Tuesday, December 31, 2013

Gioconda Belli - Book Review


                     Anchor Books, New York. 2003

Gioconda Belli is a gifted writer and her story has value as an on-the-ground historical perspective of the Sandinista Revolution. The book is autobiographical, and her perspective will not be shared by all of her contemporaries or by other historians. Truth is often a matter of perspective.

Gioconda's wealthy and privileged family were members of the upper class in Somoza's Nicaragua. Her early life included high school in Spain, college in the United States, a debutante arrival on the Managua social scene, and an early fashionable wedding at 18 years of age into another wealthy family.

In 1971, at the age of 22 years, married with a young daughter, she was asked to join the Sandinistas by Camilo Ortega, the brother of Daniel Ortega, a leader of the revolution, who was then in jail. She served as a Sandinista revolutionary in a variety of important capacities, was obliged to live in exile in Mexico and Costa Rica, and returned in July 1979 to share in the victory celebrations after Somoza fled and the National Guard dispersed.

Her book includes not only descriptions of her revolutionary activities, but also her romantic affairs with Sandinista compadres, and the complex rationalizations she needed to explain her marital infidelities and the prolonged absences from her young children.
Gioconda placed herself and the revolution first, at the expense of her family and her children. At first I was troubled by her decisions to separate from her young children, but then I realized that over the centuries men have never hesitated to make this choice. Why should she be judged for temporarily relinquishing her role as a mother?

Towards the end of the revolution, there were three major factions in the FSLN. The Tercerista Tendency faction led by Daniel and Humberto Ortega eventually assumed control of the revolution. Gioconda's sense of justice and her various amorous relationships with members of the other factions, resulted in her change in support to a non-Ortega faction. Her story has a sour grapes quality about the success of the Ortega brothers. She provides examples of the early decisions by the Ortega brothers to sacrifice principle for the expediency of success. Today, living in California, she is an outspoken critic of the current Ortega government. She maintains that Daniel Ortega was willing to sacrifice principles during the revolution and that he continues to do so today as President of Nicaragua.

Her autobiography offered personality to the day-to-day historical events of the revolution, and her excellent prose made for great reading.





Friday, December 27, 2013

The Cruel Randomness of the Awesome Energy of the Sea

The beach at Las Penitas is a destination for the Leon and area locals on Christmas Day. Dozens of buses arrived, standing room only, and the bus stop was right beside our casa, so we knew the town would be crowded.

Mid-afternoon found us walking with a Kamloops couple we'd met earlier in the day. Louise was ahead with Lynn, and Ron and I were doing our best to keep up but not to burn our feet in the scalding volcanic sand.

The surf, the shoreline, and the beach was filled with thousands of people. As we turned North on the shoreline to walk back to our casa, I saw a crowd of a hundred or so people ahead. The crowd encircled something. My first thought was a performance by a local artist. Who knew?

Crowds beget more people. What was so fascinating for so many people? We were drawn to the centre of the drama.

As we closed on a mass of humanity, with every person pushing towards the centre, some words of spoken English floated above the crowd.

"body," was the word that stood out.

I skirted the perimeter for a better sight advantage but the wall of people was five to ten bodies thick. I dropped to the sand and looked under the feet and sure enough I saw the body caged behind shuffling legs.

Ron came to me, knowing, to accept my pack, camera, and binoculars. Then I pushed my way through.

"Medico," I kept repeating.

At the centre on the ground was a young man with foam at his mouth. "Seizure," I wondered.

Beside him lay another young man, wailing, covering his eyes, writhing in an emotional collapse beside his friend or brother.

I knelt down beside the body. The young man, who looked in his early twenties, wore jeans but was naked from the waist up. My hand first searched his apex for a heart beat and then the carotid for a pulse. Nada.

He was laying on his back, perhaps drowning in the foamy fluid in his mouth. I turned him on his side and did a single finger swipe to clear the back of his throat. A lot of foamy mucous came out. Then I rolled him back onto his back and started CPR. With each chest compression the ocean poured forth from his still chest.

"Drowned, of course," I realized.

