A review of dengue as an emerging disease in Pakistan

Mitigating dengue incidence through advanced Aedes larval surveillance and control: A successful experience from Pakistan

Dengue fever is a viral disease caused by one of four dengue stereotypes (Flavivirus: Flaviviridae) that are primarily transmitted by Aedes albopictus (Skuse) and Aedes aegypti (L.). To safeguard public health, it is crucial to conduct surveys that examine the factors favouring the presence of these species. Our study surveyed 42 councils across four towns within the Bhakkar district of Punjab Province, by inspecting man-made or natural habitats containing standing water. First, door-to-door surveillance teams from the district health department were assigned to each council to surveillance Aedes species and dengue cases. Second, data collection through surveillance efforts, and validation procedures were implemented, and the verified data was uploaded onto the Dengue Tracking System by Third Party Validation teams. Third, data were analysed to identify factors influencing dengue fever cases. The findings demonstrated the following: (1) Predominantly, instances were discerned among individuals who had a documented history of having travelled beyond the confines of the province. (2) Containers associated with evaporative air coolers and tyre shops were responsible for approximately 30% of the Aedes developmental sites. (4) Variability in temperature was responsible for approximately 45% of the observed differences in the quantity of recorded Aedes mosquito developmental sites. (5) Implementation of dengue prevention initiatives precipitated a 50% reduction in Aedes-positive containers, alongside a notable 70% decline in reported cases of dengue fever during the period spanning 2019 to 2020, while the majority of reported cases were of external origin. Aedes control measures substantially curtailed mosquito populations and lowered vector-virus interactions. Notably, local dengue transmission was eliminated through advanced and effective Aedes control efforts, emphasising the need for persistent surveillance and eradication of larval habitats in affected regions.

Demographic and clinical features of dengue fever infection in Pakistan: a cross-sectional epidemiological study

BACKGROUND

Dengue fever caused by dengue virus is a tropical disease and is among the deadliest vector-borne diseases. The humid and hot summers of Pakistan support the probation of the vectors responsible for the transmission of viral and other parasitic diseases.

METHODOLOGY

A retrospective study, from 2012- 2019, of dengue infected individuals from the Punjab province of Pakistan was carried out to analyze epidemiology, clinical and laboratory findings of subjects with dengue virus infection. Data was derived from National Institute of Health (NIH) followed by Dengue control program of Pakistan, covering the incidence rate in 36 districts of Punjab and Islamabad Capital Territory (ICT) respectively. Patients data including the presence of dengue specific antigen or/and antibodies such as NS1 and IgG/IgM were observed. The study also included the analysis of demographic data, geographic data, and the month-wise distribution of dengue cases to examine seasonal trends.

RESULTS

We analyzed 25,682 dengue infected individuals. The statistical analysis revealed a significant association between genders in which male population was more affected by dengue than females. It was also noted that the middle age group was the most affected age group while the highest number of cases were reported in October. Rawalpindi and Lahore were the most affected cities in Punjab province while Islamabad represented the highest number of cases during the recent outbreak in 2019. The IgM and IgG antibodies were highly prevalent among the infected patients.

CONCLUSION

Dengue is endemic in Pakistan, circulating throughout the year. Highest number of cases were observed in the month of October, September and November respectively. Association between climate change and vector-borne diseases need to be investigated in Pakistan as they significantly influence the timing and intensity of dengue and other disease outbreaks. Further exploration of hematological parameters is required to better diagnose and treat the disease. For the effective control of dengue outbreaks, awareness campaigns on sewage management and vector control along with social factors are strongly recommended for better control and eradication of the disease.

Dengue-Related Information Needs and Information-Seeking Behavior in Pakistan

This present study aims to examine the information needs and information-seeking behavior of Dengue-affected and non-affected people by exploring their information needs, resources used, and obstacles encountered. A structured questionnaire was used to collect data from 100 Dengue patients and 200 non-patients. The collected data were analyzed by applying descriptive and inferential statistics. The findings revealed that a majority of the respondents had information needs regarding nutritional options, best approaches to treatment, and expected benefits of treatment. They mostly sought information to keep themselves up-to-date and to prevent the disease. Television, Internet search engines, and social media outlets were frequently used information sources along with information-seeking from family and friends. Respondents with higher academic qualifications reported comparatively higher Dengue-related information needs. Moreover, age was a positive predictor of both their information needs and frequency of using health information sources. The findings will be helpful for healthcare providers to tailor Dengue awareness campaigns and prevention strategies according to the public needs and preferences.

Vector-Borne and Zoonotic Diseases in the Eastern Mediterranean Region: A Systematic Review

BACKGROUND AND OBJECTIVE

World Health Organization Eastern Mediterranean Region (WHO EMR) has 40% people in the world in need of humanitarian assistance. This systematic review explores selected vector-borne and zoonotic diseases (VBZDs) of importance to EMR in terms of disease burden across countries and periods, disaggregated across sex, age groups, education levels, income status, and rural/urban areas, related vector or animal source reduction measures, and public health, social and economic impacts and related interventions.

METHODS

We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and reviewed articles in PubMed, Embase, and WHO Global Index Medicus published between 1st of January 2011 and 27th of June 2022. Thirteen VBZDs with at least one reported outbreak in the last five years in the region or prioritized as per previous analysis at the WHO global and regional level and based on expert consultations, were included as part of the analysis.

RESULTS

The review included 295 studies-55% on leishmaniasis and dengue combined, and 75% studies from Pakistan, Kingdom of Saudi Arabia, and Iran combined. Hospital-based and nationally representative studies constituted 60% and 10% respectively. Males were predominantly affected in most diseases; children reported high burden of Leishmaniasis, whereas elderly had a higher burden of Dengue Fever and Middle East Respiratory Syndrome. Although very few studies reported on socioeconomic differences in burden, the ones that reported showed higher burden of diseases among the disadvantaged socioeconomic groups such as the poor and the less educated. More than 80% studies reported an increase in burden over the years.

CONCLUSION

The literature is scanty for most of the diseases reviewed and the number of studies from countries with humanitarian challenges is very low. The need for more nationally representative, population-based studies calls for prioritizing research investments.

Knowledge, attitude and practices regarding dengue and its vector among medical practitioners in Malakand region, Pakistan

Abstract Dengue fever (DF) is increasingly recognized as one of the world’s major mosquito borne diseases and causes significant morbidity and mortality in tropical and subtropical countries. Dengue fever is endemic in most part of Pakistan and continues to be a public health concern. Knowledge, attitude and practices can play an important role in management of the disease. Current study was aimed to determine the level of knowledge, attitude and practices regarding dengue fever among health practitioners, to study the level of knowledge and attitude with preventive practices for dengue fever. A cross sectional study was carried out in medical practitioners of the four districts of Malakand region during October to November 2019. A pre-structured questionnaire was used to collect data from medical practitioners. Data was analyzed using Graph Pad version 5. Significant value was considered when less than 0.05 (at 95% confidence of interval). The results revealed that most of participants have seen dengue vector (62%), the media being the most quoted source of information. Nearly 81.2% participants were aware from transmission of dengue fever is by mosquito bite. Practices based upon preventive measures were found to be predominantly focused towards prevention of mosquito bites rather than elimination of breeding places. Although the knowledge regarding DF and mosquito control measure was quite high among the medical practitioners but this knowledge was not put into practice. Further studies are required to aware the people about dengue and its vector in order to get prevention and control.

