Infectious or communicable disease can be defined as an illness caused by another living agent, or its products, that can be spread from one person to another.[1] An emergency condition can be defined as a state of disarray that has occurred during or after a regional conflict, or a natural disaster (i.e.: flood, earthquake, hurricane, drought).

Infectious disease during an emergency condition can raise the death rate 60 times in comparison to other causes including trauma.[2] Greater than 40% of deaths in emergency conditions occur secondary to diarrheal illness with 80% of those involving children less than 2 years of age.[3]

Of note, there is no dependable performance assessment tool in improving communicable disease surveillance in regards to outbreaks of infectious disease although the Centers for Disease Control (CDC) has proposed viable mechanisms for public health in general.[1]

Ebola virus has been raging through Western Africa for seventeen months by now. The number of new cases is declining but an end to the epidemic is not in sight. The World Health Organization registered about 27,500 cases thus far, of which 11,220 have died. It will probably take several more months until the largest EVD outbreak in history can be declared over. Guinea, Liberia, and Sierra Leone will suffer from the economic consequences for many years to come. Scientists and politicians now unanimously argue that international aid came too late and was for the most part ineffective. The WHO in particular has been facing intense criticism not having reacted appropriately to the outbreak. The horrendous images coming out of Western Africa and concern for their own safety have finally woken up the industrialized nations.

How, then, can we protect ourselves against future outbreaks of deadly microbial diseases?

The influenza virus has been responsible for influenza pandemics causing severe disruptions all around the world. In 1918, 1957 and 1968, the “Spanish influenza” A (H1N1), the “Asian influenza” A (H2N2) and the “Hong Kong influenza” A (H3N2) pandemics caused millions of deaths worldwide. Even in 2009, H1N1 influenza A led to between 200,000 and 400,000 deaths. Influenza virus spreads through air droplet, and people in crowded places can be susceptible to infection, for example, in the military camps. In recent years, influenza has been a common infectious disease in the Chinese army, which directly disturbs military training and affects the soldiers’ health. According to a research on the infectious diseases proportions in the Chinese army from 2001 to 2010, influenza virus-related respiratory infectious diseases headed the list of all of the infectious diseases, except in 2001, 2004 and 2005. Therefore, it is necessary and urgent to prevent and control influenza epidemics in the Chinese army.

An influenza surveillance system was used widely for influenza prevention and control [4–6], and virological data collected from laboratories or hospitals was a good indicator of influenza and provided a reasonable pre-peak warning at the regional level [7, 8]. China also established a national influenza surveillance (NIS) system, which covered 31 provinces. In 2014, as a theater for the Centers for Disease Prevention and Control (CDC), we established an influenza monitoring platform (IMP) to strengthen the monitoring of influenza-like illness and influenza virus infection. This paper investigates the establishment, operation, experiences and problems of a theater IMP; the IMP monitoring effect is also evaluated by comparing the monitoring data from the IMP with that of the NIS.

Measles classically presents with a high fever (often >104°F [40°C]), generally of 4–7 days in duration. This initial sign occurs after an incubation period of 1–2 weeks following exposure (average 10–12 days). During this prodromal phase, a classic triad of cough, coryza and conjunctivitis (the “3 Cs”) is often present.5 Patients may have photophobia. The eyes have a characteristic appearance, typically showing erythema of the palpebral conjunctiva with nonpurulent discharge (Figure 1) and sometimes periorbital edema. Patients may also report malaise, myalgias, anorexia, and diarrhea. Adults often develop transient hepatitis.6

Koplik spots, when seen, are pathognomonic of measles (Figure 2). If present, they manifest 1–2 days prior to the rash and last for 3–5 days. They appear as bluish-gray enanthema (“small grains of sand”) on a red base and are typically seen on the buccal mucosa opposite the second molars. Therefore, it is essential to have proper lighting to visualize them. During a measles outbreak, after donning appropriate respiratory protection, emergency physicians (EP) should carefully assess the oropharynx in patients presenting with non-specific viral syndromes and assess for the presence of Koplik spots.

The rash of measles generally erupts about 14 days after exposure, which is usually 2–4 days after onset of symptoms. Unlike rashes of some infectious diseases that start on the lower extremities or trunk, the rash of measles begins on the face and progresses cephalocaudally to the torso and extremities. Thus, assessing the pattern of rash evolution is essential to identify measles patients. Erythematous macules and papules coalesce into patches and plaques within about 48 hours (Figure 3). Petechia and ecchymosis can also be seen. By the time a rash develops, within 1–2 days, patients will be ill appearing. After 5–7 days, the exanthem begins to fade, forming coppery-brown hyperpigmented patches that may desquamate. The rash initially disappears at the location where it first appeared. The rash can be more difficult to detect on dark-skinned patients (Figure 4).