After about a dozen compressions I stopped and checked his eyes. The pupils were dilated wide and fixed in death. They didn't move a millimetre when I opened up his lid.

An official looking fellow in a white shirt and ball cap touched my shoulder. "Policia." He shook his head.

I squeezed the young man's shoulder, got up, and pushed my way back out of the crowd.

On my return to the casa I noted a bruise on my left knuckle.  While sweeping the back of his throat clear, his upper teeth had scraped my hand. Death "bit" me.
The next 24 hours included considerable reflection on the senselessness of this lost life. A lady in the next casa remarked that every year a young person drowns on Christmas day. "Alcohol," she offered as the common denominator. While the demon rum is a common factor, I sensed a randomness to this death that alcohol alone cannot explain. Something else happened. Something to do with the power of the sea, with the awesome energy of nature. 

I wondered if perhaps his neck had broken with a powerful wave, slapped down through the shallow surf, his neck at just the wrong angle as his head struck the sandy bottom. Only a good autopsy might tell the truth. This was only my sense, perhaps born from personal fears of the power of the sea. 

Monday, December 23, 2013

Augusto Sandino

Our international flight to Nicaragua will land at the Augusto Sandino International Airport in Managua. The airport and the Sandinista revolutionary movement, is named after Augusto Cesar Sandino.

Sandino was the out-of-wedlock son of a well-to-do landowner and an Indian woman and he was born in 1885. His life coincided with the American occupation of Nicaragua (1865 to 1877, 1894, 1896, 1898, 1899, 1907, 1910, 1912 to 1925, and 1926 to 1933).

He worked for his father until the age of 25 and then was obliged to leave the country after wounding a man who insulted his mother. He worked in Mexico for fifteen years and he returned to Nicaragua as a mature 40 year-old man who was passionate about his Indian heritage and who held strong nationalist and anti-imperialist ideals. When a liberal insurrection erupted in 1926 against the US occupation forces and the corrupt pro-US government of the day, Sandino organized a fighting unit. For the next 8 years until his death, he was the guerrilla hero of the people, the Robin Hood of Nicaragua. His guerrilla fighters were a constant thorn for the US military forces and he was an inspiration to the generation of young Nicaraguans who would eventually achieve independence and end the American control.

The sovereignty and liberty of a people 
are not to be discussed but rather, 
defended with weapons in hand.

Liberty is won not with flowers but with bullets.

The US has an almost two century record of intervention in Nicaragua. The Monroe Doctrine, a US policy introduced in 1823, "legalized" US hegemony over all of Latin America. In 1856, William Walker, a US soldier of fortune, invaded Nicaragua and proclaimed himself President. During the twentieth century, the US occupation sustained control in Nicaragua with a variety of measures including forced resettlement. Sandino's mountain army sustained the hope of the average Nicaraguan.

After the US military withdrew in 1933, the populace and Sandino were optimistic that true liberal reforms would be possible. However, by then the infamous National Guard was in place as a proxy for the US military, and the man chosen to head this brutal force was Anastasio Garcia Somoza. Sadly, Sandino was fooled by the rhetoric of peace and he negotiated with the government. The image below shows Sandino and Somoza after a "successful" round of peace negotiations. Several days later, Somoza had Sandino assassinated. Two years later in 1936, Somoza installed himself as President and ushered in 33 years of family dictatorship. US influence continued so strong under the Somoza regimes that the day Somoza fled the country, the Sandinistas were satisfied that finally, "the last US marine" had left the country.

The sinister embrace - Somoza and Sandino

Twenty five years later in 1961, the spirit of Augusto Sandino re-emerged with the formation of the Sandinista National Liberation Front (FSLN), the movement that achieved independence on July 19, 1979. That same month I moved back to Calgary after six years of post graduate work at the University of Toronto. During my years at U of T, I followed the Sandinista struggle, and like many university students of my generation, I was not comfortable with the colonialist and imperialist attitudes that were so prevalent in my parents generation. I supported changes that would lead to democracy, freedom of speech, and improved education and health care. The Sandinista revolution accomplished this. Even so, there is still work to be done, and I like to think that my efforts are supportive of the original liberal and social ideals of the Sandinista Revolution.