Species diversity pattern of mosquitoes (Diptera: Culicidae) breeding in different permanent, temporary and natural container habitats of Peshawar, KP Pakistan

To determine the species composition, relative abundance and seasonal variation of different mosquitoes Genera (Aedes, Anopheles, Armigeres, Culex, and Culiseta) in different habitats the present research work was carried out in Entomology Research Laboratory of The University of Peshawar. Sampling performed from variety of permanent and temporary breeding habitats was carried out on monthly basis from targeted breeding sites for two consecutive years through dipping method. Species diversity in the survey sites was noted. Collection from these seventeen various types of potential larval habitats, yielded a total of 42,430 immature constituting 41,556 larvae and 874 pupae. Among these only 19,651 adult mosquitoes emerged comprising 11,512 female and 8,139 male mosquitoes. 78% (n= 15333) of mosquito larvae were from permanent and 22% (n=4318) were from temporary breeding sites. This study showed that Peshawar valley harbours 15 species from the genera Aedes, Anopheles, Armigeres, Culex and Culiseta. When the density of each species was examined, Culex quinquifasciatus was found to be dominant (79%) and constant in distribution. Among the temporary habitats Aedes albopictus was found as the most prevalent species particularly from tree holes and water cisterns. The highest intensity of mosquitoes was in June (2243 emerged adults) and November (2667 emerged adults) while the lowest was in January (203 emerged adults). A perfect positive correlation (r = +0.8) was found between temperature and population of mosquitoes (df 10 and α 0.05). The species diversity index for mosquitoes remained between 0.12 and 1.76. The Margalef's richness components was noticeably low for bamboo traps (0.2) and fairly high for rice fields, Percolating water and Animal tracks (1.3) which shows the abundance of mosquito species in these habitats. Similarly Pielou's Evenness was highest for bamboo traps (E=1) showing species uniform distribution. Animal tracks were presumed not only the diverse habitat rather also possessed high value for species richness and species evenness. Temperature, rainfall, humidity and other related attributes responsible for species variation and abundance need to be analysed further to pave way for controlling vector species in their oviposition targeted sites.

Entomological Surveillance of the Invasive Aedes Species at Higher-Priority Entry Points in Northern Iran: Exploratory Report on a Field Study

Background

Arboviral diseases such as dengue, Zika, and chikungunya are transmitted by Aedes aegypti and Ae albopictus and are emerging global public health concerns.

Objective

This study aimed to provide up-to-date data on the occurrence of the invasive Aedes species in a given area as this is essential for planning and implementing timely control strategies.

Methods

Entomological surveillance was planned and carried out monthly from May 2018 to December 2019 at higher-priority entry points in Guilan Province, Northern Iran, using ovitraps, larval collection, and human-baited traps. Species richness (R), Simpson (D), evenness (E), and Shannon-Wiener indexes (H̕) were measured to better understand the diversity of the Aedes species. The Spearman correlation coefficient and regression models were used for data analysis.

Results

We collected a total of 3964 mosquito samples including 17.20% (682/3964) belonging to the Aedes species, from 3 genera and 13 species, and morphologically identified them from May 2018 to December 2019. Ae vexans and Ae geniculatus, which showed a peak in activity levels and population in October (226/564, 40.07% and 26/103, 25.2%), were the eudominant species (D=75.7%; D=21.2%) with constant (C=100) and frequent (C=66.7%) distributions, respectively. The population of Ae vexans had a significant positive correlation with precipitation (r=0.521; P=.009) and relative humidity (r=0.510; P=.01), whereas it was inversely associated with temperature (r=−0.432; P=.04). The Shannon-Wiener Index was up to 0.84 and 1.04 in the city of Rasht and in July, respectively. The rarefaction curve showed sufficiency in sampling efforts by reaching the asymptotic line at all spatial and temporal scales, except in Rasht and in October.

Conclusions

Although no specimens of the Ae aegypti and Ae albopictus species were collected, this surveillance provides a better understanding of the native Aedes species in the northern regions of Iran. These data will assist the health system in future arbovirus research, and in the implementation of effective vector control and prevention strategies, should Ae aegypti and Ae albopictus be found in the province.

A Privacy-Preserved Internet-of-Medical-Things Scheme for Eradication and Control of Dengue Using UAV

Dengue is a mosquito-borne viral infection, found in tropical and sub-tropical climates worldwide, mostly in urban and semi-urban areas. Countries like Pakistan receive heavy rains annually resulting in floods in urban cities due to poor drainage systems. Currently, different cities of Pakistan are at high risk of dengue outbreaks, as multiple dengue cases have been reported due to poor flood control and drainage systems. After heavy rain in urban areas, mosquitoes are provided with a favorable environment for their breeding and transmission through stagnant water due to poor maintenance of the drainage system. The history of the dengue virus in Pakistan shows that there is a closed relationship between dengue outbreaks and a rainfall. There is no specific treatment for dengue; however, the outbreak can be controlled through internet of medical things (IoMT). In this paper, we propose a novel privacy-preserved IoMT model to control dengue virus outbreaks by tracking dengue virus-infected patients based on bedding location extracted using call data record analysis (CDRA). Once the bedding location of the patient is identified, then the actual infected spot can be easily located by using geographic information system mapping. Once the targeted spots are identified, then it is very easy to eliminate the dengue by spraying the affected areas with the help of unmanned aerial vehicles (UAVs). The proposed model identifies the targeted spots up to 100%, based on the bedding location of the patient using CDRA.

Dengue risk zone mapping of Thiruvananthapuram district, India: a comparison of the AHP and F-AHP methods

Dengue fever, which is spread by Aedes mosquitoes, has claimed many lives in Kerala, with the Thiruvananthapuram district bearing the brunt of the toll. This study aims to demarcate the dengue risk zones in Thiruvananthapuram district using the analytical hierarchy process (AHP) and the fuzzy-AHP (F-AHP) methods. For the risk modelling, geo-environmental factors (normalized difference vegetation index, land surface temperature, topographic wetness index, land use/land cover types, elevation, normalized difference built-up index) and demographic factors (household density, population density) have been utilized. The ArcGIS 10.8 and ERDAS Imagine 8.4 software tools have been used to derive the risk zone maps. The area of the risk maps is classified into five zones. The dengue risk zone maps were validated using dengue case data collected from the Integrated Disease Surveillance Programme portal. From the receiver operating characteristic (ROC) curve analysis and the area under the ROC curve (AUC) values, it is proved that the F-AHP method (AUC value of 0.971) has comparatively more prediction capability than the AHP method (AUC value of 0.954) in demarcating the dengue risk zones. Also, based on the comparison of the risk zone map with actual case data, it was confirmed that around 82.87% of the dengue cases occurred in the very high and high-risk zones, thus proving the efficacy of the model. According to the dengue risk map prepared using the F-AHP model, 9.09% of the area of Thiruvananthapuram district is categorized as very high risk. The prepared dengue risk maps will be helpful for decision-makers, staff with the health, and disaster management departments in adopting effective measures to prevent the risks of dengue spread and thereby minimize loss of life.

Screening for Arboviruses in Healthy Blood Donors: Experience from Karachi, Pakistan (Jul-Dec 2018)

•

DENV, WNV and JEV status was investigated in healthy blood donors at the Aga Khan University July to December 2018.

•

ELISA for IgM antibodies and RT-PCR for viral RNA detection were performed.

•

IgM antibodies for DENV and WNV were positive in 3.9% and JEV in 0.28% of the blood donors.

•

Blood donors aged 19 and 30 years and residents of urban areas, of Karachi City were most frequent.

•

DENV and WNV seropositivity were significantly associated with residence in Malir District of Karachi.

