The typical malaria infection will present with recurrent attacks of high grade fever with moderate to severe chills. Patients will also present with profuse diaphoresis (sweating) as the core body temperature drops. Other common signs and symptoms of malaria include vomiting, headache, and diarrhea. These signs usually develop within a few weeks from the mosquito bite; however, some parasites may lie dormant within the blood stream for months to years.

• Fever

  Antipyretic measures for treating fever in malaria Fever is a common symptom of malaria. [doi.org]

  For a thorough discussion of yellow fever and guidance for vaccination, see the Yellow Fever section earlier in this chapter. [wwwnc.cdc.gov]

  The correct diagnosis of these non-malaria fevers is a major concern, and there is an urgent need to develop more point-of-care diagnostic tests and capacities to identify and treat the causes of these fevers. [ncbi.nlm.nih.gov]

• Chills

  CASE REPORT A 29-year-old primigravida at 37 weeks of gestation, with no significant medical history, presented complaining of fever, chills, and generalized body aches. [ncbi.nlm.nih.gov]

  […] for a rare disease Malaria Disease definition A life-threatening parasitic disease caused by Plasmodium ( P. ) parasites that are transmitted by Anophles mosquito bites to humans and is typically clinically characterized by attacks of fever, headache, chills [orpha.net]

  Rupture of the red blood cells occurs in a synchronized manner, resulting in the periodic episodes of chills and fever that are typical of malaria. Copyright 2017 · All Rights Reserved · MaxAnim [maxanim.com]

• Anemia

  Abstract AbstractRecently, reports of delayed hemolytic anemia after treatment with artemisinin and its derivatives have emerged. [ncbi.nlm.nih.gov]

  Malaria is a parasitic disease that involves high fevers, shaking chills, flu-like symptoms, and anemia. Malaria is caused by a parasite. It is passed to humans by the bite of infected anopheles mosquitoes. [medlineplus.gov]

  Malaria is a parasitic disease that involves high fevers, shaking chills, flu-like symptoms, and anemia. Malaria is caused by a parasite that is passed to humans by the bite of infected anopheles mosquitoes. [nlm.nih.gov]

• Malaise

  The protean and nonspecific clinical findings occurring in malaria (fever, malaise, headache, myalgias, jaundice and sometimes gastrointestinal symptoms of nausea, vomiting and diarrhoea) may lead physicians who see malaria infrequently to a wrong diagnosis [ncbi.nlm.nih.gov]

  These symptoms include chills, headache, myalgias, and malaise, and they occur in a cyclic pattern. The parasite may also cause jaundice and anemia due to the lysis of the RBCs. [emedicine.com]

• High Fever

  Abstract We report the case of a 12-year-old child who was admitted to our Department, with 7 days' history of high fever and splenomegaly. His father had similar symptoms starting on the same day. [ncbi.nlm.nih.gov]

  Why Malaria Is Harmful Malaria can cause high fever, chills, and flu-like symptoms that can be life-threatening when not treated quickly. The disease is caused by Plasmodium parasites, which are carried by Anopheles mosquitoes. [webmd.com]

  fever, sweating, shaking chills, and anemia; malaria in animals is caused by other species of plasmodia. 084 Malaria 084.0 Falciparum malaria [malignant tertian] convert 084.0 to ICD-10-CM 084.1 Vivax malaria [benign tertian] convert 084.1 to ICD-10- [icd9data.com]

  Signs and symptoms include paroxysmal high fever, sweating, chills, and anemia. [fpnotebook.com]

• Splenomegaly

  Abstract We report the case of a 12-year-old child who was admitted to our Department, with 7 days' history of high fever and splenomegaly. His father had similar symptoms starting on the same day. [ncbi.nlm.nih.gov]

  Splenic rupture may be associated with P vivax infection secondary to splenomegaly resulting from RBC sequestration. P vivax infects only immature RBCs, leading to limited parasitemia. [emedicine.com]

• Palpable Spleen

  On examination, he was jaundiced and hypotensive, and he had generalized abdominal tenderness and a palpable spleen. Malaria was suspected, and a blood film was reported to show 112,000 P. malariae parasites/µL. [doi.org]

  On examination, he was jaundiced, hypotensive and had generalised abdominal tenderness and a palpable spleen. Malaria was suspected and a blood film was reported as showing 112,000 P. malariae parasites/μl. A diagnosis of severe malaria was made. [ncbi.nlm.nih.gov]