•Significant epidemics with Vibrio cholerae subgroups: O1 and O139.•Bacterial infection of bowels.•Clinical: sudden onset, profuse, clear diarrhea. If untreated, can lead to acidosis, hypovolemic shock, and renal failure in addition to other end-organ damage.•Associated with natural disasters, overcrowding, poor hygiene, and soiled water supply.•Diagnosis: stool culture, or microscopic examination of stool for “shooting stars.”

∘During epidemics, cholera should be presumed after the first batch of confirmed cases, by history and exam alone, and money should not be spent confirming every case of cholera thereafter.•Incubation: 2-3 days.•Transmission: consumption of water, or food contaminated with feces of infected persons.•Vaccinations: as discussed in previous section.•Management:

∘Strict isolation is not important although hygiene and handwashing is crucial.∘Rehydration is key. Less severe cases can be managed with oral rehydration solution (ORS) alone. Moderate to severe cases must be managed with intravenous fluid.∘In severe cases, doxycycline, or other antibiotics, can be used.

Influenza-like illness was defined as an axillary temperature ≥38°C and cough or sore throat in an outpatient of any age.

Disease manifestations are often more severe in children under five and adults over 20 years of age. Patients who are immunocompromised may present atypically and may not develop a rash. During a measles outbreak, clinicians should advise patients with viral syndromes who are being discharged from the ED to monitor for appearance of a rash, especially one that first appears on the face. If a rash develops, children or adult patients should avoid public places and seek immediate medical advice.

In Study 1, attack rate of the swimming department was higher than that of others (RR: 1.90; 95% confidence interval (CI): 1.01-3.60) (Table 2). In Study 2, being a member of the shooting department (RR: 20.70; 95% CI: 4.90 - 87.47) and being a first grade student of high school (RR: 10.95; 95% CI: 2.90 - 41.33) were identified as risk factors for infections, according to the results of multivariable logistic regression (Table 3).

Theater IMP is constituted of 3 levels of medical units, including monitoring sites, testing laboratories and a checking laboratory. The platform runs from October 1 to March 31 of the following year and covers the prevalent season of influenza. Monitoring sites are setup in basic units, mostly in regiment medical teams, which are responsible for collecting nasopharyngeal swab samples, transporting collected samples to the testing laboratory, and isolating and treating confirmed influenza patients. Nasopharyngeal swab and morbidity information are collected from soldiers or officers based on whether there is a fever combined with influenza-like symptoms. Testing laboratories are responsible for the reception, detection and storage of samples from monitoring sites, and they are set up in regional military hospitals. Between 3 and 6 monitoring sites typically are under the management of one testing laboratory. Testing laboratories also need to inform the monitoring sites of the detection results in a timely fashion in case the influenza viruses spread widely. A checking laboratory is a laboratory that runs a repeated detection on influenza virus positive samples from testing laboratories, which is set up in the theater CDC. The checking laboratory is also responsible for the disposal of influenza outbreak in regiments, training IMP staffs and supervising the platform.

Swimming pools have been implicated in the transmission of infections. The risk of infection has mainly been linked to fecal contamination of the water, generally due to feces released by bathers or to contaminated source water. Failure in disinfection has been recorded as the main cause of many of the outbreaks associated with swimming pools.

The majority of reported swimming pool-related outbreaks have been caused by enteric viruses. Sinclair and collaborators reported that 48% of viral outbreaks occur in swimming pools, 40% in lakes or ponds, and the remaining 12% in fountains, hot springs, and rivers (4% each).

Viruses cannot replicate outside their host’s tissues and cannot multiply in the environment. Therefore, the presence of viruses in a swimming pool is the result of direct contamination by bathers, who may shed viruses through unintentional fecal release, or through the release of body fluids such as saliva, mucus, or vomitus. Evidence suggests that skin may also be a potential source of pathogenic viruses.

