistan for the baseline (1976-2005) and future (2006-2035, 2041-2070, and 2071-2099) periods under Representative Concentration Pathway (RCP4.5 and RCP8.5) scenarios. Moreover, potential spatiotemporal shift and future hotspots of DTSD due to climate change were also identified. The analysis is based on fourteen CMIP5 models that have been downscaled and bias-corrected with quantile delta mapping technique, which addresses data stationarity constraints while preserving future climate signal. The results show a higher DTSD during the monsoon season in the baseline in the study area except for Sindh (SN) and South Punjab (SP). In future periods, there is a temporal shift (extension) towards pre- and post-monsoon. During the baseline period, the top ten hotspot cities with a higher frequency of DTSD are Karachi, Hyderabad, Sialkot, Jhelum, Lahore, Islamabad, Balakot, Peshawar, Kohat, and Faisalabad. However, as a result of climate change, there is an elevation-dependent shift in DTSD to high-altitude cities, e.g. in the 2020s, Kotli, Muzaffarabad, and Drosh; in the 2050s, Garhi Dopatta, Quetta, and Zhob; and in the 2080s, Chitral and Bunji. Karachi, Islamabad, and Balakot will remain highly vulnerable to dengue outbreaks for all the future periods of the twenty-first century. Our findings also indicate that DTSD would spread across Pakistan, particularly in areas where we have never seen dengue infections previously. The good news is that the DTSD in current hotspot cities is projected to decrease in the future due to climate change. There is also a temporal shift in the region during the post- and pre-monsoon season, which provides suitable breeding conditions for dengue mosquitos due to freshwater; therefore, local authorities need to take adaption and mitigation actions.

Burden and distribution of dengue infection in Pakistan (2000-19): a review

The goal of this study is to review the overall prevalence, burden, and distribution of the dengue disease in Pakistan from 2000 to 2019. Literature was searched using different search engines like Google scholar, PubMed, etc. providing the keywords "Dengue disease/infection, Dengue virus, DENV, DF/DHF/ DSS Pakistan". All the published research papers/reports on the dengue virus over the period 2000 to 2019 were studied and selected data were summarized using MS Excel for windows such as total cases, age wise, gender, DENV serotype distribution, total DHF, and DSS patients. The literature providing insufficient data was excluded. The total number of cases reported during 2000-19 were 201,269. The maximum number of cases during the mentioned literature survey period was reported in Khyber Pakhtunkhwa (KP) (23.3%) followed by Punjab (3.8%) and Sindh (1.9%). The majority of dengue-infected cases were reported as Dengue fever (74.4%) followed by DHF (24.1%) and DSS (1.5%). Overall the deaths during the mentioned literature survey were 1082, of which the maximum mortalities were reported from KP (N=248) followed by Punjab (N=220). DENV remains a major public health problem in Pakistan and seems to remain endemic for a long time. The total prevalence of dengue infection is increased accordingly with time from 2000 to 2019. Moreover, all the four serotypes exist in Pakistan with increased mortalities.

Epidemiology of dengue in SAARC territory: a systematic review and meta-analysis

BACKGROUND

Dengue is one of the common arboviral infections and is a public health problem in South East Asia. The aim of this systematic review and meta-analysis was to evaluate the prevalence and distribution of dengue in SAARC (South Asian Association for Regional Cooperation) countries.

METHODS

The PubMed, PubMed Central, Embase and Scopus databases were searched for relevant studies. Statistical analysis on data extracted from the selected studied was conducted using the Comprehensive Meta-Analysis Software (CMA) version 3 software package. Proportions were used to estimate the outcome with a 95% confidence interval (CI).

RESULTS

Across all studies, among cases of suspected dengue, 30.7% were confirmed dengue cases (proportion: 0.307, 95% CI: 0.277-0.339). The seroprevalence of dengue immunoglobulin (Ig)G, IgM or both (IgM and IgG) antibodies and dengue NS1 antigen was 34.6, 34.2, 29.0 and 24.1%, respectively. Among the different strains of dengue, dengue virus (DENV) strains DENV-1, DENV-2, DENV-3 and DENV-4 accounted for 21.8, 41.2, 14.7 and 6.3% of cases, respectively. The prevalence of dengue fever, dengue hemorrhagic fever and dengue shock syndrome was 80.5, 18.2 and 1.5%, respectively. Fever was a commonly reported symptom, and thrombocytopenia was present in 44.7% of cases. Mortality was reported in 1.9% of dengue cases.

CONCLUSIONS

Dengue is a common health problem in South East Asia with high seroprevalence. DENV-2 was found to be the most common strain causing infection, and most dengue cases were dengue fever. In addition, thrombocytopenia was reported in almost half of the dengue cases.

Mathematical modeling in perspective of vector-borne viral infections: a review

Background

Viral diseases are highly widespread infections caused by viruses. These viruses are passing from one human to other humans through a certain medium. The medium might be mosquito, animal, reservoir and food, etc. Here, the population of both human and mosquito vectors are important.

Main body of the abstract

The main objectives are here to introduce the historical perspective of mathematical modeling, enable the mathematical modeler to understand the basic mathematical theory behind this and present a systematic review on mathematical modeling for four vector-borne viral diseases using the deterministic approach. Furthermore, we also introduced other mathematical techniques to deal with vector-borne diseases. Mathematical models could help forecast the infectious population of humans and vectors during the outbreak.

Short conclusion

This study will be helpful for mathematical modelers in vector-borne diseases and ready-made material in the review for future advancement in the subject. This study will not only benefit vector-borne conditions but will enable ideas for other illnesses.

Risk Factors Associated with a Dengue Fever Outbreak in Islamabad, Pakistan: Case-Control Study

Background

On October 23, 2016, 79 dengue fever cases were reported from the Union Council Tarlai to Federal Disease Surveillance and Response Unit Islamabad. A team was established to investigate the suspected dengue outbreak.

Objective

The aim of this study was to determine the extent of the outbreak and identify the possible risk factors.

Methods

Active case finding was performed through a house-to-house survey. A case was defined as an acute onset of fever ≥38℃ in a resident of Tarlai from October 2 to November 11, 2016, with a positive dengue virus (nonstructural protein, NS-1) test and any of the two of following signs and symptoms: retroorbital/ocular pain, headache, rash, myalgia, arthralgia, and hemorrhagic manifestations. A structured questionnaire was used to collect data. Age- and sex-matched controls (1:1) were identified from residents in the same area as cases. Blood samples were taken and sent to the National Institute of Health for genotype identification.

Results

During the active case search, 145 cases of dengue fever were identified by surveying 928 houses from October 23 to November 11, 2016. The attack rate (AR) was 17.0/10,000. The mean age was 34.4 (SD 14.4) years. More than half of the cases were male (80/145, 55.2%). Among all cases, 29% belonged to the 25-34 years age group and the highest AR was found in the 35-44 years age group (35.6/10,000), followed by the 55-64 years age group (35.5/10,000). All five blood samples tested positive for NS-1 (genotype DENV-2). The most frequent presenting signs/symptoms were fever and headache (both 100%). Stagnant water around houses (odds ratio [OR] 4.86, 95% CI 2.94-8.01; P<.001), presence of flower pots in the home (OR 2.73, 95% CI 1.67-4.45; P<.001), and open water containers (OR 2.24, 95% CI 1.36-3.60; P<.001) showed higher odds among cases. Conversely, use of bed nets (OR 0.44, 95% CI 0.25-0.77; P=.003), insecticidal spray (OR 0.33, 95% CI 0.22-0.55; P<.001), door screens (OR 0.27, 95% CI 0.15-0.46; P<.001), mosquito coil/mat (OR 0.26, 95% CI 0.16-0.44; P<.001), and cleanliness of the house (OR 0.12, 95% CI 0.05-0.26; P<.001) showed significant protective effects.