• Vomiting

  […] disease Malaria Disease definition A life-threatening parasitic disease caused by Plasmodium ( P. ) parasites that are transmitted by Anophles mosquito bites to humans and is typically clinically characterized by attacks of fever, headache, chills and vomiting [orpha.net]

  The dose was repeated if the patient vomited within 45 minutes. [ncbi.nlm.nih.gov]

• Nausea

  The protean and nonspecific clinical findings occurring in malaria (fever, malaise, headache, myalgias, jaundice and sometimes gastrointestinal symptoms of nausea, vomiting and diarrhoea) may lead physicians who see malaria infrequently to a wrong diagnosis [ncbi.nlm.nih.gov]

  Symptoms Eight to 30 days after the mosquito bites, the victim will suffer from headache; fatique; nausea; hard, shaking chills with a fever that lasts from 12 to 24 hours; rapid breathing and sweating that causes a drop in body temperature. [web.archive.org]

• Diarrhea

  A 15-year-old boy who had traveled to Africa (South Africa, Kenya, and Nigeria between January 3 and 25, 2011) presented with fever persisting over 5 days, headache, diarrhea, and dysuria, approximately 17 days after his return from the journey. [ncbi.nlm.nih.gov]

  Malaria symptoms include chills, flu-like symptoms, fever, vomiting, diarrhea, and jaundice. A blood test can diagnose it. It can be life-threatening. However, you can treat malaria with drugs. [nlm.nih.gov]

  Misdiagnosis of fever can lead to overuse of ACT as well as avoidable deaths from other febrile illnesses like pneumonia and diarrhea. [psi.org]

• Hypotension

  CASE REPORT: A 76-year-old male presented with fever, hypotension, tachycardia, and a urinalysis consistent with a urinary tract infection. He was admitted to the intensive care unit and initiated on broad-spectrum antibiotics. [ncbi.nlm.nih.gov]

  Postural hypotension may be secondary to autonomic dysfunction. Severe hypotension can develop suddenly, usually with pulmonary edema, metabolic acidosis, sepsis, and/or massive hemorrhage due to splenic rupture or from the gastrointestinal tract. [doi.org]

• Tachycardia

  CASE REPORT: A 76-year-old male presented with fever, hypotension, tachycardia, and a urinalysis consistent with a urinary tract infection. He was admitted to the intensive care unit and initiated on broad-spectrum antibiotics. [ncbi.nlm.nih.gov]

  In the Brazil study, two of the 37 patients who were getting high doses of chloroquine developed ventricular tachycardia, a dangerous heart arrhythmia that led to their deaths. [latimes.com]

  It may be overlooked because all clinical features of hypoglycemia (anxiety, dyspnea, tachycardia, sweating, coma, abnormal posturing, generalized convulsions) are also typical of severe malaria itself. [doi.org]

• Orthostatic Hypotension

  hypotension ) muscle aches poor appetite In people infected with P. falciparum, the following symptoms may also occur: anemia caused by the destruction of infected red blood cells extreme tiredness, delirium, unconsciousness, convulsions, and coma kidney [medbroadcast.com]

  Physical signs include fever, tachycardia, jaundice, pallor, orthostatic hypotension, hepatomegaly, and splenomegaly. Clinical examination in nonimmune persons may be completely unremarkable, even without fever. [ncbi.nlm.nih.gov]

• Jaundice

  Abstract A 5-year-old immunocompetent girl presented with fever, jaundice, hepatosplenomegaly and pancytopenia. The peripheral blood smear demonstrated mixed malaria infection (Plasmodium vivax and Plasmodium falciparum). [ncbi.nlm.nih.gov]

  The protean and nonspecific clinical findings occurring in malaria (fever, malaise, headache, myalgias, jaundice and sometimes gastrointestinal symptoms of nausea, vomiting and diarrhoea) may lead physicians who see malaria infrequently to a wrong diagnosis [doi.org]

• Hepatomegaly

  Enlargement of the liver (hepatomegaly) and spleen (splenomegaly) may be found during a physical examination. Malaria is usually diagnosed with a blood test that screens for the presence of malaria parasites. [betterhealth.vic.gov.au]

  Patients with heavy hepatocyte load may present with hepatomegaly. [symptoma.com]