Epidemiological and hematological investigation of Dengue Virus infection

Dengue is a mosquito-borne viral illness that infects humans. For the last few decades, it has been declared a global public health problem. The current study was conducted at the district headquarter hospital (DHQ) Bannu between June to September 2018 based on the seroprevalence of antibodies against dengue virus serotypes and their hematological parameters among the patients. A total of 1738 suspected individuals were diagnosed through NS1, IgG, and IgM antibodies and RT-PCR techniques. Out of all the samples, 716 (41.19%) were found to be positive for dengue. A higher infection rate was found in males (65.92%) as compared to females (34.07%). The most affected age group was 16-40 years, whereas the most affected tehsil was Bannu, where the DENV-3 serotype was prevalent. The rare serotype (DENV-4) was found in 1% of cases. Symptoms including fever (100%), myalgia (100%), headache (61.31%), vomiting (34.63%), and rashes were common among the dengue patients. However, the mild cases showed fewer clinical signs compared to the severe infected cases. The study also revealed a significant association (P<0.05) between hematological parameters and dengue infection, showing a significant decrease in TC, eosinophils, neutrophils, and platelets and a significant increase in monocytes and lymphocytes. Based on the current report, it is concluded that patients with the above symptoms and hematological changes may have increased probability of Dengue and should be kept under observation to separate dengue positive patients and enhance treatment process. This article is protected by copyright. All rights reserved.

Epidemiological trends of mosquito-borne viral diseases in Pakistan

Globally, arboviruses are public health problems. Pakistan has seen a fast-paced increase in mosquito-borne Flavivirus diseases such as dengue because of deforestation, climate change, urbanization, poor sanitation and natural disasters. The magnitude and distribution of these diseases are poorly understood due to the lack of a competitive nationwide surveillance system. In dengue-endemic countries, the recent epidemics of chikungunya (CHIKV) and human West Nile virus (WNV) have created panic among the public and are thought to provoke an outbreak of Zika virus (ZIKV) in Pakistan. Recently, hospital-based surveillance has indicated the presence of Japanese encephalitis virus (JEV), which is deeply concerned by developing countries such as Pakistan. The situation could become more devastating because of poorly developed diagnostic infrastructure. To date, no licensed vaccine has been used in Pakistan, and preventive measures are mainly based on vector control. This review provides comprehensive information concerning the association of risk factors with disease occurrence, epidemiological trends, and prediction of the spread of mosquito-borne diseases, attention to new threats of ZIKV, and future perspectives by benchmarking global health policies.

The simultaneous crises of dengue and COVID-19 in Pakistan: a double hazard for the country's debilitated healthcare system

Dengue fever is an arthropod-borne viral illness caused by four dengue virus serotypes (DENV 1-4), spread by Aedes mosquitos. Common symptoms of dengue include high peak temperature, headache, myalgia, and malaise following infection, with a rash emerging after 3 to 4 days. More than half of the world's population lives in dengue-endemic areas. Every year, around 100 million dengue cases are reported, with Southeast Asia comprising the majority. Nearly every day, there is a breakout of dengue infections in many areas of Pakistan, in addition to the ongoing COVID-19 pandemic. As a result, combating the dual burden of dengue and COVID-19 is difficult for the nation's healthcare system. Misdiagnosis owing to overlapping symptoms with COVID-19, overburdening of the healthcare system, and a lack of appropriate vaccination are some of the obstacles for dengue infection management. The government of Pakistan is pursuing a variety of measures to combat dengue fever outbreaks, including, The Pakistan Red Crescent Society was asked by the Department of Malaria Control Program to aid in promoting awareness and organizing clean-up campaigns in polluted regions and stagnant water for vector control.

Effectiveness of Positive Deviance, an Asset-Based Behavior Change Approach, to Improve Knowledge, Attitudes, and Practices Regarding Dengue in Low-Income Communities (Slums) of Islamabad, Pakistan: A Mixed-Method Study

Simple Summary

Dengue is a mosquito-borne infection caused by the Aedes mosquito, expanding at an alarming pace around the world. Recently, Pakistan has witnessed some major dengue outbreaks, affecting thousands of individuals across the country. As there is no specific cure or vaccine, prevention and vector control remain the key methods to avoid dengue infection. In Pakistan, dengue control activities are mainly focused on information-sharing through mass media and communication materials such as pamphlets and posters. The main challenge is a lack of community participation that can create an enabling environment for communities to follow the desired behaviors. There is a strong need to design and implement community-led behavior change approaches to ensure community participation and translate the knowledge into practices. This study was conducted to better understand the effectiveness of a community engagement approach, ‘positive deviance’, on dengue prevention and control. The study was carried out in two slums affected by the recent dengue outbreak in Islamabad, Pakistan. A total of 112 persons participated in the study, which was conducted from June–October 2020. The community discovered already-existing positive behaviors surrounding dengue prevention and control, which were shared with other participants through interactive activities. The study demonstrated positive changes in knowledge, attitudes, and practices, and could be a potential tool for dengue prevention and control programs worldwide.

Abstract

Dengue is a mosquito-borne, viral disease that has emerged as a global health concern in recent years. In the absence of specific antiviral treatment and vaccines, prevention remains the key strategy for dengue control. Therefore, innovative and community-driven approaches are required to improve the vector control practices. This study applied and evaluated the positive deviance (PD) approach on dengue prevention and control in selected slums of Islamabad during June–October 2020. The two most dengue-affected slums, the Faisal colony and France colony, were purposively selected as intervention and control groups, respectively. A total of 112 participants (56 for the intervention and 56 for the control group) participated in the study. The intervention group was exposed for two months to locally identified role model behaviors through weekly interactive sessions, dengue sketch competitions, and role plays. Another two months enabled the community to practice these behaviors without any external support in order to explore the intervention’s sustainability. Three surveys were conducted: before the intervention, after two months, and after four months, to assess any changes in the knowledge, attitudes, and practices of participating communities. Results found that the PD intervention had a significant positive impact on dengue knowledge, attitudes, and practices in the intervention group. PD could offer an empowering and efficient community engagement tool for future dengue prevention and control, both in Pakistan and more globally.

Diversity, distribution and relative abundance of the mosquito fauna (Diptera: Culicidae) of Malakand and Dir Lower, Pakistan

The present study was conducted to evaluate the diversity, distribution (C) and relative abundance (RA) of the mosquito fauna (Diptera: Culicidae) of Malakand and Dir Lower, Pakistan. Collection of specimens (n = 1087) was made during September 2018 to July 2019 at six different habitats including freshwater bodies, rice fields, animal sheds, indoors, drains and sewage waters. Specimens were collected through light traps, pyrethrum spray, aspirators and nets and subsequently killed, preserved and then arranged in entomological boxes for identification. Three genera were identified namely Culex, Anopheles and Aedes. A total of fourteen species were identified namely: Cx. quinquefasciatus (Say, 1823), An. stephensi (Liston, 1901), Cx. tritaeniorhynchus (Giles, 1901), Ae. vittatus (Bigot, 1861), An. maculatus (Theobald, 1901), An. fluviatilis (James, 1902), Cx. vishnui (Theobald, 1901), Ae. aegypti (Linnaeus, 1762) An. subpictus (Grassi, 1899), An. dthali (Patton, 1905), An. culicifascies (Giles, 1901), An. pallidus (Theobald, 1901), Ae. albopictus (Skuse, 1894) and An. annularis (van der Wulp, 1884). Cx. quinquefasciatus was found constantly distributed in the study area with RA = 16.5% and C = 100%. An. annularis was found as a satellite species, sporadically distributed in the study area having RA = 0.9% and C = 17%. Diversity indices of mosquitoes in the studied habitats were found as, Shannon-Wiener Index (2.415), Simpson Index (9.919), Fisher's Index (2.269) and Margalef's Index (1.859). A statistically significant difference was recorded in mosquito diversity in the six habitats (Kruskal-Wallis, chi-squared, H = 17.5, df = 5, P = 0.003 at α = 0.05). The present study encompasses mosquito fauna of Malakand, Pakistan with respect to diversity, relative abundance and distribution in diverse habitats and all seasons of the year. This will assist scientists working in various fields related with epidemiology, medical and veterinary entomology, ecology and allied areas of biological sciences.