Conclusions

Stagnant water acting as breeding grounds for vectors was identified as the probable cause of spread of the dengue outbreak. Establishment of surveillance and an early reporting system along with use of protective measures against the vector are strongly recommended.

Dengue and Chikungunya virus co-infection in major metropolitan cities of provinces of Punjab and Khyber Pakhtunkhwa: A multi-center study

Dengue has become endemic in Pakistan with annual recurrence. A sudden increase in the dengue cases was reported from Rawalpindi in 2016, while an outbreak occurred for the first time in Peshawar in 2017. Therefore, a multi-center study was carried out to determine the circulating dengue virus (DENV) serotypes and Chikungunya virus (CHIKV) co-infection in Lahore, Rawalpindi, and Peshawar cities in 2016–18. A hospital-based cross-sectional study was carried out in Lahore and Rawalpindi in 2016–18, while a community-based study was carried out in Peshawar in 2017. The study participants were tested for dengue NS1 antigen using an immunochromatographic device while anti-dengue IgM/IgG antibodies were detected by indirect ELISA. All NS1 positive samples were used for DENV serotyping using multiplex real-time PCR assay. Additionally, dengue samples were tested for CHIKV co-infection using IgM/IgG ELISA. A total of 6291 samples were collected among which 8.11% were NS1 positive while 2.5% were PCR positive. DENV-2 was the most common serotype (75.5%) detected, followed by DENV-1 in 16.1%, DENV-3 in 3.9% and DENV-4 in 0.7% while DENV-1 and DENV-4 concurrent infections were detected in 3.9% samples. DENV-1 was the predominant serotype (62.5%) detected from Lahore and Rawalpindi, while DENV-2 was the only serotype detected from Peshawar. Comorbidities resulted in a significant increase (p-value<0.001) in the duration of hospital stay of the patients. Type 2 diabetes mellitus substantially (p-value = 0.004) contributed to the severity of the disease. Among a total of 590 dengue positive samples, 11.8% were also positive for CHIKV co-infection. Co-circulation of multiple DENV serotypes and CHIKV infection in Pakistan is a worrisome situation demanding the urgent attention of the public health experts to strengthen vector surveillance.

Mosquitoes are responsible for the transmission of many different types of infectious pathogens and parasites to humans. Some of these pathogens include viruses like dengue and chikungunya viruses which cause diseases in humans. Dengue virus has four different types (1, 2, 3, and 4) present in nature. In this study, we detected all four dengue virus types in hospitalized patients in Lahore and Rawalpindi. While only dengue virus type-2 was detected from Peshawar city. The secondary infections with different dengue virus types than the previous one might result in a more severe form of the disease. Therefore, the population of Peshawar is at risk of developing a severe form of dengue fever in the future in case of infection from another dengue virus type. The data of hospitalized patients showed that other diseases in addition to dengue fever result in an increased hospital stay. Comorbidities like diabetes also increase the risk of developing a more severe form of dengue fever. Combined infections of both dengue and chikungunya viruses were detected from Lahore, Rawalpindi, and Peshawar. The transmission of dengue and chikungunya viruses and the co-circulation of multiple dengue virus types not only impose public health burden but also result in economic losses.

Cosmopolitan A1 lineage of dengue virus serotype 2 is circulating in Pakistan: A study from 2017 dengue viral outbreak

Dengue viral infection has become a challenge in tropical and subtropical countries where dengue virus is endemic. Its epidemics are occurring at higher rates amid its circulation throughout the year. Since the first documented outbreak in Pakistan in 1994, this region has reported many sporadic cases and epidemics. There is availability of small scale demographic and epidemiological studies on dengue viral infection in Pakistan. The year 2017 witnessed a huge dengue outbreak in Peshawar city of Pakistan with 69 deaths and 24 807 laboratory-confirmed cases. We suspect that the circulation of a different lineage or genotype could be responsible for the enhanced number of infected patients in Pakistan's 2017 outbreak since previous studies have already described this phenomenon in other countries. For this, we collected 1447 suspected blood samples and their epidemiological data. After serotyping through polymerase chain reaction nine samples of Dengue virus2 (DENV2) were randomly selected and were subjected to Sanger's sequencing for genotyping analysis. The mean distance, genetic diversity, and phylogenetic analysis were carried out using K2 model. The phylogenetic analysis split Pakistani isolates into two lineages, the sequences from 2017 outbreak in Peshawar grouped within A1 lineage of cosmopolitan genotype (IV) of DENV2. The difference in distance, genetic diversity, and amino acids composition strongly back the results that the new lineage is circulating in the region. This is significant as Pakistan is struggling to control dengue epidemics which have caused much loss in both monetary and health sectors.

Dengue Outbreaks in Khyber Pakhtunkhwa (KPK), Pakistan in 2017: An Integrated Disease Surveillance and Response System (IDSRS)-Based Report

The current study is a retrospective epidemic report regarding dengue fever (DF) virus infection cases (2017) from fifteen districts of KPK, Pakistan. Medical records of 120 948 patients were reviewed retrospectively for demographic, clinical and laboratory data. The presence of dengue infection was confirmed by NS1-ELISA and RT-PCR, respectively. The total positive cases (of suspected DF samples) were 24 938 (20.6%), whereas seventy cases (0.28%) had a fatal outcome. Mean age ± SD of the dengue patients was 26 ± 19.8 years, while; the most affected age group was from 16 to 30 years (Chi-square: 12 820.125, p: 0.00). The infected males were 65.3%, and that of the female was 34.7%. All the dengue-infected patients were observed with symptoms of severe fever (100%), body aches (95%), gums and nose bleeding (5%), skin rashes (30%), vomiting (70%). The highest infection rate was found in district Peshawar and that of the lowest was in Bannu, Hungu and Luki Marwat. A high rate of dengue infection was found in post-monsoon months i.e. October (41%) and September (32%) of the year. The results proved that if the dengue outbreaks reveal further in KPK, it could alarmingly increase the mortality rate. Therefore, the Department of Public Health in KPK, Pakistan may take proper measures to avoid and control dengue epidemics in the future.

