Review: indications for ultrasound use in low- and middle-income countries

Authors


Corresponding Author Reinou S. Groen, Surgeons OverSeas (SOS), 225 E 6th St, Suite 7F, New York, NY 10003, USA. Tel.: +1 917 603 0479; Fax: +1 201 768 7517; E-mail: reinougroen@yahoo.com

Summary

Objective  To determine the indications for using ultrasound, in low- and middle-income countries (LMICs) and to assess whether its use alters clinical management.

Methods  Literature review. We conducted a Pubmed search on the clinical use of ultrasound in LMIC for articles published between January 2000 and December 2010, recording country of origin, speciality and whether ultrasound use led to a change in management.

Results  Fifty-eight articles were identified from 32 countries and represented nine specialties. Ultrasound was most commonly used for assisting with the diagnosis of obstetrical conditions, followed by intra-abdominal conditions such as liver abscesses and intussusceptions. Clinical management was altered in >30% of cases.

Conclusion  Ultrasound is a highly valuable diagnostic tool in LMICs and its use should be considered essential for all district medical facilities. The use could be applied more widely, eg., for tropical and non-communicable diseases. Additional research is needed to further characterize the impact of task shifting on ultrasound use in LMICs.

Abstract

Objectifs:  Evaluer l’adoption du dépistage du VIH chez les enfants d’âge préscolaire avec des mères séropositives dans une étude basées sur la population périurbaine dans le KwaZulu-Natal (KZN), en Afrique du Sud, une zone à forte prévalence du VIH.

Méthodes:  Tous les enfants de quatre à six ans de la région et leurs principaux soignants ont été invités à participer. Tous les participants ont été interrogés sur un éventuel dépistage précédent du VIH et ont reçu des conseils et dépistage volontaire du VIH, indépendamment du test précédent. 27 mères infectées par le VIH ont été interrogées afin d’identifier les obstacles au dépistage de leurs enfants.

Résultats:  1583 enfants (88% des enfants éligibles) et leurs soignants ont participé. 86% des mères biologiques avaient déjàété testées pour le VIH (27% testées positives). Parmi les 244 enfants survivants nés de mères infectées, seuls 41% avaient été testés pour le VIH (23% testés positifs). Par la suite, 90% des enfants de mères infectées, non testés préalablement ont subi le test du VIH (9,3%étaient positifs). La séroprévalence globale chez les enfants dans l’étude était de 4,9%. Toutes les mères infectées interrogées ont approuvé le fait que les enfants de femmes séropositives devraient être testés pour le VIH. Les femmes qui ont raté des occasions de dépistage prénatal du VIH n’ont rapporté aucun dépistage systématique de leurs enfants à des âges plus avancés.

Conclusions:  Dans cette communautéà forte prévalence du VIH, le dépistage du VIH chez les enfants est rare, malgré la couverture élevée du dépistage chez les soignants. La faible proportion d’enfants testés pour le VIH, en particulier ceux de mères infectées, est une grande préoccupation car ils sont à risque élevé de morbidité et de mortalité associées à l’infection VIH de l’enfance non traitée. Les programmes de dépistage du VIH devraient renforcer leurs protocoles afin d’inclure les enfants, surtout ceux qui ont raté des occasions de programme PTME dans la petite enfance.

Abstract

Objetivos:  Evaluar la aceptación de la prueba para el VIH entre niños en edad preescolar con madres VIH positivas en un estudio realizado en una población peri-urbana en KwaZulu-Natal (KZN), Sudáfrica, un área con alta prevalencia de VIH.

Métodos:  Se invitó a participar a todos los niños con edades entre los cuatro y seis años y sus cuidadores directos. Se preguntó a todos los participantes si previamente habían sido testados para VIH y se les ofreció aconsejamiento y testaje voluntario para VIH independientemente de si previamente se habían hecho la prueba o no. Se entrevistó a 27 madres infectadas con VIH para identificar las barreras existentes para la realización de la prueba en sus niños.

