Who this is for: GPs and medical officers evaluating prolonged fever in OPDs anywhere in Pakistan, where extensively drug-resistant (XDR) Salmonella Typhi must now be assumed possible until proven otherwise.

Epidemiology in Pakistan

Pakistan is the global epicentre of XDR typhoid. The outbreak that began in Hyderabad, Sindh in late 2016 involved an H58-lineage strain resistant to chloramphenicol, ampicillin, trimethoprim-sulfamethoxazole, fluoroquinolones and third-generation cephalosporins, and it has since spread to Karachi, Punjab and beyond, with tens of thousands of confirmed cases. The CDC issued Health Alert Network advisories (2018, updated 2021) after travel-associated XDR cases appeared in the United States. In practical terms, a majority of Typhi isolates in Sindh and a growing share elsewhere are now XDR, which collapses the empiric options to two drug classes.

Presentation and differentials

Enteric fever presents with a stepwise rising fever over the first week, headache, malaise, abdominal discomfort, constipation or diarrhoea, and sometimes relative bradycardia or rose spots (rarely visible on darker skin). Children may present atypically with predominant GI symptoms. Untreated illness risks intestinal perforation and haemorrhage in week 3.

Differentials: malaria, dengue (seasonal overlap is real), brucellosis, tuberculosis, urinary infection, and viscerally invasive amoebiasis. A fever beyond 3 to 5 days without localising signs in Pakistan should put enteric fever near the top of the list.

Diagnostic workup, cheapest first

  1. CBC: normal or low white count with lymphopenia is suggestive; anaemia and mildly raised transaminases are common.
  2. Malaria smear or RDT to exclude the key mimic.
  3. Blood culture before the first antibiotic dose is the gold standard and, critically, the only way to obtain sensitivities. Yield is highest in week 1 (around 60 to 80 percent) and falls with prior antibiotics. Most cities have private labs offering culture for a modest fee; drawing the sample before dispensing antibiotics is the single most important habit change for Pakistani OPDs.
  4. Typhidot and Widal are unreliable. Both have poor specificity in endemic settings and neither gives resistance data. Do not let a positive Typhidot end the workup or a negative one exclude the diagnosis.
  5. Where culture is truly unavailable, treat empirically for XDR and document the reasoning.

Antibiotic selection

Empiric therapy for suspected typhoid in Pakistan should now cover XDR strains:

Outpatient, clinically stable:

  • Azithromycin is the only reliable oral option: adults 1 g once daily (or 20 mg per kg, maximum 1 g) for 7 days; children 20 mg per kg once daily for 7 days. Counsel that fever may take 4 to 7 days to settle even on effective therapy; early defervescence is not expected and does not mean failure.

Ill, toxic, vomiting, or complicated disease:

  • Meropenem IV 1 g every 8 hours in adults (children 20 to 40 mg per kg per dose every 8 hours) for 10 to 14 days, in hospital. Imipenem is an alternative. Refer; do not attempt outpatient parenteral carbapenems.
  • Some units add azithromycin to a carbapenem in severe disease; follow the receiving hospital protocol.

What no longer works and should not be prescribed empirically: ciprofloxacin and other fluoroquinolones, ceftriaxone and cefixime, amoxicillin, chloramphenicol, and co-trimoxazole. If culture later shows a sensitive strain, de-escalate accordingly. Sporadic azithromycin resistance has already been reported in Pakistan and Bangladesh, which is exactly why every culture matters for surveillance.

Adjuncts: paracetamol for fever, oral hydration, and dexamethasone only in hospital for shock or encephalopathy per specialist guidance.

Dosing discipline matters as much as drug choice. Under-dosed azithromycin (the common 500 mg for 3 days sinusitis pack) is a recognised driver of treatment failure and resistance selection; write the full 7-day course at the correct weight-based dose, dispense or prescribe the entire course at once, and warn the family explicitly not to stop when the fever breaks. Document the start date so a day-7 failure assessment is possible.

Red flags: refer or admit

  • Persistent vomiting, inability to take oral drugs, severe abdominal pain or distension (perforation risk), GI bleeding, altered consciousness, shock.
  • Fever not settling after 5 to 7 days of adherent azithromycin therapy (treatment failure or wrong diagnosis).
  • Infants, pregnant women, and immunocompromised patients merit early specialist input.

Follow-up and prevention

  • Review at 48 to 72 hours, then at day 7 to confirm defervescence trajectory and adherence.
  • Advise safe water (boiled or bottled), food hygiene, and hand washing; household contacts share the exposure.
  • Typhoid conjugate vaccine (TCV) entered Pakistan EPI schedule from 2019 and is recommended by WHO for children from 6 months in endemic settings; check and complete vaccination for children in the household at the same visit.
  • Food handlers with typhoid should not return to work until cleared per local public health guidance; chronic carriage can follow untreated infection.

A tidy record helps: the MyPatient EHR problem list flags prior culture-confirmed typhoid and antibiotic history, so repeat presentations are not treated blind. Give families the patient guide to share covering prevention and vaccination.

Key points

  • Assume XDR: azithromycin orally for stable patients, meropenem in hospital for the sick ones.
  • Draw blood culture before the first antibiotic dose; Typhidot and Widal do not guide therapy.
  • Fluoroquinolones and third-generation cephalosporins are empirically dead in Pakistan for typhoid.
  • Counsel that defervescence on azithromycin commonly takes 4 to 7 days.
  • Refer for vomiting, abdominal signs, altered sensorium, or failure at day 5 to 7.
  • Vaccinate household children with TCV and reinforce water and food hygiene.

References

  • Extensively Drug-Resistant Typhoid Fever in Pakistan. CDC Health Alert Network Advisory, 2018 (updated 2021).
  • Typhoid Vaccines: WHO Position Paper. World Health Organization, 2018.
  • Guidelines for the Management of Typhoid Fever. World Health Organization, 2011.
  • Background document: Diagnosis, Treatment and Prevention of Typhoid Fever. World Health Organization, 2003.
  • Clinical Practice Guidelines for Enteric Fever. Medical Microbiology and Infectious Diseases Society of Pakistan, 2022.

Clinical judgement and local protocols take precedence.