Complete genome amplification and sequencing of DENV-2 Pakistani isolates: analysis reveals molecular evolution of DENV-2

Aim: This study was aimed to amplify, characterize and analyze complete genomes of dengue virus serotype-2 (DENV-2) Pakistani isolates. Patients & methods: Complete genomes of DENV-2 (n = 4) in nine overlapping fragments from two dengue outbreaks (2011 and 2013) were sequenced; deposited in GenBank (Punjab Isolates: KM217157 and KM217156; Swat Isolates: KM217158 and KJ701507) and characterized using specific primers, we designed. Results: Analysis clustered Pakistani isolates with the cosmopolitan genotypes and further indicated that codons 65 of C, 155 of PrM, 203 of E and 254 of NS1 genes were under negative selection pressure. A substitution of alanine with proline in NS5 gene at nucleotide position 885 in Swat isolates was observed. Conclusion: DENV-2 is spreading to other parts of Pakistan with the possible adaptability of the virus molecularly.

Dengue Outbreak in Peshawar: Clinical Features and Laboratory Markers of Dengue Virus Infection

BACKGROUND

Dengue is a tropical disease caused by dengue virus (DENV). It is one of the most significant arthropod-borne viral infection.

OBJECTIVES

The aim of the current study was to characterize epidemiological, clinical features and laboratory markers of dengue infection during the recent epidemic in Peshawar, KP.

METHODS

During the prospective hospital-based observational study, 2000 dengue suspected cases were serologically examined at Lady Reading Hospital (LRH) Peshawar. Dengue NS1 antigen and Dengue IgG and IgM antibody ELISA tests were conducted for the confirmation of dengue infection. Data regarding the clinical features, platelet count and liver function tests were also recorded for the dengue positive patients.

RESULTS

Out of total samples 415 (21%) cases including 309 (74%) male and 106 (25%) female were detected positive for the dengue infection. In the dengue positive patients, the highest prevalence was observed in the age group of 21-40years with 160 (38%) followed by the age group of 1-20years with 89 (21%) patients. Fever was recorded in 100% of the dengue patients followed by a headache and fatigue in 73% and liver abnormality observed in 70% of the cases. During laboratory examinations IgM antibody was detected in 180 cases, followed by IgG antibody in 87, NS1 antigen in 43, NS1 antigen along with IgG and IgM antibodies in 41 dengue positive cases. Another combine detection of NS1 antigen with IgM antibody, NS1 antigen with IgG antibody and both IgG and IgM antibodies was observed in 21, 21, 22 dengue cases respectively.

CONCLUSION

It was concluded that the dengue infection can be early diagnosed on the basis of described clinical features and with the detection of dengue-specific NS1 antigen along with antibodies such as IgG and IgM.

Seasonal Distribution and Container Preference Ratio of the Dengue Fever Vector (Aedes aegypti, Diptera: Culicidae) in Rawalpindi, Pakistan

Aedes aegypti (L.) and Aedes albopictus (Skuse) are known vectors of dengue, chikungunya, and other pathogens; however, their ecology and role in virus transmission has not been well studied in Pakistan. Here, we report on an intensive survey of potential breeding sites of Ae. aegypti in Rawalpindi, Punjab Province, Pakistan. The study continued for 11 mo and was divided into three seasons: January to June (pre-monsoon), July to September (monsoon), and October-November (post-monsoon). Larval mosquitoes were collected from all wet containers present in and around the houses. Altogether 5,570,418, 2,930,508, and 1,507,111 water-filled containers were examined during each season, of which 2,703, 8,843, and 3,439 were found positive for Ae. aegypti larvae or pupae, yielding Breteau indices of 0.46, 2.92, and 1.99%, respectively. Among 14 container types examined, the breeding preference ratio during all seasons was highest for roof-top water tanks and room evaporative coolers, followed by discarded tires and urban trash. The study concluded that increased urbanization, insufficient water supply and inefficient removal of urban trash resulted in increased numbers of nonbiodegradable containers around human dwellings, thereby creating ideal breeding habitats for Ae. aegypti. Measures such as integrated vector management, minimization of the breeding potential of Ae. aegypti by water management, proper disposal of discarded tires and urban trash, and health education were recommended for control of Ae. aegypti.

Epidemiological trends and risk factors associated with dengue disease in Pakistan (1980-2014): a systematic literature search and analysis

BACKGROUND

Dengue is becoming more common in Pakistan with its alarming spreading rate. A historical review needs to be carried out to find the root causes of dengue dynamics, the factors responsible for its spread and lastly to formulate future strategies for its control.

METHODS

We searched (January, 2015) all the published literature between 1980 and 2014 to determine spread/burden of dengue disease in Pakistan.

RESULTS

A total of 81 reports were identified, showing high numbers of dengue cases in 2010, 2011, and 2013. The tendency of dengue to occur in younger than in older age groups was evident throughout the survey period and all four serotypes were recorded, with DENV1 the least common. Most dengue hemorrhagic fever (DHF) cases fell in the 20-45 years age range. High frequencies tended to be observed first in the Southern coastal region characterized by mild winters and humid warm summers and then the disease progressed towards the lowland areas of the Indus plain with cool winters, hot summers and monsoon rainfall. Based on this survey, new risk maps and infection estimates were identified reflecting public health burden imposed by dengue at the national level.

CONCLUSIONS

Our study showed that dengue is common in the three provinces of Pakistan, i.e., Khyber Pakhtunkhwa (KP), Punjab and Sindh. Based on the literature review as well as on our study analysis the current expansion of dengue seems multifactorial and may include climate change, virus evolution, and societal factors such as rapid urbanization, population growth and development, socioeconomic factors, as well as global travel and trade. Due to inadequate remedial strategies, effective vector control measures are essential to target the dengue vector mosquito where high levels of human-vector contact occur. The known social, economic, and disease burden of dengue is alarming globally and it is evident that the wider impact of this disease is grossly underestimated. An international multi-sectoral response, outlined in the WHO Global Strategy for Dengue Prevention and Control, 2012-2020, is now essential to reduce the significant influence of this disease in Dengue endemic areas. Overall gaps were identified in knowledge around seroprevalence, dengue incidence, vector control, genotype evolution and age-stratified serotype circulation.

Global dengue death before and after the new World Health Organization 2009 case classification: A systematic review and meta-regression analysis

BACKGROUND

Since the introduction of 2009 WHO dengue case classification, no literature was found regarding its effect on dengue death. This study was to evaluate the effect of 2009 WHO dengue case classification towards dengue case fatality rate.

METHODS

Various databases were used to search relevant articles since 1995. Studies included were cohort and cross-sectional studies, all patients with dengue infection and must report the number of death or case fatality rate. The Joanna Briggs Institute appraisal checklist was used to evaluate the risk of bias of the full-texts. The studies were grouped according to the classification adopted: WHO 1997 and WHO 2009. Meta-regression was employed using a logistic transformation (log-odds) of the case fatality rate. The result of the meta-regression was the adjusted case fatality rate and odds ratio on the explanatory variables.

RESULTS

A total of 77 studies were included in the meta-regression analysis. The case fatality rate for all studies combined was 1.14% with 95% confidence interval (CI) of 0.82-1.58%. The combined (unadjusted) case fatality rate for 69 studies which adopted WHO 1997 dengue case classification was 1.09% with 95% CI of 0.77-1.55%; and for eight studies with WHO 2009 was 1.62% with 95% CI of 0.64-4.02%. The unadjusted and adjusted odds ratio of case fatality using WHO 2009 dengue case classification was 1.49 (95% CI: 0.52, 4.24) and 0.83 (95% CI: 0.26, 2.63) respectively, compared to WHO 1997 dengue case classification. There was an apparent increase in trend of case fatality rate from the year 1992-2016. Neither was statistically significant.

