Explore the growing concern of unidentified respiratory infections. Stay informed with Meri Sehat for updates and precautions.

Unidentified Respiratory Infections: A Public Health Concern

A. JABBAR DENTAL CLINIC KARACHI

Sadia Khan

Overview

Occasionally, Primary Care Physicians encounter cases that present considerable diagnostic challenges. It becomes particularly noteworthy when one observes the nth instance of a case with identical clinical presentations.

1. Fever with chills

2. Severe body ache

3. Cough and sore throat

4. Nausea and vomiting

5. Chest congestion

6. Runny nose and sneezing spells 
&nbsp;

The condition in question defies categorization as mere influenza or a benign pharyngitis. It exhibits a multifaceted etiology, oscillating between viral origins and secondary bacterial infections, with a substantial number of cases attributable to seasonal variations. Despite comprehensive screening for SARS-CoV-2, Dengue fever and Malaria, diagnostic clarity remains elusive. However, the persistence of a cough beyond a 4-5 month period warrants a heightened level of clinical scrutiny.

On October 26th, The Nation reported an alarming rise in respiratory infections across Karachi. Health experts have advised citizens to use facemasks and wash their hands to avoid contraction of the influenza virus as it is easily transmissible from one infected person to another. Infected people have been recommended to stay home for at least 24 hours, limit contact with others and avoid traveling. The Sindh health department has also suggested vaccination against influenza, describing it as the most important step for protection.<a href="#accordion">[4]</a>&nbsp;Since we have not been able to nail the exact diagnosis for this host of symptoms, let&rsquo;s try to work our way through with some clues. 
&nbsp;

Fever of unknown origin

This is defined as a fever exceeding 101&deg;F (38.3&deg;C) on multiple occasions, persisting without diagnosis for at least three weeks despite thorough investigation. The term &quot;unknown&quot; underscores the elusiveness of its cause even after extensive diagnostic efforts.

The differential diagnosis for Fever of Unknown Origin (FUO) includes:

<ol>
	<li>Infections</li>
	<li>Malignancies</li>
	<li>Noninfectious inflammatory diseases</li>
	<li>Miscellaneous (autoimmune conditions, thyroid disorders etc.)<a href="#accordion">[5]</a> 
	&nbsp;</li>
</ol>

The approach to differential diagnosis involves a meticulous history and physical examination to narrow potential etiologies. Initial testing evaluates for infections, malignancies, inflammatory diseases and all other possible causes. If initial noninvasive tests are inconclusive, imaging and even invasive procedures like tissue biopsy can be carried out.<a href="#accordion">[6]</a>

Empirical antimicrobial therapy is generally not effective. The diagnostic journey of FUO is often complex, with up to 75% of cases resolving spontaneously without a definitive diagnosis. Geographical location and the level of healthcare resources also influence the differential diagnosis of FUO, with infections being more common in lower-income countries.<a href="#accordion">[5]</a> 
&nbsp;

COVID-19 Aftermath

In recent years, there has been concern about the potential impact of COVID-19 on the severity of the flu. This has been concern about a &quot;twindemic&quot; of severe COVID-19 and flu or at the very least an exceptionally severe flu season.<a href="#accordion">[7]</a>&nbsp;However, it is important to note that the relationship between COVID-19 and the severity of the flu is complex and not fully understood. While underlying respiratory diseases are associated with more severe outcomes of both viral respiratory infections, chronic respiratory conditions may have an even higher impact on the severity of seasonal influenza than on the severity of COVID-19.<a href="#accordion">[3]</a> Additionally, there is evidence to suggest that the impact of COVID-19 on the severity of the flu may vary depending on factors such as COVID-19 severity and vaccination rates.<a href="#accordion">[1]</a>

It is also worth noting that COVID-19 itself can cause severe respiratory illness and has led to a worldwide increase in hospitalizations for pneumonia with multiorgan disease.<a href="#accordion">[9]</a>&nbsp;Further research is needed to better understand the impact of COVID-19 on the severity of the flu and to inform public health measures during flu seasons. 
&nbsp;

The Hygiene Hypothesis

The Hygiene Hypothesis posits that the immune system requires a certain level of exposure to pathogens to develop properly. Without this exposure, the immune system may become unbalanced, which could lead to an increase in the prevalence of allergies, asthma, and autoimmune diseases. The hypothesis also extends to the severity of illnesses such as the flu and cough. The argument is that if the immune system is not well-trained to recognize and combat pathogens, the body may not respond effectively when exposed to them. This could result in more severe symptoms or complications when encountering common respiratory infections.<a href="#accordion">[2]</a>