References

Morris, KE. Unfinished Revolution - Daniel Ortega and Nicaragua’s Struggle for Liberation. Lawrence Hill Books. Chicago, USA. 2010.

Walker TW, Wade CJ. Nicaragua. Living in the Shadow of the Eagle. Westview Press. Colorado, USA. Third Edition. 2011.




Friday, December 20, 2013

Malaria Update

The Centre for Disease Control (CDC) reports that malaria is present in the Atlantic and Pacific coastal areas of Nicaragua, but in only 6 of the 17 provinces. Although not reported in the interior, this is presumably because mosquitoes are not as prevalent at the higher elevations in the more mountainous interior, and otherwise this is likely a reporting anomaly, because mosquitoes do not acknowledge provincial borders.

Malaria in Nicaragua is due to Plasmodium vivax (P. vivax) in 95% of cases and Plasmodium falciparum (P. facliparum) in the remaining 5%. This is good news because P. vivax is chloroquine sensitive and has a good prognosis for full recovery. P. falciparum is a much more serious infection. A 2013 study in neighboring Honduras confirms that the P. falciparum in the region is still chloroquine sensitive. 

The Anopheles mosquito transmits the parasite into the bloodstream. The parasites enter red blood cells. About a week or two later, the red blood cells release thousands of parasites and inflammatory chemicals into the blood. The inflammatory chemicals include pyrogens, which cause the fever. The fever in P. vivax develops every 48 hours. The red blood cell destruction results in anemia.


The incubation period varies from 7 to 30 days.

Malaria is most severe among children 6 months to five years of age. Those over six months of age no longer have maternal immunity and those under five years have not reached full immunologic maturity. In endemic areas such as Nicaragua, malaria is the cause of up to 10% of all deaths in young children!

Parasitemia in neonates within 7 days of birth implies transplacental transmission. Babies have fever, irritability, refuse feeds, and often develop anemia, jaundice, and hepatosplenomegaly.

In younger children, the fever is usually continuous and might be very high (40°C) from the first day. The symptoms are often non-specific. Children become restless, drowsy, apathetic, and anorexic.

Older children might present with the classic periodic fever with chills and shivering. Other symptoms include generalized ache, headache, and nausea. Flu-like respiratory symptoms, with mild cough and cold are common. Vomiting is very common. Mild diarrhea with dark green mucoid stools is common. The liver might be slightly tender. Splenomegaly is classic but takes many days to develop, especially in the first attack in non immune children.

Children with partial immunity might develop only a low-grade fever, anemia, poor appetite, and malaise.

P. vivax malaria might relapse for up to 3 years.

Cerebral Malaria Cerebral malaria is due to P. falciparum and has a mortality of 25%, even with modern treatment. Cerebral malaria is most common in children 6 months to 3 years and survivors often have serious neurological sequelae such as hemiparesis. P. falciparum-infected red blood cells adhere to the walls of veins and do not freely circulate in the blood. The sequestration of these infected cells in the brain is considered a factor in cerebral malaria. In children, seizures might occur at the onset of the disease. Differentiating a febrile seizure from cerebral malaria is often difficult.

Laboratory Diagnosis The traditional method to confirm a diagnosis is microscopy of a thick blood smear stained with Giemsa. A rapid diagnostic test is now available. Neither of these options are usually available in rural Nicaragua. 
Blood smear with two RBC on right infected with P. Falciparum. 
Image courtesy of CDC. 

Treatment Since the symptoms are often non-specific, high fever in a susceptible young child requires a high index of suspicion, and in the absence of a recognized cause for the fever, empirical treatment might be necessary.

Children five years or younger should seek malaria treatment within 48 hours of the development of fever. In Nicaragua the local names for fever include calentura, fiebre, or mal de ojo.

