Chlamydia: A Silent Threat to Sexual Health

Chlamydia is a widespread sexually transmitted infection (STI) caused by the bacterium Chlamydia trachomatis. It is among the most frequently reported STIs worldwide, particularly affecting young adults aged 15 to 24. According to the World Health Organization (WHO), chlamydia accounts for over 130 million new infections annually, making it a significant public health concern.

Symptoms and Asymptomatic Nature

One of the most concerning aspects of chlamydia is its asymptomatic nature. Studies indicate that approximately 70% of women and 50% of men with chlamydia do not experience noticeable symptoms, leading to undiagnosed and untreated infections. When symptoms do appear, they may include abnormal genital discharge, burning sensation during urination, pain during sexual intercourse, and, in some cases, rectal pain or bleeding in individuals who engage in anal sex.

Health Complications

If left untreated, chlamydia can result in severe health complications. In women, it is a major cause of pelvic inflammatory disease (PID), a condition that can lead to chronic pelvic pain, ectopic pregnancy, and infertility. Recent studies show that untreated chlamydia is responsible for nearly 30% of infertility cases in women. In men, chlamydia can cause epididymitis, characterized by inflammation and pain in the testicles, which can also contribute to infertility. Additionally, chlamydia increases susceptibility to other infections, including HIV, by weakening mucosal barriers and promoting inflammation.

Diagnosis and Treatment

Chlamydia is diagnosed through laboratory testing, with nucleic acid amplification tests (NAATs) being the most sensitive and reliable method. These tests detect bacterial DNA in urine samples or swabs from the cervix, urethra, rectum, or throat. The infection is treatable with antibiotics, primarily azithromycin (a single-dose treatment) or doxycycline (a seven-day regimen). Recent research suggests that adherence to the full course of antibiotics is crucial to prevent reinfection and antibiotic resistance.

Prevention and Public Awareness

Preventing chlamydia requires a combination of safe sexual practices and routine screenings. Using condoms consistently and correctly significantly reduces the risk of transmission. Regular STI testing, especially for sexually active individuals with multiple partners, is essential for early detection and treatment. Public health campaigns emphasize education on chlamydia’s risks and encourage open discussions about sexual health to reduce stigma and increase awareness. By prioritizing prevention, timely diagnosis, and effective treatment, the global burden of chlamydia can be significantly reduced.
Chlamydia: A Silent Threat to Sexual Health

Genital Herpes: Causes, Symptoms, and Management

Genital herpes, a prevalent sexually transmitted infection (STI), is caused by the herpes simplex virus (HSV). The virus exists in two forms: HSV-1, commonly linked to oral herpes, and HSV-2, predominantly associated with genital herpes. Both strains, however, are capable of infecting the genital region through sexual contact.

The virus is highly transmissible, even in the absence of visible sores or symptoms, through skin-to-skin contact with an infected individual. Once contracted, HSV establishes a lifelong presence in the body, residing dormant in nerve cells and reactivating intermittently, leading to recurrent outbreaks. These recurrences can be triggered by factors such as stress, illness, or hormonal changes.

Symptoms of genital herpes vary, but typical signs include painful blisters or sores in the genital, buttocks, or thigh areas, often accompanied by itching and burning sensations. During the initial outbreak, individuals may experience systemic symptoms like fever, swollen lymph nodes, and body aches. For some, the infection remains asymptomatic, contributing to unintentional transmission.

Diagnosis is based on clinical evaluation and confirmatory laboratory tests. Viral culture and polymerase chain reaction (PCR) tests are the gold standards for detecting HSV, while blood tests may identify past exposure. Early diagnosis is crucial for effective management and reducing transmission risks.

Although there is no cure for genital herpes, antiviral medications like acyclovir, valacyclovir, and famciclovir significantly mitigate symptoms, reduce outbreak frequency, and lower the likelihood of transmission. Advances in suppressive therapy have made daily antiviral regimens an effective option for individuals with frequent outbreaks.

Preventive strategies are essential in managing genital herpes. Consistent use of condoms can reduce, though not eliminate, transmission risks. Avoiding sexual contact during active outbreaks is critical, as viral shedding is highest during this time. For individuals with recurrent outbreaks, taking antiviral medications prophylactically can further decrease transmission risks.

Equally important is fostering open communication with sexual partners and seeking regular STI screenings, especially in high-risk populations. Recent public health initiatives emphasize reducing stigma around genital herpes, promoting early diagnosis, and encouraging preventive measures to control its spread.