CONCLUSIONS

The WHO 2009 dengue case classification might have no effect towards the case fatality rate although the adjusted results indicated a lower case fatality rate. Future studies are required for an update in the meta-regression analysis to confirm the findings.

Effect of introduction of single-donor apheresis platelets in dengue management: A comparative analysis of two consecutive dengue epidemics

BACKGROUND:

The frequency of dengue outbreak is increasing in Southeast Asian countries these days and since there are no specific drugs against the dengue virus; therefore, treatment consists of mainly symptomatic and supportive care.

AIMS:

Platelet transfusion forms one of the major parts of treatment therapy in dengue; therefore, this study was initiated to elicit the effect of introduction of single-donor apheresis platelets (SDAPs) in dengue management.

SETTINGS AND DESIGN:

This is a retrospective study conducted on 622 clinically suspected cases of dengue infection who received platelet transfusions between August 2013 and December 2015 in a teaching hospital of North India.

MATERIALS AND METHODS:

Clinical data, reports of hematological investigation, transfusion request forms, platelet requirements, and data obtained from daily follow-up and blood bank records were analyzed using IBM SPSS version 20.

RESULTS:

Average platelet count at which platelet transfusion initiated was 25,703/cumm. Average number of random donor platelets (RDPs) transfused significantly decreased in 2015 (2013 vs. 2015 is 5.4 vs. 4.3) due to the transfusion of SDAP to patients with very low platelet count and those with superimposed high-risk factors. Mean length of stay in hospital was similar for patients receiving RDP only and for those receiving RDP and SDAP both (5.48 vs. 5.54) while that for patients receiving SDAP only was quite lower (3.6). Overall cost of stay was higher for those receiving SDAP transfusions.

CONCLUSION:

Decision for initiating platelet transfusions and calculating its dose for dengue patients is highly variable, but transfusing high-dose platelets such as SDAP at an appropriate stage can reduce further requirement of platelet transfusions, fasten the recovery, reduce the hospital stay, lower the risk of transfusion-associated adverse reactions, and can further minimize the associated morbidity and mortality.

Analysis of dengue virus burden and serotypes pattern in Faisalabad, 2016–2017

Dengue is the fastest growing mosquito-borne viral infection and has become a public epidemic in Pakistan. This cross-sectional study was carried out to explore the prevalence and characterization of dengue virus serotypes in Faisalabad, Pakistan during 2016–2017. Aim: To determine most prevalent dengue serotype in Faisalabad, Pakistan. Methodology: Cross-sectional study of stored serum specimens for dengue virus genotype by multiplex real time (RT)-PCR, antidengue IgM, IgG and NS1.Results: Viral RNA detection of 42 patients revealed positive results in 125 (34.4%) samples. DENV-3 (76%) was the predominant genotype followed by DENV-2 (17%) and 7% of DENV1. None of the samples were positive for DENV-4. Conclusion: DENV-3 is the most prevalent serotype of dengue virus observed in Faisalabad, Pakistan.

Flaviviruses as a Cause of Undifferentiated Fever in Sindh Province, Pakistan: A Preliminary Report

Arboviral diseases are expanding worldwide, yet global surveillance is often limited due to diplomatic and cultural barriers between nations. With human encroachment into new habitats, mosquito-borne viruses are also invading new areas. The actual prevalence of expanding arboviruses is unknown in Pakistan due to inappropriate diagnosis and poor testing for arboviral diseases. The primary objective of this study was to document evidence of flavivirus infections as the cause of undifferentiated fever in Pakistan. Through a cooperative effort between the USA and Pakistan, patient exposure to dengue virus (DENV), West Nile virus (WNV), and Japanese encephalitis virus (JEV) was examined in Sindh Province for the first time in decades. Initial results from the 2015 arbovirus season consisting of a cross-sectional study of 467 patients in 5 sites, DENV NS1 antigen was identified in 63 of the screened subjects, WNV IgM antibodies in 16 patients, and JEV IgM antibodies in 32 patients. In addition, a number of practical findings were made including (1) in silico optimization of RT-PCR primers for flavivirus strains circulating in the Middle East, (2) shipping and storage of RT-PCR master mix and other reagents at ambient temperature, (3) Smart phone applications for the collection of data in areas with limited infrastructure, and (4) fast and reliable shipping for transport of reagents and specimens to and from the Middle East. Furthermore, this work is producing a group of highly trained local scientists and medical professionals disseminating modern scientific methods and more accurate diagnostic procedures to the community.

Complete genome sequencing and comparative analysis of three dengue virus type 2 Pakistani isolates

Dengue is currently one of the most important arthropod borne human viral diseases caused by a flavivirus named as dengue virus. It is now endemic in Pakistan since many dengue fever outbreaks have been observed in Pakistan during the last three decades. Major serotype of dengue virus circulating in Pakistan is serotype 2. Complete genome sequences of three Pakistani dengue virus serotype 2 isolates were generated. Analysis of complete genome sequences showed that Pakistani isolates of dengue virus serotype 2 belonged to cosmopolitan genotype. This study identifies a number of amino acid substitutions that were introduced in local dengue virus serotype 2 isolate over the years. The study provides a significant insight into the evolution of serotype 2 of dengue virus in Pakistan. This is the first report of complete genome sequence information of dengue virus from the most recent outbreak (2013) in Punjab, Pakistan.

Wolbachia pipientis: A potential candidate for combating and eradicating dengue epidemics in Pakistan

Dengue virus syndrome is an emerging global health challenge which is endemic in tropical countries like Pakistan. In recent years dengue incidences have increased considerably in different areas of Pakistan with more sever impacts on urban and peri-urban populations. This review is an effort to highlight the changing epidemiology of dengue fever, role of Government of Pakistan in disease management and control using preventive and community based approaches in the region. Moreover, there is an emphasis on application of Wolbachia as novel, inexpensive and environmentally benign candidate for control and eradication of dengue transmitting vectors.

Introduction and evolution of dengue virus type 2 in Pakistan: a phylogeographic analysis

BACKGROUND

Pattern of Dengue periodic epidemics through the years along with sporadic cases of Dengue hemorrhagic fever followed by a severe 2011 epidemic of Dengue fever in Pakistan make Pakistan a Dengue endemic country. To study the entry and evolution of dengue virus serotype 2 (DENV-2) in Pakistan, we sequenced three full length genomes and 24 complete envelope sequences of DENV-2 from the years 2010, 2011 and 2013 collected from Punjab province of Pakistan.

METHODS

Phylogenetic and Bayesian phylogeographic analyses was applied to three full genome sequences as well as 24 envelope sequences to study the spatiotemporal dynamics of DENV-2 in Pakistan.

RESULTS

Most of the DENV-2 viruses from the years 2008 to 2013 formed a monophyletic Pakistani clade in IVb sublineage of cosmopolitan genotype except one 2008 DENV-2 strain. Phylogeographic analysis revealed that this 2008 DENV-2 strain was rooted to India 25.4 years ago with a location probability of 0.88. However Pakistani clade rooted back to Sri Lanka 12.6 years ago with a location probability of 0.57.