  Symptoms Fever, often recurring Chills Rigors Headache Cough Myalgia Gastrointestinal upset Signs Fever Splenomegaly Hepatomegaly Jaundice /- abdominal tenderness Signs of severe disease (usually P. falciparum ) Impaired consciousness. [patient.info]

  His chest was clear on auscultation, but he had hepatomegaly on abdominal palpation. Malaria was suspected, and a thick film was reported to show P. malariae “ ” (this grading indicates 10 parasites/high-power microscopy field). [doi.org]

• Hepatosplenomegaly

  Abstract A 5-year-old immunocompetent girl presented with fever, jaundice, hepatosplenomegaly and pancytopenia. The peripheral blood smear demonstrated mixed malaria infection (Plasmodium vivax and Plasmodium falciparum). [ncbi.nlm.nih.gov]

  Hepatosplenomegaly may be present. Infection by Plasmodium falciparum is potentially fatal and most commonly manifests as a febrile nonspecific influenza-like illness without localizing signs. [meddean.luc.edu]

  […] places of transit, urban vs. rural Whether malaria prophylaxis was taken and, if so, which drug and compliance Prior empiric treatment for malaria Physical examination Full examination with particular attention to clinical features of severe malaria hepatosplenomegaly [rch.org.au]

• Sweating

  […] bite of an infected female mosquito of the genus anopheles; malaria is endemic in parts of asia, africa, central and south america, oceania, and certain caribbean islands; characterized by extreme exhaustion associated with paroxysms of high fever, sweating [icd9data.com]

  Symptoms Eight to 30 days after the mosquito bites, the victim will suffer from headache; fatique; nausea; hard, shaking chills with a fever that lasts from 12 to 24 hours; rapid breathing and sweating that causes a drop in body temperature. [web.archive.org]

  It consists of A cold stage (sensation of cold, shivering) A hot stage (fever, headaches, vomiting; seizures in young children); and Finally a sweating stage (sweats, return to normal temperature, tiredness). [cdc.gov]

  In uncomplicated malaria, symptoms progress as follows, through cold, hot, and sweating stages: a sensation of cold with shivering fever, headaches, and vomiting seizures sometimes occur in younger people with the disease sweats, followed by a return [medicalnewstoday.com]

  Signs and symptoms include paroxysmal high fever, sweating, chills, and anemia. [fpnotebook.com]

• Epistaxis

  Clinical features: impaired consciousness or coma (cerebral malaria) unable to sit up without assistance vomiting or failure to feed seizures respiratory distress shock/severe dehydration haemoglobinuria spontaneous bleeding (e.g. epistaxis, gum bleeding [rch.org.au]

• Kidney Failure

  Patients with severe falciparum malaria may develop liver and kidney failure, convulsions, and coma. [stanfordhealthcare.org]

  However, if it is known to be greater than 10% or if the patient is experiencing life-threatening complications (ie, coma, respiratory failure, coagulopathy, fulminant kidney failure), exchange transfusion may be investigated as a treatment option. [emedicine.com]

  Symptoms usually appear 7 to 30 days after an infective bite and include: Fever Chills Sweats Headache Breathing problems Tiredness Vomiting Diarrhea Cough Sometimes malaria causes fluid in the lungs, liver and kidney failure, swelling of the brain, coma [phpa.health.maryland.gov]

  P. falciparum symptoms are more severe and include behavioural changes, confusion, seizures, anemia, respiratory failure, kidney failure, coma and shock. If not treated immediately, P. falciparum malaria can lead to death. [hr.un.org]

• Dark Urine

  Nausea/vomiting, poor appetite, chills, bitter taste in the mouth and dark urine were symptoms that were significantly associated with malaria among the adult clients (P CONCLUSION: Misuse of ACTs following overtreatment of malaria based on clinical diagnosis [ncbi.nlm.nih.gov]

  Other symptoms may include confusion or other neurological signs, diarrhoea, dark urine, jaundice, cough and respiratory distress. [www2.health.vic.gov.au]

  If you have this liver disease, you might feel flu-like symptoms and have belly pain, dark urine, and pale stools. Fibromyalgia. [webmd.com]