By combining medical intervention, preventive strategies, and public education, the burden of genital herpes can be effectively managed, improving outcomes for those affected while minimizing transmission within the broader population.
Genital Herpes: Causes, Symptoms, and Management

Angiostrongyliasis: A Parasitic Threat to the Nervous System

Angiostrongyliasis is a parasitic infection caused by roundworms of the Angiostrongylus genus, primarily Angiostrongylus cantonensis, or rat lungworm. This zoonotic disease affects the central nervous system, leading to eosinophilic meningitis—a rare but severe condition involving inflammation of the brain and spinal cord membranes.

Humans acquire the infection by consuming raw or undercooked intermediate hosts such as snails, slugs, freshwater prawns, or crabs. Contaminated vegetables, fruits, and water are additional sources. After ingestion, infective larvae migrate to the brain, triggering a cascade of neurological symptoms.

Symptoms typically emerge within one to four weeks and range from mild to severe. Patients often experience intense headaches, neck stiffness, nausea, and vomiting. Neurological symptoms, including numbness, tingling, and hypersensitivity, are common. Severe cases can progress to paralysis, coma, or even death. Although fatalities are rare, the infection's neurological complications can lead to long-term disability.

Diagnosing angiostrongyliasis is challenging due to its nonspecific symptoms. Clinicians rely on a combination of patient history—particularly exposure to potential infection sources—and the presence of elevated eosinophils in cerebrospinal fluid. Advanced imaging techniques like MRI can help identify inflammation in the central nervous system, but definitive diagnosis requires specialized laboratory tests, including PCR for parasite DNA.

Currently, no specific antiparasitic drug is approved for treating angiostrongyliasis. Management focuses on alleviating symptoms. Corticosteroids help reduce inflammation, while pain relievers address severe headaches. In some cases, lumbar punctures are performed to relieve intracranial pressure. Experimental treatments, such as albendazole and other anthelmintics, have shown promise but require further study.

Preventive measures are critical. Thoroughly washing and cooking food, especially leafy vegetables, and avoiding raw or undercooked snails and slugs are essential. Public health education in endemic regions, including Southeast Asia, the Pacific Islands, and parts of the Americas, plays a pivotal role in reducing infection rates.

In conclusion, angiostrongyliasis poses a significant public health threat in endemic areas. Heightened awareness, rigorous hygiene practices, and research into effective treatments are vital for mitigating its impact.
Angiostrongyliasis: A Parasitic Threat to the Nervous System

Histoplasma Meningitis: Causes, Symptoms, Diagnosis, and Prevention

Histoplasma meningitis is a rare but serious infection caused by the fungus Histoplasma capsulatum, which is primarily found in soil contaminated with bird or bat droppings. This fungus thrives in warm, moist environments, especially in areas like the Mississippi and Ohio River valleys in the United States. When soil or dust containing the fungal spores is disturbed, the spores become airborne and can be inhaled. This typically leads to a lung infection called histoplasmosis, which is often mild and self-limiting. However, in certain cases, especially in individuals with compromised immune systems, such as those with HIV/AIDS, undergoing chemotherapy, or on immunosuppressive drugs, the infection can spread beyond the lungs. One of the most severe complications is the spread to the central nervous system, resulting in histoplasma meningitis.

The symptoms of histoplasma meningitis overlap significantly with other forms of meningitis, such as bacterial and viral meningitis, complicating the diagnosis. Common symptoms include severe headache, fever, stiff neck, nausea, vomiting, and altered mental state, such as confusion or lethargy. Due to the similarities in symptoms with other types of meningitis, it is often misdiagnosed, potentially delaying crucial treatment. Early detection and accurate diagnosis are critical because untreated histoplasma meningitis can lead to devastating outcomes, including permanent neurological damage or death.

Diagnosis of histoplasma meningitis involves a combination of laboratory tests. Blood cultures and cerebrospinal fluid (CSF) analysis are essential to confirm the presence of the fungus. A CSF test can reveal fungal elements or specific markers, helping to differentiate fungal meningitis from other causes. Imaging studies like MRI or CT scans may also be conducted to assess brain inflammation.

Treatment for histoplasma meningitis typically requires prolonged antifungal therapy. Amphotericin B is often used initially due to its potency, followed by itraconazole for long-term maintenance. Treatment can last for months to ensure that the infection is fully eradicated, especially since the central nervous system is a difficult area to treat.