Resultado:  Participaron 1583 niños (88% de los niños aptos) y sus cuidadores. De las madres biológicas, un 86% había realizado previamente la prueba del VIH (27% eran positivas). Entre los 244 niños supervivientes, nacidos de una madre infectada, solo a un 41% se le había realizado la prueba del VIH (23% eran positivos). Posteriormente, al 90% de los niños no testados previamente y nacidos de madres infectadas, se les realizó la prueba del VIH (9.3% eran positivos). En general, la seroprevalencia entre los niños del estudio era del 4.9%. Todas las madres infectadas entrevistadas apoyaron la creencia de que a los niños nacidos de madres infectadas con VIH se les debía realizar la prueba del VIH. Las mujeres que no aprovecharon la oportunidad de realizarse la prueba prenatal del VIH no reportaron haber realizado pruebas sistemáticas a sus hijos posteriormente.

Conclusiones:  En esta comunidad con una alta prevalencia de VIH, la prueba para el VIH en niños no es frecuente a pesar de la alta cobertura entre los padres / cuidadores. La baja proporción de niños a los que se les ha realizado la prueba del VIH, particularmente entre aquellos nacidos de madres infectadas, es preocupante ya que tienen un alto riesgo de morbilidad y mortalidad asociada a la infección infantil por VIH sin tratar. Los programas para realizar la prueba del VIH deberían reforzar los protocolos de inclusión de niños, especialmente aquellos que no ingresaron en los programas de prevención de la transmisión vertical durante la infancia.

Introduction

In high-income countries, radiology imaging studies are frequently used in everyday clinical practice. Ultra-sonography, or sonography, herein referred to as ultrasound, has been widely used and valued as a clinical diagnostic modality, since its introduction in the 1960s (Raptopoulos et al. 1987). However, in low- and middle-income countries (LMICs), health providers are still highly dependent on obtaining a thorough history and using their physical examination skills. According to WHO (1998), 60% of the world has no access to radiological services.

With limited funding, district and community hospitals often find it difficult to improve diagnostic and therapeutic infrastructure that would enable better healthcare delivery. Non-governmental organizations (NGOs) trying to improve the working conditions and diagnostic capabilities of healthcare professionals in resource-poor settings should consider the usefulness and cost-effectiveness of ultrasound as a diagnostic tool. WHO states that ultrasound is cost effective, safe and should be available worldwide to assist the clinician in the diagnostic process (Mindel 1997). Numerous experts agree that ultrasound should be available at the district health care level of LMICs (Mets 1991; Mindel 1997). Our aim was to review the recent literature regarding the current use of ultrasound in LMICs, and identify gaps where greater usage is possible.

Methods

A Pubmed search using the terms ultrasound, sonography, developing country/countries, developing world, low resource settings, low-income country/countries was conducted. Original research articles, case reports, reviews, opinions and descriptive studies in English, French, Dutch and German were included. The search was then expanded using the references of each article. Included where all articles published between 2000 and 2010 addressing ultrasound use in LMICs. All articles were obtained and reviewed by the first author (RSG) for inclusion into the review.

Data were collected on type of research, country of origin and medical specialty. If the medical specialty was debatable, the department represented by the first author was used. Articles which included an estimation of the change in clinical management with the introduction of the use of ultrasound were separately addressed.

Results

A total of 58 articles met inclusion criteria on the current clinical use of ultrasound in LMICs. Of these, 27 (47%) articles were descriptive research studies: cross-sectional 9 (16%), prospective 8 (14%), social science 7 (12%), retrospective 2 (3%) and longitudinal 1 (2%). Another 12 (20%) articles were expert opinions, 7 (12%) case reports, 5 (9%) experience descriptions, 4 (7%) reviews, 2 (3%) case–control studies and only 1 (2%) randomized control trial (Table 1). The reviews covered small bowel obstruction, biliary ascariasis, schistosomiasis and tropical diseases in general.