The treatment of P. vivax is a 3-day course of chloroquine, (10 mg/kg orally up to 600 mg, then 5 mg/kg at 6 hours, 24 hours, & 48 hours after the larger first dose) followed by a 14-day course of primaquine. The primaquine is necessary to eliminate the dormant stage of the parasite in the liver.

Prevention DEET may be used to prevent mosquito bites. 95% DEET lasts up to 10-12 h and 35% DEET lasts 4-6 h.

Increased precautions are needed during the night, because Anopheles species are nocturnal. Sleeping under insecticide-treated (permethrin 0.2 g/m2 of material every 6 mo) mosquito nets is efficacious.

References
  
http://www.cdc.gov/malaria/index.html

http://emedicine.medscape.com/article/998942-overview

Torres REM et al. Efficacy of Chloroquine for the Treatment of Uncomplicated Plasmodium falciparum Malaria in Honduras. American Journal of Tropical Medicine and Hygiene. http://ajtmh.org/cgi/doi/10.4269/ajtmh.12-0671 

Monday, December 16, 2013

Toys for Children in Nicaragua

Children in Calgary are often apprehensive with visits to a physician, and the children in Gigante, Nicaragua, will not be any different. A toy often minimizes the apprehension and allows for a happier visit.

With prior trips to Nicaragua we have brought toys to offer the children and our experience is that these gifts can smooth the way for a pleasant encounter.

With this visit, we are fortunate to have toys purchased with funds raised by children at the Before and After School Care Program at Alexander Ferguson Elementary School. Anneline Webb, the Director of the program, initiated the project, and Denae, her charming daughter, selected the appropriate gifts.

Thank you Denae and Anneline Webb, and the Students at the Before and After School Care Program at Alexander Ferguson Elementary School.

Thank you Children at Before & After School Program 
Alexander Ferguson Elementary School. 
Great toys for the girls and boys in Gigante. 
Thank you Denae Webb!!



Friday, December 13, 2013

Mystery Kidney Disease in Nicaragua

Kidney failure in men is a lot more common in Nicaragua than in North America. The usual causes in Canada and the US are high blood pressure and diabetes, but these are not the explanation in Nicaragua.

Dialysis and transplantation are not practical options in Nicaragua, so when a young man develops end stage kidney failure, this means the individual will die.

Nicaragua is struggling to offer basic primary care and does not have the resources to investigate this serious health problem. International interest has resulted in some research and a variety of risk factors have been identified. I did a Google Scholar literature search with the words kidney and Nicaragua, and 15 articles were identified in the world medical literature.

A 2010 article reported on a community based survey of individuals in five villages in Northwest Nicaragua. Eighteen (18) percent of the men in the community had an abnormal serum creatinine, which is the main laboratory marker of kidney failure. This is six times higher than the prevalence in Canada!

Occupation appears to have a major influence on the prevalence. The table below shows the differences in prevalence of an abnormal serum creatinine by occupation.


Occupation
Percent
all men
18
subsistence farmer
26
banana/sugarcane worker
22
construction worker
15
fisherman
13
coffee worker
7
service industry worker
0
Other reports have also noted the higher prevalence in the farming and sugarcane sectors.

Age is clearly a factor. The prevalence increases with age.

Dehydration is a commonly reported consideration, which makes perfect sense, because as dehydration worsens, blood flow to the kidney decreases, and the risk of kidney damage increases. One article reported that sugarcane workers are paid based on how many tons of sugarcane they harvest. The incentive is therefore to work longer hours and to take fewer breaks, which results in more severe dehydration. The same report noted that some men lose up to 5 pounds over a work day! Fear of contaminated water might be another reason why the workers drink so little. Makes no sense, since better hydration would improve their mental alertness and physical energy. Sounds crazy that men would continue to work while so thirsty, but I can imagine that this does happen. History is replete with workers suffering under terrible conditions to earn a living for their family.

Likely there are additional factors. Pesticides are mentioned as a possible kidney toxin. The plantations in Nicaragua use chemicals that are banned in Canada. Modern safety precautions to protect workers are not usually practiced.

Treatment with diuretic, non-steroidal anti-inflammatory, and antibiotic medications might play a role. These are common treatments for "urine infection" in Nicaragua.