Preventive measures are essential, particularly for at-risk individuals. Avoiding environments where the fungus is prevalent, wearing masks, and taking precautions in areas with bird or bat droppings can reduce the likelihood of exposure.
Histoplasma Meningitis: Causes, Symptoms, Diagnosis, and Prevention

The Deadly Threat of Meningitis B

Meningitis, an infection of the protective membranes around the brain and spinal cord, poses a grave risk to individuals of all ages. Among its various forms, meningitis B (MenB) stands out as a particularly dangerous strain caused by Neisseria meningitidis group B bacteria. While relatively rare, MenB disproportionately affects infants and young adults aged 16-24, with potentially devastating consequences.

MenB manifests initially with flu-like symptoms, such as fever, headache, and stiff neck, making early diagnosis challenging. However, its rapid progression can turn fatal within a mere 24-36 hours from the onset of symptoms. Shockingly, up to 1 in 10 patients succumb to the infection, sometimes within a day after symptoms appear, even with prompt medical intervention.

The aftermath of MenB can be severe and life-altering. Survivors may suffer permanent brain or nerve damage, kidney impairment, loss of limbs due to sepsis-induced vascular compromise, or severe scarring from skin grafts used to treat the infection. The impact extends beyond physical scars, often leading to long-term psychological and emotional challenges for patients and their families.

Recent advancements in vaccine development have provided a critical defense against MenB. Vaccination campaigns targeting infants and adolescents have significantly reduced the incidence of this deadly infection. Public health initiatives emphasizing the importance of early recognition and treatment have also played a pivotal role in improving outcomes.

Despite progress, challenges persist. Awareness remains key in ensuring timely intervention. Efforts to enhance public education, especially among parents and healthcare providers, are paramount. Encouraging routine vaccinations and vigilance in recognizing symptoms are vital steps in safeguarding vulnerable populations against the silent threat of meningitis B.
The Deadly Threat of Meningitis B

Bird Flu: Causes and Impact

Bird flu, scientifically known as avian influenza, refers to a highly contagious viral infection primarily affecting birds. The term encompasses a range of influenza viruses that mainly afflict avian species, though some strains can also infect humans and other animals. Historically, bird flu has been documented since the early 20th century, with notable outbreaks occurring sporadically around the world.

The significance of bird flu lies in its potential to cause devastating outbreaks, both in terms of animal health and human public health. While not all strains pose a direct threat to humans, certain variants, such as H5N1 and H7N9, have raised concerns due to their ability to infect humans and occasionally result in severe illness or even death.

Bird flu viruses typically originate from wild aquatic birds, such as ducks and geese, which serve as natural reservoirs for these viruses. Through various modes of transmission, including direct contact with infected birds, contaminated surfaces, and inhalation of airborne particles, the virus can spread rapidly within poultry flocks and occasionally spill over to humans.

Humans infected with bird flu may experience a range of symptoms, including fever, cough, sore throat, and muscle aches, similar to seasonal flu. However, severe cases can progress to pneumonia or acute respiratory distress syndrome, posing significant challenges for diagnosis and treatment. Diagnostic methods include laboratory tests such as polymerase chain reaction (PCR) and serological assays, which help identify the specific strain and assess the extent of infection.

Prevention and control measures play a crucial role in mitigating the spread of bird flu. Vaccination of poultry, especially in high-risk regions, helps reduce the likelihood of outbreaks. Additionally, implementing strict biosecurity measures on farms, such as restricting access to outsiders and regularly disinfecting facilities, can minimize the risk of transmission. Surveillance and monitoring programs enable early detection of outbreaks, facilitating prompt intervention and containment efforts.

Despite efforts to control bird flu, global impact and outbreaks continue to pose significant challenges. Historical outbreaks, such as the 1997 Hong Kong H5N1 outbreak and the 2004 H7N3 outbreak in Canada, underscore the unpredictable nature of the virus. Recent cases, including sporadic human infections and localized poultry outbreaks, highlight ongoing concerns regarding the virus's persistence and potential for resurgence. The economic and social consequences of outbreaks, ranging from loss of livelihoods in the poultry industry to disruptions in international trade, emphasize the need for sustained vigilance and collaboration in combating bird flu on a global scale.
Bird Flu: Causes and Impact

Symptoms of Campylobacter jejuni Infection

Campylobacter jejuni, a bacterial pathogen recognized as a leading cause of global gastroenteritis, often presents symptoms that many individuals may not be fully aware of. This essay endeavors to illuminate the common symptoms associated with Campylobacter jejuni infection, underscoring the importance of early recognition and suitable management.