Screening of ZIKA virus infection among dengue-like illness patients with negative RT-PCR for dengue virus in Punjab - Pakistan

Objective

To detect ZIKV using reverse transcription-polymerase chain reaction (RT-PCR) among clinical samples tested negative for Dengue virus (DENV) by RT-PCR in Punjab, 2016.

Methods

A descriptive cross-sectional study was carried out for duration of two months. Total of 506 samples were collected within seven days from onset of illness from all over hospitals of Punjab, Pakistan of which 350 were selected simply randomly to test for presence of ZIKV by using "Trioplex Real-Time RT-PCR Assay (Trioplex)". Cohen's kappa coefficient (κ) and 95% confidence interval (CI) were used to assess the degree of concordance between DENV positive results of non-structural protein 1 (NS1) and IgM solid-phase enzyme immunoassay (ELISA).

Results

No samples were positive for any ZIKV, DENV or Chikungunya virus (CHIKV) by Trioplex. Among the 350 samples, 26 samples were positive concordant and the degree of concordance between NS1- and IgM-ELISA was 13% and κ coefficient was -0.71 (95% CI -0.79, -0.63).

Conclusion

At study time, no samples were positive for ZIKV. Strengthening laboratory capacity to confirm arboviruses for Punjab's laboratories is warranted. Trioplex RT-PCR has 100% sensitivity so there are nominal chances of false negative results. Establishing syndromic surveillance for Zika and conducting a sero-surveillance survey for Zika in areas with high human and Aedes mosquito density are recommended in Punjab.

Devastating urban flooding and dengue outbreak during the COVID-19 pandemic in Pakistan

Pakistan has recently been overwhelmed by extreme torrential rains, with its most populous city of Karachi experiencing its worst floods in almost a century. Poor flood control and water disposal facilities have led to an immense risk of another dengue outbreak, with multiple cases being reported recently. The enormous accumulation of stagnant water in urban areas is a major source of mosquito breeding and transmission. Historical data has shown the correlation between the number of dengue cases and average rainfall in the region. The monsoon rains have pounded at a time where health authorities are battling to contain the Coronavirus (COVID-19) pandemic. There is a need to implement centralized dengue control strategies to undertake large scale water drainage, sanitation, and disinfection drives in disaster-stricken areas alongside public health awareness programs to combat the after-effects of this natural calamity.

A lateral flow biosensor based on gold nanoparticles detects four hemorrhagic fever viruses

The pathogen of viral hemorrhagic fever (VHF), which is harmful to human health, is a hemorrhagic fever virus. Clinicians have long needed convenient and sensitive point-of-care rapid diagnostic tests (RDTs) for hemorrhagic fever viruses. Commonly used methods for pathogen detection rely on conventional culture-based tests, antibody-based assays and polymerase chain reaction (PCR)-based techniques. However, these methods are costly, laborious and time-consuming. Herein, we present a simple and sensitive biosensor for the rapid detection of hemorrhagic fever viruses. For this assay, we develop lateral flow biosensors (LFBs) based on magnetic beads and nicking enzyme-assisted isothermal strand-displacement amplification (SDA) for the detection of hemorrhagic fever viruses. The detection limit of this assay is 10 fM.

A Comprehensive Study of Dengue Epidemics and Persistence of Anti-Dengue Virus Antibodies in District Swat, Pakistan

BACKGROUND

Dengue fever is one of the most common human arbovirus infections worldwide. In Pakistan, dengue initially became endemic in the big cities and then expanded to remote areas of the country. The current study reports the dengue epidemics, anti-DENV antibodies prevalence during the active and post-dengue infection, risk factors, disease symptoms, and spotting dengue infection densities in district Swat of Pakistan.

METHODS

Clinical signs and demographic data of dengue suspected individuals were collected at the time of screening through non-structural protein-1 antigen detection test during 2013-2015. Moreover, selected dengue confirmed individuals were screened for the presence of anti-dengue immunoglobulin (Ig) M and G during the active infection period and post-dengue infection.

RESULTS

A total of 8,770 individuals were infected with dengue in 2013 with 36 (0.41%) case fatalities, 307 in 2014 with no case fatality, and 13 in 2015 with no case fatality. The number of male and female cases were 6,139 and 2,631 in 2013, 183 and 124 in 2014, and only 10 and 3 in 2015, respectively. Among all the localities, Tehsil Babozai, an urban setting, reported the highest number of dengue patients during all the study years, that is, 7,673 (87.49% of the total cases) in 2013, 294 (95.76% of the total cases) in 2014, and 13 (100% cases) in 2015. Among 6 age groups, 21-30 years was found to be highly infected in 2013 (37.13% of all cases) and 2014 (33.55%). Furthermore, 1,231 (21.94% of all cases) had IgM antibodies and 71 (1.26%) had IgG antibodies in 2013, 78 (26% of all cases) had IgM antibodies and 7 (2.33%) had IgG antibodies in 2014, and only 4 (30.76%) patients had IgM and 0 (0%) had IgG antibodies in 2015. Furthermore, urban areas had the highest infection density in district Swat. The majority of the patients in rural areas had a traveling history to the urban areas before their illness.

CONCLUSION

To sum up, male gender, young individuals, and those living in urban areas were at the greater risk of dengue infection.

Dengue outbreak 2018 in district Shangla KPK; clinical features and laboratory markers of dengue virus infection

Aim: To analyze and quantify the 2018 dengue outbreak which occurred in district Shangla, Pakistan. Materials & methods: 964 suspected dengue samples were collected and examined for clinical manifestation and laboratory markers. Results: In all, 375 suspected cases were confirmed with dengue virus infection using nonstructural protein 1 (NS1) antigen, immunoglobulin M (IgM) & Immunoglobulin G (IgG) antibodies and real-time PCR whereas PCR was 92.2% sensitive. The most prevalent serotype was dengue virus 3 (60.26%). The male/female ratio was 1.84 and the most highly affected tehsil was Alpuri. The most affected age group was 16–40 years (70.4%). A significant number of cases were reported in September (48.54%). Conclusion: Recurrence of the dengue outbreaks in the study area could alarmingly increase the mortality rate, therefore, proper measures are essential to control dengue epidemics in the future.

A Rare Case of Dengue Fever Presenting With Acute Disseminated Encephalomyelitis

Dengue fever is a viral infection transmitted by mosquitoes with a clinical spectrum that ranges from asymptomatic infection to dengue shock syndrome. Neurologic manifestations are rare. We report a case of dengue fever presented with acute disseminated encephalomyelitis. An 18-year-old boy presented with high-grade fever, generalized headache for three days, intermittent altered sensorium, nausea, and vomiting for one day. Dengue-IgG and Dengue-IgM were positive. Magnetic resonance imaging (MRI) showed abnormal signal intensity areas in the bilateral deep white matter at centrum semiovale more on the right side, which seemed hypointense on T1 and hyperintense on T2 and fluid-attenuated inversion recovery (FLAIR) images, with open ring enhancement on contrast-enhanced T1 image, and peripheral diffusion restriction on diffusion-weighted 1 (DW1) image. These features were suggestive of acute disseminated encephalomyelitis. He improved within a week of taking IV methylprednisolone 1 g once daily for five days and supportive care. Follow up MRI after three weeks showed the resolution of all abnormalities. Thus we conclude that patients with acute disseminated encephalomyelitis should be checked for dengue fever, especially in areas of high prevalence, for early diagnosis and appropriate treatment and to prevent excessively aggressive surgery and/or treatment for such abnormal MRI findings.