While the Hygiene Hypothesis provides a plausible explanation for the increased incidence of allergic diseases and possibly more severe symptoms of illnesses like flu and cough, it is a complex issue. The relationship between pathogen exposure, immune system development and disease severity is multifaceted and influenced by a variety of genetic, environmental and social factors. Further research is needed to fully understand these dynamics and to develop strategies that can help maintain a balance between preventing infectious diseases and allowing the immune system to develop properly.<a href="#accordion">[8]</a> 
&nbsp;

Guidelines

<ul>
	<li>Use facemasks to prevent the spread of respiratory infections.</li>
	<li>Wash hands regularly to maintain hygiene and avoid infection.</li>
	<li>Stay home for at least 24 hours if infected to limit contact with others and use masks when out in public.</li>
	<li>Avoid traveling when sick to prevent widespread transmission.</li>
	<li>Get vaccinated against influenza as a crucial protective measure.</li>
	<li>Seek medical advice if experiencing symptoms of respiratory infection.</li>
	<li>Cover mouth and nose with a tissue or elbow when coughing or sneezing.</li>
	<li>Avoid close contact with people who are sick.</li>
	<li>Clean and disinfect frequently touched objects and surfaces.</li>
	<li>Maintain a healthy lifestyle, including proper diet and exercise, to strengthen the immune system. 
	&nbsp;</li>
</ul>

Recommendations And Suggestions

<ul>
	<li>Public awareness campaigns to educate on the symptoms and prevention of respiratory infections.</li>
	<li>Increase access to hand sanitizers and face masks in public spaces and communal areas.</li>
	<li>Establish sanitation tunnels in all public spaces in order to promote decontamination and reduce the risk of pathogen transmission among the population.</li>
	<li>Encourage the public to report symptoms to health authorities for early detection and response.</li>
	<li>Implement temperature checks in public spaces where feasible.</li>
	<li>Corporations should implement work-from-home policies during sick days, informed by COVID-19 pandemic experiences, to mitigate disease transmission.</li>
	<li>Enhance corporate surveillance and establish rapid response teams for effective outbreak containment within the workplace.</li>
	<li>Develop a robust reporting system to bridge the gap between health ministry guidelines and actual workplace conditions, ensuring timely intervention in infection clusters.</li>
	<li>Set up medical camps and promote dialogue among healthcare professionals at higher levels to improve health crisis management.</li>
	<li>Promote telemedicine services for non-emergency consultations to reduce the burden on healthcare facilities and limit infection spread.</li>
</ul>

[1] Alshahrani, S., Fatease, A., Orayj, K., Alqahtani, A., & Alqahtani, T. (2023). Public perception towards vaccines as preventive measures against a twindemic (seasonal influenza and covid-19): a cross-sectional study from the aseer region, saudi arabia. Vaccines, 11(3), 558.

[2] Blackwell, A. D. (2022). The ecoimmunology of health and disease: the hygiene hypothesis and plasticity in human immune function. Annual Review of Anthropology, 51, 401-418.

[3] Brehm, T., Meirschen, M., Hennigs, A., Roedl, K., Jarczak, D., Wichmann, D., … & Wiesch, J. (2021). Comparison of clinical characteristics and disease outcome of covid-19 and seasonal influenza. Scientific Reports, 11(1). https://doi.org/10.1038/s41598-021-85081-0

[4] Desk, W. (2023b, October 26). Influenza virus cases on the rise in Karachi. The Nation.

[5] Fever of unknown origin in adults. (2022, February 1). PubMed.

[6] Fusco, F. M., Pisapia, R., Nardiello, S., Cicala, S. D., Gaeta, G. B., & Brancaccio, G. (2019). Fever of unknown origin (FUO): which are the factors influencing the final diagnosis? A 2005–2015 systematic review. BMC Infectious Diseases, 19(1).

[7] Trent, M., Moa, A., & MacIntyre, C. (2022). “i’ll be back”: australia’s experience of flu in 2022. BMJ, o2998.

[8] Verheij, T., Cianci, D., Van Der Velden, A. W., Butler, C., Bongard, E., Coenen, S., Colliers, A., Francis, N., Little, P., Godycki-Cwirko, M., Llor, C., Chlabicz, S., Lionis, C., Sundvall, P., Bjerrum, L., De Sutter, A., Aabenhus, R., Harbin, N. J., Lindbæk, M., . . . Ieven, M. (2021b). Clinical presentation, microbiological aetiology and disease course in patients with flu-like illness: a post hoc analysis of randomised controlled trial data. British Journal of General Practice, 72(716), e217–e224.

[9] Wiersinga, W., Rhodes, A., Cheng, A., Peacock, S., & Prescott, H. (2020). Pathophysiology, transmission, diagnosis, and treatment of coronavirus disease 2019 (covid-19). Jama, 324(8), 782.