Characteristic symptoms of Campylobacter jejuni infection revolve around gastrointestinal manifestations. Diarrhea, frequently watery and accompanied by abdominal cramps, stands out as a prevalent symptom. Nausea and vomiting also contribute to the overall discomfort experienced by those affected. Furthermore, systemic symptoms such as fever and headache are widespread, indicating the broad impact of the infection on the body.

The onset of Campylobacter jejuni symptoms typically occurs within 2-5 days after exposure, lasting approximately a week. However, the severity of symptoms varies, with some cases being milder and self-limiting, while others may lead to more serious complications. Severe instances can result in prolonged illness and potential complications like Guillain-Barré syndrome, underscoring the importance of vigilant symptom monitoring.

Treatment primarily involves supportive care to manage symptoms and maintain hydration. Essential in preventing Campylobacter jejuni infections are hygiene practices, encompassing thorough handwashing and proper food safety measures. Education regarding these preventive measures proves indispensable for public health, aiming to reduce the incidence and impact of this common bacterial infection.

In conclusion, comprehension of the symptoms of Campylobacter jejuni is pivotal for early detection and proper management. By spotlighting gastrointestinal and systemic manifestations, duration and severity, as well as treatment and prevention strategies, individuals can be empowered to adopt proactive measures, minimizing the impact of this prevalent bacterial pathogen.
Symptoms of Campylobacter jejuni Infection

Giardiasis: Symptoms and Transmission

Giardiasis emerges as a result of Giardia lamblia, a microscopic, single-celled parasite that establishes itself in the intestines of both humans and animals.

Initial indicators of infection may encompass sensations of nausea, a decline in appetite, and discomfort in the upper intestine, coupled with an overall feeling of malaise, potentially accompanied by a mild fever and chills.

Following this, there is typically a sudden onset of explosive, watery diarrhea with an unpleasant odor, accompanied by increased flatulence and abdominal swelling. Additional acute symptoms include bloating, belching, cramping, and a reduced desire to eat; these manifestations typically appear 1 to 2 weeks after the ingestion of cysts. Individuals under stress or with weakened immune systems may experience more severe symptoms and a diminished ability to fend off the disorder.

The illness usually resolves on its own, lasting for a span of 2 to 6 weeks, but it may sporadically reoccur or progress into a chronic state. Nevertheless, not everyone who acquires the infection exhibits symptoms. Giardiasis is more prevalent in children, elderly individuals with compromised health, and those with dysgammaglobulinemias.
Giardiasis: Symptoms and Transmission

Polio: Causes, Symptoms, Vaccination

Poliomyelitis, commonly referred to as polio, is a profoundly contagious disease caused by the poliovirus, a member of the Picornaviridae family. Historical records of this ailment can even be spotted in ancient Egyptian art.

The virus spreads via person-to-person transmission, primarily through the fecal-oral route, and occasionally through contaminated water or food, where it then proliferates within the gastrointestinal system.

The array of clinical presentations varies, encompassing mild occurrences of respiratory troubles, gastrointestinal disturbances, and general unease, to more severe cases resulting in paralysis. These expressions of the disease are classified as asymptomatic infections, mild instances (known as abortive poliomyelitis), non-paralytic meningitis (referred to as aseptic meningitis), and paralytic poliomyelitis.

Approximately a quarter of individuals infected with the poliovirus undergo flu-like symptoms, such as a sore throat, fever, fatigue, nausea, headache, and stomach discomfort. These symptoms persist for approximately 2 to 5 days before resolving on their own.

A smaller subset of those afflicted by the poliovirus exhibit more grave symptoms impacting the brain and spinal cord:Meningitis, occurring in approximately 1–5% of cases depending on the virus type, involves infection of the protective coverings of the spinal cord and/or brain.
Paralysis or weakness in the arms, legs, or both is discerned in about 0.5% to 0.05% of cases, contingent on the virus type.

The poliovirus is categorized into three strains: wild poliovirus type 1, 2, and 3 (WPV1, WPV2, and WPV3). While types 2 and 3 have been eradicated, type 1 persists in a few isolated regions. Type 1 carries the highest likelihood of causing paralysis.