  IPTc (AS AQ) versus placebo or no IPTc: Non‐serious adverse events (during intervention) Prevention Treatment IPTc HMM IPTc Adverse event ( N 429) ( N 86) ( N 64) Dark urine 5.4 (23) 4.7 (4) 0 (0) Dizziness 0.9 (4) 1.2 (1) 3.1 (2) Dysphagia 0 (0) 0 (0 [doi.org]

• Oliguria

  Clinical features: impaired consciousness or coma (cerebral malaria) unable to sit up without assistance vomiting or failure to feed seizures respiratory distress shock/severe dehydration haemoglobinuria spontaneous bleeding (e.g. epistaxis, gum bleeding) oliguria [rch.org.au]

  Plasma glucose measured at 0, 4, 8, 12, 16, 20, and 24 h and then every 6 h Seizures, bleeding and sepsis after admission, pulmonary oedema, oliguria, time in intensive care unit Figures and Tables - Table 2. [doi.org]

  […] malaria) Weight within 20% of the standards of the population Ability to take oral medication Not having received an antimalarial agent for last 14 days Exclusion criteria: Pregnancy and G6PD deficiency Mixed infections Haematocrit 25% Protracted vomiting Oliguria [web.archive.org]

• Headache

  Although fever represents the cardinal feature, clinical findings in malaria are extremely diverse and may range in severity from mild headache to serious complications leading to death, particularly in falciparum malaria. [ncbi.nlm.nih.gov]

  Search for a rare disease Malaria Disease definition A life-threatening parasitic disease caused by Plasmodium ( P. ) parasites that are transmitted by Anophles mosquito bites to humans and is typically clinically characterized by attacks of fever, headache [orpha.net]

• Seizure

  Abnormal motor posturing, seizures and raised ICP AMP was associated with recurrence of seizures after admission, mostly as short multiple seizures, but not seizures before admission. [pubmedcentral.nih.gov]

  Seizures are a common feature of childhood cerebral malaria; 80% are admitted with seizures and seizures recur in 60% during admission ( 56 ). [doi.org]

  Recurrent seizures do not cause hippocampal damage. J Neurol. 2004; 251 :458–463. [ PubMed ] [ Google Scholar ] 60. Verity CM. Do seizures damage the brain? The epidemiological evidence. [ncbi.nlm.nih.gov]

• Confusion

  Group 1 includes all patients who present with prostration or altered mental status (ie, confusion, agitation, or coma). [emedicine.com]

  PMNS signs were confusion (72%), fever (46%), seizures (35%), cerebellar impairment (28%), psychosis (26%), and motor disorders (13%). [ncbi.nlm.nih.gov]

  Not to be confused with miliaria. Malaria Malaria parasite connecting to a red blood cell Pronunciation Specialty Infectious disease Symptoms Fever, vomiting, headache Bynum WF; Overy C, eds. (1998). [en.wikipedia.org]

  It is this latter complication—known as cerebral malaria and manifested by confusion, convulsions, and coma—that frequently kills victims of P. falciparum malaria. [britannica.com]

  P. falciparum symptoms are more severe and include behavioural changes, confusion, seizures, anemia, respiratory failure, kidney failure, coma and shock. If not treated immediately, P. falciparum malaria can lead to death. [hr.un.org]

• Stroke

  Malaria may have been a contributory factor rather than the sole cause in our patient who presented with a stroke. [doi.org]

  The disease was not stroke, hepatic coma, or neonatal encephalopathy. It was general paresis of the insane (GPI), the dreaded neurosyphilis, and the magical remedy was “fever therapy,” induced by injecting blood from malaria patients. [pediatrics.aappublications.org]

  Erythropoietin therapy for acute stroke is both safe and beneficial. Mol Med. 2002; 8 :495–505. [ PMC free article ] [ PubMed ] [ Google Scholar ] 83. Casals-Pascual C, Idro R, Picot S, Roberts DJ, Newton CR. [ncbi.nlm.nih.gov]

• Altered Mental Status

  Group 1 includes all patients who present with prostration or altered mental status (ie, confusion, agitation, or coma). [emedicine.com]

  As in malaria, altered mental status is highly associated with a fatal outcome in septic encephalopathy ( 381 ). [cmr.asm.org]

A detailed clinical history of the patient with a history of travel in malaria endemic areas would usually clinch the diagnosis. Blood tests are paramount in the diagnosis of malarial diseases. Malarial peripheral smears can demonstrate whether the host is infected, what particular plasmodium strain is causing the infection, whether malarial infections have affected other bodily organs, and resistant strains to certain anti-malarial drugs.