CONCLUSION

DENV-2 genotype IV was introduced in Pakistan in two time events. First event was introduction from India to Pakistan in the late 1980s (around 1986), and second event was introduction from Sri Lanka to Pakistan around 2000. The later introduction event was responsible for major outbreaks in the Punjab region of Pakistan, including major 2011 outbreak. After the second Introduction event, DENV-2 circulated locally in the region forming a distinct Sublineage within the IVb cosmopolitan genotype of DENV-2.

Dengue viremia in blood donors in Northern India: Challenges of emerging dengue outbreaks to blood transfusion safety

BACKDROUND

Emerging infectious diseases pose threats to the general human population; including recipients of blood transfusions. Dengue is spreading rapidly to new areas and with increasing frequency of major outbreaks. Screening blood for dengue antigens in dengue-endemic countries would be costly and should, therefore, be recommended only after careful assessment of risk for infection and cost.

AIM

A prospective study was conducted to establish the magnitude of the threat that dengue poses to blood safety where it is sporadic with seasonal variations, to quantify risk and to assess that whether screening is feasible and cost-effective.

MATERIALS AND METHODS

Nonstructural protein 1 (NS1) antigen test was done on 1709 donations during dengue outbreak in the months August to November 2013 as an additional test using Bio-Rad Platelia Dengue NS1AG test kit which is one step sandwich format microplate enzyme immunoassay using murine monoclonal antibodies for capture and revelation. Chi-square test was used to find statistical significance.

RESULTS AND CONCLUSIONS

Majority cases were whole blood, replacement, male donors with 76.10% donors in <35 years age group. About 17.85% were single donor platelet donations. NS1 antigen in all donors was negative. In the past, dengue affected mainly children who do not donate blood. With the changing trend, mean age of infection increased affecting the population that does donate blood, further reducing blood donation pool. Further studies need to be done in different geographic regions of the country during dengue transmission season to establish maximum incidence of viremic donations, rates of transfusion transmission and clinical consequences in recipients. If risk is found to be substantial, decision will be taken by the policymakers at what threshold screening should be instituted to ensure safe blood transfusion.

Predictive symptoms and signs of severe dengue disease for patients with dengue fever: a meta-analysis

The aim of the meta-analysis was to provide more solid evidence for the reliability of the new classification. A systematic literature search was performed using PubMed, Armed Forces Pest Management Board Literature Retrieval System, and Google Scholar up to August 2012. A pooled odds ratio (OR) was calculated using either a random-effect or a fixed-effect model. A total of 16 papers were identified. Among the 11 factors studied, five symptoms demonstrated an increased risk for SDD, including bleeding [OR: 13.617; 95% confidence interval (CI): 3.281, 56.508], vomiting/nausea (OR: 1.692; 95% CI: 1.256, 2.280), abdominal pain (OR: 2.278; 95% CI: 1.631, 3.182), skin rashes (OR: 2.031; 95% CI: 1.269, 3.250), and hepatomegaly (OR: 4.751; 95% CI: 1.769, 12.570). Among the four bleeding-related symptoms including hematemesis, melena, gum bleeding, and epistaxis, only hematemesis (OR: 6.174; 95% CI: 2.66, 14.334; P < 0.001) and melena (OR: 10.351; 95% CI: 3.065, 34.956; P < 0.001) were significantly associated with SDD. No significant associations with SDD were found for gender, lethargy, retroorbital pain, diarrhea, or tourniquet test, whereas headache appeared protective (OR: 0.555; 95% CI: 0.455, 0.676). The meta-analysis suggests that bleeding (hematemesis/melena), vomiting/nausea, abdominal pain, skin rashes, and hepatomegaly may predict the development of SDD in patients with DF, while headache may predict otherwise.

Clinical presentation and outcome of dengue viral infection in live-related renal transplant recipients in Karachi, Pakistan

INTRODUCTION

In Pakistan, dengue viral infection has become hyper-endemic. Renal transplantation is also expanding. We aimed to study dengue in renal transplant recipients (RTR).

METHODS

We conducted a study of RTR reported to be anti-dengue immunoglobulin-M antibody positive from January 2009 to December 2010 at our institution in Karachi and follow their clinical course and outcome.

RESULTS

Median age was 28 years; 75 (73.7%) were males. Clinical presentation included fever in 82 (80.4%), gastrointestinal symptoms in 35 (34.3%), hemorrhagic complications in 9 (8.8%), and thrombocytopenia in 97 (95%), which was of >15 days duration in 24%. Fever was seen less frequently in patients on high-dose (>7.5 mg) steroids as compared with low-dose (≤7.5 mg) steroids. Forty-four patients (43%) had primary and 58 (56.8%) had secondary dengue infection. Dengue fever (DF) occurred in 90 (88%), and dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) occurred in 12 (11.7%). DHF/DSS was seen in 3 (6.8%) of those with primary and in 9 (15.5%) of those with secondary infection (P < 0.22). In secondary infection, patients on cyclosporine-containing regimen had less severe disease, with DHF/DSS in 22% as opposed to DF in 59% (P < 0.04). Of 102 RTR, 68 (66.7%) had graft dysfunction, 5 of whom died. Of the remaining 63, in 54 patients (85.7%) creatinine returned to baseline by an average of 12.6 days. Of 102 patients, 95 (93%) recovered and 7 (6.9%) died, 6 of whom had bacteremia with sepsis and 1 had respiratory failure. None died due to dengue infection alone.

CONCLUSION

In conclusion, in RTR without life-threatening co-morbidities, the clinical course of dengue infection is mild, with good recovery and preserved renal function.

Seroepidemiology of dengue fever in Khyber Pakhtunkhawa, Pakistan

BACKGROUND

Dengue is the most important vector-borne disease in many different parts of the world and is expanding into other areas of the globe without hindrance. The morbidity and mortality due to dengue complications are increasing globally at an alarming rate. Although transmission of the dengue virus has been documented in well-characterized areas of Pakistan, its incidence in Khyber Pakhtunkhawa has not been characterized. To address this issue we aimed to determine the seroprevalence of dengue (IgM and IgG) antibodies and the disease symptoms in the population of Khyber Pakhtunkhawa, and to investigate the incidence of dengue fever in different seasons and in urban as well as in rural areas.

METHODS

From August to October 2011, data of suspected dengue patients were collected from different primary, secondary, and tertiary collection centers situated in Khyber Pakhtunkhawa in order to determine the actual seroprevalence of dengue antibodies (IgM and IgG) in Khyber Pakhtunkhawa.