Global campaigns for vaccination have significantly curtailed the global incidence of cases in recent years. Nevertheless, instances of polio still emerge in regions with insufficient vaccination coverage.

The U.S. Centers for Disease Control and Prevention (CDC) furnishes travel advisories for countries with heightened polio risk. Typically, these countries are situated in Africa, the Middle East, and certain parts of Asia.
Polio: Causes, Symptoms, Vaccination

Meningitis: Causes and symptoms

Meningitis is an infection of the protective membranes that surround the brain and spinal cord (meninges). When the membranes become infected, they swell and press on the spinal cord or brain. This can cause life-threatening problems. Meningitis symptoms strike suddenly and worsen quickly.

A bacterial or viral infection of the fluid surrounding the brain and spinal cord usually causes the swelling. However, injuries, cancer, certain drugs, and other types of infections also can cause meningitis.

Viral meningitis is the most common and least serious type. Bacterial meningitis is rare, but can be very serious if not treated.

Some cases of meningitis improve without treatment in a few weeks. Others can cause death and require emergency antibiotic treatment.

The viruses and bacteria that cause meningitis can be spread through: sneezing, coughing, and kissing. The infection is usually spread by people who carry these viruses or bacteria in their nose or throat, but are not ill themselves.

Early symptoms of meningitis can include:
*A high temperature (fever)
*Headache
*Drowsiness or unresponsiveness
*Vomiting
*Diarrhea
*Muscle pain
*Stomach cramps
*Fever with cold hands and feet
*A rash on the skin

It can affect anyone, but is most common in babies, young children, teenagers and young adults. Bacterial meningitis is more common in infants under 1 year of age and people ages 16 to 21. Meningitis can be very serious if not treated quickly. It can cause life-threatening blood poisoning (sepsis) and result in permanent damage to the brain or nerves.
Meningitis: Causes and symptoms

Symptoms of scarlet fever

Bacteria called group A Streptococcus or group A strep cause scarlet fever. The bacteria sometimes make a poison (toxin), which causes a rash — the “scarlet” of scarlet fever. Also known as scarlatina, scarlet fever features a bright red rash that covers most of the body.

Scarlet fever is much less common than it used to be but in recent years there have been a number of significant outbreaks. The first signs of scarlet fever can be flu-like symptoms, including a high temperature, a sore throat and swollen neck glands.

A rash appears 12 to 48 hours later. It looks like small, raised bumps and starts on the chest and tummy, then spreads. The symptoms of scarlet fever usually develop two to five days after infection, although the incubation period (the period between exposure to the infection and symptoms appearing) can be as short as one day or as long as seven days.

The group A streptococcal bacteria are found in the nose and throat. They are spread by:
*Coughing and sneezing
*Contact with a contaminated surface, such as a plate or glass
*Touching or kissing an infected person

Scarlet fever is most common in children 5 to 15 years of age. The symptoms are the same for children and adults, although scarlet fever is less common in adults.
Symptoms of scarlet fever

Marburg hemorrhagic fevers

Marburg hemorrhagic fevers is a rare, severe type of hemorrhagic fever which affects both humans and non-human primates.

Marburg virus infection causes coagulation abnormalities, increased vascular permeability and hemorrhagic manifestations, all of which are closely inter–related and result in the development of typical viral hemorrhagic fever (VHF) manifestations. Coagulation abnormalities are observed as thrombocytopenia associated with prolonged coagulation times, reduced factor V and II levels and deficiency in fibrinogen.

Marburg virus was first recognized in 1967, when outbreaks of hemorrhagic fever occurred simultaneously in laboratories in Marburg and Frankfurt, Germany and in Belgrade, Yugoslavia (now Serbia). A total of 31 people became ill with seven deaths; they included laboratory workers as well as medical personnel and family members who had cared for them.

The first people infected had been exposed to imported African green monkeys or their tissues while conducting research.

The largest outbreak of Marburg hemorrhagic fevers recorded to date began in late 1998 in northeastern Democratic Republic of the Congo (DRC).

The new virus, named after Marburg Germany, was the first recognized Filovirus. The second known member was the Ebola virus which produces a similar illness.

Scientific studies implicate the African fruit bat (Rousettus aegyptiacus) as the reservoir host of the Marburg virus. The African fruit bat is a sighted, cave-dwelling bat which is widely distributed across Africa. Marburg virus is believed to be native only to Africa.