The general population knows about the Mystery Kidney Disease, and the populace is worried. I experienced this concern in my previous visits. Many mothers wanted me to check their child for urine infection. This heightened concern for urine problems perplexed me at first, but once I learned about the Mystery Kidney Disease problem, I understood.

The at-risk men who work as sugarcane workers often complain of chistata. A common symptom of chistata is discomfort with voiding. Discomfort with voiding is a typical symptom of infection in the bladder or urethra, but this is also a symptom associated with severe dehydration because the urine is very concentrated (dark) and in this situation, tiny crystals of calcium, phosphate, oxalate, or uric acid can precipitate out in the urine, and these crystals can be painful to pass. However, the discomfort with voiding in men with chistata is mostly presumed to be due to urine infection and since some of these men develop kidney failure, there is a common perception that the kidney failure is due to urine infection. The general population believe this and so do the many of the physicians.

The physicians I met on prior visits commonly over treat children and adults for possible urinary tract infection. Any urine symptom at all, or any positive urine dipstick test is usually treated with an antibiotic. This didn't make any sense to me and my first thought was that the medical education system in Nicaragua was to blame for the over-diagnosis and over-treatment. Now, I realize that the physicians might not be any more objective than the mothers! A recent article confirms my observations. Based on interviews, the study reported that pharmacists and physicians commonly prescribed antibiotics for individuals with "chistata." Other commonly prescribed medications included diuretics and non-steroidal anti-inflammatory agents. All of these medications are potentially toxic to the kidneys, especially in a dehydrated individual. It is possible, therefore, that local treatment practices are a factor! A very plausible scenario for the Mystery Kidney Disease might be repeated episodes of dehydration, treatment with medications toxic to the kidney while dehydrated, and time. 

Since Gigante, the community where I will help out as a paediatrician, is a fishing village, and since fishermen are at risk, during a visit I will talk to the mothers about the vital importance of hydration. As with families everywhere, if the mother understands, there is a good chance that all the family members will benefit.

References

Torres C et al. Decreased Kidney Function of Unknown Cause in Nicaragua: A Community-Based Survey. AJKD 2010;55:485-96.

Ramirez-Rubio O et al. Chronic Kidney Disease in Nicaragua: a Qualitative Analysis of Semi-structured Interviews with Physicians and Pharmacists. BMC Public Health 2013;13:350

Wednesday, December 11, 2013

Preventing Dental Disease in Nicaragua

Tooth decay is a worldwide problem, and dental hygiene is an important part of preventative care for every child.

With our trips this winter, courtesy of a generous donation from Sierra Dental, we will help provide preventative dental care for every child we see in the new clinic in Gigante, Nicaragua.

Anneline Webb is the Director of the Before and After School Care Program at Alexander Ferguson Elementary School in Calgary. Prior to this position, Anneline served with distinction as my assistant in The Childrens' Clinic. Denae Webb, Anneline's beautiful daughter, attends Alexander Ferguson. Her friend, Zoe Waxmann, also attends the school. Zoe's Mom, Clarissa Waxmann, heard about the planning for our trips to Nicaragua this winter, and she decided she wanted to help. Clarissa Waxmann works at Sierra Dental, a popular full service dental clinic in SW Calgary, and she arranged a donation of toothbrushes and dental floss. Thank you Anneline and Denae, Clarissa and Zoe, and Sierra Dental for arranging this thoughtful donation.
Thank you Clarissa Waxmann and Sierra Dental!


Sunday, December 8, 2013

Breakbone Fever

AKA Dengue Fever. The name fits, because the bone pain suffered by some individuals is severe.

Nicaragua Dispatch, an online English-language newspaper, ran this headline October 30, 2013 
Dengue Claims 14th Victim in Nicaragua. 
The headline a week earlier on October 24, 2013 - Nicaragua on Red Alert for Dengue.
After reading these articles, a review of Dengue seemed prudent. 
Dengue is caused by a virus and there are four different serotypes. Individuals who live in an endemic region such as Nicaragua are usually infected by several or all of the strains over their lifetime.