A Case Report on Dengue Encephalitis With Optic Neuropathy

The dengue virus is a type of Flavivirus, responsible for causing dengue fever. It mostly prevails in tropical and subtropical countries, with Southeast Asia reporting the greatest disease burden. The virus can affect a multitude of organ systems and the disease spectrum varies from a mild flu-like illness to severe dengue hemorrhagic fever or dengue shock syndrome. Two serotypes, DENV-2 and DENV-3, have been most frequently associated with neurological complications. We report a case of a 19-year-old male presented with signs and symptoms of encephalitis and optic neuropathy, following a diagnosis of dengue fever. Our diagnosis was supported by findings from brain MRI, electroencephalogram, fundoscopy, and a visual evoked potential test. A high-dose intravenous steroid therapy was given in pulses, which resulted in complete visual and neurological recovery. Dengue fever can present with atypical findings due to its propensity to affect multiple organ systems throughout the body. Neurological involvement is not uncommon and hence, clinicians should be aware of such systemic manifestations in order to diagnose promptly. Effective and timely treatment can reduce associated morbidity and result in complete recovery.

Prevalence of dengue virus serotypes in the 2017 outbreak in Peshawar, KP, Pakistan

Background

Dengue is a viral disease, transmitted by infected Aedes aegypti and Aedes albopictus female mosquitoes. Worldwide, 96 million infections were estimated in 2010. The dengue virus comprises four distinct serotypes (DENV‐1, DENV‐2, DENV‐3, and DENV‐4) which belong to the genus Flavivirus. Determining the serotypes during dengue outbreaks is crucial for its effective management in terms of diagnostics improvement and polyvalent vaccine development. The aim of the present study is to determine the prevalence rate of dengue virus serotypes in the samples collected from patients during the 2017 outbreak in Khyber Pakhtunkhwa, Pakistan.

Methods

A total of 800 ELISA‐positive samples were collected, of which 513 (290 males, 223 females) samples were confirmed positive by PCR.

Results

Out of 513, 25 were found serotype 1 (5%), 196 were serotype 2 (38%), 192 were serotype 3 (37%), 56 were serotype 4 (11%), and 44 (8%) were found to have mix serotypes.

Conclusion

We can conclude that serotypes 2 and 3 of dengue virus were the predominated serotypes of dengue virus in the 2017 outbreak in Peshawar, capital city of Khyber Pakhtunkhwa, Pakistan.

Evaluation of Susceptibility of Aedes caspius (Diptera: Culicidae) to Insecticides in a Potent Arboviral-Prone Area, Southern Iran

Background:

Southern part of the country is a high risk for mosquito transmitted Arboviruses. This study was carried out to determine the base line susceptibility of the Aedini mosquitoes to the WHO-recommended insecticide.

Methods:

Larval collection was carried out by dipping method and adult collection occurred by suction tube from January to December 2017. The adult susceptibility test was assessed to Bendiocarb 0.1%, DDT 4%, Deltamethrin 0.05%, Lambda-cyhalothrin 0.05%, Malathion 5% and, Permethrin 0.75% at different interval times as well as at discriminative dose recommended by WHO. The larval susceptibility test was occurred using Temephos and Bacillus thuringiensis serotype H-14, at different concentrations. The LT₅₀, LT₉₀ and LC₅₀, LC₉₀ values were calculated for plotting the regression line using Microsoft office Excel software ver. 2007.

Results:

Aedes caspius was quite resistant to DDT, Malathion, Bendiocarb and showed susceptible or tolerant to other insecticides.The LT₅₀ and LT₉₀ values to DDT in this species were 157.896, and 301.006 minutes, respectively. The LC₅₀ and LC₉₀ values of Ae. caspius to Temephos were 0.000068, and 0.000130ppm, the figures for B. thuringiensis was 111.62 and 210.2ppm, respectively.

Conclusion:

A routine and continuous study for monitoring and evaluation of different species of Aedes to insectides is recommend at different parts of country for decision making.

Dengue Outbreak Response and Control in Khyber Pakhtunkhwa, Pakistan: A Mixed Methods Study

Background: Since 2008, dengue fever outbreaks had occurred repeatedly in various districts of Khyber Pakhtunkhwa (KP) province of Pakistan. Most importantly the outbreak of 2017 caused 70 deaths, about 121,083 suspected and 24,938 confirmed cases in 23 districts of KP. In 2018, an abrupt decline in suspected and confirmed dengue cases was observed and 2018 was declared as dengue outbreak free. This study characterizes and explores the control and response measure activities of the outbreak. In addition, we explored the challenges faced and lessons learned for control of future dengue outbreaks from the perspectives of health authorities and dengue response staff in the KP province of Pakistan.

Methods: This was a mixed methods study with quantitative data on dengue outbreaks obtained from health department in KP followed by qualitative study to explore activities and responses that enabled the Dengue Response Unit (DRU) for a successful dengue outbreak control in 2018. In-depth interviews were conducted with the key informants from the department of health and the dengue response unit.

Results: The quantitative data analysis revealed a huge decline of suspected and confirmed dengue cases in comparison with the previous year in most of the KP districts. A similar decline in dengue reported cases was also observed from previously high dengue burden 14 union counsels of Peshawar district. Among the 70 verified deaths in 2017, 44 (63%) were males and 26 (37%) were females. The cases were about 20% each from age groups of 21–30, 41–50, and 51–60 years. The qualitative study findings showed four prominent major themes for successful control: (1) control and response strategy; (2) organizing specific dengue control and response intervention activities; (3) addressing dengue control and response challenges; and (4) generating lesson for future dengue control and response.

Seroepidemiology of dengue and chikungunya fever in patients with rash and fever in Iran, 2017

After the mass campaign of Measles and Rubella vaccination in 2003 in Iran, the cases of measles and rubella infection decreased but still, the cases of rash and fever were reported. It is worth noting that some other viral infections show signs similar to measles and rubella such as some arboviruses. Considering the epidemic outbreak of arbovirus infections in countries neighbouring Iran, we performed this study to estimate the possibility of chikungunya and dengue fever among measles and rubella IgM negative patients presenting with rash and fever from December 2016 to November 2017 in the National Measles Laboratory at Tehran University of Medical Sciences. Serum samples were selected at random from patients from eight provinces. The presence of DENV IgM and CHIKV IgM was examined by enzyme-linked immunosorbent assay. Of the 1306 sera tested, 210 were CHIKV seropositive and 82 were dengue seropositive. Statistical analysis demonstrated a significant increase in the CHIKV IgM antibody seropositivity rate in Kerman (OR = 2.07, 95% CI: 1.10–3.92; P = 0.024) and Fars (OR = 1.77, 95% CI: 1.06–2.93; P = 0.027). The DENV and CHIKV seropositivity rate in summer is higher than in other seasons (P < 0.01). Our seropositive samples suggest possible CHIKV and DENV infection in Iran. It is likely that these viruses are circulating in Iran and there is a need to study vector carriage of these two viruses.