The incubation period in humans ranges from 2 to 21 days, with an average overall incubation period of 5–9 days. The disease course largely presents in three distinct phases: a generalization phase, an early organ phase and a late organ or convalescence phase, depending on the outcome of infection.

Symptoms of the disease: After an incubation period of 5-10 days, the onset of the disease is sudden and is marked by fever, chills, headache, and myalgia. Around the fifth day after the onset of symptoms, a maculopapular rash, most prominent on the trunk (chest, back, stomach), may occur. Nausea, vomiting, chest pain, a sore throat, abdominal pain, and diarrhea then may appear.
Marburg hemorrhagic fevers

Symptoms of tuberculosis

Tuberculosis is an airborne disease caused by the bacterium Mycobacterium tuberculosis. It is a contagious infection that usually attacks lungs and it can also spread to other parts of the body, like brain and spine.

M. tuberculosis is carried in airborne particles, called droplet nuclei, of 1– 5 microns in diameter. Infectious droplet nuclei are generated when persons who have pulmonary or laryngeal tuberculosis disease cough, sneeze, shout, or sing. Depending on the environment, these tiny particles can remain suspended in the air for several hours.

Symptoms are usually mild and tend to present over a period of weeks, months, or sometimes years. The classic symptoms of tuberculosis in the lungs include:
■ Cough lasting more than three weeks
■ Unexplained weight loss
■ Low-grade fever
■ Night sweats

Chest symptoms are often nonspecific, and can mimic virtually any respiratory condition: cough is almost always present, with sputum production, possibly chest pain and/or dyspnoea as accompanying symptoms.
Symptoms of tuberculosis

Leptospirosis: The Great Mimicker

Leptospirosis is a disease that is caused by spirochete bacteria in the genus Leptospira. There are 10 pathogenic species, and more than 250 pathogenic serovars. Pathogenic leptospires belong to the species Leptospira interrogans, which is subdivided into more than 200 serovars with 25 serogroups.

It is a zoonosis of worldwide distribution, endemic mainly in countries with humid subtropical or tropical climates and has epidemic potential. Leptospirosis is a severe, water-borne disease transmitted from animals to humans, with tens of millions of human cases worldwide each year.

Leptospirosis is also known as “the Great Mimicker” and may be overlooked and underdiagnosed due to its varied clinical presentations. Fatality rates can range as high as 20 to 25 percent in some regions, and it is particularly prevalent in tropical countries where poor people live under highly crowded condition, or in rural areas where people are exposed to water contaminated by the urine of Leptospira.

Feral and domestic animals constitute the reservoir of the agent, transmitted through contact of mucous membranes or (broken) skin with water (swimming or immersion), moist soil or vegetation contaminated with the urine of infected animals; occasional infection occurs through ingestion/inhalation of food/droplet aerosols of fluids contaminated by urine.

Outbreaks of leptospirosis tend to occur after heavy rainfall or flooding in endemic areas, especially areas with poor housing and sanitation conditions.

Symptoms can include fever, headache, myalgia (typically of the calves and lower back), conjunctival suffusion, nausea, vomiting, diarrhea, abdominal pain, cough, and sometimes a skin rash.

Leptospirosis: The Great Mimicker

Sign and symptoms of leprosy disease

This disease is a slowly developing, progressive disease that damages the skin and nervous system.

Leprosy is a disease caused by a type of bacteria called Mycobacterium leprae. These bacteria attack nerves in the hands, feet and face, causing numbness and loss of sensation to those parts of the body. It can also affect the nose and the eyes.

It is classified into tuberculoid leprosy (TT), lepromatous leprosy (LL), borderline leprosy, and indeterminate leprosy (IL), according to the cellular immunity against M. leprae.

Early signs include discoloration or light patches on the skin with loss of sensation. Hypopigmented or erythematous macules are present in many newly diagnosed leprosy patients, and are often the first clinical sign of the disease. Many other conditions produce similar lesions, however. Therefore, to be specific for leprosy, the lesions must be accompanied by definite loss of sensation.

The longer the delay between the appearance of the first symptoms of leprosy and the start of treatment, the more likely nerve damage will occur. Untreated leprosy can cause progressive and permanent damage to the skin, nerves, limbs and eyes.

When nerves in the arm are affected, part of the hand becomes numb and small muscles become paralyzed, leading to curling of the fingers and thumb.