In 2004 a prospective study of about 3800 children, 2 to 9 years of age, was started in Managua, the capital of Nicaragua. The children had annual blood tests to identify infection with dengue virus. Over the first four years of the study, 22 to 40% of the two year-olds and 90 to 95% of the nine year-olds showed evidence of Dengue. So, every child is eventually infected.


Infection with one dengue serotype confers lifelong immunity, but only to that serotype. Most adults are immune.

The virus is transmitted by a female Aedes mosquito. These mosquitoes thrive in stagnant water such as might be found in old tires or other small containers around a home.

The mosquitoes acquire the virus when they feed (bite) an individual already infected with the virus. The mosquito can immediately transmit the virus if the insect bites another individual, which is common, and which accounts for epidemics. Entire families often develop infection within a 24 to 36 hour period, presumably from the bites of a single infected female mosquito.


Once inoculated into a human, dengue has an incubation period of 3 to 14 days (average 4 to 7 days).


The majority (50 to 90%) of infected individuals have no symptoms and do not realize they are infected. Data from a 1997 Cuban epidemic suggest that for every symptomatic case of dengue fever, there are 14 unrecognized cases.


Classic dengue fever is defined by the Pan American Health Organization (PAHO) as an acute febrile illness of 2 to 7 days duration associated with two or more of the following - severe headache, pain behind the eyes, severe muscle pain, joint pain, characteristic rash, hemorrhagic manifestations, low white blood cell count.


Many patients experience a prodrome of chills, red mottling of the skin, and facial flushing, which is considered a sensitive and specific indicator of dengue fever. The prodrome might last for 2 to 3 days. The illness presents with the rapid onset of high fever. The fever might reach 41°C. In addition to the symptoms and signs above, the patient might also have weakness, vomiting, sore throat, or altered taste sensation. The rash is a centrifugal, maculopapular or macular confluent rash over the face, thorax, and flexor surfaces, with islands of skin sparing. The rash typically begins on day 3 and persists 2-3 days. Fever typically resolves with the cessation of viremia.


Leukopenia and thrombocytopenia are common findings in dengue fever and might be caused by direct destructive actions of the virus on bone marrow precursor cells. Approximately one third of patients with dengue fever have mild hemorrhagic symptoms, including petechiae, gingival bleeding, and a positive tourniquet test.


Dengue fever is typically a self-limiting disease with a mortality rate of less than 1%. Supportive care with analgesics, fluid replacement, and bed rest is usually sufficient. Acetaminophen can be used to treat fever and relieve other symptoms. Aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), and corticosteroids should not be used.


A small percentage of persons who were previously infected by one dengue serotype and who are later infected with a second serotype, develop the potentially fatal complications
Dengue Hemorrhagic Fever (DHF) and Dengue Shock Syndrome (DSS). The severity of the secondary dengue infection appears to intensify as the interval increases between the infections.

When a previously infected individual is later infected with a different serotype, non-neutralizing antibodies recognize the dengue virus but do not neutralize or inhibit virus replication. Instead, the virus and antibody form an antigen-antibody complex. This complex is recognized by receptors on macrophages, which then internalize the immune complex and allow the virus to replicate unchecked. This phenomenon is called antibody-dependent enhancement. The affected macrophages release vasoactive mediators that increase vascular permeability. This serious complication usually develops just as the dengue fever episode is resolving.

Abdominal pain in conjunction with restlessness, change in mental status, hypothermia, and a drop in the platelet count presages the development of DHF.

Ninety percent of patients with DHF are younger than 15 years of age.