Estimating the Threshold Effects of Climate on Dengue: A Case Study of Taiwan

Climate change is regarded as one of the major factors enhancing the transmission intensity of dengue fever. In this study, we estimated the threshold effects of temperature on Aedes mosquito larval index as an early warning tool for dengue prevention. We also investigated the relationship between dengue vector index and dengue epidemics in Taiwan using weekly panel data for 17 counties from January 2012 to May 2019. To achieve our goals, we first applied the panel threshold regression technique to test for threshold effects and determine critical temperature values. Data were then further decomposed into different sets corresponding to different temperature regimes. Finally, negative binomial regression models were applied to assess the non-linear relationship between meteorological factors and Breteau index (BI). At the national level, we found that a 1°C temperature increase caused the expected value of BI to increase by 0.09 units when the temperature is less than 27.21 °C, and by 0.26 units when the temperature is greater than 27.21 °C. At the regional level, the dengue vector index was more sensitive to temperature changes because double threshold effects were found in the southern Taiwan model. For southern Taiwan, as the temperature increased by 1°C, the expected value of BI increased by 0.29, 0.63, and 1.49 units when the average temperature was less than 27.27 °C, between 27.27 and 30.17 °C, and higher than 30.17 °C, respectively. In addition, the effects of precipitation and relative humidity on BI became stronger when the average temperature exceeded the thresholds. Regarding the impacts of climate change on BI, our results showed that the potential effects on BI range from 3.5 to 54.42% under alternative temperature scenarios. By combining threshold regression techniques with count data regression models, this study provides evidence of threshold effects between climate factors and the dengue vector index. The proposed threshold of temperature could be incorporated into the implementation of public health measures and risk prediction to prevent and control dengue fever in the future.

Dengue and malaria infections in pregnancy : Maternal, fetal and neonatal outcomes at a tertiary care hospital

Background

Malaria and dengue cause major morbidity in developing nations and are more severe in pregnancy. Maternal, fetal, and neonatal outcomes in pregnant patients infected with dengue or malaria were studied.

Methods

The medical records of pregnant women admitted with either dengue or malaria infections from 2011–2015 to this hospital were reviewed. Clinical outcomes and laboratory tests were examined.

Results

Of 85 women, 56%, 21%, and 22% had contracted dengue, malaria, and multiple infections, respectively. Pregnant women who had contracted dengue fever alone were more likely to present to the hospital at an earlier gestational age (24 weeks, p = 0.03). Women with multiple infections, were more likely to deliver earlier (30 weeks, p < 0.01). Women with malaria were more likely to have low birth weight deliveries (mean birth weight 2394 g, p = 0.03). The incidence of in-hospital deaths among the cohort was 7%.

Conclusion

It is imperative to develop guidelines to screen for and diagnose dengue and malaria in pregnancy.

Electronic supplementary material

The online version of this article (10.1007/s00508-019-01606-8) contains supplementary material, which is available to authorized users.

Promoting Healthcare Sustainability in Developing Countries: Analysis of Knowledge Management Drivers in Public and Private Hospitals of Pakistan

Investing in a sustainable future has no alternative; the healthcare sector in developing countries has failed to achieve sustainability objectives. Knowledge management (KM) is a concrete application of sustainability in healthcare, as organizations (hospitals) that manage their knowledge assets will gain sustainable competitive advantage. Several organizations in developed countries are moving towards the adoption of knowledge management so that they can manage their knowledge well and improve their performance. Due to the effective implementation of KM in developed countries, developing countries are also considering adopting KM in their healthcare. In this study, an attempt has been made to identify the drivers of KM adoption in public and private hospitals of Pakistan. With the help of an extensive literature review and expert opinion, the drivers were identified and a hierarchical structure was developed. Nineteen drivers were identified and screened out by experts. The experts identified the contextual relationships between the drivers during a brainstorming session. The hierarchical model of the drivers for KM in the healthcare of Pakistan was eventually developed using interpretive structural modeling (ISM). The structure has 10 levels, in which “developed competitive advantage” formed the foundation of the structure and “job creation” and “improvement in the reputation of healthcare” formed the topmost level. The “Matrices d’Impacts Croises Multiplication Appliqué a un Classement” (MICMAC) analysis classified the drivers by categorizing them according to their driving and dependence powers. One driver is identified as autonomous, six drivers as dependent, seven drivers as linkage, and five drivers as independent. The analysis of KM drivers will provide a good understanding of the interdependence and interactions between them and support the effect adoption of KM in developing countries especially in Pakistan.

Spatiotemporal analysis of dengue outbreaks in Samanabad town, Lahore metropolitan area, using geospatial techniques

Dengue is endemic to Pakistan with its usual peak incidence in the post-monsoon period. In the last decade, dengue outbreaks have occurred in major urban areas particularly Karachi and Lahore, affecting large numbers of people. This study is an attempt to analyze the spatiotemporal variation of dengue fever (DF) in Samanabad town, Lahore metropolitan area. The study is based on secondary data, acquired from concerned government departments. Point level geo-coding is used to transform the relative location to the absolute location using Google Earth, and Global Position System (GPS) is used to validate the geo-coded location. Geographic information system (GIS) has been used to perform spatial analysis. It has been found that temporally DF prevalence varies from month to month and year to year. Major outbreak was observed in the year 2013 with more than 900 confirmed DF cases. Rainfall, temperature, and humidity have played a central role in outbreaks. The land cover pattern and population density further intensified the outbreak. Spatially, the number of DF incidence was high in those localities where the entire land is built-up and with little/no green space areas. Analysis reveals that DF is still a major threat to the area as socioeconomic and geographic conditions favor vector breeding and transfer of disease from one person/place to another. This study presents useful information regarding spatiotemporal patterns of dengue outbreak and may bring the attention of public health departments to formulate dengue-combating strategies. The methodology is general for spatiotemporal analysis and can be applied to other infectious diseases as well.

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.

Dengue in Taiwan: Pointing the finger at Aedes aegypti

In this issue of the Biomedical Journal we explore the history of dengue infection in Taiwan and what current trends have to say about the vector responsible for transmitting the disease on the island. We focus on original research reporting the development of a new perfusion bioreactor to engineer bone from human cord blood stem cells. Finally, we look at trends in osteoporosis in Taiwan and how they highlight the success of public health campaigns.

Dengue outbreaks and the geographic distribution of dengue vectors in Taiwan: A 20-year epidemiological analysis

Dengue fever is an important mosquito-borne viral infectious disease that mostly occurs in tropical and subtropical areas of the world. According to epidemiological data from the Center for Disease Control of Taiwan, more than 98.62% of outbreaks of indigenous total dengue cases were reported in the southern part of Taiwan. Southern Taiwan is an aggregate area encompassing Tainan, Kaohsiung, and Pingtung, all of which are located below the Tropic of Cancer (23º35'N). With a few exceptions, dengue outbreaks mainly occur in southern Taiwan which is highly associated or overlaps with the prevalence of Aedes aegypti. A.aegypti is presumed to be absent from the northern part of Taiwan, while Aedes albopictus breeds in areas throughout the island. According a collection of 20 years of epidemiological data from Taiwan, the inability of A. aegypti to survive the winter weather in northern Taiwan may account for its restricted geographical distribution and that of dengue outbreaks it transmits. A.aegypti, unlike temperate strains of A. albopictus, lacks embryonic diapause signaled by a short photoperiod which thus reduces its cold-hardiness. Therefore it is intolerant of low temperatures that frequently accompany rains and unable to survive during winter in the northern part of Taiwan.

Dengue seroprevalence and its socioeconomic determinants in Faisalabad, Pakistan: a cross-sectional study

INTRODUCTION

Socioeconomic disparities in the community make some groups more vulnerable to dengue infection.

METHODS

Fourteen dengue cases (IgM positive) served as index cases for the positive geographic cluster investigations.

RESULTS

Of 292 individuals, the overall dengue seroprevalence was 22.9% (IgM positive 4.8%; IgG positive 18.1%). The highest (45%) seroprevalence was reported in the most socioeconomically vulnerable lower class, followed by the middle class (39%). Orthogonal comparisons showed that socioeconomic factors play a significant role in the prevalence of dengue.

