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

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.

Incidence of Animal-Bite Injuries Registered in Public Hospitals of Post-Conflict Swat District, Pakistan in 2014

The Swat district, a conflict-hit territory due to Taliban militancy, had a damaged local health infrastructure. Animal-bite injuries leading to rabies is one of the major health concerns in developing countries, especially within conflict zones. The current prospective epidemiological study was conducted to estimate the cumulative incidence of animal-bite injuries, to summarize characteristics of bite victims and biting animals, and to collect information about post-exposure prophylaxis (PEP) practices in Swat district, Pakistan, during 2014. A questionnaire was designed to collect data about the sociodemography of the patients, bite incident situation (provoked or unprovoked), injury pattern, animal type, PEP, and vaccination. Descriptive analyses were conducted using bar graphs, frequency tables, and chi-square tests were used to determine associations. The cumulative incidence of animal-bite injuries was 39 per 100,000 people during the study period (May-August 2014). The majority of incidents were reported from rural regions (77.7%) and were males (76.6%) younger than 10 years (37.3%). Dogs were the most frequent biting animal (86.8%) followed by rats (4.7%). About 77.7% patients washed their wound before arrival at hospital. After an eclipse phase of 10 days, 44 (10.1%) animals developed sign of rabies. The current study has highlighted a topic of interest for health, education, veterinary, and local government policy makers regarding prevention of animal bites, benefits of PEP, vaccination of human and domestic animals, control of stray dogs, and eradication of rabies in developing countries with damaged healthcare structures.

Electrolyte Imbalance at Admission Does Not Predict the Length of Stay or Mortality in Dengue-Infected Patients

Background

A pattern of both clinical and biochemical abnormalities is associated with dengue virus infection (DVI). Among the various DVI-related biochemical defects, electrolyte imbalance is one that can alter the morbidity and mortality among patients. However, there is a dearth of evidence to assess the relationship between electrolyte imbalance and the length of stay or mortality in dengue-infected patients in Pakistan. In the current study, we aimed to investigate the association between electrolyte imbalance at the time of admission and the length of stay and mortality among dengue-infected patients.

Methods

We conducted a retrospective study at a large tertiary care hospital from November 2018 to November 2019. All patients with known chronic diseases and coinfections or those who were taking diuretics therapies or angiotensin-converting enzyme inhibitors were excluded. Our main exposure of interest was electrolytes imbalance and the outcome measure was the length of stay and mortality.

Results

A total of 1,008 dengue patients were enrolled with a mean length of stay of 2.56 days. Around 29.3% had hyponatremia and 23.2% had hypokalemia at the time of admission, and 21.9% of patients had a stay beyond three days. In multivariable analysis, hyponatremia [adjusted odds ratios (aOR) = 1.29; 95% confidence interval (CI): 0.59-2.84] and hypokalemia (aOR = 2.36; 95% CI: 0.91-6.10) were not found to be associated with the length of stay. However, patients with high troponin levels at admission had a prolonged stay beyond three days (aOR = 5.74; 95% CI: 2.34-14.11). There was a statistically significant association of creatinine levels (aOR = 14.74; 95% CI: 4.19-15.85) and diabetes mellitus (DM) (aOR = 4.36; 95% CI: 1.21-15.74) with mortality after controlling for potential confounders.

Conclusion

Electrolyte imbalance at admission is not a predictor of length of stay or fatalities in the hospital among patients with DVI. However, troponin levels at admission can increase hospitalization days whereas DM and renal injury have been found to worsen mortality rates.

An Agent-Based Simulation of the Spread of Dengue Fever

Vector-borne diseases (VBDs) account for more than 17% of all infectious diseases, causing more than 700,000 annual deaths. Lack of a robust infrastructure for timely collection, reporting, and analysis of epidemic data undermines necessary preparedness and thus posing serious health challenges to the general public. By developing a simulation framework that models population dynamics and the interactions of both humans and mosquitoes, we may enable epidemiologists to analyze and forecast the transmission and spread of an infectious disease in specific areas. We extend the traditional SEIR (Susceptible, Exposed, Infectious, Recovered) mathematical model and propose an Agent-based model to analyze the interactions between the host and the vector using: (i) our proposed algorithm to compute vector density, based on the reproductive behavior of the vector; and (ii) agent interactions to simulate transmission of virus in a spatio-temporal environment, and forecast the spread of the disease in a given area over a period of time. Our simulation results identify several expected dengue cases and their direction of spread, which can help in detecting epidemic outbreaks. Our proposed framework provides visualization and forecasting capabilities to study the epidemiology of a certain region and aid public health departments in emergency preparedness.