However, as
has already been noted, PLHIV with TB often don’t have chronic cough — and if that is the only symptom that is being looked for,
a lot of possible TB cases could be overlooked among PLHIV.
There are other symptoms of TB but these are either very
non-specific (they could be symptoms of almost anything) or not consistently
found, including constitutional symptoms (feeling generally ill), fatigue,
chills, night sweats, fever, sometimes coughing with blood, chest pain,
shortness of breath, weight loss, swollen lymph nodes and loss of appetite. This
means that not every person with HIV-related TB is coughing up blood or has
swollen lymph nodes.
For years, researchers did studies that combined these
symptoms in checklists to try to find an easier way to identify who might have
TB — without much luck. The checklists were either too general or too specific,
missing cases.
Then WHO’s STOP TB Department came up with a TB symptom
screen, based on a systematic analysis of the available clinical data. It
cannot tell you if someone has TB, but it does a pretty good job of identifying
which PLHIV do not have TB — which makes it possible to provide isoniazid
preventive therapy (IPT) without much fear of undertreating an active case of
TB.
Note: this symptom screen asks whether the person has been
coughing, not whether the person has
chronic cough (a classic symptom of TB). While it is important to remember
that the longer someone has had a cough, the more likely that it could be
caused by TB, many people living with HIV and TB never have a chronic cough.
Some symptom screens ask for ‘any’ current cough
in the past 24 hours, or longer, but some national guidelines use a
screen that asks for a cough of more than 24 hours.
WHO guidelines recommend the use of the WHO 4-symptom
TB screen every time HIV-positive people come into contact with the health system,
scheduled or otherwise.
The WHO 4-symptom TB screen asks:
Some countries have added additional symptoms to the symptom
screen to make it slightly more sensitive for conditions reported in their
population. For instance, Namibia has a 5-symptom Screen, after adding swollen
lymph nodes to the list. In some settings, ICAP’s screening tool also includes
swollen lymph nodes and ‘pain or difficulty breathing.
If the answer for all four symptoms is “no”, TB can be ruled out with confidence, and the patient given
IPT.
A case or two of TB might be missed, so WHO recommends
repeating the symptom screen every time a PLHIV interacts with health services
(including home visits)— even in people taking ART, and especially in people
taking IPT, to eliminate any chance of a breakthrough case of TB going
undertreated.
South African Department of Health TB screening tool
The 4 TB symptom screen is the first critical step in intensified case finding. It is essential that TB
programmes and facilities focus first on how to do symptom-based screening
well.
If the answer for any symptom on the 4 symptom screen is yes, WHO recommends investigating for TB and other
infections in accordance with national guidelines and principles of sound
clinical practice to identify either active TB or an alternative diagnosis.
Local guidelines do
vary. Some programmes or facilities call for referral for TB diagnosis, or
sputum specimens to be collected from every PLHIV with a positive symptom
screen and sent off to the lab. Others do this only for symptomatic people with
a cough and call for a clinical assessment of the rest. Some national programmes
call for a clinical assessment first before referring or sending out specimens
for diagnosis. What is done in practice may also depend upon the burden of
disease in the region and local lab capacity. Nurses and other healthcare workers should
check local guidelines.
It also pays to have good clinical common sense, and
consider a range of factors from the patient’s other signs, symptoms, and
general clinical condition. Any number
of illnesses can also cause these symptoms and need to be diagnosed. For instance,
in many parts of Africa and Asia, the most common cause of fever is
malaria.
If a person in your care is reporting symptoms, especially a
person living with HIV, he or she needs a good clinical assessment to be sure
they are receiving proper diagnosis and care, whatever their ailment, as many national guidelines recommend. For example,
according to the South African guidelines, individuals whoscreen positive for symptoms of TB
should undergo an evaluation by a doctor or nurse trained in TB diagnosis
(and, then, if necessary further investigations, including labwork and chest
x-rays as needed).
This may
simply involve taking a good history, with special attention to:
- duration of the symptoms,
- TB risk factors,
- whether the person has
previously received TB treatment,
- whether there is a history of
TB exposure at home (and note, whether there are young children in the
household should there need to be contact tracing),
- whether they have worked in a
congregate setting (like the mines);
- whether they have other risk
factors for cough (like smoking), or other obvious explanations for any
particular symptom.
A physical
examination and consideration of other diagnoses should proceed as usual.
“Someone
with simple common cold can present with one or more of the TB symptoms, but
probably does not need to go through the complete TB diagnostic workup,” Dr
Haileyesus Getahun of WHO’s STOP TB department told HATIP. “Similarly, in the deep sea
of TB in Guguletu, one symptom may give you a good indication for TB, but not
in the slums of Addis,” he added.
Sound
clinical practice should eliminate most of the cases that are obviously due to
something else, and make certain that other important causes of illness are
addressed. As for the other cases where the positive symptom cannot be easily
explained after the clinical assessment, the case requires further evaluation.
With the nurse clinician or doctor’s signoff, the diagnostic process can get
underway, including whatever lab tests or radiography services are necessary. If TB is not thought to be likely, the patient should be
managed appropriately and followed up to ensure that their symptoms have resolved.
Remember, in people living with HIV:
the
risk of TB is very high
TB
may not have the classical symptoms, and
the
purpose of ICF is to identify TB early