RESULTS

A total 612 subjects with a suspected infection were enrolled in our study. Of the 612 suspected cases, 319 were found positive for dengue IgG, IgM, or both IgG and IgM. The overall weighted prevalence of dengue-specific antibodies (IgM and/or IgG) was 52.12%. Overall, of the 52.12%, 31.86% (95% confidence interval (CI) 28.17-35.55) were positive for dengue IgM and 20.26% (95% CI 17.03-23.39) were positive for dengue IgG. Only 23 (3.75%) samples showed both IgG and IgM antibodies. A higher prevalence of IgM (39.35%, 95% CI 32.84-45.86) and IgG (22.42%, 95% CI 16.86-27.98) antibodies was found in the age group 21-30 years as compared to the children age group (≤10 years) and the oldest age group (≥51 years). The mean age of the febrile cohort was 53.16 ± 44.22 years, ranging from 4 to 85 years. Age group was not statistically associated with IgM (p=0.64) or IgG (p=0.49) positivity. A higher seroprevalence of IgM (37.24%, 95%CI 32.84-45.86) was observed in males as compared to females (IgM 17.88%, 95% CI 11.11-24.65) while higher seroprevalnce of IgG (22.76%, 95% CI 15.35-30.17) was seen in females as compared to males (IgG 17.58%, 95% CI 14.21-20.95). Gender was not significantly associated with IgM (p=0.06) or IgG (p=0.53) positivity. Dengue IgM (35.38%, 95% CI 38.61-62.91) and IgG (50.76%, 95% CI 38.61-62.91) were higher in patients who had a history of travel to a dengue endemic area as compared to those who did not (IgM 33%, 95% CI 29.06-36.94, and IgG 15%, 95% CI 12.01-17.99). History of travel to an endemic area was significantly associated with IgM (p=0.023) and IgG (p=0.041) positivity. A higher incidence of IgM (41.13%, 95% CI 35.55-46.71) and IgG (27.42%, 95% CI 22.36-32.48) was observed in urban areas than in rural areas (IgM 23%, 95% CI 18.34- 27.66, and IgG 13.41%, 95% CI 9.63-17.19). IgM (p=0.0005) and IgG (p=0.0007) positivity was significantly associated with area of residence. Symptoms including fever (p=0.007), headache (p=0.001), Skin rash (0.005), joint pain (0.004) and Fatigue were significantly linked to dengue fever. IgM and IgG antibodies were more frequently seen in the post-monsoon season (68.33%) than in the monsoon period (31.68%). The death ratio in the overall weighted prevalence was 2.19%.

CONCLUSION

The results of the present cohort study of febrile subjects show that young people and males are more susceptible to dengue fever. Dengue infection was most prominent in the post-monsoon season, in urban areas, and in patients with a history of travel to an endemic locality. Furthermore seven deaths were found in our cohort study.

Factors predicting severe dengue in patients with dengue Fever

Introduction

Dengue virus (DENV) affects over half the world’s population in 112 countries, and dengue fever (DF) is the second largest arthropod borne infectious global hazard after malaria with complications like Dengue Hemorrhagic Fever (DHF) and Dengue Shock Syndrome (DSS), accounting for significant morbidity and mortality world-over. Pakistan is significantly affected with DENV infection and to-date no study identifying risk factors associated with development of severe complications of DF has been done.

Methods

997 confirmed cases of DF were collected from a tertiary care hospital in Lahore, Pakistan and their clinical and biochemical data were collected. Univariate, multivariate and logistics regression analysis was performed to identify risk factors associated with development of DHF and DSS.

Results

Bleeding OR 70.7 (CI 38.4–129.9), deranged liver function test OR 1.9 (CI 0.97–0.99), presence of urinary red blood cells OR 1.4 (95%CI 0.179–0.900) and presence of urinary protein OR 1.1 (95%CI 0.191–0.974) were related to development of DHF and DSS.

Discussion

Severe Dengue, like DHF and DSS can be predicted by the presence of clinical and biochemical factors like signs of bleeding, deranged liver function test, presence of urinary red blood cells and urinary protein; so that the patients at high risk for complication be identified early and started on treatment timely.

Conclusion

Predictors of severe dengue are identified in this study but further large scale multi-centered studies are needed for better interpretation.

Missing the boat: odds for the patients who leave ED without being seen

BACKGROUND

A patient left without being seen is a well-recognized indicator of Emergency Department overcrowding. The aim of this study was to define the characteristics of LWBS patients, their rates and associated factors from a tertiary care hospital of Pakistan.

METHODS

A retrospective patient record review was undertaken. All patients presenting to the Aga Khan University Hospital, Karachi, between April and December of the year 2010, were included in the study. Information was collected on age, sex, presenting complaints, ED capacity, month, time, shift, day of the week, and waiting times in the ED. A basic descriptive analysis was made and the rates of LWBS patients were determined among the patient subgroups. Logistic regression analysis was used to assess the risk factors associated with a patient not being seen in the ED.

RESULTS

A total of 38,762 patients visited ED during the study period. Among them 5,086 (13%) patients left without being seen. Percentage of leaving was highest in the night shift (20%). The percentage was twice as high when the ED was on diversion (19.8%) compared to regular periods of operation (9.8%). Mean waiting time before leaving the ED in pediatric patients was 154 minutes while for adults it was 171 minutes. More than 32% of patients had waited for more than 180 minutes before they left without being seen, compared to the patients who were seen in ED. Important predictors for LWBS included; Triage category P4 i.e. walk -in-patients had an OR of 13.62(8.72-21.3), Diversion status, OR 1.49(1.26-1.76), night shift , OR 2.44(1.95-3.05) and Pediatric age, OR 0.57(0.48-0.66).

CONCLUSIONS

Our study elucidates the LWBS population characteristics and identifies the risk factors for this phenomenon. Targeted interventions should be planned and implemented to decrease the waiting time and alternate services should be provided for high-risk patients (for LWBS) to minimize their number.

A review of dengue as an emerging disease in Pakistan

The presence of dengue virus has been detected using neutralization and haemagglutination inhibition antibodies in local populations in Pakistan since the 1960s. However, the first epidemic was not reported until 1994. This was followed by some cases in 1995, but the disease was confined to the port city of Karachi. Since 2006, dengue epidemics have occurred every year and the range has extended to most cities in Pakistan. Dengue now affects thousands of people and has caused hundreds of deaths. It has become a major health problem in Pakistan, and it is likely to become an even greater health problem in the coming years. This review gives an insight into the dengue situation from the early 1960s to the most recent epidemics in Pakistan, and also describes the primary vector of this disease (Aedes aegypti) in Pakistan. As such, it provides the first comprehensive review of the emergence of this important public health problem.

A brief review on dengue molecular virology, diagnosis, treatment and prevalence in Pakistan

Dengue virus infection is a serious health problem infecting 2.5 billion people worldwide. Dengue is now endemic in more than 100 countries, including Pakistan. Each year hundreds of people get infected with dengue in Pakistan. Currently, there is no vaccine available for the prevention of Dengue virus infection due to four viral serotypes. Dengue infection can cause death of patients in its most severity, meanwhile many antiviral compounds are being tested against dengue virus infection to eradicate this disease but still there is a need to develop an efficient, low-cost and safe vaccine that can target all the four serotypes of dengue virus. This review summarizes dengue molecular virology, important drug targets, prevalence in Pakistan, diagnosis, treatment and medicinal plant inhibitors against dengue.