Table 1.   Reviewed articles with county of origin and specialty focus
Type of research (total reviewed 58 articles)First authorYearTitleJournalCountrySpecialty
Randomized control trial (1)Van Dyk2007Routine second-trimester ultrasound for low-risk pregnancies in a South African communityInt J Gynaecol ObstetSouth AfricaObstetrics
Case report/case series (7)Bahú2001Hepatobiliary and pancreatic complications of ascariasis in children: a study of seven casesJ Pediat Gastroenterol NutrBrazilInternal Medicine
Bawa2010Even a single third trimester antenatal fetal screening for congenital anomalies can be life savingIndian J PediatrIndiaObstetrics
Egba2008Closed drainage of liver abscesses: the ‘UNICAL’ drain as an efficient and cost saving device in a tropical settingNiger J Clin PractNigeriaSurgery
Krishnakumar2006Ultrasound-guided hydrostatic reduction in the management of intussusceptionIndian J PediatrIndiaRadiology
Sharma2007Radiological manifestations of splenic tuberculosis: a 23-patient case series from IndiaIndian J Med ResIndiaRadiology
Sharma2010Amoebic liver abscess in the medical emergency of a North Indian hospitalBMC Research NotesIndiaInternal Medicine
Torre2002Amebic liver abscessAnn HepatolMexicoInternal Medicine
Case control (2)Hoffman2005The value of saline salpingosonography as a surrogate test of tubal patency in low-resource settingsInt J Fertil Women MedUnited KingdomGynecology
Rijken2009Obstetric ultrasound scanning by local health workers in a refugee camp on the Thai-Burmese borderUltrasound Obstet GynecolTai-Burmeese borderObstetrics
Prospective descriptive research (8)Bussmann2001Feasibility of an ultrasound service on district health care level in BotswanaTrop Med Int HealthBotswanaRadiology
Justice2007Accuracy of ultrasonography for the diagnosis of intussusception in infants in VietnamPed RadiologyVietnamPaediatrics
Kotlyar2008Assessing the utility of ultrasound in LiberiaJ Emerg Trauma ShockLiberiaEmergency Medicine
Madani2006Treatment of Wilms Tumor According to SIOP 9 Protocol in Casablanca, MoroccoPediatr Blood CancerMoroccoPaediatrics
Obajimi2008Abdominal ultrasonography in HIV/AIDS patients in southwesternBMJ Medical ImagingNigeriaRadiology
Paul2007Incidence of hepatocellular carcinoma among Indian patients with cirrhosis of liver: an experience from a tertiary care center in northen IndiaIndian J GastroenterolIndiaInternal Medicine
Smith2010FAST scanning in the developing world emergency departmentS Afr Med JSouth AfricaEmergency Medicine
Sy2009Management of ectopic pregnancy in Conakry, GuineaMed TropGuineaGynecology
Cross-sectional descriptive research (9)Adekanle2007Predictors of request for antenatal sex determination among pregnant women in Osogbo, NigeriaNiger J MedNigeriaObstetrics
Amoah2004Feasibility of thyroid ultrasonography in field studies in a developing country, GhanaAfr J Med Med SciGhanaInternal Medicine
Bartholomot2002Combined ultrasound and serologic screening for hepatic alveolar echinococcosis in central ChinaAm J Trop Med HygChinaInternal Medicine
King2003Measuring morbidity in schistosomiasis mansoni: relationship between image pattern, portal vein diameter and portal branch thickness in large-scale surveys utilizing new WHO coding guidelines for ultrasound in schistosomiasisTrop Med Int HealthKenya and EgyptInternal Medicine
Kobal2004Hand-carried ultrasound improves the bedside cardiovascular examinationChestGambiaCardiology
Kobal2004Hand-carried cardiac ultrasound enhances healthcare delivery in developing countriesAm J CardiolMexicoCardiology
Mand2010The role of ultrasonography in the differentiation of the various types of filaricele because of bancroftian filariasisActa TropGhanaInternal Medicine
Sinkala2009Clinical and ultrasonographic features of abdominal tuberculosis in HIV positive adults in ZambiaBMC Infect DisZambiaInternal Medicine
Spencer2008Serologic screening for hepatic alveolar echinococcosis in central China. Am J Trop Med HygJ Ultrasound MedGhanaPrimary Health
Retrospective descriptive research (2)Bai2006Ultrasound-guided hydrostatic reduction of intussusceptions by saline enema: a review of 5218 cases in 17 yearsAm J SurgChinaRadiology
Karki2004Liver abscess in the tropics: an experience from NepalSoutheast Asian J Trop Med Public HealthNepalInternal Medicine