• Hemoglobin Decreased

  (3.1) Hemoglobin decreased § 14 (5.4) 2 (1.5) 2 (1.6) Diarrhea 1 (0.4) 0 1 (0.8) Drug-induced liver injury ¶ 1 (0.4) 0 0 Hepatitis E 1 (0.4) 0 0 Limb abscess 1 (0.4) 0 0 Menorrhagia 1 (0.4) 0 0 Spontaneous abortion 1 (0.4) 0 0 Urinary tract infection [nejm.org]

• Hyponatremia

  Hyponatremia is probably associated with continued oral hypotonic fluid intake in the setting of hypovolemia and does not require treatment beyond rehydration. [6] Overly aggressive treatment of hyponatremia may lead to death. [emedicine.com]

• Plasmodium Falciparum

  Basigin is a receptor essential for erythrocyte invasion by Plasmodium falciparum. Nature 480, 534–537 (2011). 84. Tham, W.H., Healer, J. & Cowman, A.F. Erythrocyte and reticulocyte binding-like proteins of Plasmodium falciparum. [oadoi.org]

  Metabolic information is extracted from the universal metabolic databases and presented in a format suitable to Plasmodium falciparum. [web.archive.org]

In cases of malarial infections, the choice of anti-malarial drug and duration of treatment are heavily dependent on the type of etiologic agent, severity of the symptomatology, age of patients and whether the patient is pregnant. The following anti-malarial agents are commonly used to treat malaria.

• Quinine sulfate
• Chloroquine
• Hydroxychloroquine
• Mefloquine
• Malarone
• Primaquine [9]

High doses of quinine and chloroquine may cause complications of methemoglobinemia among patients; thus, frequent blood monitoring is imperative [10].

The majority of uncomplicated malarial cases carries a good prognosis with early treatment. Patients who are treated early will usually show signs of marked improvement in the signs and symptoms. An afebrile period of more than 96 hours after 48 hours from the start of antimalarial treatment is good prognostic indicator. Infections with Plasmodium falciparum especially with complications spell out a grimmer prognosis with relatively high mortality rates if left untreated.

Cerebral malaria is the most common cause of deaths among children and adult patients. Even with adequate medications and treatment, cerebral malaria carries a mortality rate of 15 to 20% in most cases. Patients with hemoglobinopathies like sickle cell anemia, Thalassemia, and Hemoglobin C have an inherent resistance to P. vivax and P. falciparum infections and complications [8]. However, they may not be immune to Plasmodium parasitemia which usually confers no significant medical signs and symptoms.

There are at least five Plasmodium species that cause human malaria, these are: Plasmodium falciparum, Plasmodium malariae, Plasmodium vivax, Plasmodium ovale, and Plasmodium knowlesi [2]. The prevalence of the etiologic agents vary from region to region of endemicity where hosts are usually infected by a singles species of Plasmodium at a time. In 5% to 7% of cases, multiple species of the Plasmodium parasites can infect a human host at the same time [3]. Different species of malaria may have a different incubation period varying from 2 to 4 weeks that is why malarial prophylaxis is continually given for weeks after the traveler has returned home from a malaria infected region.

In the United States, isolated cases of malaria are predominantly imported from other tropical and subtropical countries because they have successfully eradicated the parasite during the 19th century until the turn of the 20th century [4]. Although, recent CDC reports as of 2010 have shown an increase of approximately 14% compared to the 2009 malaria census which are largely due to airport passenger transmissions [5]. The massive death annual death toll that reaches more than a million cases on malaria are predominantly seen among the children from the sub-saharan regions of Africa and are usually caused by the P. falciparum species. The life threatening malarial infections has been amply documented to reach approximately 300 to 500 Million infections per year worldwide [6].

There are no sexual predilection for malarial infections. Infected mothers may result to fetal complications like anemia, low-birth weight, premature birth, and death. Maternal malarial infection during the first trimester of pregnancy often results to abortion or miscarriage [7].