CONCLUSIONS

An integrated approach is required to control the menace through vector control strategies and improvement of socioeconomic conditions.

Patterns of occurrence of dengue and chikungunya, and spatial distribution of mosquito vector Aedes albopictus in Swabi district, Pakistan

OBJECTIVE

Two principal vector species, Aedes aegypti and Aedes albopictus, are known for transmission of dengue (DEN) and chikungunya (CHK) in Pakistan. We aimed to investigate their spatial and temporal distribution.

METHODS AND RESULTS

The Maximum Entropy algorithm revealed current climatic suitability of A. albopictus by highlighting variables contributing to its spatial distribution: Land use cover was the most important environmental factor (63.1%) followed by elevation-normalised difference vegetation index (10.9%), NDVI (8.5%) and annual precipitation (7.9%). As per Normalized Difference Vegetation Index values, the vector's presence was highly likely in areas with little vegetation such as built-up spaces or uncultivated fields, and in areas with sparse vegetation such as grasslands and cultivated fields. Temperature variables showed differing effects on vector ecology with annual temperature being the most important. Logistic regression models showed that presence of the vector, build-up and distance to roads contributed significantly to the distribution of both DEN and CHIK.

CONCLUSION

In Swabi, the mean temperatures of warmest and driest quarters are more important in the spatial distribution of A. albopictus than mean temperatures of the wettest and coldest quarters. Finally, disease modelling reflects a high probability for both DEN and CHIK in the same regions over a huge area.

Investigating spatio-temporal distribution and diffusion patterns of the dengue outbreak in Swat, Pakistan

INTRODUCTION

Dengue has been endemic to Pakistan in the last two decades. There was a massive outbreak in the Swat valley in 2013. Here we demonstrate the spatio-temporal clustering and diffusion patterns of the dengue outbreak.

METHODS

Dengue case data were acquired from the hospital records in the Swat district of Pakistan. Ring maps visualize the distribution and diffusion of the number of cases and incidence of dengue at the level of the union council. We applied space-time scan statistics to identify spatio-temporal clusters. Ordinary least squares and geographically weighted regression models were used to evaluate the impact of elevation, population density, and distance to the river.

RESULTS

The results show that dengue distribution is not random, but clustered in space and time in the Swat district. Males constituted 68% of the cases while females accounted for about 32%. A majority of the cases (>55%) were younger than 40 years of age. The southern part was a major hotspot affected by the dengue outbreak in 2013. There are two space-time clusters in the spatio-temporal analysis. GWR and OLS show that population density is a significant explanatory variable for the dengue outbreak, while GWR exhibits better performance in terms of 'R²=0.49 and AICc=700'.

CONCLUSION

Dengue fever is clustered in the southern part of the Swat district. This region is relatively urban in character, with most of the population of the district residing here. There is a need to strengthen the surveillance system for reporting dengue cases in order to respond to future outbreaks in a robust way.

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.

The changing epidemiological pattern of Dengue in Swat, Khyber Pakhtunkhwa

Background

Pakistan is suffering from dengue fever since 1994. In the country, major dengue outbreaks have been documented in 2010, 2011 and 2013 in Punjab (Lahore) and Sindh (Karachi) Provinces. District Swat was hit for the first time by dengue virus in 2013, claiming 57 deaths and 8000 morbidities. The molecular and entomological aspects along with the ecological and social context of the dengue outbreaks were investigated in this study.

Method

In addition to entomological survey, the data collected from patients' files (Saidu Sharif Teaching Hospital, Swat) and by directly questioning the patients (field data) was analyzed for epidemiological trends, molecular identification (RT-PCR based serotyping of DENV), clinical profile, socioeconomic status (SES) and demographic features.

Results

The peak prevalence of dengue was documented in September (56% in 2013, 38% in 2014) and October (33% in 2013, 24% in 2014), whereas in 2015, in October (54.5%) and November (30.5%). The serotype 3 (≤60%) and serotype 2 (≤40%) were found dominant in the area. Among the reported patients (5513), 69% were males and 31% females. Majority of them were found in the age of 14–30 years (52.5%) as compared to 31–60 years (34.5%) (Chi-square: 3219.463, p-value: 0.00). About 63% cases reported in low SES. Among the different categories of government employees affected with dengue, majority (4%) were belonging to health department (Chi-square: 4541.011, p-value: 0.00). Similarly, dengue targeted the dwellers living in multiple-storey houses (65%) as compared to those in the single-storeyed houses (35%) (Chi-square: 495.630, p-value: 0.00). The overall death toll observed was of 57 persons. Dengue prevailed more (38.4%) among low qualified individuals as compared to high qualified (11.5%) (Chi-square: 884.315, p-value: 0.00).

Conclusion

Our analysis indicated a decrease in the epidemiological trend of dengue (now) in the area, though initially it was observed affecting all types of communities on a larger scale. However, the DENV-2 and DENV-3 were dominantly circulating in the area and the prevalence (with usual peaks in post-monsoon) found high in males, illiterate (less educated) individuals and in those with low SES. Urbanization, infected human travelling, climate change, socioeconomic, sociodemographic as well as the wide range adaptation of vector mosquitoes, altogether, are the important factors playing role in the expansion of dengue. Further studies are needed to determine the association of these variables with the dengue spread in the area.

Knowledge of Dengue Among Students Exposed to Various Awareness Campaigns in Model Schools of Islamabad: A Cross-Sectional Study

Objective

To determine the knowledge of dengue among school students exposed to various awareness campaigns in model schools of Islamabad.

Methods

We conducted a cross-sectional study of students who were studying in Islamabad Model School for Girls F-7/2 and Islamabad Model College for Boys F-7/3 from September 2017 to October 2017. Students in the ninth and tenth grades who were willing to participate in the study and who were studying in the school for more than six months were included in the study. The data was collected through a self-constructed questionnaire. Cronbach's alpha was used to assess the internal consistency of the questionnaire, and it was found to be 0.83. The data obtained was analyzed on IBM's statistical package for the social sciences (SPSS) version 21 (IBM, Armonk, NY).

Results

Out of 601 participants, 345 (57.4%) were males and 256 (42.6%) were females. The mean age of the participants was 14.72±1.09. About 380 participants (63.2%) were studying in the ninth grade and 221 participants (36.8%) were studying in the tenth grade. A majority of the participants (67.2%) had poor knowledge of dengue. The participants scored highest in knowledge of prevention of the dengue domain and scored the lowest in knowledge of transmission of dengue. A majority of the participants (72.9%) reported that they acquire knowledge about dengue fever through television and radio. About 44.60% of the participants reported that they acquired knowledge about dengue fever through awareness campaigns in school.

Conclusions

The knowledge of the students was found to be insufficient despite several awareness campaigns. There is a need to re-evaluate the structure of the awareness campaigns as they fail to reach their target. Electronic media was identified as the most useful source of knowledge, and its incorporation can help increase the effectiveness of awareness campaigns.

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.

Targeting Dengue Virus NS-3 Helicase by Ligand based Pharmacophore Modeling and Structure based Virtual Screening

Dengue fever is an emerging public health concern, with several million viral infections occur annually, for which no effective therapy currently exist. Non-structural protein 3 (NS-3) Helicase encoded by the dengue virus (DENV) is considered as a potential drug target to design new and effective drugs against dengue. Helicase is involved in unwinding of dengue RNA. This study was conducted to design new NS-3 Helicase inhibitor by in silico ligand- and structure based approaches. Initially ligand-based pharmacophore model was generated that was used to screen a set of 1201474 compounds collected from ZINC Database. The compounds matched with the pharmacophore model were docked into the active site of NS-3 helicase. Based on docking scores and binding interactions, 25 compounds are suggested to be potential inhibitors of NS3 Helicase. The pharmacokinetic properties of these hits were predicted. The selected hits revealed acceptable ADMET properties. This study identified potential inhibitors of NS-3 Helicase in silico, and can be helpful in the treatment of Dengue.