Influenza-like illness (ILI) is often used for influenza surveillance, as influenza is a disease of global interest with 5% of adults developing symptomatic disease annually and with case fatalities of 3.5% in susceptible populations. While influenza surveillance remains a priority, ILI can also be caused by a wide range of viral pathogens that present with a spectrum of respiratory symptoms. In the tropics, viral respiratory pathogens have been reported to exhibit different seasonality and transmission characteristics compared to temperate climates. This necessitates a better understanding of their epidemiology to assess the utility and importance of surveillance in these settings. The year-round circulation of respiratory viruses in the tropics may also predispose patients to co-infection with multiple pathogens, with implications for severity of disease and secondary bacteria infection.

While there have been studies comparing differences in clinical presentation between influenza and non-influenza cases, few describe the epidemiology and differences in clinical presentation among various non-influenza respiratory viruses. As influenza viruses have accounted for only between 10.1% to 53.0% of all ILI cases, it is important to understand the contribution of other respiratory pathogens to overall morbidity and to determine their epidemiological distribution and clinical presentation.

To address these issues, this study explores data obtained from a respiratory disease sentinel surveillance system in the Singapore military to examine the etiologic viral agents of respiratory illnesses in a tropical environment, to determine the viruses that circulate post-influenza vaccination, and to compare the differences in clinical presentation.

Outbreaks of diseases such as avian influenza, SARS and West Nile Virus have alerted us to the potentially grave public health threat from emerging and re-emerging pathogens–[3]. Many important infectious diseases persist on a knife-edge: rapid rates of transmission coupled with brief infectious periods. Such violent epidemic behavior has been observed in plague, cholera, pertussis and more recently Hepatitis E. The recent outbreak of Hepatitis E in northern Uganda, has left many dead and a number of infectives that continue to spread the infection. Hepatitis E is caused by infection with the Hepatitis E virus (HEV) which has a fecal-oral transmission route. It is a self-limiting disease but occasionally develops into an acute severe liver disease. As emerging and re-emerging infectious diseases increase in outbreak frequency, there is a compelling interest in understanding their dynamics–[10].

The Kitgum outbreak, which we study here, has been linked to contaminated water or food supplies. An assessment conducted by the Uganda Red Cross and district representatives in Agoro revealed that for a population of about 28,045 with 6,039 households mainly living in camps for internally displaced people in Potika as well as Agoro and Oboko satellite camps, the latrine coverage was as low as 3.7%. This means that there is one latrine for every 27 people. Further, only 23 boreholes were functional implying that the bore hole coverage is , or one bore hole per 263 households.

Another possible factor that could be implicated in the outbreak of Hepatitis E is its possible relationship with malaria. Malaria has been shown to disarm the immune system and increase susceptibility to viral infections such as HIV. Recently, in a 3-month follow-up study the pattern of co-infection of Plasmodium falciparum malaria and acute Hepatitis A (HAV), in 222 Kenyan children under the age of 5 years was observed. The incidence of HAV infections during P. falciparum malaria was found to be 6.3 times higher than the cumulative incidence of HAV, suggesting that co-infection of the two pathogens may result from changes in host susceptibility. There is also evidence both for, and against, an association between Hepatitis B viruses and malaria. HEV transmission route is similar to the Hepatitis A virus and thus for HEV it is important to consider possible links to co-infection with malaria. This can be done using mathematical models of multiple pathogens–[22].

In this paper, mathematical models are used to study the effects of both environmental conditions and malaria on Hepatitis E infections. The models designed are fit to data from the Kitgum outbreak, to estimate the basic reproduction number and to relate them to the level of contamination of the environment. We assume that the small number of latrines, leads to contamination of environment. This in turn leads to contaminated water. Owing to the few number of bore holes in the region, lack of access to clean water gives rise to the viral infection of Hepatitis E.

The case definition used for severe acute respiratory illness was different for persons <5 and those ≥5 years old. For children <5 years old, a modified version of the World Health Organization's Integrated Management of Childhood Illness (IMCI) definition for pneumonia was used, requiring the presence of cough or difficulty breathing plus one of the following danger signs: chest in-drawing, stridor, unable to breastfeed or drink, vomits everything, convulsions, lethargy, or unconsciousness. For patients ≥5 years old, SARI was defined as axillary temperature ≥38°C plus cough, difficulty breathing or shortness of breath. Hospitalization was a required criterion for SARI cases, regardless of age.