After the infected female Anopheles mosquito takes her blood meal on the human skin, she injects up to 15 malarial sporozoites in the blood stream which rapidly enter the liver cells. The sporozoites then undergoes rapid reproduction in the hepatocytes by asexual fission to form the pre-erythrocytic schizonts. The malarial merozoites multiply by the thousands within the hepatocyte schizont until they are released to the blood stream to attach to red blood cells. The merozoites may rapidly reproduce within the erythrocytes to form malarial trophozoites where red blood cell (rbc) rupture takes place after the schizont is filled and a new set of merozoites is released in the blood stream to infect a new sets of rbc.

The erythrocyte rupture and the progressive anemia causes the main presentation in malaria. The erythrocytic rupture releases toxins to the blood stream and induces cytokine release from macrophages causing the distinct fever and chills in the patients. Patients with heavy hepatocyte load may present with hepatomegaly. Larger merozoites in the blood develop to either male or female gametocytes which are ingested by the mosquito through a blood meal where they sexually reproduce within the mosquito vectors. The same cycle repeats in every human and mosquito infection encountered.

The most effective way to prevent malaria is to avoid visiting regions with known malarial endemicity. When visits becomes unavoidable, adequate drug prophylaxis should be taken at the prescribed period before the trip to avoid parasitic infections. Patients suspecting malaria infections should opt for prompt medical attention and treatment to prevent serious complications.

Malaria is a parasitic infection that causes recurrent attacks of fever and chills. Malaria claims approximately 1 million lives annually on a worldwide scale. Because many malarial strains are now immune to common anti-malarial drugs, it is most prudent to take drug prophylaxis before travelling to tropical and subtropical countries where malaria is still endemic. Current researche on malaria is focusing on the development of a vaccine to eradicate this worldwide menace [1].

Definition

Malaria is a major cause of death worldwide and is brought about by the protozoan parasite Plasmodium acquired from a bite of a female Anopheles mosquito carrier.

Cause

The five Plasmodium parasite species (P. falciparum, P. malariae, Plasmodium vivax, P. ovale, and P. knowlesi) cause malaria.

Symptoms

Patients usually presents with intermittent fever, chills, vomiting, headache and diarrhea.

Diagnosis

Diagnosis is made by demonstration of the Plasmodium merozoite or trophozoite in the blood from blood smears.

Treatment and follow-up

Anti-malarial agentsare Quinine sulfate, Chloroquine, Hydroxychloroquine, Mefloquine, Malarone and Primaquine.

1. Olotu A, Fegan G, Wambua J. Estimating individual exposure to malaria using local prevalence of malaria infection in the field. PLoS One. 2012; 7(3):e32929 (ISSN: 1932-6203)
2. Cox-Singh J, Davis TM, Lee KS, Shamsul SS, Matusop A, Ratnam S, et al. Plasmodium knowlesi malaria in humans is widely distributed and potentially life threatening. Clin Infect Dis. Jan 15 2008; 46(2):165-71.
3. Marchand RP, Culleton R, Maeno Y, Quang NT, Nakazawa S. Co-infections of Plasmodium knowlesi, P. falciparum, and P. vivax among Humans and Anopheles dirus Mosquitoes, Southern Vietnam. Emerg Infect Dis. Jul 2011; 17(7):1232-9.
4. Cullen KA; Arguin PM. Malaria surveillance--United States, 2011.MMWR Surveill Summ. 2013; 62(5):1-17 (ISSN: 1545-8636)
5. Malaria Surveillance — United States, 2010. Centers for Disease Control and Prevention. Accessed November 13, 2014.
6. Centers for Disease Control and Prevention. Malaria. Accessed November 13, 2014.
7. McGready R, Lee S, Wiladphaingern J, Ashley E, Rijken M, Boel M, et al. Adverse effects of falciparum and vivax malaria and the safety of antimalarial treatment in early pregnancy: a population-based study. Lancet Infect Dis. Dec 12 2011.
8. Taylor SM, Parobek CM, Fairhurst RM. Haemoglobinopathies and the clinical epidemiology of malaria: a systematic review and meta-analysis. Lancet Infect Dis. Mar 22 2012.
9. Janeczko LL. Primaquine protects against P. vivax malaria relapse. Medscape Medical News. Jan 3, 2013.
10. Amaratunga C, Sreng S, Suon S, et al. Artemisinin-resistant Plasmodium falciparum in Pursat province, western Cambodia: a parasite clearance rate study. Lancet Infect Dis. Nov 2012; 12(11):851-8.