In persons with DHF, the fever reappears, as a biphasic or "saddleback" fever curve. Along with this biphasic fever, patients with DHF have more obvious hemorrhagic manifestations and plasma leakage. The critical feature of DHF is plasma leakage. Plasma leakage is caused by increased capillary permeability. Bleeding is caused by capillary fragility and thrombocytopenia. DSS is essentially DHF with progression into circulatory failure, with ensuing hypotension, and, ultimately, shock and death. Death can occur within 8-24 hours after onset of signs of circulatory failure. The most common clinical findings with impending shock include hypothermia, abdominal pain, vomiting, and restlessness. DHF has a mortality rate of 2-5% when treated and up to 50% when not treated. In the October 24th Nicaragua Dispatch article, Sonia Castro, the Sandinista Minister of Health, is quoted,


I want the population to know that if they are showing serious signs of dengue, there is a 50% chance they could die even if they are in the health clinic. So we have to destroy the mosquitos' nests for breeding.

This statement is an official acknowledgement that the health care available in Nicaragua is not sufficient to offer the modern intensive medical care necessary. If you live in Canada, the mortality rate is 2 to 5%. If you live in Nicaragua, the mortality rate is 50%. 

The only treatment is supportive care with hydration, blood pressure support with pressors, and platelets and plasma for bleeding. No specific antiviral medication is available.


Prevention is therefore fundamental for control.

Nicaragua insecticide spray program in operation. 
The worker is not wearing a mask. Ouch!!!!! 
Photo courtesy of Nicaragua Dispatch.
The mosquito that transmits the virus bites only by day so mosquito nets are of limited use. Only takes one bite, and the ankles and the back of the neck are the preferred sites.

The only way to prevent dengue virus is to avoid bites. Susceptible individuals should wear N,N-diethyl-3-methylbenzamide (DEET)–containing mosquito repellent and protective clothing, preferably impregnated with permethrin insecticide. They should choose well-screened or air-conditioned places. Larval habitats (stagnant water) should be eliminated or treated with larvacides. Indoor sprays should be considered to eliminate mosquitoes.


References


Trends in Patterns of Dengue Transmission over 4 Years in a Pediatric Cohort Study in Nicaragua. J Infect Dis. 2010;201:5-14.


Nicaragua Dispatch 

http://www.nicaraguadispatch.com/news/2013/10/dengue-claims-14th-victim-in-nicaragua/8301

eMedicine
http://emedicine.medscape.com/article/215840-overview

Friday, November 29, 2013

Worms in Nicaragua

Worms in Nicaragua


Worm disease is common in Nicaragua. One study showed Ascaris infection in 13% of individuals.

Worms are present worldwide in the moist warm soil found in the tropical latitudes. There are three common worms, Ascaris lumbricoides, Trichuris trichiura (whipworm), and Anclostoma duodenale & Necator americanus (hookworm).
 Ascaris eggs on R & L. Adult female in center. Images courtesy CDC.

Ascaris live in the lumen of the small intestine. A female can produce approximately 200,000 eggs per day, which are passed with the feces. Fertile eggs are infective after 18 days to several weeks, depending on the environmental conditions. After infective eggs are swallowed, the larvae hatch, invade the intestinal mucosa, and are carried via the blood to the lungs. The larvae mature further in the lungs (10 to 14 days), penetrate the alveolar walls, ascend the bronchial tree to the throat, and are swallowed. Upon reaching the small intestine, they develop into adult worms. Between 2 and 3 months are required from ingestion of the infective eggs to oviposition by the adult female. Adult worms can live 1 to 2 years.
Hookworm larva. Images courtesy CDC.

Hookworm eggs are passed in the stool, and the 
larvae hatch in 1 to 2 days. The larvae are infective after 5 to 10 days, and can survive 3 to 4 weeks. On contact with the human host (bare feet), the larvae penetrate the skin and are carried through the blood vessels to the heart and then to the lungs. They penetrate into the pulmonary alveoli, ascend the bronchial tree to the pharynx, and are swallowed. The larvae reach the small intestine, where they mature into adults. Adult worms attach to the intestinal wall with resultant blood loss. Most adult worms are eliminated within 1 to 2 years.
Whipworm eggs on R & L. Adult female in center. Images courtesy CDC.

Whipworm eggs are passed in the stool, and the eggs are infective in 15 to 30 days. The eggs hatch in the small intestine and release larvae that mature and migrate to the colon. Female worms in the cecum shed between 3,000 and 20,000 eggs per day. The lifespan of an adult is about 1 year.