Acute respiratory infections make up a huge proportion of disease burden in the United States and globally, with an estimated 94 037 000 disability adjusted life years and 3.9 million deaths worldwide each year. Respiratory infections are often difficult to diagnose clinically due to nonspecific and overlapping symptoms. Additionally, diagnostic tests can be time-consuming and costly and often require trained and well-equipped laboratories, making laboratory confirmation of each case impractical. However, laboratory results from various surveillance populations can be paired with clinical, demographic, and seasonality variables to create models that can give timely predictions of disease outcomes. Preventive measures and treatments to reduce respiratory disease burden can also be improved through routine surveillance by gaining a better understanding of the percent positivity of pathogens among acute respiratory cases, seasonality, and coinfection occurrence.

Currently, limited respiratory disease etiology studies have been done in the United States,,, despite many being done in other countries,,,,,,,,,. Additionally, few viral etiology studies have collected clinical signs and symptoms and assessed their association with a broad range of respiratory pathogens,,. Most descriptive studies and predictive models for respiratory diseases have focused on identifying influenza using clinical signs and symptoms,,,,,, however few have been age-stratified and therefore may have missed some important differences in clinical presentation by age. Understanding US-specific disease burden and seasonality is important, since disease incidence, distribution, and seasonality may vary between populations, regions, and climates. This study aimed to describe characteristics associated with specific respiratory pathogens, as well as the etiology, seasonality, and coinfection rates among three US populations: military recruits, Department of Defense (DoD) beneficiaries, and civilians living near the US–Mexico border.

The results of this study can help improve timely and more accurate diagnosis, inform treatment plans, establish baselines of infection, identify outbreaks, and help prioritize the development of new vaccines and future treatments.

The first cases of the new H1N1 pandemic influenza virus (H1N1sw), in metropolitan France, were detected in April 2009 in patients returning from Mexico. Systematic analysis of suspected cases was undertaken and the virus was identified, using molecular methods, in the Public Hospital virology “Level A” laboratories of the seven French Defence Zones. Accordingly, samples from the Southern Defence Zone (a large geographical region encompassing Corsica and the Mediterranean costal zone from the Spanish border to the Italian border with approximately 8 million inhabitants), were received and analysed in our department, at the Virology Level A laboratory of the Public Hospitals of Marseille.

The current study refers to samples received between the end of April and the end of August 2009. During the first period (until mid-July), samples were systematically collected using strict and identical criteria, mainly based either on the presence of an acute respiratory illness and recent travel history in an affected area, or on contact with a confirmed or suspected case. During the second period, biological confirmation of suspected cases was no longer required and criteria used for requesting biological diagnosis (grouped cases, severe or atypical presentations, pre-existing condition etc.) were more heterogeneous.

Here, we present the results of virological analyses performed during the first three months that followed the introduction of the novel H1N1sw pandemic influenza variant in metropolitan France. This included the detection and characterization of influenza viruses, the evaluation of rapid Influenza detection tests (RIDTs) detection of the H1N1sw pandemic variant, the detection of other respiratory viruses and the investigation of grouped cases. In addition, the distribution of specific antibody to the new virus was investigated according to age groups in a sample of 600 individuals. Altogether, these data shed new light on the determinants of the epidemiological distribution of viral infection in the French population.

In the western United States Ixodes pacificus ticks are the vector of Borrelia burgdorferi, the causative agent of Lyme disease. I. pacificus ticks are also vectors for several other vector-borne pathogens including Borrelia miyamotoi and Anaplasma phagocytophilum. In addition, I. pacificus ticks have been shown to carry Spiroplasma ixodetis, a microorganism that has no known role in human disease. Broad-range PCR and electrospray ionization mass spectrometry (PCR/ESI-MS) can detect multiple pathogens in a single test including tick-borne pathogens [4–14]. PCR/ESI-MS can also detect novel and uncharacterized organisms [10,12,15–19]. We have previously used PCR/ESI-MS to characterize a large collection of ticks, including I. pacificus ticks from California, for the prevalence of B. miyamotoi. Most studies of I. pacificus ticks have employed tests designed to detect single pathogens and not co-infections. In this study we used PCR/ESI-MS to characterize the breadth of microorganisms carried by I. pacificus collected from throughout the state of California. In the ticks analyzed, we detected several previously described endemic zoonotic pathogens as well as Babesia odocoilei, a protozoan not previously known to be carried by I. pacificus. Many of the microbes carried by ticks are obligate intracellular microbes and have not been cultured but have been identified and characterized genetically such as ‘Candidatus Rickettsia andeanae’, ‘Candidatus Rickettsia vini’ and ‘Candidatus Neoehrlichia mikurensis' [20–23]. In our study we identified and genetically characterized a novel and widespread Anaplasmataceae species which is genetically most closely related to isolates from Asia.