Longitudinal descriptive research (1)Tshibwabwa2000Four-year study of abdominal ultrasound in 900 Central African adults with AIDS referred for diagnostic imagingAbdom ImaginCentral AfricaRadiology
Experience description (on US training program) (5)Adler2008Introduction of a portable ultrasound unit into the health services of the Lugufu refugee camp, Kigoma District, TanzaniaInt J Emerg MedTanzaniaEmergency Medicine
Crouch2010Perceived confidence in the FAST exam before and after an educational intervention in a developing countryInt J Emerg MedPeruEmergency medicine
Heller2010Short Course for Focused Assessment with Sonography for Human Immunodeficiency Virus/Tuberculosis: Preliminary Results in a Rural Setting in South Africa with High Prevalence of Human Immunodeficiency Virus and TuberculosisAm J Trop Med HygSouth Africa/Kwazulu-NatalInternal Medicine
Shah2008Development of an ultrasound training curriculum in a limited resource international setting: successes and challenges of ultrasound training in rural RwandaInt J Emerg MedRwandaEmergency Medicine
Shah2008Impact of the introduction of ultrasound services in a limited resource setting: rural Rwanda 2008BMC Int Health Hum RightsRwandaEmergency Medicine
Social science descriptive research (7)Bashour2005Syrian women’s perceptions and experiences of ultrasound screening in pregnancy: implications for antenatal policyReproduct Health MattersSyriaObstetrics
Chaturvedi2007Fetal sex-determination in Delhi: a population-based investigationTrop DoctIndiaObstetrics
Chigbu2008Implications of incorrect determination of fetal sex by ultrasoundInt J Gynaecol ObstetNigeriaObstetrics
Enakpene2009Clients’ reasons for prenatal ultrasonography in Ibadan, South West of NigeriaBMC Women’s HealthNigeriaObstetrics
Tautz2000Between fear and relief: how rural pregnant women experience foetal ultrasound in a Botswana district hospitalSocial Science and MedicineBotswanaObstetrics
Gammeltoft2007Fetal conditions and fatal decisions: ethical dilemmas in ultrasound screening in VietnamSoc Sci MedVietnamObstetrics
Gammeltoft2007The commodification of obstetric ultrasound scanning in Hanoi, Viet NamReproduct Health MattersVietnamObstetrics
Review (4)Kidmas2005A review of the radiological diagnosis of small bowel obstruction using various imaging modalitiesNiger Post Grad Med JNigeriaSurgery
Koumanidou2004Sonographic features of intestinal and biliary ascariasis in childhood: case report and review of the literatureAnn Trop PaediatricsGreeceRadiology
Ohmae2003Imaging diagnosis of schistosomiasis japonica--the use in Japan and application for field study in the present endemic areaParasitol IntJapanInternal Medicine
Richter2003Ultrasound in tropical and parasitic diseasesLancetUnited KingdomInternal Medicine
Experts opinions (12)Akhtar2010Ultrasound-related research in Pakistan: a perspective from the developing worldJ Ultrasound MedPakistanRadiology
Cerri2000Latin AmericaUltrasound in Med and BiolBrazilRadiology
Galukande2010Rethinking breast cancer screening strategies in resource-limited settingsAfr Health SciUgandaSurgery
Gharbi2000AfricaUltrasound in Med and BiolTunisiaRadiology
Harris2009Compact ultrasound for improving maternal and perinatal care in low-resource settings: review of the potential benefits, implementation challenges and public health issuesJ Ultrasound MedUSAObstetrics
Hofmeyr2009Routine ultrasound examination in early pregnancy: is it worthwhile in low-income countries?Ultrasound Obstet GynecolSouth AfricaObstetrics
Kongnyuy2007The use of ultrasonography in obstetrics in developing countriesTrop DoctUnited KingdomObstetrics
Ostensen2000Developing countriesUltrasound in Med and BiolSwitserlandRadiology
Ostensen2000Diagnostic imaging in developing countries: considerations for improvementEur RadiolSwitserlandRadiology
Rogo2004Improving technologies to reduce abortion-related morbidity and mortalityInt J Gynaecol ObstetUSAGynecology
Seffah2009Obstetric ultrasonography in low-income countriesClin Obstet GynecolGhanaObstetrics
Vangeenderhuysen2003Training midwives in developing countries in obstetric ultrasonography: goals and applicationGynecol Obstr Biol ReprodMauritanieObstetrics