Dengue outbreak in Hadramout, Yemen, 2010: an epidemiological perspective

We analyzed surveillance data of a dengue outbreak (2010) reported to the Hadramout Health Office (Yemen) and retrospectively analyzed dengue-related epidemiological and entomological events reported in Hadramout from 2005 to 2009. A total of 630 immunoglobulin M (IgM) -confirmed dengue cases of 982 febrile cases was reported during the period from February to June of 2010; 12 cases died, giving case fatality a rate of 1.9%. Among febrile cases, the highest proportion of dengue cases (37.3%) was reported in the 15- to 24-year-old age group. The overall attack rate was 0.89/1,000. The average number of cases reported by month over the preceding 5-year period compared with the 2010 data is consistent with endemicity of dengue in the region and supports epidemic designation for the dengue activity in 2010. Recognition of endemic dengue transmission and potential for substantial dengue epidemics highlight the need for consistent laboratory-based surveillance that can support prevention and control activities accordingly.

Serotype and genotype analysis of dengue virus by sequencing followed by phylogenetic analysis using samples from three mini outbreaks-2007-2009 in Pakistan

Background

Since the first reported outbreak of dengue hemorrhagic fever in Pakistan, several mini outbreaks have erupted in the region. Dengue virus serotype 3 (DEN-3) was first documented in 2005 outbreak in Karachi. Reports show that serotype 3 is prevalent in Lahore since 2008. Serotype 2 (DEN-2) is the major circulating serotype in Pakistan as it is documented since 1994. We have conducted a detailed study of three outbreaks of dengue virus infection that occurred in years 2007, 2008 and 2009 in Lahore by using molecular techniques such as PCR and nucleotide sequencing of the C-prM gene junction of Dengue virus.

Results

Through the analysis of 114 serum samples collected over the period of three years (2007-2009), total 20 patients were found to be infected with dengue virus. In year 2007, four were positive for serotype 2 and one sample was positive for serotype DEN-3. In 2008, five samples had concurrent infection with serotypes DEN-2 and DEN-3 while three samples were infected only with serotype DEN-2. In year 2009, one sample had concurrent infection with serotypes DEN-2 and DEN-3 while six were positive for serotype DEN-2 only.

Conclusions

Our study showed that serotype DEN-2 was dominant in positive samples of dengue virus infection collected during the period of three years (2007-2009). The other serotype present was serotype DEN-3. Genotypes of serotype DEN-2 and serotype DEN-3 were subtype IV and subtype III, respectively.

Managing patients with dengue fever during an epidemic: the importance of a hydration tent and of a multidisciplinary approach

BACKGROUND

Dengue fever is one of the most common tropical diseases worldwide. Early detection of the disease, followed by intravenous fluid therapy in patients with dengue hemorrhagic fever (DHF) or with warning signs of dengue has a major impact on the prognosis. The purpose of this study is to describe the care provided in a hydration tent, including early detection, treatment, and serial follow-up of patients with dengue fever.

FINDINGS

The analysis included all patients treated in the hydration tent from April 8 to May 9, 2008. The tent was set up inside the premises of the 2nd Military Firemen Group, located in Meier, a neighborhood in Rio de Janeiro, Brazil. The case form data were stored in a computerized database for subsequent assessment. Patients were referred to the tent from primary care units and from secondary city and state hospitals. The routine procedure consisted of an initial screening including vital signs (temperature, blood pressure, heart rate, and respiratory rate), tourniquet test and blood sampling for complete blood count. Over a 31-day period, 3,393 case recordings were seen at the hydration tent. The mean was 109 patients per day. A total of 2,102 initial visits and 1,291 return visits were conducted. Of the patients who returned to the hydration tent for reevaluation, 850 returned once, 230 returned twice, 114 returned three times, and 97 returned four times or more. Overall, 93 (5.3%) patients with DHF seen at the tent were transferred to a tertiary hospital. There were no deaths among these patients.

DISCUSSION

As the epidemics were already widespread and there were no technical conditions for routine serology, all cases of suspected dengue fever were treated as such. Implementing hydration tents decrease the number of dengue fever hospitalizations.

Clinical manifestations and trend of dengue cases admitted in a tertiary care hospital, udupi district, karnataka

Background:

India is one of the seven identified countries in the South-East Asia region regularly reporting dengue fever (DF)/dengue hemorrhagic fever (DHF) outbreaks and may soon transform into a major niche for dengue infection in the future with more and more new areas being struck by dengue epidemics

Objective:

To study the clinical manifestations, trend and outcome of all confirmed dengue cases admitted in a tertiary care hospital.

Study Design:

Record-based study conducted in a coastal district of Karnataka. Required data from all the laboratory confirmed cases from 2002 to 2008 were collected from Medical Records Department (MRD) and analyzed using SPSS 13.5 version.

Results:

Study included 466 patients. Majority were males, 301(64.6%) and in the and in the age group of 15-44 years, 267 (57.5%). Maximum number of cases were seen in 2007, 219 (47%) and in the month of September, 89 (19.1%). The most common presentation was fever 462 (99.1%), followed by myalgia 301 (64.6%), vomiting 222 (47.6%), headache 222 (47.6%) and abdominal pain 175 (37.6%). The most common hemorrhagic manifestation was petechiae 84 (67.2%). 391 (83.9%) cases presented with dengue fever, 41 (8.8%) dengue hemorrhagic fever, and 34 (7.3%) with dengue shock syndrome. Out of 66 (14.1%) patients who developed clinical complications, 22 (33.3%) had ARDS and 20 (30.3%) had pleural effusion. Deaths reported were 11(2.4%).

Conclusion:

Community awareness, early diagnosis and management and vector control measures need to be strengthened, during peri-monsoon period, in order to curb the increasing number of dengue cases.

Demographic and clinical features of dengue fever in Pakistan from 2003-2007: a retrospective cross-sectional study

Background

Demographic features of dengue fever have changed tremendously in Pakistan over the past two decades. Small scale studies from all over the country have reported different aspects of individual outbreaks during this time. However, there is scarcity of data looking at the overall trend of dengue virus infection in the country. In this study, we examined annual trends, seasonality, and clinical features of dengue fever in the Pakistani population.

Methods

Demographic information and dengue IgM status of all patients tested for dengue IgM antibody at Aga Khan University Hospital from January 2003 to December 2007 were analyzed to look for trends of IgM-positive cases in Pakistan. In addition, clinical and biochemical parameters were abstracted retrospectively from medical records of all patients hospitalized with IgM-proven dengue fever between January 2006 and December 2007. These patients were categorized into dengue fever and dengue hemorrhagic fever according to the WHO severity grading scale.

Results

Out of a total of 15040 patients (63.2% male and 36.8% female), 3952 (26.3%) tested positive for dengue IgM antibody. 209 IgM proven dengue patients were hospitalized during the study period. During 2003, IgM positive cases were seen only during the months of July-December. In contrast, such cases were detected throughout the year from the 2004–2007. The median age of IgM positive patients decreased every year from 32.0 years in 2003 to 24.0 years in 2007 (p<0.001). Among hospitalized patients, nausea was the most common presenting feature found in 124/209 (59.3%) patients. Children presented with a higher median body temperature than adults (p = 0.010). In addition, neutropenia was seen more commonly in children while raised serum ALT levels were seen more commonly in adults (both p = 0.006). While a low total white cell count was more common in patients with dengue fever as compared to Dengue Hemorrhagic Fever (p = 0.020), neutropenia (p = 0.019), monocytosis (p = 0.001) and raised serum ALT level (p = 0.005) were observed more commonly in the latter group.