Diphtheria, a bacterial disease caused by Corynebacterium diphtheriae, is a vaccine-preventable disease. Symptomatic patients initially complain sore throat and fever. Additionally, a gray or white patch causes the “croup,” blocking the airway and causing a barking cough. Due to widespread use of diphtheria–tetanus–pertussis (DTP) vaccine globally, the incidence has steadily declined over time, and thus, diphtheria is commonly perceived as a disease of pre-vaccination era. Nevertheless, sporadic cases and even epidemics of the disease have been yet reported especially in politically unstable areas, and many cases have been considered as arising from susceptible pockets of the vulnerable population (Rusmil et al., 2015; Hosseinpoor et al., 2016; Sangal et al., 2017).

In 2017, multiple diphtheria outbreaks were reported in refugee camps, including those in Yemen and Bangladesh (World Health Organization (WHO), 2017a). Of these, a Rohingya refugee camp in Bangladesh, which is temporarily located in Cox’s Bazar, experienced a large-scale diphtheria epidemic. As of December 26, 2017, the cumulative number of 2,526 cases and 27 deaths were reported (World Health Organization (WHO), 2017a). To interrupt chains of transmission, emergency vaccination has been conducted among children since December 12, 2017, achieving the overall coverage greater than 90% by the end of 2017 (World Health Organization (WHO), 2018). Due to vaccination effort and other countermeasures, including contact tracing and hospital admission of cases, the epidemic has been brought under control, with incidence beginning to decline by the end of December 2017 (World Health Organization (WHO), 2017a).

Considering that diphtheria has become a rare disease in industrialized countries, epidemiological information on model parameters that govern the transmission dynamics has become very limited, and thus, it is valuable to assess how transmissible diphtheria would be through the analysis of the recent outbreak data. The basic reproduction number, R0, is interpreted as the average number of secondary cases that are produced by a single primary case in a fully susceptible population, acting as the critical measure of the transmissibility. To date, an explicit epidemiological estimate of R0 for diphtheria has been reported only by Anderson & May (1982): using a static modeling approach to age-dependent incidence data with an assumption of the endemic equilibrium, R0 was estimated as 6.6 in Pennsylvania, 1910s and 6.4 in Virginia and New York from 1934 to 1947. Subsequently, a few additional modeling studies of diphtheria took place (Kolibo & Romaniuk, 2001; Sornbundit, Triampo & Modchang, 2017; Torrea, Ortega & Torera, 2017), but none of these offered an empirical estimate of R0.

Here we analyze the epidemiological dataset of diphtheria in Rohingya refugee camp, 2017, aiming to estimate R0 in this particular epidemic setting. Given that the epidemic occurred among refugees, we explicitly account for uncertainties associated with unknown background information, including the fraction of previously immune individuals and ascertainment rate of cases.

We carried out a comprehensive literature review aimed at investigating waterborne viral outbreaks linked to swimming pools, to explore the etiological agents implicated, pathways of transmission, associations between indicator organisms and disease, and key issues related to chlorination/disinfection procedures. Viral outbreaks are summarized in Table 1. The presence of enteric viruses in swimming pools under non-epidemic conditions was also reviewed. Different databases (Scopus, PubMed, and Google Scholar) were accessed using the terms norovirus, Norwalk virus, adenovirus, enterovirus, echovirus, coxsackievirus, and hepatitis A, in combination with terms recreation, swimming, pool, and water.

Pneumonia remains a leading cause of mortality globally: 4.2 million pneumonia deaths were recorded in 2004. The highest incidence of disease occurs in young children. An estimated 156 million pneumonia episodes occur annually in children less than five years old. Over 95% of these occur in the developing world, where the incidence of clinical pneumonia is estimated to be 0.29 episodes per child-year. Almost three-quarters of childhood pneumonia deaths occur in sub-Saharan Africa and Southeast Asia. Bacterial pathogens, most notably Streptococcus pneumoniae and Haemophilus influenzae type B, are important vaccine-preventable causes of pneumonia. Viruses, in particular influenza and respiratory syncytial virus (RSV), are also responsible for a large number of pneumonia cases each year. Using global population data for 2005, for children under the age of five years, it was estimated that RSV was responsible for over 30 million episodes of lower respiratory tract infections (LRTI), with ~3 million of these requiring hospital admission, and 66,000-199,000 deaths. By similar analyses of data from 2008, influenza viruses were estimated to cause 20 million LRTI and 1 million severe LRTI, with 28,000-111,500 deaths, in children aged less than five years. In both of these reviews, 99% of deaths from either influenza–or RSV–associated LRTI occurred in the developing world. These viruses may be responsible for up to 35% of LRTI (RSV 22% and influenza 13%) in children under the age of five years. Other viral pathogens associated with childhood pneumonia include adenoviruses, human metapneumovirus (hMPV), and parainfluenza viruses.