The specialties represented were obstetrics/gynaecology 19 (33%), internal medicine 13 (22%), radiology 12 (20%), emergency medicine 6 (10%), surgery 3 (5%), cardiology 2 (3%), paediatrics 2 (3%) and public health 1 (2%) (Table 1). Of 13 articles from internal medicine departments, 7 (54%) dealt with liver pathology; the others were on thyroid, abdominal HIV/TB, testicular and general tropical disease imaging. Five of the 12 radiological articles (42%) were expert opinions, and the others addressed ultrasound use for intestinal morbidities such as intussusception and HIV-related conditions.

Twenty-five articles (43%) describe ultrasound use in sub-Sahara Africa, 13 (22%) in Asia and 4 (7%) in South America. Of the expert opinion articles, 4 (33%) were from sub-Saharan Africa and 9 (75%) from high-income countries. (Table 1) Four articles documented the use of ultrasound by medical volunteers on missions in Ghana, Liberia, Mexico and Gambia (Kobal et al. 2004a,b; Kotlyar & Moore 2008; Spencer & Adler 2008).

Six articles documented the impact or the change of clinical management because of the use of ultrasound in LMICs (Table 2). Clinical management changes ranged from 30% to 86% after ultrasound was performed. Especially in obstetrics, clinical management was altered by the availability of ultrasound. Specificity was high: 100% for focused assessment with sonography for trauma (FAST) and 99% for an abdominal scan for intussusception (Smith et al. 2010, Justice et al. 2007).

Table 2.   Impact of the ultrasound on change of clinical management
First authorYearCountrySpecialtyNo. of scansImpact
  1. FAST, focused assessment with sonography for trauma; US, ultrasound; COM, change of management because of ultrasound; RUQ, right upper quadrant.

Smith2010South AfricaEmergency Medicine7271% sensitivity for FAST
100% specificity for FAST
Justice2007VietnamPaediatrics64097.5% sensitivity for Intussusception
99% specificity for Intussusception
Spencer2008GhanaPrimary Health3240% COM
Kotlyar2008LiberiaEmergency Medicine12686% COM for obstetrics
83% COM for FAST
47% COM for RUQ pain
31% COM for gynecological US
Shah2009RwandaEmergency Medicine34543% COM often resulting in surgical procedures (puncture, biopsy, laparotomy or c-section)
Bussmann2001BotswanaRadiology230930% COM

Discussion

Although ultrasound use in LMICs is documented in the medical literature, no recent review exists. For this review, 58 articles published between 2000 and 2010 met the inclusion criteria. While experts agree that there is a need for more ultrasound usage in LMICs (Galukande & Kiguli-Malwadde 2010; Harris and Marks 2009; Seffah & Adanu 2009), because of shortages of machines or trained operators, the full need is unmet. Although many call for action via WHO or NGOs (Ostensen 2000; Ostensen & Volodin 2000; Rogo 2004), Cerri and De Oliveira (2000) from South America and Gharbi and Chehida (2000) from Africa emphasize the important role that national and regional radiology societies should play in education and regulations concerning ultrasound use in clinical practice.