Once infected with a worm, a child can develop abdominal pain and distension, intestinal obstruction, iron-deficiency anemia, malnutrition and poor growth, and allergic reactions.

Mebendazole kills the worms. Mebendazole is on the World Health Organization (WHO) List of Essential Medicines for Children, and is intended for the use in children up to 12 years of age. There is limited data on the safety in children under the age of 2 years. In Nicaragua, a government program is in place to administer the medication. Each school-aged child receives a 500 mg dose of mebendazole. Reinfection is common, so the medication needs to be re-administered. 


Prevention is preferable to regular re-administration of the medication. 
The fundamentals of prevention for all worms include access to clean water, modern sanitation to dispose of infected feces, good personal hygiene with regular hand washing, and careful cleansing of soil-grown-vegetables and fruits.

To prevent hookworm infection, individuals should not walk barefoot in the soil and should otherwise avoid skin contact with soil.

Friday, November 22, 2013

Parasites in Nicaragua

Parasites in Nicaragua

Intestinal parasites in Nicaragua are endemic and contaminated water is the most common source. The common parasites include Entamoeba histolytica, Giardia lamblia, and Cryptosporium species. 

In one recent study, 53% of tested wells in Nicaragua contained amoeboflagellates. A study of 480 apparently healthy individuals in Leon, Nicaragua reported that Entamoeba histolytica or Entamoeba dispar was present in 12% of stool specimens. Another study found that Entamoeba histolytica or Entamoeba dispar was present in 19% of individuals and that Giardia lamblia was present in 16%. These percentages are high enough, that all rural children who drink well water should be presumed to have parasites in their intestine.

Infection by Giardia lamblia occurs by ingestion of mature cysts from fecally contaminated food, water, or hands. Swallowing as few as 10 cysts is enough to cause illness. The cysts are hardy and can survive several months in cold water. The symptoms of giardiasis normally begin 1 to 3 weeks after a person has been infected.
Giardia lamblia trophozoites L & R images, cyst in center. Images courtesy of CDC.

Infection by Entamoeba histolytica occurs by ingestion of mature cysts in fecally contaminated food, water, or hands. Although Entamoeba histolytica is commonly found in the stool, the majority of individuals are not symptomatic, but are potential carriers (able to transmit parasite but not symptomatic). About 10% of individuals develop amoebic dysentery. Amoebic dysentery has a gradual onset with watery or bloody diarrhea, crampy abdominal pain, and poor appetite and weight loss. Liver abscess is a possible complication. The infection is more common and more severe in malnourished children. 
Entamoeba histolytica trophozoites with ingested red blood cells. Images courtesy CDC.

Amoebic dysentery and giardiasis are treated with metronidazole. Unless the source of the infection is eliminated, many individuals will be re-infected after treatment. 

Prevention is therefore important. To prevent infection, the contaminated water source needs to be eliminated or the water needs to be treated. Drinking only bottled water is a good idea but might be too expensive for the average Nicaraguan family. Water can treated in a variety of ways shown in the table below. Careful hand washing and cleaning uncooked vegetables and fruits with clean or treated water is important.



Boiling
Filter
1 micron
Chemical

Solar
Irradiation
Entamoeba histolytica
Yes
Yes
Yes
?
Giardia lamblia
Yes
Yes
No
?
Cryptosporidium species
Yes
Yes/No
No
?


For chemical disinfection, two drops of bleach per liter of water is sufficient. Let the treated water stand for at least thirty minutes. Chemical disinfection is not sufficient for Giardia lamblia or Cryptosporidium

Not all filtration systems work for Cryptosporidium. A filtration system is adequate for Cryptosporidium only if the description includes one of the following three statements - reverse osmosis, absolute pore size 1 micron or less, or tested and certified by National Safety Foundation (NSF) Standard 53 or 58 for cyst removal.

Solar Irradiation is a promising method but the Centre for Disease Control (CDC) does not comment on effectiveness for parasites. There are emerging studies that do report effectiveness.