Approximately one-third of the worldwide refugee population of 15 million live in camps. These camps are often crowded with poor sanitation, providing ideal conditions for transmission of respiratory pathogens. There have been refugees from Myanmar (Burma) living in camps in Thailand since 1984. In 2006, lower respiratory tract infections were estimated to be the cause of 9% of deaths, and were responsible for 25% of all reported morbidity, in the under-5 age group of the border refugee population. The overall under-5 year mortality rate was 6 per 1,000, giving an estimated LRTI-specific mortality rate of 0.5 per 1,000.

In 2007, the US Centers for Disease Control and Prevention (CDC) and the Shoklo Malaria Research Unit (SMRU) established a respiratory virus surveillance programme in the Burmese refugee population living in Maela camp, Northwest Thailand. The programme included patients admitted to hospital with pneumonia during April 2009-September 2011. The aim of in-patient surveillance was to determine the relative burden of virus-associated pneumonia. The results of 30 months of in-patient surveillance are presented here.

There were 33 identified cases in Study 1, of which 32 were students and 1 was a swimming teacher. 23 (69.7%) of the 33 cases were male. 1st and 3rd grade of the high school had the largest number of the cases (8 each). Swimming and modern sports departments had 26 (78.8%) and 6 (18.2%) cases, respectively. There were 14 identified cases in Study 2, and all of them were students. Ten (71.4%) of these cases were male. Nine (64.3%) of the 14 cases were 1st grade students of the high school, and 6 (42.9%) were from the Shooting department. The common symptoms in 47 cases were headache (33, 71.7%), fever (32, 69.6%), rhinorrhea (29, 63.0%), sputum (26, 56.5%), and sore throat (25, 54.3%). Eleven (23.9%) cases were accompanied with vomiting or diarrhea, and 9 (19.6%) showed eye congestion. Although none of the cases showed signs of pneumonia, 15 (32.6%) of all cases were hospitalized due to acute respiratory infection (Table 1).

High population density, in addition to physical and mental stress to adapt to a new environment, has been recognized to contribute to increased susceptibility of military recruits to respiratory infection. To better protect the recruits and reduce loss in training time, a surveillance programme was put in place to monitor the etiological agents responsible for febrile respiratory illnesses (FRIs) among Singapore military recruits since 2009. Data from the surveillance programme showed that Influenza, Coxsackie, Rhinovirus and Adenovirus are the primary causative agents of FRIs in military camps [2, 3]. Mass vaccination of military recruits against pandemic H1N1 (A(H1N1)pdm09) in 2009 demonstrated that such a policy can reduce disease burden among recruits. A subsequent study also showed that routine administration of influenza vaccine to recruits resulted in significant protection against both A(H1N1)pdm09 and influenza B, and thus, was recommended for all military personnel since.

While the initial focus of the surveillance programme is on etiological agents that cause febrile illnesses, some recruits were excluded from the programme as they only presented respiratory symptoms without elevation in body temperature (termed as Acute Respiratory Illnesses (ARIs)). Since late 2015, the surveillance programme was expanded to monitor the etiological agents responsible for ARIs cases as well, owing to the paucity of information on causative agents for ARI cases. Using molecular diagnostic technology, the current study aimed to evaluate the contribution of 26 different pathogens to FRI and ARI cases. This report highlights findings on both the FRI and ARI cases captured by the surveillance programme in its first year of ARI survey. Additionally, there is a focus on significant relationship between pathogens presented as co-infections.