When leprosy attacks nerves in the legs, it interrupts communication of sensation to the feet. As a result, the person does not feel pain, and can have injuries to their hands and feet without realizing it. The damaged nerves also lead to the skin peeling off, and the tissue beneath the skin is exposed.
Sign and symptoms of leprosy disease

Coronavirus disease

Coronaviruses are a group of viruses belonging to the family of Coronaviridae, which infect both animals and humans. Coronavirus (COVID-19) is an illness caused by a virus that can spread from person to person. The virus that causes COVID-19 is a new coronavirus that has spread throughout the world.

This pandemic (caused by the virus SARS-CoV-2) is the greatest threat not only to global health but also has far-reaching socio-economic impact on nearly all the countries in the world.

The first cases of coronaviruses in human found in 1965 by Tyrrell and Bynoe. They observed that they could passage a virus named B814. It was observed in human embryonic tracheal organ cultures obtained from the respiratory tract of an adult with a common cold symptom. The first 4 cases of COVID-19 were first reported on the 29th December 2019, all linked to Huanan (Southern China) seafood wholesale market. Many of the initial patients were either stall owners, market employees, or regular visitors to this market. Environmental samples taken from this market in December 2019 tested positive for SARS-CoV-2, further suggesting that the market in Wuhan City was the source of this outbreak or played a role in the initial amplification of the outbreak.

Another coronavirus, SARS-CoV-1, the cause of the Severe Acute Respiratory Syndrome (SARS) outbreak in 2003, was also closely related to other coronaviruses isolated from bats. These close genetic relations of SARS-CoV-1, SARSCoV-2 and other coronaviruses, suggest that they all have their ecological origin in bat populations.

Signs and symptoms include respiratory symptoms and include fever, cough and shortness of breath. In more severe cases, infection can cause pneumonia, severe acute respiratory syndrome and sometimes death.

Standard recommendations to prevent the spread of COVID-19 include frequent cleaning of hands using alcohol-based hand rub or soap and water; covering the nose and mouth with a flexed elbow or disposable tissue when coughing and sneezing; and avoiding close contact with anyone that has a fever and cough.
Coronavirus disease

Anaplasmosis

Anaplasmosis was first recognized in the mid-1990s and was previously known as human granulocytic ehrlichiosis.

It is a rickettsial infection of granulocytes caused by the intracellular bacterium Anaplasma phagocytophilum.

People can get anaplasmosis through the bite of a blacklegged tick (deer tick) that is infected with Anaplasma phagocytophilum bacteria. Blacklegged ticks live on the ground in areas that are wooded or have lots of brush. The ticks search for hosts at or near ground level and grab onto a person or animal as they walk by.

Anaplasma belong to obligate intracellular microorganisms, Gram-negative bacteria, living in the blood cells of mammals. Vertebrates can be their reservoir, i.e. an environment where the pathogen can live and proliferate for many years. However, in many cases bacteria from the genus Anaplasma cause diseases in domestic animals and people.

An essential part in the life cycle of the bacteria is played by vectors, organisms which contribute to their circulation in the environment. The main vectors of the Anaplasma bacteria are ticks, common arachnida occurring everywhere in the world, especially the genera Ixodes, Dermacentor, Rhipicephalus and Amblyomma.

Symptoms of anaplasmosis may include:
▪ Fever
▪ Headache
▪ Muscle aches
▪ Nausea or abdominal pain

Tick-exposure, if known, usually precedes symptom development by one to two weeks. Although complications, such as sepsis, heart failure, renal failure, neurologic disease and rhabdomyolysis remain infrequent, almost half of patients with anaplasmosis require hospital admission.
Anaplasmosis

Chikungunya fever: transmission and symptoms

Chikungunya is a mosquito-borne viral disease, caused by the Chikungunya virus (family: Togaviridae, genus: Alphavirus). The disease was documented first time in the form of an outbreak in Tanzania. The name is derived from the ‘makonde’ dialect which means ‘that which bends up’, indicating the physical appearance of a patient with severe clinical features.

In recent decades the Aedes mosquitoes carrying chikungunya have spread to the European Region. In 2007, a chikungunya outbreak was reported for the first time in Italy. In 2013, chikungunya was found for the first time in the Americas and has spread to the Caribbean, South and Central America, and North America.

The virus is transmitted from human to human by the bites of infected female mosquito. Aedes aegypti is the common vector responsible for transmission in urban areas whereas Aedes albopictus has been implicated in rural areas. Recent studies indicate that the virus has mutated enabling it to be transmitted by Aedes albopictus. The Aedes mosquito breeds in domestic settings such as flower vases, water-storage containers, air coolers, etc. and peri-domestic areas such as construction sites, coconut shells, discarded household junk items (tyres, plastic and metal cans, etc.).