Ultrasound in obstetrics and gynaecology

Documented ultrasound use in LMICs is mainly for obstetrical conditions; however, articles we categorized as emergency medicine often included large numbers of patients treated for obstetric/gynaecological conditions as well: a prospective single-centre study from Monrovia, Liberia (Kotlyar & Moore 2008) documented 53% of scans as performed for obstetric or gynaecological reasons. The proportions were similar in other articles addressing the use of ultrasound in emergency medicine in LMICs (Adler et al. 2008; Shah et al. 2008, 2009). In a prospective radiological study from Botswana, one-third of ultrasounds performed were for obstetrical indications (Bussmann et al. 2001).

Regardless of whether an ultrasound is performed in an emergency or radiology department, there appears to be a low threshold for obstetric patients. Seffah and Adanu (2009) attributed this to the high fertility rate in most developing countries and the popularity of having an ultrasound performed during pregnancy. Ultrasound can contribute considerably to diagnosis and treatment of ectopic pregnancy and abortion as well as complications later in pregnancy (Rogo 2004; Sy et al. 2009; Bawa & Kannan 2010). Harris and Marks (2009) described the coincidental reduction in maternal mortality in Nicaragua from 12% to 5% with the implementation of ultrasound. They argue that evidence for causality cannot be given and call for more research. Collectively, these reports suggest that ultrasound should be part of safe obstetric practice in LMICs.

Kongnyuy and van den Broek (2007) opined that routine ultrasound should also be available for all pregnant women in LMICs. They state that since ultrasound is safe and cheap, it will save hospital costs if women are routinely screened and problems with pregnancy are detected early. Conversely, establishing routine screening in settings with limited human resources may divert needed resources away from patients with existing pathologies (Hofmeyr 2009). Women who have greater resources (time, money and transportation) at their disposal are likely to benefit more than others. In a randomized controlled trial from South Africa, no difference was found in maternal or neonatal mortality by randomly screening half of 804 women in the second trimester. The only results were fewer inductions for post-term pregnancies in the screened group and one induced abortion in the scanned group for multiple foetal deformities (van Dyk et al. 2007).

Hofmeyr (2009) commented on his concern about the psychological impact of routine ultrasound screening in pregnancy: As social descriptive studies from Vietnam (Gammeltoft & Nguyen 2007a,b) and Botswana (Tautz et al. 2000) indicate, women tend to overestimate the power of the ultrasound, and health care workers admit to devoting less time to obtaining a full medical history and performing thorough physical exams when ultrasound is available, this concern is realistic. Woman in Vietnam overused ultrasound by requesting up to 22 scans per pregnancy for reassurance only. This overuse was driven partly by physicians and partly by women who were willing to pay for it (Gammeltoft & Nguyen 2007a,b). The same reasoning was seen in Nigeria and Syria (Bashour et al. 2005; Enakpene et al. 2009). A study from Nigeria found that in 69.5% of cases, ultrasounds for sex determination would influence the wish to expand the family after an index pregnancy (Adekanle et al.2007). When pre-natal ultrasound incorrectly determined a foetus’ gender, 63% of mothers had a negative feeling about the newborn which then resulted in marital conflicts in 39% of the cases (Chigbu et al. 2008). This is worrying in countries where certification and regulations for ultrasound practice are limited.

In India, there is great concern about sex determination and female foetal feticide despite the presence of laws prohibiting such practices. A population-based study from Delhi documented that 2.3% of ultrasounds were performed to determine the gender, which is illegal in India. Thirty per cent (30%) were unaware of the fact that this was illegal, and half of the couples with a known female foetus obtained an illegal induced abortion; none of the male foetuses were aborted (Chaturvedi et al. 2007).

Two articles on observations and arguments for implementation of obstetrical ultrasound argue that task-shifting is possible for obstetrical ultrasound. Task-shifting is a delegation of a specific task to a less specialized health worker (WHO 2008, http://www.who.int). As nurses and midwives are often in charge for the care of pregnant women, they are seen as the most appropriate candidates for task-shifting in obstetrical ultrasound (Vangeenderhuysen et al. 2002; Rijken et al. 2009). From the reviewed articles on ultrasound for obstetrics in LMICs, it appears that training should not only consist of learning the technique but should also include education on the social and legal aspects of ultrasound. Continuous education about expectations is needed for pregnant women and their societies, because women tend to overestimate its capability and usefulness.