Human adenoviruses (HAdV) are a common cause of acute respiratory diseases, causing sporadic infections, as well as community and institutional outbreaks.1 Infection with HAdV rarely causes serious or fatal illness in otherwise healthy individuals, but may cause severe disease in newborn, elderly, or immunocompromised persons.1 There are at least 69 recognized HAdV genotypes (http://hadvwg.gmu.edu/), which are assigned to seven subgroups (A–G) according to biophysical, biochemical, and genetic characteristics.2 The spectrum of clinical disease associated with HAdV is broad and depends largely upon the infecting HAdV genotype. Clinical signs and symptoms include fever, rhinorrhea, pharyngitis, conjunctivitis, gastroenteritis, bronchitis, pneumonia, acute hemorrhagic cystitis, meningoencephalitis, and rarely life-threatening disseminated diseases.1 New adenovirus genotypes are increasingly recognized through the use of phylogenetic analysis based on complete genomic sequences. Novel strains may arise from mutations or recombinations of two different adenovirus strains between the hexon gene and fiber genes.3,4 Recently, an emergent variant, HAdV-55,5,6 with a proposed recombination of hexon gene between HAdV-11 and HAdV-14 strains, has been described in association with multiple outbreaks of acute respiratory disease, mostly occurring in military camps.7–10 In 2005, a large outbreak of acute respiratory disease likely from HAdV-55 occurred in a military camp in Turkey.8 Another two HAdV-55 outbreaks occurred among military training camps in 2005 (226 patients in Singapore9) and in 2009 (108 patients in China10). Nucleotide sequence analysis showed the strains from the two outbreaks were highly similar to the QS-DLL strain, which was the first HAdV-55 in China isolated from an ARDS outbreak in Shaanxi in t 2006 that occurred in a senior high school.7 The most recent HAdV-55 outbreak occurred in February 2012 among patients with febrile respiratory tract infection admitted to PLA 252 hospital, Hebei Province, China (unpublished data). With rare precedent circulation of HAdV-11 and HAdV-14 in China, an increasing trend of adenovirus type 55 infections was observed among both civilian and military populations, probably due to the lack of immunity herd. This concern, in combination with its higher tendency in causing severe respiratory illness than other adenovirus, posed great threats to Chinese military that it has the potential to spread widely and cause severe epidemics. The status highlights the need for improved surveillance, with extensive molecular characterization, to identify the prevalence and the genetic variants of this emerging adenovirus. Thus far, HAdV surveillance in China is sparse, and HAdV-55 infections were chiefly identified during outbreak events. The current study was sought to acquire a better understanding of the prevalence and molecular evolution of HAdV-55 strains by performing an active surveillance for HAdV infections. This knowledge might assist with targeted population for disease prevention and geographic regions where type-specific vaccines should be administered if developed.

Recruitment into the military and congregation of recruits in training camps brings together many people from geographically diverse areas into close living conditions. Similar to other settings, such as college dormitories, sports teams, and cruise ships, the close physical proximity of individuals in military barracks enhances the risk of the transmission of respiratory and enteric pathogens. The congregation of diverse individuals can lead to the introduction of one or more pathogens into a confined population, leading to an outbreak of infections. Institutions that permit frequent, longer term, and intimate contacts among individuals generally can be expected to have higher attack rates.1 Other factors such as physical exertion and the prevalence of immunologically naïve individuals can contribute to the unique vulnerability of military recruits.2

Militaries are a unique subset of institutions that potentially have higher attack rates than other societal groupings. Military personnel and children may be at greater risk of infection than other groups.1 The effect of school closures during epidemics have demonstrated that environments with high people density can function as amplifying arenas for influenza and other respiratory diseases.3 The large-scale mobilization of military forces during World War I was a contributing factor to the global influenza pandemic of 1918–1919.4,5 In the years since then, much research has been done to study respiratory illness among U.S. military recruits. The Commission on Acute Respiratory Diseases conducted studies at United States recruiting camps documenting that rates of respiratory disease among recruits were higher than other ‘seasoned’ military groups.6 Miller et al. noted a direct correlation between changes in rates of pneumonia and respiratory illness with the number of recruits in training. The number of recruits proved to be an even stronger determinant of infection rates than seasonal factors.7 In a more recent study examining influenza vaccine, rates of influenza-like illness (ILI) among recruits were found to be 2–16 times higher than non-recruit service members.8 In spite of widespread immunization among U.S. military personnel, influenza outbreaks continue to occur in crowded military settings.9,10 More recently, human adenovirus (H-AdV) has been a predominant cause of febrile respiratory illness in the U.S. military.11

While more is known about the respiratory illness experience of U.S. military personnel, little is known about the experience of military populations of other countries in the tropics and Asia, an area that is very important in the global ecology of influenza.12 Vaccination uptake in developing nations is considerably less than it is in developed countries and is not mandatory in the militaries of many countries including Thailand. Furthermore, the prevailing circulating viruses are unknown. Influenza which has well defined seasonality in temperate climates is far more difficult to characterize in the middle latitudes of the tropics.13

We report the results of a respiratory illness study among new military recruits at a Royal Thai Army (RTA) barracks in Bangkok, Thailand. These results were complemented by laboratory testing to confirm infection including multiplex PCR.