Conclusions

Dengue virus is now endemic in Pakistan, circulating throughout the year with a peak incidence in the post monsoon period. Median age of dengue patients has decreased and younger patients may be more susceptible. Total and differential leukocyte counts may help identify patients at risk of hemorrhage.

A profile of dengue cases admitted to a tertiary care hospital in Karnataka, southern India

During the past two decades, epidemics of dengue fever have been causing concern in several South-East Asian countries, including India. A study was conducted in a tertiary care hospital situated in Southern India to determine the trends and outcome of dengue cases. There was a steady rise in number of cases from 2002 to 2007, with the largest number of cases seen in 2007. Most cases were observed in the post-monsoon season in the month of September. Out of a total of 344 cases, 285 (82.8%) patients had dengue fever, 34 (9.8%) had dengue haemorrhagic fever and 25 (7.3%) had dengue shock syndrome. Deaths were reported in nine cases, with the majority of deaths occuring in 2003. The disease control programme should emphasise on vector surveillance, integrated vector control, emergency response, early clinical diagnosis and appropriate management of the cases.

Is dengue a threat to the blood supply?

Dengue is the most common arthropod-borne infection worldwide, affecting at least 50 million people every year and endemic in more than 100 countries. The dengue virus is a single-stranded RNA virus with four major serotypes. Infection with one serotype confers homotypic immunity but not heterologous immunity, and secondary infection with another serotype may lead to more severe disease. The major route of transmission occurs through the Aedes aegypti mosquito vector, but dengue has also been transmitted through blood transfusion and organ transplantation. Infection results in a spectrum of clinical illness ranging from asymptomatic infection, undifferentiated fever, dengue fever, dengue haemorrhagic fever (DHF) to dengue shock syndrome (DSS). Dengue is spreading rapidly to new areas and with increasing frequency of major outbreaks. A trend has also been observed towards increasing age among infected patients. This will impact blood supply availability as more blood donors are deferred because of dengue infection or exposure to infection. The risk of transmission through transfusion of blood from asymptomatic viraemic donors will also increase. Although screening tests for dengue and effective pathogen reduction processes are now available for the blood supply, the value of implementing these costly measures needs to be carefully considered. Demand for platelets and fresh frozen plasma will rise with increasing number of DHF/DSS. Evidence-based guidelines for the clinical use of these blood components in the management of patients with DHF/DSS have not been well established, and inappropriate use will contribute to the challenges faced by blood services.

Distribution of dengue cases in the state of Oaxaca, Mexico, during the period 2004-2006

BACKGROUND

Dengue virus infection is an emergent viral disease and the most important transmitted by a vector worldwide. In Mexico it has been an important public health problem since 1995 and Oaxaca is one of the most affected states in the country.

OBJECTIVE

To determine the geographic distribution of confirmed dengue cases in the state of Oaxaca, Mexico, the serotypes circulating, and the main gender and age groups affected.

STUDY DESIGN

Information about confirmed dengue cases obtained by LESPO during the period 2004-2006 was classified, sorted, and analysed. A RT-PCR technique was used to determine the serotype of the virus in serum samples.

RESULTS

A substantial increment in the number of dengue cases was noticed during the period of this study. The most affected sanitary jurisdiction was located on the coast where the climatic conditions were ideal for vector development and where there is significant migratory activity. The most affected group was the 11-15-year-old group. Dengue haemorrhagic fever was more frequent in men than in women over 16 years old, with a significant difference evaluated by chi(2)-test (p<0.001). Four serotypes of the virus were detected in the state and two co-infections with DEN2-3 and DEN3-4 were identified.

CONCLUSIONS

The increment in the number of dengue cases in the state of Oaxaca could be explained by several factors such as the presence of the four serotypes of the virus, the migratory phenomenon, the climatic conditions and the socioeconomic level of the population.

Co-circulations of two genotypes of dengue virus in 2006 out-break of dengue hemorrhagic fever in Karachi, Pakistan

BACKGROUND

The status of dengue genotypes involved in the recent epidemic out-breaks in Pakistan is not well defined.

OBJECTIVES

We sought to analyze the predominant genotype responsible for the most severe and largest out-break of dengue hemorrhagic fever (DHF) that hit Karachi in 2006.

STUDY DESIGN

Retrospective analysis of stored serum samples for dengue virus genotype by multiplex RT-PCR, anti-dengue IgM, IgG and review of clinical charts of patients admitted to Aga Khan University Hospital.

RESULTS

Viral RNA detection of 250 patients revealed positive results in 185 (74.0%) samples. DEN-2 was predominant genotype (n=104, 56.2%) Dengue specific antibodies were detected in 139 samples of which 81 were classified as primary cases. DEN-2 accounted for these. Within secondary cases, 63.2% were due to DEN-2 (total 57), the rest were positive for DEN-3. DHF (p=0.064) and abdominal pain (p=0.059) were more frequently associated with DEN-2 as compared to DEN-3. None of the samples were positive for DEN-1 or DEN-4.

CONCLUSION

Co-circulation of DEN-2 and DEN-3 was responsible for the 2006 out-break in Karachi. Primary and secondary cases were seen in both groups. Cases with DHF showed marginal association with DEN-2. Introduction of a new serotype (DEN-3) and or a genotypic shift of endemic serotype (DEN-2) are the probable factors for the recent out-break of DHF in this region.

Knowledge, awareness and practices regarding dengue fever among the adult population of dengue hit cosmopolitan

Background

The World health Organization (WHO) declares dengue and dengue hemorrhagic fever to be endemic in South Asia. Despite the magnitude of problem, no documented evidence exists in Pakistan which reveals the awareness and practices of the country's adult population regarding dengue fever, its spread, symptoms, treatment and prevention. This study was conducted to assess the level of knowledge, attitudes and practices regarding dengue fever in people visiting tertiary care hospitals in Karachi, Pakistan.

Methods

A cross-sectional pilot study was conducted among people visiting tertiary care hospitals in Karachi. Through convenience sampling, a pre-tested and structured questionnaire was administered through a face-to-face unprompted interview with 447 visitors. Knowledge was recorded on a scale of 1–3.

Results

About 89.9% of individuals interviewed had heard of dengue fever. Sufficient knowledge about dengue was found to be in 38.5% of the sample, with 66% of these in Aga Khan University Hospital and 33% in Civil Hospital Karachi. Literate individuals were relatively more well-informed about dengue fever as compared to the illiterate people (p<0.001). Knowledge based upon preventive measures was found to be predominantly focused towards prevention of mosquito bites (78.3%) rather than eradication of mosquito population (17.3%). Use of anti- mosquito spray was the most prevalent (48.1%) preventive measure. Television was considered as the most important and useful source of information on the disease.

Conclusion

Adult population of Karachi has adequate knowledge related to the disease ‘dengue’ on isolated aspects, but the overall prevalence of ‘sufficient knowledge’ based on our criteria is poor. We demonstrated adequate prevalence of preventive practices against the disease. Further studies correlating the association between knowledge and its effectiveness against dengue will be helpful in demonstrating the implications of awareness campaigns.