Ultrasound in trauma

The use of FAST as an important adjunct in trauma care has been documented in articles from South Africa, Liberia, Rwanda and Peru (Kotlyar & Moore 2008; Shah et al. 2009; Crouch et al. 2010; Smith et al. 2010). In locations where there is often limited availability of computer tomography (CT), ultrasound is a reliable and affordable alternative. In Rwanda, the use of FAST reduced the incidence of exploratory laparotomy (Shah et al. 2009).

Ultrasound for infectious diseases

Ultrasound is successfully used to diagnose and follow-up multiple infectious diseases: Chagas’ disease, filariasis, myiasis and other protozoal, helminthic, viral and bacterial infections or their sequelae; however, its potential has not been fully explored (Richter et al. 2003). A population-based cross-sectional study from Ghana showed that ultrasound can be used in case of schistosomiasis to determine whether patients with urogenital filariasis need surgery or can be treated medically (Mand et al. 2010). A WHO informal working group has also developed a standardized classification system for schistosomiasis and echinococcosis (King et al. 2003; Ohmae et al. 2003; WHO 2001). These classifications are used for epidemiology and for patient follow-up. Standard treatment for echinococcal cysts now includes the use of ultrasound for a minimally invasive percutaneous puncture, aspiration, alcohol injection and re-aspiration (PAIR) (WHO 2003). This treatment was also described in a series of 6 patients from Niger who underwent ultrasound-guided drainage of liver abscesses instead of a laparotomy; overall costs were less, surgeon workload diminished, and hospital length of stay greatly reduced (Egba et al. 2008). In another case report from Mexico, a patient with non-specific pain in his right shoulder was investigated using ultrasound, which revealed an amoebic liver abscess. Without ultrasound, this diagnosis is hard to make and treat (Torre & Kershenobich 2002). Sharma et al. (2010) and Karki et al.(2004) describe 86 and 36 cases of liver abscesses from Northern India and Nepal, respectively; both state that ultrasound is the most useful tool to diagnose and appropriately treat liver abscesses which are often endemic in LMICs. Ultrasound is also important for follow-up of liver abscess and much more effective as a screening tool for echinococcosis than serology (Bartholomot et al. 2002).

Bahúet al. (2001) discuss seven cases of paediatric patients with ascaris, stating that even if CT is available, ultrasound is preferable because sedation is not needed and the real-time ultrasound will reveal whether the worms are still alive or not.

Ultrasound use for human immunodeficiency virus (HIV) and tuberculosis (TB)

Several studies describe the use of ultrasound in HIV and TB patients. Obajimi et al. (2008) from Nigeria viewed 391 abdominal ultrasounds performed in HIV positive and negative patients and found that HIV positive patients had more lymphadenopathy, splenomegaly and increased renal morbidity, but fewer gallstones. An observational study by Tshibwabwa et al. (2000) on the use of ultrasound in 900 HIV positive patients found that patients with AIDS had more lymphadenopathy, hepatomegaly, splenomegaly, biliary abnormalities, gut wall thickening and ascites than HIV positive individuals without AIDS. The results of these studies are important in that apparently HIV positive patients with AIDS need a different approach regarding abdominal ultrasound findings than other patients. Sinkala et al.(2009) studied patients with abdominal TB and found ascites, para-aortic lymphadenopathy and hepatomegaly. They concluded that HIV positive patients with fever, weight loss, abdominal tenderness, abdominal lymphadenopathy, ascites and/or hepatomegaly have a high probability of abdominal TB regardless of the CD4 counts. HIV and TB often coexist, so using ultrasound alone will not help one distinguish between these two infections; however, an ultrasound-guided biopsy can detect Mycobacterium tuberculosis. A case series of 23 patients with splenic TB from India highlighted that during anti-TB treatment, ultrasound was useful for follow-up (Sharma et al. 2007). Heller et al. (2010) described a Focused Assessment Sonography for HIV/TB (FASH) and subsequent training in this diagnostic method for general medical doctors.