Mass gatherings create environments conducive to the transmission of infectious disease including pandemic influenza. [1–11]. Some mass gatherings such as outdoor sporting events may involve limited social mixing and are held in settings with ample ventilation. Other mass gatherings, however, can involve significant social mixing over several days such as professional conferences and music festivals [1–4]. Intensely crowded settings can lead to high secondary attack rates even when a circulating pathogen has a relatively low transmission probability [1–4]. Travelers to mass gatherings can not only introduce an infectious disease to a previously unaffected area, but can also amplify transmission at the gathering and further disseminate transmission following their return home. This was recently demonstrated by the propagation of the first wave of the 2009 H1N1 pandemic (pdm09H1N1) following a large Easter holiday gathering in Iztapalapa, Mexico. Similar mass gatherings have been linked to the propagation of the Great Pandemic in 1918 and the Asian Flu Pandemic in 1957 [7–8].

During future influenza pandemics or other public health emergencies in the United States, state and local public health officials will have to consider modifying, postponing, or cancelling mass gatherings. This decision could depend on the severity of the pandemic as well as the timing, duration and size of the event and whether people will be traveling to and from the event from other (affected or not-yet-affected) communities. If the risk of severe disease is low, then other non-pharmaceutical interventions could be recommended to minimize the potential for disease transmission. Despite these recommendations, limited empirical information exists on the frequency and characteristics of mass gathering-related respiratory disease outbreaks in the United States.

To address this gap, we conducted a systemic review of the published literature and analyzed the National Outbreak Reporting System (NORS) database maintained by the United States (U.S.) Centers for Disease Control and Prevention (CDC) since 2009. The objectives of this project included describing the frequency of mass gathering-related respiratory disease outbreaks occurring in the United States, highlighting the likely causes of these outbreaks, and documenting any patterns or shared characteristics across the identified outbreaks.

Porcine respiratory disease complex (PRDC) is a syndrome caused by mixed viral and bacterial pathogens together with environmental, managerial and genetic factors. A combination of pathogens are involved, e.g. viruses such as porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus type 2 (PCV2), swine influenza virus (SIV), porcine respiratory coronavirus (PRCV), and various bacteria e.g. Actinobacillus pleuropneumoniae (APP), Mycoplasma hyopneumoniae (MHyo), Mycoplasma hyorhinis, Haemophilus parasuis (H.parasuis), Pasteurella multocida and Streptococcus suis [1–6]. Often it remains unclear which the primary pathogen is and which one is acting as a predisposing agent for other infections or as a secondary infection [2, 6, 7]. Many of these pathogens can also be found in clinically healthy pigs, but they are detected more often in pigs with respiratory symptoms. The pathogenesis of multifactorial PRDC is difficult to determine, because primary and opportunistic pathogens modify their impacts in different cases.

Pathogens involved in PRDC vary considerably in various countries, regions and herds over time. In Finland, the prevalence of porcine respiratory pathogens differs substantially from the situation in continental Europe. The country has been free of ADV, PRCV and PRRSV for decades. Also, Finland is nearly free of swine enzootic pneumonia. In 2015, MHyo was detected in only one Finnish pig herd, and most Finnish pig production (97%) is included in the national health programme requiring the absence of this pathogen. On the contrary, APP is a common pathogen causing respiratory problems. SIV is a newcomer in the country. Avian-like H1N1 swine influenza A virus was found in the Finnish pig population for the first time in 2008 and A(H1N1)pdm09 influenza virus in 2009. PCV2 is a pathogen commonly found in the Finnish pig population, and many herd owners control it by vaccination. However, its role in respiratory infections in Finland has not been studied earlier. Overall, assessing which respiratory pathogens are involved in acute respiratory disease outbreaks in a country lacking major viral pathogens is very important.

The objective of our study was to clinically and etiologically investigate acute outbreaks of respiratory disease in Finland. This field study also aimed to evaluate the clinical use of various methods in diagnosing the respiratory infections under field conditions and to describe the antimicrobial resistance profile of the main bacterial pathogen(s) found during our study.