Both mosquitoes can be found biting throughout day lighthours, though there may be peaks of activity at dawn and dusk. Both species are found biting outdoors, but Aedes aegypti will also readily feed indoors.

What are the symptoms?
Common symptoms include fever and severe joint pain. Other symptoms may include headache, muscle pain, joint swelling, or rash.ŠSymptoms usually begin 3—7 days after being bitten by an infected mosquito.ŠMost patients will feel better within a week. In some people, the joint pain may persist for months. Death is rare.

Outbreaks are most likely to occur in post-monsoon period when the vector density is very high. Human beings serve as the chikungunya virus reservoir during epidemic periods. During inter-epidemic periods, a number of vertebrates have been implicated as reservoirs. These include monkeys, rodents, birds, and other vertebrates.

Chikungunya fever: transmission and symptoms

Rickettsial infections

Rickettsial infections are caused by bacterial organisms (Rickettsiae), which are found throughout the world. The genus Rickettsia is included in the bacterial tribe Rickettsiae, family Rickettsiaceae, and order Rickettsiales.

Family Rickettsiaceae comprise a group of microorganisms that phylogenetically occupy a position between bacteria and viruses. Rickettsiae are small, non-flagellate, gram negative pleomorphic cocco-bacilli adapted to obligate intracellular parasitism and transmitted by arthropod vectors.

The diseases caused by Rickettsia species are often collectively referred to as rickettsioses. Rickettsiae live in small insects such as ticks, fleas, mites, and lice and can infect mammals (including humans), but cannot survive for any significant period outside their host.

Among returned travelers, rickettsial diseases have been estimated to be the fourth most common cause of fever, with symptoms such as rash, abdominal pain, and a dry, black/dark scab at the site of the infecting bite.

The incubation period ranges from 2-14 days. The disease begins with fever, myalgia and headache. Headache is usually quite severe, young children may not complain of pain at all. Onset of nausea, vomiting, pain abdomen, diarrhea and abdominal tenderness occur in substantial number of patients suggesting gastroenteritis or an acute surgical abdomen.

Tick-borne rickettsioses are often acquired in rural settings in risk areas; however, urban transmission also occurs. Most rickettsial infections are transmitted to humans by the bite or feces of fleas, ticks, mites, or lice. Even the smallest forms of ticks (such as larvae) can transmit the infection to humans, meaning that many infected individuals do not recall a tick bite before symptoms appear.

Rickettsiae microorganisms appear to exert their pathologic effects by adhering to and then invading the endothelial lining of the vasculature within the various organs affected.

Infected ticks and mites transmit rickettsiae primarily through their infected salivary glands directly into the bite. In lice and fleas, rickettsiae do not infect the salivary glands but multiply in the cells of the gut wall and are excreted in the faeces in large amounts, contaminating the skin area around the bite.

The most important pathophysiologic effect is increased vascular permeability with consequent edema, loss of blood volume, hypoalbuminemia, decreased osmotic pressure, and hypotension.
Rickettsial infections

Filariasis: disease and symptoms

Filarial infections are caused by skin and tissue-dwelling worms (filariae) that are transmitted through the bites of infected flies. Filarial infections are caused by a group of worms (filariae) found throughout tropical countries and are transmitted to humans through the bite of infected flies, mosquitoes, or midges.

Filariasis is a helminthic infection found principally in tropical and subtropical areas in Africa, and in the South Pacific regions. The disease is transmitted from man through several genera and species of mosquitoes. The acute disease is manifested by recurrent chills and fever and by visible swelling or nodules of the lymphatics and redness of the overlaying skin due to parasitic involvement.

Infections with human filarial nematodes affect 170 million people world wide out of which more than 150 million people are from the tropics. The illness usually subsides gradually with or without therapy. But in those who have been repeatedly infected and are chronically ill, the inflammatory reaction and scarring of the tissues surrounding the vessels may impede the flow of lymph and blood, and mammoth enlargement (“elephantiasis”) of the arms, legs, scrotum and breasts can occur.

During World War II approximately fifteen thousand American military personnel became infected, but prompted withdrawal of these patients from the endemic zones prevented chronic disease and elephantiasis.
Filariasis: disease and symptoms

Wuchereria bancrofti