Potential Risk Areas of Aedes albopictus in South-Eastern Iran: A Vector of Dengue Fever, Zika, and Chikungunya

The possibility of the rapid and global spread of Zika, chikungunya, yellow fever, and dengue fever by Aedes albopictus is well documented and may be facilitated by changes in climate. To avert and manage health risks, climatic and topographic information can be used to model and forecast which areas may be most prone to the establishment of Ae. albopictus. We aimed to weigh and prioritize the predictive value of various meteorological and climatic variables on distributions of Ae. albopictus in south-eastern Iran using the Analytical Hierarchy Process. Out of eight factors used to predict the presence of Ae. albopictus, the highest weighted were land use, followed by temperature, altitude, and precipitation. The inconsistency of this analysis was 0.03 with no missing judgments. The areas predicted to be most at risk of Ae. albopictus-borne diseases were mapped using Geographic Information Systems and remote sensing data. Five-year (2011-2015) meteorological data was collected from 11 meteorological stations and other data was acquired from Landsat and Terra satellite images. Southernmost regions were at greatest risk of Ae. albopictus colonization as well as more urban sites connected by provincial roads. This is the first study in Iran to determine the regional probability of Ae. albopictus establishment. Monitoring and collection of Ae. albopictus from the environment confirmed our projections, though on-going field work is necessary to track the spread of this vector of life-threatening disease.

Outbreak of dengue virus type-3 in Malakand, Pakistan 2015; A laboratory perspective

An outbreak of dengue fever was reported in Malakand district, Khyber Pakhtunkhwa (KP) province of Pakistan during 2015. Detection of viral RNA by real-time PCR confirmed dengue virus serotype-3 (DENV-3) to be the causative agent causing the outbreak. Phylogenetic analysis based on partial E-NS1 gene sequences showed that the DENV-3 viruses belonged to genotype III with maximum homology with the dengue-3 strains previously reported from Pakistan and India. Our current report provides updated information on molecular epidemiology and phylogenetic analysis of dengue virus serotypes responsible for 2015 outbreak in KP.

"Preliminary Seroepidemiological survey of dengue infections in Pakistan, 2009-2014"

Background

Dengue virus is the causative agent of dengue fever, a vector borne infection which causes self-limiting to life threatening disease in humans. A sero-epidemiological study was conducted to understand the current epidemiology of dengue virus in Pakistan which is now known as a dengue endemic country after its first reported outbreak in 1994.

Methods

To investigate the prevalence of dengue virus in Pakistan during 2009-2014, a total of 9,493 blood samples were screened for the detection of anti-dengue IgM antibodies using ELISA. Clinical and demographic features available with hospital records were reviewed to ascertain mortalities related to dengue hemorrhagic shock syndrome.

Results

Out of 9,493 samples tested, 37% (3,504) were found positive for anti-dengue IgM antibodies. Of the seropositive cases, 73.6% (2,578/3,504) were male and 26.4% (926/3,504) were female. The highest number (382/929; 41.1%) of sero-positive cases was observed among the individuals of age group 31-40 years. The highest number of symptomatic cases was reported in October (46%; 4,400/9,493), and the highest number of sero-positive cases among symptomatic cases was observed in November (45.7%; 806/1,764). Mean annual patient incidence (MAPI) during 2009-2014 in Pakistan remained 0.30 with the highest annual patient incidence (11.03) found in Islamabad. According to the available medical case record, 472 dengue related deaths were reported during 2009-2014.

Conclusion

The data from earlier reports in Pakistan described the dengue virus incidence from limited areas of the country. Our findings are important considering the testing of clinical samples at a larger scale covering patients of vast geographical regions and warrants timely implementation of dengue vector surveillance and control programs.

Trial registration number

It is an epidemiological research study, so trial registration is not required.

Electronic supplementary material

The online version of this article (doi:10.1186/s40249-017-0258-6) contains supplementary material, which is available to authorized users.

Value of routine dengue diagnosis in endemic countries

Dengue is one of the most common arthropod-borne viral diseases in humans and it is a leading cause of illness and death in the tropical and subtropical regions of the world. It is thought to account for 400 million cases annually among approximately 3.97 billion people at risk of infection in 128 endemic countries. Despite the global prevalence of the disease, the availability of a vaccine is limited in most countries in the endemic areas. Most endemic countries in South America, South East Asia and Africa serve as attractive touristic sites for people from non-endemic countries who become infected and export the virus to dengue-free regions. Dengue fever typically resembles malaria and in endemic countries most cases of dengue are treated as presumptive malaria. Consequently, routine dengue diagnosis among persons with fever will offer early treatment and reduce the burden of the disease. Also, routine testing among travellers from endemic countries will reduce importation and prevent the geographical expansion of dengue. In this essay, we seek to highlight the usefulness of routine dengue testing in endemic countries.

Mosquito-borne viruses circulating in Kinshasa, Democratic Republic of the Congo

BACKGROUND

Diseases caused by mosquito-borne viruses are among the most important emerging diseases that threaten human and animal health, particularly in Africa. However, little attention has been paid to these diseases in the Democratic Republic of the Congo (DRC). The present cross-sectional study was undertaken between March and May 2014 to investigate the presence of mosquito-borne viruses in mosquitoes collected from five municipalities of Kinshasa, DRC.

METHODS

Mosquitoes were collected using BG-Sentinel traps and battery-powered aspirators. Female mosquitoes were pooled according to their genera and sampling locations, preserved in RNAlater, and later screened for viruses using reverse transcription PCR (RT-PCR) assays.

RESULTS

A total of 2922 mosquitoes were collected and 29 pools of female mosquitoes, containing approximately 30 mosquitoes each, were tested. Twelve of the 29 (41.4%) mosquito pools were found to be infected with at least one arbovirus, with eight (27.5%) pools positive for Alphavirus, nine (31%) for Flavivirus, and five (17.2%) for Bunyaviridae. Chikungunya, o'nyong'nyong, and Rift valley fever viruses were detected.

CONCLUSIONS

The present study shows that mosquitoes in Kinshasa carry mosquito-borne viruses that may have serious public health implications. Further investigations on the presence of mosquito-borne viruses in the human and livestock populations of Kinshasa and DRC are recommended.

Dengue Epidemic in Postconflict Swat District, Khyber Pakhtunkhwa, Pakistan, 2013

AbstractSwat, a lush green valley of 1.3 million persons, remained under militant insurgency from 2007 to 2009, which damaged the health infrastructure. An outbreak of dengue fever (DF) was declared in the valley in 2013. To investigate this outbreak, we established active surveillance of national hospitals and private clinics, reviewed available clinical and laboratory records, and conducted entomological survey. From August to November 2013, 16,000 suspected patients with acute febrile illness were presented to health facilities. Among those, 9,036 were confirmed positive for DF by clinical manifestation and presence of nonstructural protein 1-soluble antigen. Of 9,036 patients, majority were men and aged 21-40. The epidemic peaked in September 2013 (N = 6,487). The attack rate was 7.18/1,000 populations. Among the confirmed case-patients, 36 deaths were reported, and proportion of mortality was 0.4%. Each year, increase in age was significantly associated with risk of complication due to DF leading to death (P < 0.001).