Ultrasound for other abdominal conditions

In Vietnam, a prospective study at the national paediatric hospital in Hanoi showed that abdominal ultrasound was 97.5% (466/478) sensitive and 99% (106/107) specific in the detection of intussusception. The researchers concluded that ultrasound is a good modality to detect intussusception in LMICs (Justice et al. 2007). Ultrasound for continuous real-time monitoring during the reduction in intussusception in children using saline enema is effective, safe and does not involve ionizing radiation; its greatest disadvantage is the need for a sonographer adequately trained in the procedure (Bai et al. 2006; Krishnakumar et al. 2006).

Diagnosing abdominal cancers, such as Wilms’ tumour and Burkitt’s lymphoma, in children or screening for hepatocellular carcinoma or cirrhosis in hepatitis endemic areas are often easily performed and followed by ultrasound (Madani et al. 2006; Paul et al. 2007).

Ultrasound for screening

Ultrasound is currently not widely used in LMICs for health screening purposes; however, the lower cost, portability and better availability of ultrasound compared to X-ray imaging or invasive diagnostics make it an attractive option to include as the standard of care for screening. Screening with ultrasound has been documented for use in endemic areas with echinoccocosis (Bartholomot et al. 2002), schistosomiasis (Ohmae et al. 2003), filariasis (Mand et al. 2010) and hepatitis C (Paul et al. 2007). Ultrasound is also valuable for thyroid screening for goitre in school children (Amoah et al. 2004), for breast cancer (Galukande & Kiguli-Malwadde 2010) and for cardiac morbidity, i.e., echocardiogram (Kobal et al. 2004a,b). Breast cancer screening using ultrasound might even be a better approach in LMICs than conventional mammography used in high-income countries. Owing to differing demographics, breast cancer incidences are higher at a younger age in LMICs and mammography as a screening tool is more suitable for women older than 40 years because of the changes in breast tissue density. Ultrasound, however, can detect lesions in the breast at a younger age (Galukande & Kiguli-Malwadde 2010).

In observational studies from Mexico and Gambia (Kobal et al. 2004a,b), cardiology teams found that screening for left ventricular hypertrophy could be achieved with a portable ultrasound machine; however, such scans were performed by highly trained medical personnel. As non-communicable diseases (NCDs) such as heart disease and cancer have a greater impact on the burden of disease in LMICs (Bonow et al. 2002; Beaglehole et al. 2011), ultrasound can play a greater role and needs to be more fully implemented to strengthen their health care systems.

Morbidities such as deep venous thrombosis and musculoskeletal abnormalities can be monitored with ultrasound, which might have a great impact in clinical management. However, articles addressing these morbidities in LMICs were not found with the search terms used for this review.

Ultrasound implementation in LMIC

Although the use of ultrasound had a significant impact on clinical management (Table 2), often these scans were performed by experts. If there is a continued push for task-shifting in the use of ultrasound, measurement of the impact of ultrasound solely performed by experts, i.e., radiologists or doctors with adequate experience, is inadequate and cannot be translated directly to scans performed by trained nurses or midwives. When task-shifting is applied in high-income countries, sonographers are trained to obtain a set of images which will be interpreted together with, or independently by, a specialist physician. Therefore, problems could arise if the physician is not able to interpret the ultrasound and needs to rely on the ultrasound expertise of the trained paramedic. Before concluding that task-shifting should be applied uniformly for ultrasound imaging in LMICs, more research on the feasibility, practicality and quality of care is needed.

Conclusion

According to the literature, current ultrasound usage in LMICs is mostly for obstetrical problems and has the potential to change clinical management in at least 30% of the cases. Ultrasound use should be better exploited for tropical infectious diseases as well as non-communicable diseases. Most of the articles found for this review were descriptive. Outcome-driven prospective research in ultrasound is needed, especially to study the impact of task-shifting for ultrasound use in LMICs.

Ancillary